Random tools and EV related projects

ElectricGod

10 MW
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Nov 1, 2015
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Gauss and magnet testers:

This post is my guass meters. A linear hall with no magnet present outputs about 2.5 volts. With an N50 magnet North pole, the hall outputs .78 volts. The South pole of an N50 outputs 4.3 volts. You can test which magnet pole is which based on which way the voltage swings. Based on how much the voltage swings the center point voltage will tell you how strong a magnet is. You will want to know the specs in the halls data sheet so that you can use the output voltage to calculate the magnetic strength.

This was my original magnet tester. It stayed whole for a couple of weeks before I built a new one. I got some linear halls because the hall in a throttle died. I decided to mess around and see what else I could do with a linear hall. This is a 150mah 1S lipo battery and a 5 volt boost converter/charger board and a linear hall. The halls output gets monitored by my DMM. The fact that I needed an external meter was a bit problematic and made it NOT portable.

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This is version 2 of the guass meter. It uses a re-purposed USB watt meter that can also measure a secondary voltage source. V+ is the output from the 5 volt boost converter and D+ is the linear hall output. It uses the same lipo charge/boost board, but now has a 350mah LIPO battery. With the USB meter on board it's 100% portable. Just about all the parts I found on ebay and spent less than $20 in making it. It incorporates a tiny slider switch to turn it off and all voltages are externally measurable if desired. It charges via a micro USB port. THe battery and charge/boost board are individually wrapped in kapton and then double sided foam tape hold them together. The USB meter is stuck on top of that with more 2X tape and then the whole thin is wrapped again in kapton. Then the USB port and 2 pin connector for hall are hot glued in place. The whole thing is then covered in clear heat shrink.

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The long set of pins are 5 volts from the boost converter. The short set are the hall output.

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Hall tester for linear and digital halls:

This is the completed project. Right now it is measuring the boost converter output and the larger LED is showing the digital hall is sinking current and is therefore "on". Linear halls source current and vary their output voltage from about .5 volts to 4.5 volts. A digital hall as used in motors sinks current or provides a ground path so its output is essentially no connection when off or at ground potential when on. The LED turns on when the ground path happens through a linear hall. The LED meter can either display the boost converter voltage or the linear hall voltage.

Hall%20Tester.jpg


Essentially it is a 350mah LIPO cell, a 5 volt boost converter, charge controller, 3 pin JST connector and a small LED volt meter. I spent less than $15 in parts. My boost converter and charge controller are seperate boards which you see on the left. THe output from the charge controller cuts power to the boost converter via the green jumper. I paid a dollar for each board. The LED volt meter is the 3 wire version. I might have paid $2 for it. You want to power the volt meter from the boost converter and then measure the output voltage from the hall separately. The 3 pin JST connector is the perfect size for plugging in a single hall. You will need a neo magnet with known north and south poles for testing free standing halls. For halls in a throttle or motor, connect the wires from them to the JST connector as needed and then turn the throttle or spin the motor. The charge controller connects to the LIPO cell, includes a micro USB port and outputs to the boost converter. The 5 volts powers the LED volt meter and the hall under test. It's all held together with Kapton or double sided foam tape.
 
Motor Phase Current Tester:

I bought 3 200 amp current sensors some time back just to mess with. One day it hit me that I could use them to measure phase current in all 3 phases of a motor. It runs from a single 1000mah LIPO cell that is managed by a small charge controller and boost converter board. It charges via a micro USB port. I checked total current draw and the 1000mah cell will run this tool for 4-5 hours continuous. Other than the 3 phase wires, it's 100% electrically isolated from the EV and self powered.

This is the individual parts used in a semi-assembled state. The current sensors were the expensive part at something like $8 each. The whole thing cost less than $30 to build. I really like 5.5mm bullets and all my motors and controllers use them so that was an obvious choice for the phase terminations. The 6 large wires are 10 awg. The 3 current sensors are held together with 2X foam tape and then wrapped in Kapton. Once the legs on the sensors were wired up and the phase wires soldered in place, the sensors were buried in hot glue to ensure the phase wires are isolated from each other and can't short to anything else.

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Later the LED volt meters (3 wire version) were connected up. IF I had thought about it, I would have used blue, green and yellow volt meters to indicate the phases. Oh well, I just labeled then in the end...same difference! Current sensors incorporate a linear hall. The volt meters display the hall output voltage and then I the conversion ratio from the spec sheet to calculate current from the output voltage. These little volt meters have a tiny pot on them that I need to set to 2.5 volts so that all 3 meters measure the same at no load. I haven't done this yet in this picture.

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Future development...
I want to replace the volt meters with a small o-scope so that I can visually see current wave forms per phase. The DSO203 scope is very small and fairly ideal except that it's 2 channels only. I really want to display all 3 current sensor signals on the same screen so that I can see each phase changing side by side. I also want to add hall signals into this device and to display them graphically on a small o-scope as well. Probably I will get 3 DSO203 scopes and use one channel for phase current and the other for its corresponding hall signal. I've looked at cheaper 2 channel o-scopes, but the LCD's generally have poor resolution and you can't set the voltage and timing for each channel individually. With 3 DSO203 scopes on it, that will make this test tool cost around $350. I will be able to see/measure anything the motor is doing.
 
LED light conversion project:

I used to mess with LED's a few years back, but it's been a good while and they have gotten so much better since then! A friend suggested that I get a few XHP70.2 LED's. I bought star boards and LED's from digi-key and then reflowed the LED's to the boards in a frying pan on my stove. Here's a couple videos of the reflow process. My friend suggested that I buy LEDs already flowed onto star boards, but I'm already familiar with the process so I did it myself. Originally I had the LED's oriented backwards so that plus was minus and minus was plus. I later reflowed them to turn the LED's around. My original star boards were 6 volt boards only. The XHP70 series LEDs are 2 sets of LED's on the same die. You can run them in parallel for 6 volts or series for 12 volts. I later got star boards that could do parallel or series. What you see in these pictures are those switchable boards. The 0 ohm resistor makes the series connection so that I can run these LED's from 12 volts. All my EV's have a 12 volt system so this is ideal for me. I bought 4 XHP70.2 LED's and 2 have been reflowed twice and the others 3 times. They show no evidence of heat damage and have lost no brightness or current consumption change despite multiple reflowing. You just have to do it at the right temperature so you don't over heat the LED's and then let them cool slowly so they are not thermally shocked.

Anyway...the reflow videos...
Reflowing LEDs getting the temp right:
https://www.youtube.com/watch?v=_3cGSxFe_Q0&index=2&list=PLP5ztAvpP73YZpwVWap3oppn2y0ym6nfZ

End results after reflowing them twice:
https://www.youtube.com/watch?v=91lywdF-e58&index=1&list=PLP5ztAvpP73YZpwVWap3oppn2y0ym6nfZ

I looked around on ebay and Amazon for all aluminum bike lights that used a single LED and were focusable. These shells originally had a single Chinese T6 in them and have adjustable focus. I had to beef them up a little by adding a copper disk inside for better heat transfer for the XHP70.2's. I removed the original LED controller board which did, low, high and flash. I don't care about that anyway. The center hole in the copper disk doesn't do anything in the light, but I needed a way to mount the copper disks to a screw so I could spin them in my drill press. This allowed me to file them perfectly round and to the exact size so that they are press fit into the aluminum shell. The two smaller holes are for the silicon power wires.

The T6 stars are exactly the same size as the XHP70 star boards so this was a perfect fit.

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LED's installed, wired and embedded in heatsink compound in the LED carrier. The star is held in place by a threaded plastic disk that doesn't stay in place very well. I need to rework the star retaining mechanism somehow.

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The final product. I've run both of these LED's for 10 minutes continuous and the shell does get warm with no air flow. The grey ring turns to change the LED focus. I took one outside and it threw bright light at tight focus easily 500 feet. At wide open focus I had lots of light up to about 60 feet. I put a watt meter inline with the light and measured 3.3 amps at 11.5 volts or 37.95 watts. CREE specs these LED's at 2.4 amps max, but lots of people run them a good bit hotter with no ill effect.

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This is the original light I bought that I used as the XHP70.2 shell. They are not particularly well made and the machining is a bit loose fitting. I did some modding to them to make the fitment better. Also, they are not water proof. There's no electronics inside the shell anymore so that's really no concern, but getting water behind the lense could be problematic. I suppose the LED would drive any moisture out pretty quickly. I added a few o-rings to help seal them up better.

https://www.ebay.com/itm/Bike-Light-Headlight-Headlamp-500-Lumen-T6-LED-Zoom-Adjustable-Focus-New/351989822490?hash=item51f43a741a:g:MxgAAOSwol5YxjU3

I later found these lamps that have a focus ring and look to be slightly larger. I've bought a pair of them and they will arrive soon. Hopefully they are better made as well!

https://www.ebay.com/itm/USB-Rechargeable-XML-T6-LED-Bicycle-Bike-Light-Front-Cycling-Light-Head-Lamp/172969607546?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
 
Controller and system precharging:

Huh?! What's that? LOL!

OK...so you plug in your motor controller to your battery pack and KAPOW! there's a giant spark. The inrush current that happens when the internal capacitors charge is hard on everything. Hard on the connectors, hard on the battery pack, hard on the capacitors and hard on the rest of the electronics. So just don't EVER do this! AKA...always precharge.

This isn't rocket science...it's just a 10-20 watt 1k resistor connected in such a way that your electrical system charges slowly rather than suddenly. You won't have that giant spark and everything gets charged to the pack voltage safely and without harm.

This one uses 2 connectors. The smaller power connector commonly found on laptops and portable electronics has a resistor inline with it that slowly charges the system. Then you connect the main 5.5mm bullets for handling all the current load.

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I like this one better and my blue scooter uses this design. Batt- connects together via the main power connections. Then on batt+ is a 3mm bullet with a resistor in series. Connect it first and then a second later the main batt+ connection.

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I implemented this as an experiment, but it's too complicated and completely unneeded. I used a couple of 3 watt LEDs in series with a resistor to limit current and voltage for a 48 volt system. You plug in the XT60 to precharge the system. The LED's glow until the system is charged and slowly get dimmer. Then plug in the main power connection. It seemed cool to have "status" of precharging in progress, but was extraneous.

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I use this final method in the Currie scooter and my XB-502 moped build. The precharge resistor is across the contactor contacts. It serves multiple purposes. I always turn off the contactor if I'm working on main electrical stuff, but that leaves the precharge still in place. The system maintains it's charge, but can't run anything since it can't get enough current through the 1K resistor. It also "soft connects" the contactor so that it's contacts never get scorched or burnt. It does have one possible problem. The system is never fully disconnected from power since the precharge resistor is always inline with the contactor. If I need to fully disconnect, that's when disconnecting the pack happens. I couldn't find a picture of the precharge resistor on the contactor. There's nothing to it though. Batt+ comes in one side of the contactor and out the other. Across the contactor screws is a 1K, 10 watt resistor. I'll likely continue to use this method for the long term. It's simple, automatically engaged and works well.

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This is a couple of bench use prechargers I built. I don't need lots of current, but I do need to bench test controllers and motors under no load. The rocker switch bypasses the precharge resistor like the larger contactor version does. Oh look...more 5.5mm bullets!

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I made this one a long time ago before I standardized on 5.5mm bullets. Hence adapting 5.5mm to XT60 to XT90...yuck! The leftt hand set of connectors is so I can use a small watt meter too. I keep meaning to take this all apart and do it over with the shunt integrated between sets of 5.5mm bullets and inline with the switch and precharge resistor. This thing is bulky and overly complicated.

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50 watt per channel ghetto blaster:

I want tunes on my EV's and I want to be able to blast the music so that everyone around me gets to enjoy too. LOL!

Class D audio amps have been around for a good while and they are really efficient. I poked around on ebay and picked up this board. It includes BT 4 so that's perfect for connecting to my phone. It runs on 6S which is pretty ideal. I have some 100 watt speakers and ran it at full volume on a 12,000mah 6S LIPO pack for an hour straight. The pack dipped less than 1 volt. That was awesome and it was plenty loud!

The audio amp board...
https://www.ebay.com/itm/Bluetooth-4-0-Digital-2-1-Class-D-HIFI-Power-Amplifier-Board-3CH-Super-Bass-Amp-/131894353021?_trksid=p2349526.m4383.l4275.c10

I'll later get a 6S BMS so that I can enclose the lipo pack inside the case and charge from a 24 volt PSU. I have several of them! I'll also add a ported space for a sub woofer and make a wood box for the whole thing.
 
Battery, charger and who knows what adapters:

I used to make this sort of thing, use it once and then take it apart again. Later I'd find I needed to adapt one thing to something else so now I needed to remake whatever that was. I make these things and keep them now. Yeah...there's some money tied up in connectors here, but hey, whatever it is, can be made to plug into whatever else it is that I run into. Sometimes I need XT90 to 8mm bullets or deans T to XT60 or parallel connect two LIPO packs. How about andersen to 5.5mm bullets or XLR for a charger to 5.5mm bullets on a battery pack that has a BMS? I can make up or adapt just about anything to anything else with this assortment of adapters. They are VERY useful for bench testing things.

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I've even made adapters that connect to my standard controller enable/throttle and hall connectors so that I can connect them to odd ball stuff.

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Standardized controller, motor, and peripheral connectors:

Originally I built rather ad-hoc and as a result nothing plugged into anything else. Later I decided that standardizing on certain connectors was a good thing. As a result, I have found inexpensive IP-68 connectors in 6 and 8 pin versions that interconnect just about all my control signals and small current wiring. i have also standardized on 5.5mm bullets for phase and power connections. Later, if I build something that needs more than 150 amps, I'll do that in 8mm bullets, but so far 5.5mm bullet connectors have been my "go to" power connector for a long time now. AND they are really inexpensive. I've bought 5.5mm bullets from various sources and the quality is identical if I pay 50 cents per pair out of China or $4 a pair in the USA. Anyone that asks, I tell them to just get them from China if you can wait. If there is a part that I buy purely on price, it's 5.5mm bullets.

Various places I've used 5.5mm bullets.... All my controllers, motors and battery packs use them. Any power interconnect uses them. AND I wire them male or female identically so that any motor can connect to any controller. Any battery pack can connect to any BMS or controller or power interconnect. My phase current testing tool implements 5.5mm bullets in such a way that it can quickly interconnect between any motor and any controller I have.

This is an adapter I made while transitioning to 5.5mm bullets. This was a kluge between XT60, XT90 and 5.5mm bullets. I should have just started over!
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This is the interconnects between the 2 LIPO packs in my Currie scooter...all 5.5mm bullets.

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The motor side of phase wires all get female 5.5mm bullets.

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Controllers always get male 5.5mm bullets for phases. You also see how the power wires are done. +batt on a controller is male and -batt is female. Obviously the power wires connecting here are the opposite for battery packs. BMS and power distribution so that it can all interconnect and still be keyed so you can't connect anything backwards.

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This is the full set of connectors I typically do on a motor controller. One black connector is halls and the other is enable/throttle.

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I also standardized on IP68 connectors. All my controllers and motors and system interconnects are wired identically with the same connectors. I use them on my handlebars, for connecting up lights and other things. They thread together and cost 3-4 dollars each on ebay.

This is crap! Water invades easily, connectors come apart easily. Everything here says "crap".

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These round connectors never fail, never come apart and are impermeable to water. All motor halls are wired identically into these connectors. All controller halls are wired identically in these connectors. Controller enable and throttle go in one of these and are always wired the same and so on. It's hard to see in the second picture, but this motor has 2 sets of halls wired identically into 6 pin connectors. The two connectors zip tied down are controller enable/throttle and the rear end lights. Oh look...more 5.5mm bullets too!

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This is an 8 pin version all taken apart. Everywhere something mates to something else there is a silicon o-ring.

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End view of the 6 pin version.

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These 2 pictures are on the front page of a notebook I've had for a couple of years now. All hall and controller connections are done like this. It's cut in two, but you can see how rear lights are always done too.

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Battery pack load testing:

This post is more about load testing cells than say a complete battery pack. I have acquired 400+ 18650 cells that I scrounged from laptop packs. It was common that some cells in a pack were quite literally used up and others were still pretty good. Sometimes a single cell had failed completely and the rest were nearly new. I needed a way to load test cells rapidly so that I could eliminate the cells that were mostly used up and keep the ones that were still strong. I created categories. Since laptop cells are typically 2600mah, I made the best category out of cells that were 2400-2600mah or cells that were effectively new. Next down was 2000 to 2300mah. These cells have seen some use, but are still good enough for flash lights and bench testing. Then came everything else down to 1000mah. They aren't bad per say, but their usefulness is pretty limited. Anything worse than 1000mah just gets recycled.

Thanks to these load testers, I've tested hundreds of laptop cells and ran my blue scooter on free and used cells for close to 2 years. They are a lot of weight to be sure, BUT, the cells cost me nothing and I still have 40 miles of range. I'll put up with a lot for something that costs me nothing when everyone else is paying $1200 for the same thing!!!

I originally made a load device out of an old blow drier heating element and various hodge podgery. The problem was it got firey hot, operated at a single voltage and left burns on a desk top once. It worked, but would break often.

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Later I bought a bunch of halogen bulbs that I can connect together in series or parallel for whatever voltage and current configuration I could want. Each bulb is 55 watts at 12 volts. All those bulbs still get really hot, but who cares. Heat makes for a great load. I rejumper the bulbs together in whatever combination gets me the voltage and amperage I need. It has worked reliably for a couple of years now. I think I spent $45 for all 28 bulbs. I laid them out like this in 4 rows of 7 bulbs for testing at 20S or 82 volts. At 55 watts each and 12 volts that's 4.6 amps per bulb. 4 bulbs in parallel is about 18 amps. For testing a 20S2P laptop cell pack this was pretty ideal as it was more or less 7 amps per cell. Laptop cells are typically 1 or 2C discharge rates. If a cell was going to fail or was weak, a few minutes at that load and it was done, but strong cells would survive.

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Mosfet testing:

What I want to present here is how to test a mosfet for Rds and VGS(th). These specs matter when selecting matched sets of the same kind of mosfet for a controller. I don't care terribly about testing the maximum voltage or current for a mosfet since you should NOT be running them at the limits anyway. Since the TO-220 package is leg limited to 75 amps any spec that exceeds that is meaningless. The 2 important details to matching...assuming the mosfet works at all are Rds and VGS(th).

This is the test schematic for Rds presented in the AOT290 datasheet. RL would be a watt meter and shunt to show circuit amperage. Rg can be a 1k resistor and doesn't really matter what the value is. Vdd isn't stated in this schematic, but in the one above it looks to be about 12 volts. Vgs also was shown at about 12 volts. Feed the mosfet gate a 12 volt trap wave and watch the voltage drop across source to drain on an o-scope. Do a little Ohms law math to calculate for resistance and you have Rds the "real" way. If this produces similar results to a component tester that does Rds...then this setup is irrelevant since the component tester is producing the same results.

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Hopeful results based on previous experince:
1. I bet egregious mosfets are going to be off the mark regardless of the voltage and current they are run at. IE: An inexpensive component tester capable of Rds at a minimum ought to find those components easily and quickly. Every component tester I have tried shows the voltage needed to turn on the mosfet. I have found that this voltage varies widely mosfet to mosfet of the same kind.

2. A "simple rig" that's essentially the above schematic, o-scope., function generator, watt meter and DMM will provide the "real" test set up for measuring Rds. I have everything needed to make that happen. If the component tester produces similar values as the test rig, then the test rig is irrelevant.

3. The "simple rig" with a POT on the mosfet gate instead of a trapezoidal wave form can provide a slowly increasing voltage. A DMM across the gate to ground can measure that voltage. When the mosfet turns on, this is VGS(th). According to the AOT290 spec sheet, that should not be lower than 2.9 volts. 3.5 volts is typical and 4.1 volts is the maximum. I've measured this many times via ebay component testers for lots of mosfets. Many times AOT290's turn on at the maximum voltage, NOT the typical voltage. However, some do turn on at the typical voltage.

I just purchased my third ebay component tester. The first one I bought in 2015. It still works great, but the one I bought in 2016 did lots more stuff so I bought it for the larger feature set. It's working great too. Now I have purchased a new one that measures mosfet Rds and can present graphically IR remote signals. The below URL is that unit. I'll let you know how well it does.

https://www.ebay.com/itm/Transistor-Tester-LCR-T7-TC1-TFT-Diode-Capacitance-Meter-NPN-PNP-MOSFET-US/162778613281?ssPageName=STRK%3AMEBIDX%3AIT&var=461817457942&_trksid=p2057872.m2749.l2649

I want to know that the mosfets I use in a controller upgrade or a Lebowski controller are actually all matched and good before I use them. I'm also lazy and if I don't have to do extra work, I'll avoid it. So then, will a $30 ebay component tester give me sufficient test results to find 12 or 18 matched mosfets so that I don't need to test each mosfet with a watt meter, function generator and oscilloscope?
 
Watt Meter and Precharge test tool rebuild:

I said one day I would get around to rebuilding that kludged together watt meter and precharger I had built. Well I got around to it. I replaced the original watt meter with a new one that works better and is a bit smaller. It's not quite done yet as I want to add a voltage regulator. The watt meter can be powered at up to 60 volts, but can measure up to 100 volts. This type of meter is useful for when you want to measure something without impacting that measurement with the load of the meter. In this use, that's not really needed. However, I want to be able to measure up to 100 volts, so I need to add a regulator to provide 60 volts to power the meter. The TL738 linear regulator will do what I need.

Here's the new test tool. The two silver objects are the ends of the 50 amp shunt. I bent it in half so it would take up less space. I'm not sure folding it in half is better or not.

Watt%20meter%20-%20precharge%20tool%201.jpg

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Watt%20meter%20-%20precharge%20tool%203.jpg

 
I post a lot of stuff and as a result people PM me for advice on how to do things. That just happened and the question was how to replace wheel bearings. I thought it worthwhile to repost what I just sent to BCTECH. At the end is a video on the subject that is also useful.

Ball bearings don't tolerate lateral forces very well. They are intended to take radial forces almost exclusively. When you tighten the nuts that hold the axle to the forks, you are applying lateral force to the bearings. So that this doesn't happen, inside the wheel and between the left and right bearings and between the inner races is a spacer tube. It's exactly the length needed to not allow any of the lateral forces from the axle nuts to be applied to the balls in the bearings. All lateral forces are transmitted to the inner bearing races and the spacer tube. This allows the bearing to see only radial forces from standard wheel rotation.

So then, between your wheel bearings, is that tube. Right now it is centered between the 2 inner races on the existing bearings. You need to knock it out of place so that you can get at the inner races on your bearings. You are replacing the existing bearings because dislodging them is rather hard on the bearing since you will be hitting the bearing with something metal and hitting that with a hammer and applying lots of lateral forces to the bearings which will probably damage them. I use a long flat blade screw driver. I slide it down the center of that tube and just above the inner side of the opposite bearing. Hit the side of the screw driver that is sticking out of the wheel with a hammer and it will dislodge that steel tube so that you can see the inner race of the opposite bearing. Now place the screw driver blade on the bearing race and start tapping it out of the wheel. They are press fit into place. You want to be sure that you extract the bearing straight out. If it gets cocked, that is bad. Tap the opposite side of the inner bearing race to get it coming out straight. A few taps with the hammer and the bearing is loose. The spacer tube will fall out at the same time most likely. Once one bearing is out, getting at the opposite side is easy since it will be exposed inside the wheel and you can tap it out with a screw driver and hammer. Again make sure it comes out straight and even.

Once you do this with a bearing, it's best to NOT reuse that bearing. It's likely that you've caused it some damage with hitting the inner race and transferring that energy through the balls to the outer race. It might be OK, but probably not. I just assume the bearing is now damaged and replace them with new ones.

I remember a wheel a while back that had a spacer tube that had a shoulder on it for catching the inner bearing race and it also fit inside the bearings inner race. The bearings ID was 12mm, but because of the portion of the spacer tube that fit inside the bearing ID, the axle could only be 10mm. This spacer tube design meant that I couldn't dislodge is sideways a little to get to the inner bearing race of the opposite wheel bearing. Instead, I scrounged through my socket sets for a socket that had an OD that was just slightly smaller than 12mm, but larger than 10mm. I placed the socket over the end of the spacer tube and tapped the socket with my hammer. This pushed the spacer out the other side of the wheel and pushed the opposite bearing out at the same time. Once one bearing was extracted, I grabbed a screw driver and tapped out the remaining bearing as usual. I reused the same bearing spacer when I installed the new bearings. It didn't make extracting the bearings any harder, I just needed to go about doing it a little differently.

So then...bearings...
1. If they are exposed to the weather, always use sealed bearings.
2. If the bearings are enclosed and never get exposed to dirt and water, shielded bearings work fine.
3. Never apply lateral forces to a wheel bearing you care about.
4. You have 3 types of bearings. All steel (steel races and steel balls), hybrid (steel races and ceramic balls) and all ceramic (ceramic races and ceramic balls). All steel is the cheapest and have the highest amount of internal friction. All ceramic are the most expensive and the least amount of internal friction. I typically use hybrid bearings since they are much better than all steel bearings in every way and cost about half as much as all ceramic bearings.

Installing new bearings in your wheels...
1. You want the new bearing to go in straight. IF it gets cocked in the bearing seat, don't force it, straighten out the bearing and make sure it goes in straight.
2. Never hit the inner bearing race while installing a bearing in a wheel. This is bad and damages the bearing. You only want to apply force to the outer bearing race when installing a bearing. Some bearings are press fit on the inner race (not typical on wheels). In that case you don't want to apply lateral forces to the outer race. Only apply force on the race that is press fit.
3. A socket the same diameter as the outer bearing race placed on top of the bearing is a good thing to hit to insert a new bearing. The old bearing works too since it's exactly the right diameter.
4. Once one bearing is seated fully in the wheel, flip over the wheel, insert the spacer tube and then install the other bearing the same way...straight in and applying force only to the outer race where the bearing is press fit.
5. There is the possibility that the bearing seats are a little too deep into the wheel. When you insert the second bearing, if this is the case, then you will feel it when you try to turn the bearings. They will turn together since they are jammed against the spacer tube. They will turn roughly since they are jammed together and there is lateral forces on the balls. You won't have a choice here, you have to tap gently at the inner race of a bearing through the center of the spacer tube to slightly push it out a little to relieve this. The bearings should always turn smoothly. Better yet, pay attention to the second bearing that you insert it just the right amount so that it just sits on the spacer.

This is a good video on the subject. Start at about 18 minutes and end at about 35 minutes. That's the part that's relevant to most wheels. A lot of wheels don't use a secondary seal since the bearings are sealed. This is normal. In the video the motor cycle wheel has only one bearing seat and shoulder on one side. The bearing on the other side has nothing to stop it from going in too deep. I've run into this before. Pay attention to what he says about installing the second bearing and the spacer tube so that you can avoid installing the second bearing too tightly against the spacer tube. He puts grease on the outside of the bearings before he presses them back in place. I never do, but it's fine either way.

https://www.youtube.com/watch?v=dQbKXbhyFQs

I needed to change out bearings in a new wheel so I recorded the process...

1 Removing bearings from a wheel: https://youtu.be/R83LZLUq7QI
2 Bearing placement tips: https://youtu.be/WXtD3ntKS0M
3 Installing bearings in a wheel: https://youtu.be/4Dh6-4_dge0
 
ElectricGod said:
Ball bearings don't tolerate lateral forces very well. They are intended to take radial forces almost exclusively.

Bearing balls -- the balls themselves -- don't care in what frame of reference force is applied to them. They are balls! Any force applied to them acts through the diametric centre, and if the ball is rotating, in a race, the diametrically opposed point contacts are constantly shifting.

As for rolling element bearings, using balls, the forces they "tolorate" depend entirely on their design specifications. Ie. A thrust bearing is designed to take axial loads exclusively.

In terms of cone bearings used in bicycle wheels, they are generally rated to take axial loads of 1 or 2 times the maximum radial load.
 
Buk___ said:
ElectricGod said:
Ball bearings don't tolerate lateral forces very well. They are intended to take radial forces almost exclusively.

Bearing balls -- the balls themselves -- don't care in what frame of reference force is applied to them. They are balls! Any force applied to them acts through the diametric centre, and if the ball is rotating, in a race, the diametrically opposed point contacts are constantly shifting.

As for rolling element bearings, using balls, the forces they "tolorate" depend entirely on their design specifications. Ie. A thrust bearing is designed to take axial loads exclusively.

In terms of cone bearings used in bicycle wheels, they are generally rated to take axial loads of 1 or 2 times the maximum radial load.

Thanks for pulling that quote straight out of context. You aren't wrong in what you said, just out of context to the topic.

In context of wheel bearings in a typical scooter wheel like my entire post is about, they don't take lateral loads particularly well. This post was about replacing bearings in a typical scooter wheel, not about the various kinds of bearings that exist. In context of ball bearings NOT designed for lateral loads like are typically used in scooter and motorcycle wheels, then I am dead on in saying that they don't take lateral loading particularly well.

I changed the title for that post since you were easily confused about the context.

Thanks for the input, but was it actually helpful to the topic and context of the post? I'd have to say no it wasn't. Think before you post!
 
More LED lights coming soon.

New shells are on their way and the LED's have arrived. This is XHP70.2 and XP-L2 LEDs. 18 of the XP-L2's will go in a flashlight. The focusable shells will get a couple of them as well. Those shells are too small for the XHP70.2's in them. They lack sufficient metal to pull away heat from the larger LEDs for very long. New larger shells are coming. I've also bought a 15 amp adjustable BEC so I can mess with the voltage the LED's run at. People commonly run them at 7 volts and 5 amps or more on the XHP70 series LED's.

New%20LEDs.jpg
 
I bought a Castle Creations BEC 2.0 15 amp to run the XHP70.2 LEDs on. The idea is it has an adjustable output so you can control how much you over drive the LED. This BEC gets used by LED people a good bit for this purpose. My intention is to run 2 XHP LEDs on the one BEC. Since it's rated for 15 amps, that should be no problem.

I've read about people pushing 6 amps and more through the XHP LEDs so I thought I'd give it a shot. I set the BEC to 7 volts and watched my inline watt meter. Soon I was looking at 7 amps constant draw. The LED had to be mounted to a CPU heat sink with the fan running on low to keep it cool, but it ran for more than an hour at 7 amps and the heatsink warmed up to maybe 80F. The LED was so bright that I'm sure it would cause blindness if I stared at it for very long. I pointed the LED away from me and wouldn't look at other than fleetingly. The brightness was rather painful to the eyes! To look directly at the LED while it was running, I held a piece of paper between my eyes and the LED. Even that was bright as a sunny day.

I don't know if I got a defective BEC or what is happening. It's rated to 15 amps and running it at 3 amps it would get really hot in about 10 minutes. At 7 amps, it would get hot in a minute or 2 and scorching hot in about 5 minutes. Since I wanted to do a longevity test at max drive to the LED, I mounted the BEC to another CPU heat sink. I set it to 7 volts and under no load measured 6.97 volts...close enough. Under any load at all it would immediately sag to 6.5 volts. My battery pack is 6S, 12,000mah and the watt meter showed no dip in voltage under a 7 amp load. The pack was not sagging at all. The sagging issue at the BEC output is purely internal to the BEC. I'm not thrilled with the BEC and at $40, it ought to be really good! After an hour+ the BEC case was at 120-130F, the copper plug at 100F and the aluminum fins at 90F. Everything about the BEC was hotter than the LED. I'm sure if I hadn't put it on a heat sink that it would have fried in 10-15 minutes at 50% of full power.
 
I bought XP-L2 LED's to replace the LED's on this board. The XP-L2's are supposed to be the same size as XML's but these must not be XML's. The much smaller XP-L2 is not going to fit here. Apparently I shouldn't have trusted what i read on an LED forum. OH well XML's purchased and on the way.
LED%20board.jpg
 
LED progress...

I reflowed XM-L2 LEDs onto this flashlight board last night. It's definitely a lot brighter now. Next I will replace the driver board. The one in the flashlight isn't very good. I also reflowed some onto a couple of stars that had Chinese XML's previously. They too were way brighter. I have lots of Chinese XML's now. What do I do with them?

LED%20board.jpg


I bought 2 of these lights for $20 each. They are nicely made, waterproof and all aluminum. My hope was the LED was legit, but didn't care if it wasn't. As is common for Chinese LED's, theya re not as good as a real CREE. This LED is supposed to be an XHP70 , but it's soooo not an XHP70. It solders down to the same sized pads, but that's where the similarities end.

Black%20XHP%20lamp%20-%20whole.png


Black%20%20XHP%20lamp.jpg


A real XHP70.2 next to the crappy Chinese LED. It's not that it super dim, but it's also not a real CREE LED.

chinese%20fake%20XHP70%20vs%20CREE%20XHP70.2.jpg


I made heat spreaders. The back is plenty thick, but it has this wire channel right under the LED. It's probably fine for a fake XHP70, but for a real one that's over watted...no way! My heat spreaders cover the wire channel so that there is not a hot spot where the LED isn't getting good heat transfer to the shell. I bought some heatsink compound that is glue as well. I'll stick down the heat spreader with that. I had the disks mounted on a 10-32 screw so I could spin them in my drill press for filing down to size. After I was done, I cut a short brass plug and hammered it in so it expanded into the hole. No hot spot in the middle now. The scratches in the aluminum don't really matter. They will fill in with heat sink compound.

Black%20XHP%20lamp%20heat%20spreader.jpg


Black%20XHP%20lamp%20heat%20spreader.jpg


Black%20XHP%20back%20cover%20and%20heat%20spreader.jpg
 
I have 2 of these boards with the craptastic chinese fake XHP70's on them. Last night I reflowed a real XHP70.2 onto one of them. I was curious to see if the board would support the better LED. It did run on the board, but this driver is not designed to handle what the real XHP70.2 can handle. It was a little brighter than the other board with the fake LED, but not compelling enough to leave a real CREE on the board. I reflowed the original LED back in place again. I'll use the real XHP on stars and drive it appropriately via another driver source that can handle the LED.

chinese%20fake%20XHP70%20vs%20CREE%20XHP70.2.jpg


I did something stupid last night. I had just put together 4 lights that run XM-L2's. Real CREE XM-L2's run great at 3.5 to 3.7 volts that's essentially the nominal voltage for a LIPO cell. I grabbed a 6S LIPO pack to test each light after they were all done. The idea was to use a single cell in the pack. Like an idiot, I took one light and crossed it over all 6 cells. The LED burned UBER brightly for a second and died. There goes $4 down the drain! I had spares so I pulled out the star and 5 minutes later had reflowed a new LED. Just don't ever do that. Real CREE LEDs tolerate over volting quite nicely and will really put out loads of extra light when you do. They won't survive 22 volts when they max out at 3.7 volts.

I have 25 XP-L2's. I have several mini key chain lights that are all aluminum. They produce sufficient light for seeing the key hole, but not much more. I think I can cut down an XP-L2 star to fit in one of these keychain lights. The 3 little watch batteries will need to go away and be replaced by a tiny LIPO cell. I think I can fit a charge controller that has a mini USB port in there next to the LIPO cell. Charging would be just like what I do for my phone and I'd have the brightest keychain light on the planet.
 
ElectricGod said:
I think I can cut down an XP-L2 star to fit in one of these keychain lights. The 3 little watch batteries will need to go away and be replaced by a tiny LIPO cell. I think I can fit a charge controller that has a mini USB port in there next to the LIPO cell. Charging would be just like what I do for my phone and I'd have the brightest keychain light on the planet.


Check out these NiteCore TIP flashlights: https://www.ebay.ca/itm/NiteCore-TI...671093?hash=item4d62e53835:g:ME0AAOSwgKpZsJj7

They have basically all the hardware in there already, you could swap in a different LED if you want. BigClive on youtube has done teardowns of these lights if you want to see what they look like inside. I've had one for almost a year now and I'm very happy with it. The light output on turbo mode is incredible, it's hard to believe that much light is coming out of a small keychain device.
 
Addy said:
ElectricGod said:
I think I can cut down an XP-L2 star to fit in one of these keychain lights. The 3 little watch batteries will need to go away and be replaced by a tiny LIPO cell. I think I can fit a charge controller that has a mini USB port in there next to the LIPO cell. Charging would be just like what I do for my phone and I'd have the brightest keychain light on the planet.


Check out these NiteCore TIP flashlights: https://www.ebay.ca/itm/NiteCore-TI...671093?hash=item4d62e53835:g:ME0AAOSwgKpZsJj7

They have basically all the hardware in there already, you could swap in a different LED if you want. BigClive on youtube has done teardowns of these lights if you want to see what they look like inside. I've had one for almost a year now and I'm very happy with it. The light output on turbo mode is incredible, it's hard to believe that much light is coming out of a small keychain device.

Yeah...cool little light and pretty much what I have in mind. LOL...I didn't know it existed or that anything like I was thinking of existed. I guess there really is no new thing under the sun! Of course just buying that light is no where near as much fun as building it myself.
 
Over the last couple of days, I've been working on finishing up some LED lights for EV use.

I completed 2 different sets of XM-L2 lights. Both are quite small. The left set are focus-able for a tight beam or a wide beam. The right set are fixed focus. Both make a nice hot spot in the middle and a wide splash of light around the center hot spot. The focusing lights will go on my Currie scooter. I'm currently working out a small BUCK that can sit inside each focusing shell. This LED doesn't throw light like an XHP70.2 does, but they are much brighter than the cheap Chinese lights currently on the scooter.

XM-L2%20Lights%201.jpg


XM-L2%20Lights%202.jpg


I got a little further along on the XHP70.2 lights. I got 2 sets of different reflectors that fit these shells. The new ones are lighter weight, but they fit much better than the beefier ones. I guess I'm going to use the cheaper reflectors.

The thermal glue does a good job of sticking down anything. I was going to clamp the LED's between the reflector and the back wall, but the glue makes that less important. I have some silicon o-rings coming that will act as insulators between the reflector and the LED.

XHP70.2%20lights%201.jpg


XHP70.2%20lights%202.jpg


This is a Castle Creations BEC set to 6.75 volts. I took it out of it's heat shrink cover, peeled off the sticker from the heat sink and then used thermal glue on both sides of the heat sink to stick the BEC down inside the back shell. This gives me an independent driver for each LED light that can take up to 24 volts in. The CC BEC easily drives the LED at 7 amps. I greatly shortened the 3 wire cable so it fits inside the shell. It may be that I want to turn up or down the voltage later.

XHP70.2%20lights%203.jpg
 
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