Search found 561 matches

by Burtie
Oct 20, 2016 2:57 am
Forum: E-Bike General Discussion
Topic: Buying MXUS From AliExpress
Replies: 14
Views: 917

Re: Buying MXUS From AliExpress

mgspc@hotmail.com is the payment address I have used successfully in the past to purchase from them , about 2 years ago.

burtie
by Burtie
Aug 03, 2015 9:01 am
Forum: Motor Technology
Topic: how to build a motor test stand?
Replies: 28
Views: 1070

Re: how to build a motor test stand?

Another example of a hub motor test stand... uses array of halogen lamps to dump the electrical power:

https://endless-sphere.com/forums/viewto ... 50#p966937
by Burtie
May 30, 2015 5:47 am
Forum: Items for Sale - New
Topic: Optical sensors available for Astro, Turnigy, etc.
Replies: 56
Views: 11842

Re: Optical sensors available for Astro, Turnigy, etc.

Hello Burtie, I take it that you are no longer a member on here. Dang. I was hoping that you have a couple of rotary hall sensor kits suitable for the Astro Flight 3210 motors. If so, and they worked out ok for our application, I'd put in an order for ten of your next batch. Kind regards Jeff Knews...
by Burtie
May 25, 2015 4:19 am
Forum: E-Bike Technical
Topic: torque arm picture thread
Replies: 188
Views: 36830

Re: torque arm picture thread

I was asked how I did the torque plates for my specialised big hit, so here are the pictures... torqueplatelh.jpg torqueplaterh.jpg Started as 12mm thick (rh) and 20mm thick (lh) steel bar. I used a mill to cut the 10mm slots in these plates, but I guess a bit of work with an angle grinder could yie...
by Burtie
May 06, 2015 6:00 pm
Forum: Motor Technology
Topic: Sensorless, halls, encoders, motor efficiency?
Replies: 28
Views: 3274

Re: Sensorless, halls, encoders, motor efficiency?

The more complex FOC (sine) controllers require a very much finer angle resolution to operate effectively. Another way I might write your sentence(doubtful I understand what you mean) is field oriented control is less efficient than it can be when ran sensorlessly or using hall sensors (low resolut...
by Burtie
May 04, 2015 4:34 pm
Forum: Motor Technology
Topic: Sensorless, halls, encoders, motor efficiency?
Replies: 28
Views: 3274

Re: Sensorless, halls, encoders, motor efficiency?

Hello, Has anyone made any measurements in motor efficiency differences comparing running a motor sensorless, using hall sensors, and using various encoders? Via PM... ... I'd love to read your thoughts on the subject.. :) IMHO It is not easy to generalise and say that one method is more efficient ...
by Burtie
Apr 24, 2015 9:34 am
Forum: E-Bike Photos & Video
Topic: SEXY E-BIKES WITH MOTO WHEELS SHOWOFF THREAD
Replies: 103
Views: 15721

Re: SEXY E-BIKES WITH MOTO WHEELS SHOWOFF THREAD

Since I liked the 21inch moto rim experiment, I have also fitted some 19 inch x 1.4 rims to another bike. Wheels19-1b.jpg Wheels19-2b.jpg Vee rubber 2.50-19 VRM308 tyres, these actually measure 2.75 inches wide by 25 inches diameter. I guess it is unlikely that these tyres will get a puncture in nor...
by Burtie
Apr 10, 2015 3:57 pm
Forum: E-Bike Photos & Video
Topic: SEXY E-BIKES WITH MOTO WHEELS SHOWOFF THREAD
Replies: 103
Views: 15721

Re:BigHit 21" MOTO WHEELS

Here, some 21 x 1.6 inch second hand motorcycle rims, fitted with Vee Rubber 2.75-21 VRM221 tyres. Outside diameter is 27", width is 3.1" Just fits into the '07 BigHit Swing arm without needing to shave any knobbles :wink: wheel1.jpg wheel2.jpg wheel3.jpg Wheels are fairly heavy at about 10lbs each,...
by Burtie
Mar 27, 2015 7:33 am
Forum: Motor Technology
Topic: Leaf / leafmotor / leafbike high efficiency 1500w motor
Replies: 1314
Views: 135573

Re: Leaf / leafmotor / leafbike high efficiency 1500w motor

Nep, Per previous notes you have the Kv at 13.16 ... For what its worth, I have one of these 1500w motors in my test stand here, and have just measured the Kv at 12.92 -using an optical tacho. (no field weakening or "120%" speed setting tricks) For comparison with a couple of others highish Kv hubs...
by Burtie
Nov 24, 2014 5:48 pm
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

.... But still, I cannot get high rmp/high amps from my SK6374... Pierre. Does your sensorless position estimation perhaps fail under these (high rpm/high amps) conditions ? I guess that, using only a single sensor to resolve the separate phase currents, you will need that sensor to have a suitably...
by Burtie
Nov 07, 2014 4:35 pm
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

I think this is due to a glitch in the data monitoring mechanism ( RTDM ).

If the observation was real, it would cause upset to the system -which is not evident.
by Burtie
Nov 07, 2014 4:19 pm
Forum: Items for Sale - New
Topic: Optical sensors available for Astro, Turnigy, etc.
Replies: 56
Views: 11842

Re: Optical sensors available for Astro, Turnigy, etc.

I have one or two rotary sensor boards left, they have a 1 inch (25.4mm) centre hole so only fit Astro motors with a 1 inch diameter bearing carrier. ( Some of the newer Astros have a larger carrier than this ) If the motor phase wires exit through the back cover, it will probably not fit easily wit...
by Burtie
Nov 07, 2014 3:52 pm
Forum: Items for Sale - New
Topic: Optical sensors available for Astro, Turnigy, etc.
Replies: 56
Views: 11842

Re: Optical sensors available for Astro, Turnigy, etc.

I think all three used a total of about 50mA.

I had 270 ohm resistors in series with each of them.
by Burtie
Nov 06, 2014 5:38 am
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

I think that If you pause the display, the four graphs will show static snapshots that are time aligned with each-other.
by Burtie
Nov 05, 2014 9:02 am
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

Ken Taylor wrote: ... I'm curious why it didn't match my expectation.
Yes I agree I does look a bit odd.

I think it is due to the way the RTDM graphing tool updates the snapshot for each of the four graphs in turn, starting top left, ending bottom right.
We get to see the data in 'Almost' real time.
by Burtie
Nov 03, 2014 5:22 pm
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

HubLoadBench2.jpg I wanted to be able bench test the controller with a variety of hub motors under load, to enable me to optimise the settings and the filters for a variety of different motors. The motor driven on its own is almost silent. Pretty loud now, after adding a chain and a planetary gearb...
by Burtie
Oct 28, 2014 3:14 pm
Forum: Items for Sale - New
Topic: MXUS 3000 v2 - EU Only Groupbuy (Sort of)
Replies: 39
Views: 5309

Re: MXUS 3000 v2 - EU Only Groupbuy (Sort of)

Sounds good.

I would like to register interest in one of those motors.

Cheers,
Burtie
by Burtie
Oct 26, 2014 6:09 pm
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

Thanks peters, I am currently using the controller with a 6 turn MAC on my mountain bike at 3.25kw peak power. The modest motor is able to survive these power settings because the controller now monitors the motor stator temperature, and progressively reduces the phase current limit, when the temper...
by Burtie
Jun 20, 2014 3:34 am
Forum: Motor Technology
Topic: Sine wave controller with smartphone app
Replies: 6
Views: 559

Re: Sine wave controller with smartphone app

Now that I have found my camera again, I can show some detail. Here is the bluetooth radio adapter that I use; To find these things, look for 'Bluetooth UART' BTadapter.jpg BTbrain.jpg I had to cut an apeture in the controllers aluminium housing for the bluetooth antenna to work: BTaerial.jpg This f...
by Burtie
Jun 19, 2014 6:06 pm
Forum: Motor Technology
Topic: Sine wave controller with smartphone app
Replies: 6
Views: 559

Re: Sine wave controller with smartphone app

Any controller using an ASCII based UART interface can easily employ a commercial Bluetooth adapter, allowing a smartphone to be used as a control/monitoring terminal.

example:
https://endless-sphere.com/forums/viewto ... 25#p739147

Burtie
by Burtie
May 01, 2014 5:23 pm
Forum: E-Bike Technical
Topic: mac motor pumping under high load
Replies: 32
Views: 1762

Re: mac motor pumping under high load

Phase current is proportional to torque (load). The surging is likely caused by the way your controller is regulating the phase current when it reaches the upper phase current limit. How old is your controller ? Because of their low inductance, I found Mac motors were often a problem for the older (...
by Burtie
Feb 11, 2014 10:32 am
Forum: Battery Technology
Topic: Two BC168 chargers on 12S pack?
Replies: 27
Views: 2205

Re: Two BC168 chargers on 12S pack?

I BC168#1 connected to cells #1 thru #6 and works fine by itself. BC168#2 connected to cell #7 thru #12 and works fine by itself. But when I use them together, cells #6 and #7 show 4.2 Volts while the other 10 cells show 4.0 Volts... And idea why this happens? I really wanted to be able to use the ...
by Burtie
Jan 20, 2014 3:58 pm
Forum: Items for Sale - New
Topic: Optical sensors available for Astro, Turnigy, etc.
Replies: 56
Views: 11842

Re: Optical sensors available for Astro, Turnigy, etc.

j3tch1u wrote:hi burtie, any chance you might do a batch with 1.25" hole for astro 3220's with the 12mm and 1/2" shafts? i'd be down for 10 pieces.
No plans to make any new ones.

But I do have a few left with the 1" hole.

Burtie
by Burtie
Jan 12, 2014 3:47 pm
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPic33

Hi Shenta, thanks for the tips about the current sensor. ...Can you tell me more about your regen? Regenerative braking (with AN1078 FOC) is achieved by just commanding a negative torque value. The bigger the value, the more braking effort you get. You need to add code to prevent the motor spinning ...
by Burtie
Dec 30, 2013 8:16 pm
Forum: Motor Technology
Topic: Field Oriented Control using dsPic33
Replies: 173
Views: 26274

Re: Field Oriented Control using dsPIC33

Spent the summer riding an ebike powered by one of these controllers, refining the firmware and enjoying the sunshine :D I wanted the controller to be able to monitor the motor temperature, so it could regulate the max power input when necessary, and I also had some problems with the existing I2C co...