Whereswally606's Emax Scooter Thread

[whereswally606]

so been looking into hub centred steering which is very common on feet forward PTW (passenger two wheelers) but not so common on typical upright (non-recumbent) motorcycles. Bob Tait produced a few hub centre mechanism for the voyager feet forwards and having look at photos of those and also designs critiqued by Tony Foale I have had my first go at trying to model one in Sketchup 8.

three things i've learnt to do in attempting this.
1) use the ruby console (not necessary but interesting to me as I do software for a living)
2) draw spheres in sketchup (tip you need to start at about 100mm diameter and scale down the result rather that try to follow the diameter of a circle with another circle of 1mm. Sketchup doesn't like the limits imposed by the small values.
3) repeat draw (tap ctrl key) puts the mode in additive so will naturally copy and paste new entities. for example when drawing the bearings and rotating about a common centre then this is very useful.

Anyway he is my first attempt. Came out pretty good I think.


Used corrugated metal effect to make it look more realistic.


to demonstrate where the internal bearings are.

 

[bobc]

We did hub-centre steering on a 4wheel electric racecar, some of the ideas might be of interest:
http://i543.photobucket.com/albums/gg471/bobc0/greenpower/batsteer.jpg
Not very illuminating picture, sorry: I have the designs at home
http://i543.photobucket.com/albums/gg471/bobc0/greenpower/dismantle.jpg
ah that one's a bit better

 

[whereswally606]

Why am I surprised you have already done this before. Fancy having another go but this time on a vehicle that is 70mph capable and only has two wheels? btw sent the zip of the manual which was 29 mb zipped as its quite photo heavy.

 

[whereswally606]

well not sure what i expected but my 900w bst cccv charger is not really working with it current limit anymore. It doesnt bother me too much except it would be nice to charge over night slow on the cheap electric and abuse the batteries less. Still does charge though but starts at about 13amp and tapers down from there as the batteries fill.

I also added a few links at the start of this thread to other emax owner's threads to help me find them in a hurry and also to enthuse some others about these bikes.

 

[whereswally606]

Used my cb86-plus to charge my old zippy flightmax lipo hadn't used it yet and my lipo was buried underneath a lot of junk in a metal case cause my wife had been tidying things to the far shed. Going to stored then in the bbq for easy access now. Anyways the interface is a little tricky but I think this will be genuinely useful when powered by the 12v solar bank I should be able to cycle charge the whole pack all 16 3s 4ah cells. Also Will be good to discharge the lifepo4 to bottom balance them before I go to 18s and later to 16s in theory it's capable of 46s in blocks of 6. But I will just be using it for the last few milli volts having used the energy mostly on the scooter riding. Will make a video when I get round to it.

 

[whereswally606]

Well a bit of an update to whoever is listening.

I sold one of my spare 110s Emaxes the other day and listed another both without batteries. The batteries now live on a shelving unit barely capable of holding the weight but its compact and will work well for my intention of solar storage.



the interconnects I made from solar wire from bimble solar and copper pipe cut with an angle grinder and drilled with a pillar drill. (too much work).



and the ends are not yet paralleled up as the 4 connected 12v sub packs at not at the same voltage. just waiting on the trickle charger to get them close.



I may just use 4 mm bullet connector here at the ends.

The plan with selling one was to buy an italjet dragster which didn't have the ice motor so I could have had it for £200. These are the only production scooter which have hub centred steering so I was going to use this on my emax or just electrify it to get something with a more recumbent seating feet forward position. Anyway that fell through as the gent selling it sold it before I could make the space and money to purchase is.

Turns out this is probably a good thing as the Honda insight mk1 I need for commuting started making nasty noises in gears 1 through 3. My local dealership diagnosed it as a input gear shaft bearing which insight central.net would tend to agree with. Anyway I am now £640 poorer but the car is sounding nice again in all gears.

 

[whereswally606]

At the weekend I also managed to make a start on one of the Lebowski boards at bobc's house while he worked on converting the battery in his Emax. A proper job well done there.



here is my board under bobs, He has progressed a bit further than me but I was pleased with a morning's work.

We are still waiting on Ixys for the power chips but now bob has his batteries I think the game is afoot for the Lebowski 10kw board.

 

[whereswally606]

Ordered my remaining parts for the Lebowski PCB. 200amp current sensors and the gate drivers. Going to build up two boards and maybe sell one on later, might be better though to carry it as a spare just in case. Used octopart to get the best price which happened to be Arrow which is US based. Shipping was remarkably free which I don't know whether its a glitch or not but they have my money so I hope they honour the order.

I also made a cheat sheet to help populate the board. Attached to this post.



This has the best representation of references and values for the components and an excel spreadsheet formatted to one page a4 for the refs to part ids.

Bob C contacted the rep at IXYS and I will wait on their reply as the mti145wx100gd would be the best candidate. A fall back is the IRFP4568PBF which is worst rds-on but up to 150v so more head room for spikes. The fear I have right now is that the ixys chip is like unobtainium via normal websearch, you can not seem to buy it without emailing a rep. It also requires that a pcb is made specially where as the to-247 chip is more abundant and can be diy'd similar to lebowskis original method for low inductance stages, nice to have as a back up or to get me started testing the controller.

Looked into prices for 25 of the IRFP4568PBF from arrow comes in at £75 which is pretty reasonable.

I figure that is enough to totally build up a fully populated Lebowski board
i.e. use 24 mosfets on one or
6 mosfets on one (for an ebike) and 18 fets on the other (for the emax)

Will be next week before my parts come into finish the board but Bob's will be done already so at least I can be around when he is testing and setting up his.

 

[jonescg]

Great test of strength for those racks! Always blows me away you can take 100 kg of lead out of an E-Max scooter and put 32 kg of lithium in, and it goes further, faster!

Innovative paralleling system too

Had a chance to try the new setup file on the Sevcon yet?

 

[whereswally606]

Sorry not yet Jonescg,

The sevcon belongs to bob who said I could have a go at setting it up. Trouble is its not at his house its somewhere else so remembering to get it requires me to remind him, which requires me to remember in the first place. Last cheap as in £100 sevcon sold from ebay the other day so puts a dampner on the idea sort of. I am trying to push the Lebowski production up a gear. Ordered one set of parts and I'm trying to order a second set as I type. Using various bom importers after lots of text parsing in excel to get a nice list

This is the list without sensors or gate drivers or power stage fets.

26, 10QBK
34,399-9776
1,P13622
3, 399-4260
1,1N4740A
6, 15QBK
1, 15KQBK
1, 18QBK
6, 1.0KQBK
1,535-11425
1, 445-4342
11,1N4148TACT
1,AIUR-02H-221K
6, 22KQBK
7, 2.2KQBK
24, 33QBK
6, 330QBK
1,IRFB4115PBF
1,495-4996-1
31,P5151
5, 4.7KQBK
2,399-7739
1,1N5231B
4, 680QBK
1, 820QBK
2, BC547BTACT
1, 754-1606
1, 754-1892
1, 754-1892
1, 754-1603
1,FQP7P06
2, 754-1603
1, 10KQBK
1, 10KQBK
1, 39KQBK
1, 39KQBK
9, 5.6KQBK
1, 39KQBK
24,497-2447-1
10,497-3213-1

comes to about £41 which I'm sure could be better.
Using BOM import tools
Digikey works well, but minimum £50 order or £12 shipping.
Mouser works kinda but lots of things which are not substituted so a job to manually replace missing parts.
Arrow (US) checked too but they must have engineers to do it as its not instant.
Farnell/element14 website says its processing but I can see anything getting done, very slow if it is working.
Rapid electronics, none of the numbers match arrgh

 

[marcexec]

few lessons learned:
- keep the spare
- somehow I keep blowing up the TO247s (OK the first set were fakes)
- note you can only have one pair of IRFP4568PBF per driver (and need to change the resistor) - details in the "disciple" thread I think

and sand the copper plate...
I have a 150W soldering iron on the way, the 80W one is a tiny bit too slow to work comfortably.

 

[whereswally606]

Ok thanks for the advice marc. well ordering from digikey sucks for the reason of £50 minimum order before £12 shipping but otherwise their service is excellent. Getting the parts from Arrow America seems possible but an arduous task not sure if it worth the extra effort but for now the shipping is free. just gonna hold off before pulling the trigger on the rest of the parts from the US as I'm not sure whether ill get stung for taxes, but it is cheaper. Also the longer I hold off the better the pound is looking against the dollar so there's that.

2 per driver hey for the IRFP4568PBF so basically on the through hole board you can only do 12fets not 24. as their are only 6 gate driver positions. That's still more power than I need or can realistically abuse this hub motor with.

Still waiting on the IXYS rep to sort bob out with the mti chips.

 

[whereswally606]

This weekend we didn’t have the part to further the lebowski project. Still waiting on sensors gates and rs232 to usb programmer plus the ixys chip for the power board. Arrow have just delivered both sensors and gates to my work. So only waiting on IXYS and the programmer now.
Instead I brought another project to Bobs house and he kindly agreed to help me not kill myself with high voltage.
A long while ago when Mr Victor Gondars first started reselling Fuji flexible 100w cells on ebay I bought 3. A while back bob said these could be run straight though the AC of a server power supply as it should pass straight through the AC rectifier and be used directly. Well this weekend I bought along the panels and some solar wire, mc4 connectors, wire stripper and psus and we did a few tests.



The first psu is a hp 12v fanless low profile one from a server. This is the one I want to use longterm. The other was a meanwell clone 24v trimmed to 20v.
We began by wiring up the panel to the meanwell via a kettle lead IEC connector. Croc clips on the plug that would normally go in the wall. The meanwell fired up straight away and output 20v, success. After that we tried the HP server which didn’t as it couldn’t get past its starter circuit. Lots of relay clacking but no 12v output 
This spurred me on to make up the parallel harness to connect the other two panels in. after about 2 hours of wire stripping and soldering, and making decent ends to the panels with mc4 connectors, we had a working array of 3 panels i.e. 300w by this time my wife was calling to get me home and the sun had gone behind the clouds.



We retested the array but still not enough juice to get the hp from delivering its 12v. then we retested the 20v meanwell and put a huge load resistor on it to simulate powering the battery bank. The panels voltage dropped below 350v and the meanwell stopped outputting its 20v.
The lesson here is that the load on the psu has to be small and controlled according to the voltage that the panels are putting out. An arduino sensing the voltage of the panels via a large resistor could directly control the pot which controls the current limit on a stepup dcdc. In this way the load could be optimised to output the most power possible out of the array given the sun.
Also the arduino could be sent sunup and sundown times (if it had a real time clock) to connect and disconnect the panels so that there is no load at night and the psu might live a little longer.
I’m confident I can get this working and thus have my 12v battery bank totally off grid. We shall see.

 

[bobc]

Isn't my back lawn in super condition.....

 

[marcexec]

Farnell has IRFB4115s quite cheap: http://ie.farnell.com/international-rectifier/irfb4115pbf/mosfet-n-ch-150v-104a-to220/dp/1698286, 25+ are €1.89 a piece, IRFP4568 are €4.19 and one wouldn't need as much.

I'm thinking of building up that 2nd board to help me troubleshoot the DC/DC circuit, maybe swap parts one by one?

 

[whereswally606]

Just got a hefty bill from DHL/arrow for customs on the drivers and the gates £50. am quite angry at myself, kinda knew this might happen, didn't think it would be so much though. Have written an email to arrow customer services after talking to one of their agents who told me that I shouldn't have been charged since they started free dhl shipping the day before I placed the order. Just hoping I get reimbursed but I am not holding my breathe about it.

 

[bobc]

Ouch (very) - fingers crossed they sort you out;- they should do, there's no way you'd go back to them if they pull this sh1t...

 

[whereswally606]

Went to bobc's house this bank holiday Monday.

Have seen the first peak at the schematic for the power stage ixys for the Lebowski controller.

dropped off the lebowski chip and powersupply pic, so now my board will be complete bar the last resistor for tuning the 5v and 15v lines.

I had a go on Bobs red scooter. fun and different and no helmet so couldn't really push it too hard round the estate. His has done few miles than mine and consequently is in far better shape.

a future step will be bench testing the Lebowski controller with the motor from an emax. also we want to keep the functionality of the mcu from the emax and the screen. Quite a job for me is stripping all the electronics from one of the mopeds so it can all be tested on the bench. Bob doesn't have space for another scooter and I have no means of transporting a whole one to his house.

on another note. Bob helped me with a task to gain brownie (girlscout) points with my heavily pregnant wife. making a bespoke curtain rail.
A while ago I bought some alloy 45 degree 32mm bends (typically used in car cooling systems) to mate to some 1+3/8 inch wardrobe rail. Last approach attempted used a bender to just put 45 degree bends in the ward robe rail but it was too thin and just kinked the walls. Bob used his lathe and machine skills to get a nice fit with the alloy elbows and the wardrobe rail. We need to make the last two elbows (currently on way from ebay) as well for a whole bay window but however the method is proven and soon the whole rail will be up. pictures to follow when complete. Big thanks to Bob for this.

Today I scooted in but after faffing with my tp1430c and the paralleled greensaver pb sla in my garage I forgot a wire I needed for charging the scooter at work. Thankfully I had a spare two 4mm bullets connected to terminal block on my car tyre electric pump. Was nice to see that I had a backup but must be more careful with my connectors. A spare 900w dcdc would be smart too since no telling how long it will last. Been solid so far though.

Also received two large 400v caps to use on my solar panels (fujiwave ones) to try stablise the input to the Server power supply which couldn't get past the starter circuit (lots of relay clacking no 12v output). Stay tuned for this experiment (disclaimer don't do this at home).

 

[whereswally606]

tested the two large 400v caps on the 3 solar Fuji solar panels yesterday hooked up to two different HP server supplies.

Despite good sun I think I didn't have enough juice to overcome the server supplies starter circuit. less clacking of relays than before the added capacitors but still not enough.

I had more joy with the meanwell clone last time we tried it. It maybe worth ordering a cheap 12v version and if that doesn't work calling it a day on the Fuji flexible solar cells.

mr gondors who sells them seems to package a meanwell clone with them so perhaps it will work.

Scooted into work today. It was a lot colder. I need some better warm gear.

 

[bobc]

Andy
it might not be a startup issue - the server supplies might have PFC, (extra circuitry to take a nice sinewave of current from the mains) in which case a DC supply will never work...

 

[marcexec]

Andy
it might not be a startup issue - the server supplies might have PFC, (extra circuitry to take a nice sinewave of current from the mains) in which case a DC supply will never work...

Good call.
Any PS for the European market would have PFC - the Meanwell clones wouldn't, Meanwell itself has a variety with and without PFC.
Go original once you have it figured out - you want this reliable and safe.

 

[whereswally606]

I have ordered a 12v 30amp mw clone from ebay from a birmingham seller £16.09
couldnt seem to get it cheaper on aliexpress.

Will have all the HV parts water tight and away from prying hands.

Will update when i have given this one ago.

I feel from the initial tests we did at bobs that the mw clone that i had that is a 36v one would have worked with a variable load which was switch based on the amount of sun on the panels i.e. the panel voltage.

 

[whereswally606]

have received my 12v meanwell clone, with weather/sunlight permitting resume the experiment this weekend

 

[whereswally606]

didn't get a chance this weekend to test the 12v meanwell clone but have just been looking through the thread of cheap toolbox bargains by drkangel

https://endless-sphere.com/forums/viewtopic.php?f=2&t=47924&start=110

This top item gave me an idea for a series parallel connection with three of these switches to go from 12v to 48v for charging and discharging using the old emax chargers as they can do 48v at 20amps and I can parallel a few of them (if I'm felt like it)

so for £15ish I can do one between each 4pack (shelf) which would give me the option to easily switch from 12 to 48 or back again.

http://www.ebay.com/itm/AC-500V-20A...385564?hash=item25ba5c101c:g:GPoAAOSwVghXEmoz
here is one on ebay that would do for me I think.

I understand there is a potential pitfall of screwing this up by putting 12v and 24 volts together. (very bad with batteries this big) so a procedure of every thing to 0 first (disconnected)

doing 48 volts is fine all switches to 0 the all switches to 2 (series link) in sequence (actually done wrong 36v into 12v )
i.e. (1p4s shelves) actually 4p4s

doing 24 volts can also be problematic, if done wrong 24volts can be feed into a 12volt set.
Have to do top two to 1 and bottom two to 1 first then middle one to 2
i.e. 2p2s (shelves) actually 8p2s

doing 12 volts is all switches to 0 then all switches to 1
i.e. 4p (shelves) actually 16p

I think the key is don't adjust under load and break in the middle to zero first.

Question here is, do I need to add this functionality?
I am not even sure of equal capacity either so anything above 12v becomes iffy.

 

[whereswally606]

MOT test time again. Passed no problem bar the stop light being permanently on which drains the battery unnecessarily. After passing I got the zero £ tax sorted. Then I went to charge it full intending to use it for a while. I noticed on my cell log taps that cell nine's voltage was jumping all over the place. When I inspected the terminals the washers on the -'ve of cell 9 were really corroded and a bit loose. So I disconnected it cleaned the terminal and the lug and got a new bolt and new washers, swapped them out and the voltage went back to normal. I wonder how long it's been like this since the washers were really rusted. Anyway take home message is check you battery bolts. Need to do a discharge test and see what capacity remains in these alleged 60ah cells.

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