Direct drive brushless motor from powerchair.

[electric_snowshoes]

First off I'm on a borrowed computer so my response may not be punctual. Second issue is I need to learn photo transfer to ES Forum site. I have got the images from the SD camera card to a computer file.

Amberwolf has a topic for the same motor class but a different reason than mine. He has succeeded in placing hall sensors to bypass the manufacturers 2 sensor method & use an ebike controller instead of the factory controller & joystick. I have the matching controller but no joystick.

This is a different motor (L & R pair) than in Amberwolf's thread. Its a Invacare, part # 1079291 from Elyria, Ohio, date stamped Jan 03, 2003. We know these motors can run at low rpm without overheating.

The Topic : Can the matching controller be utilized / converted to run a single motor of the pair, ebike style?

I'm aware there are various sensing methods in the controller, such as all wheelchair drive components must be attached & working. There is also limiters for speed & user reaction time usually programmed by the retailer staff to meet the need. Can these be removed or bypassed?

The missing joystick may or may not have an on/off switch & indicator / troubleshoot bar lights like Perry & Giles echairs & carts. The joystick function needs to be replaced as only forward & throttle functions are wanted.

Are there members interested in this? Is there members with the knowledge & time to guide a photo study of the motor & controller?

There may be useful info in robotics forums, please PM instead of posting off topic here. Lets see if solutions exist first. Thank you for considering this topic.

 

[amberwolf]

Second issue is I need to learn photo transfer to ES Forum site.

A start:
http://www.endless-sphere.com/forums/viewtopic.php?p=230300#p230300

Its a Invacare, part # 1079291 from Elyria, Ohio, date stamped Jan 03, 2003.

Attached at the end of the post are some pics of one I found on Ebay; unfortunatley I can't find it in the Invacare service catalogs on their site.

The Topic : Can the matching controller be utilized / converted to run a single motor of the pair, ebike style?

Probably. But you may have to duplicate the sensor feedback from the one present motor to the other's inputs.

Then if the joystick input is analog, you could just put equal resistors or voltages on the steering inputs, so that both motors would always be equal power output and thus equal speed, so that the sensors should be fooled correctly.

Then setup your throttle for the other two inputs sort of like the Vectrix, so it accelerates for center to one end, and reverses (rather than brakes) for the other direction. Or if you need no reverse, setup the voltage range so it only uses the forward part.

If the controller is designed to use a *switch* for the joystick, so it has the speed controlled by a separate pot, then that pot becomes your throttle, and you can add a switch for forward or reverse in case you need to back up under power. Then you need no input at all for the steering input(s). Maybe tie them high or low with resistors if necessary, so they never go active.

I'm aware there are various sensing methods in the controller, such as all wheelchair drive components must be attached & working. There is also limiters for speed & user reaction time usually programmed by the retailer staff to meet the need. Can these be removed or bypassed?

Maybe. If you could get a programmer for the controller, almost certainly. But it depends partly on the max speed you can achieve at the max voltage the controller will take (probably about 28-29V, as that is what two fully charged 12V SLA would be at, typical of powerchair systems).

You may be able to up that a little bit, depending on the regulator inputs and stuff for the low-voltage innards of the controller, but I'd guess that 30-35V is probably the absolute most you could put on there, and that would probably be pushing some of the components. We'd have to see what's in there to find that out. I have a brushed Perry & Giles controller here that I am going to see what components are like inside, but we'll still need to find out what's in yours before we can determine if it can run higher voltages unmodified (assuming that it is even necessary).


Assuming it's not already running at the max speed at the original voltage, One way to bypass is if you are not going to use the motor to directly run a wheel. Simply use it's original speed range, and gear that up to drive your wheel up to the speed your vehicle needs to achieve, either by a fixed ratio or by a variable-speed transmission.

But I don't know if that will have enough power for anything really heavy at higher speeds. You would probably need to be able to run it faster at higher voltages, as I am going to do with mine, to be able to then convert that speed into torque via gearing, without overheating the motor and the controller. (I hope)


I'm sure you can bypass or defeat the other sensors one way or another, once you find out what pins are what on teh controller. Not having the whole chair to do a reverse-engineering and wire tracing on is going to make it harder--you'll probably have to do some experimenting. If you run across another of the same chair (especially a working one), then doing some "diagnostics" on it that let you trace out all the wiring would help you immensely.

 

[electric_snowshoes]

Thank you Amberwolf, you know lots on this, my topic needs this guidance. Your photos above are the same motor, looks different that the photos in your topic thread. Sort this out later (my memory).

First I need to get these photos on site, I see your link for that, thank you. Got a Snapfish account as its on this computer, need to download their transfer tool. One or the other...

I got a motor opened, its 2 sensors, appears to have a flywheel to trigger sensors, they are not located at the coils/magnets. I did not fight the magnets as all electrical is visible.

I have the complete harness minus joystick, this may assist the reverse study. I'll open the matching controller today for photos.

 

[electric_snowshoes]

I'm not getting photo transfer, the link to Tylers topic isn't clear either, I don't understand the terms.

Snapfish : need to download their photo uploader. Find this tool download link. Usual HP bloatwear run around. HP engineer : "boss, look at how long our customers visit our site, we must be very important to the internet". Me to memory banks : Remember HP maggots, never, ever buy anything HP.

ES Attachments : "Upload attachment" bar, them "browse" gets my various photo files on a "file upload" screen. I have a 4 photo file to attach, I don't have them one click available, need to open "my documents", then "my pictures". I click the file I want, this opens the 4 photos wanted. Can't get this to ES filename : _______Browse / Add the file.

I don't know what filename means, supposed to type something here. Tried the file name below the box of 4 photo thumbnails, "new file".

Highjack distraction into my own thread out of stupidity. No...remember the HP engineers, one must go to school...what happened to point & click ???

R&R : Its 2pm, a bright sunny day, above freezing & dry roads, 'nuff with the mind numbing tools to nowhere. I will be back for more said the stubborn old fool.

 

[amberwolf]

Got a Snapfish account as its on this computer, need to download their transfer tool. One or the other...

Well, you can upload your photos directly to your posts, using the "upload attachment" section below the part where you type in your post, while you are typing one in or while you are editing your post afterward. No need for any accounts or installing any software on your computer.

I got a motor opened, its 2 sensors, appears to have a flywheel to trigger sensors, they are not located at the coils/magnets. I did not fight the magnets as all electrical is visible.

If there are 2 sensors then they are probably set up the same way mine is, for SIN/COS and use a magnetic ring, probably with one pole change per actual motor pole change.

I have the complete harness minus joystick, this may assist the reverse study.

The harness will help you a LOT because you can check continuity from place to place and find out what pins are for what.

 

[amberwolf]

I'm not getting photo transfer, the link to Tylers topic isn't clear either, I don't understand the terms.

Which terms? Best to ask/answer that question in that thread, as it could also help others in the future, but here's the help I can offer:

ES Attachments : "Upload attachment" bar, them "browse" gets my various photo files on a "file upload" screen. I have a 4 photo file to attach, I don't have them one click available, need to open "my documents", then "my pictures".

That's normal. Right off the camera card, I put all my pics that I'm about to upload in a folder named "Pics to Upload", then after I'm done doing that I move them to folders based on the project they are for, so I can find them later. Makes it easier for me.

I click the file I want, this opens the 4 photos wanted. Can't get this to ES filename : _______Browse / Add the file.

I'm guessing your photos are in a folder; you can't select a whole folder for upload at once, just a single file. So click on one single photo (pic) and then it should work.

I don't know what filename means, supposed to type something here. Tried the file name below the box of 4 photo thumbnails, "new file".

You can only select one file at a time. Filename just means the name of the photo.

 

[amberwolf]

This may end up a hunt for 2 sensor controllers with enough amps, instead of bypassing the limiters of existing units.

It's probably going to be easier. Lyen here on the forum has some (not cheap) controllers that will work at pretty high power levels, even enough for a large scooter or something (probably enough to damage the motor if sustained at high power levels), if you are willing to add 3 hall sensors like I did. It's not that hard to do once you get the motor apart, and may not even be necessary to disassemble it in your case, because you have access to your SIN/COS encoder already. If yours works the same way as mine, that encoder has the same pole pairs as the rotor, and you could use that magnet ring instead of the rotor magnets.


But still may be well worth trying to at least figure out if one of these controllers can be used on an ebike at all.

 

[electric_snowshoes]

Thanks for response & help Amberwolf.

OK, one photo at a time. My only experience with photo upload is with kiji, no problems that I can remember. (add senior's memory jokes here)

Fail : "the file is too big...max 512kb". Thought I set this size (minimum size pre-checked in 3 box choice), while moving SD chip images to the computer. Photo is 1.28 mb, 3072 x 2304.

Well this morning I have my confidence back that I can read & understand instructions. I also remember not to look in HP for any answers.

I'll upload 2 images showing the opened motor. I did not get to the controller yesterday, soonest.

 

[electric_snowshoes]

I got Irfanview loaded onto this computer. This may be a mistake as there is no download at the irfanview site, links to a page of download sites that don't have the download, just like hp run around, full circle, right back to the original page.

One link works, do the download, opens at a Q&A page, first one says "check windows why its running slow", I thought slow was normal, so click it, Uniblue. WTF ???

Do I want a download from this site that links to a known scam ?

Delete irfanview & run CCleaner. Run regedit more than once.

Of to general topics to find photo resize options.

 

[amberwolf]

Never seen that with irfanview before; sounds like something else from the download site itself. Mostly I use AT32Resizer (free)
http://www.at32.com/doc/resizer.htm
http://www.mnetz.fsnet.co.uk/at32/resizer.exe
for batch resizing of JPG files, but for individual stuff I just use Paint that's built into Windows:
CTRL-O
browse to file, select and enter
CTRL-W
type percent resize desired
TAB
type same number again
ENTER
ALT-F
A
add "small" to filename (so I don't save over original) (or start with a copy rather than the original)
Repeat with next file if there's another.

 

[amberwolf]

This is the conversation so far with the other person I mentioned, with his reply first and mine to him (and thoughts for here) subset inline:

Electric_snowshoes' Invacare motor is an older type that uses the same pinout as your newer motor; his motor has a more conventional axle/hub assembly for attaching a sprocket.

I'm not sure how one would go about bypassing the one channel although if it's possible to parallel the outputs to the one motor having twice the output current of one channel would certainly be useful.

I doubt that will work simply because the timing of each channel may be different, and even a slight difference could result in a shoot-thru from power to ground thru part of each channel. If timing coudl be guaranteed identical then you could do it, but the only way I know of to do that is to cut the gate control lines from one set and connect both sets to the same gate control lines. Since both are using the same MCU (presumably) in this controller, however, it may well be possible to reprogram the MCU to send the same timing and sequence to both channels...but you'd need the source code and ability to program the MCU to do that.

A brushed motor controller *could* be setup like this, as long as you could guarantee that they would both be given the same throttle and braking signals. But brushless is a whole other ball of wax.

The only way I can think to bypass the channel is to provide the SIN/COS sensor data from one motor to both channels, if the controller will only continue "straight forward" motion when it detects both motors are running the same.

E_S' plan to use the controller sans joystick sounds like a *very* difficult way to go about it unless he can reverse-engineer the controller without a functioning joystick attached. The controller expects to have a joystick or at least a display module attached in order to function at all unless some very clever means of bypassing these can be found. If I was planning to use the factory controller I'd just program reverse and turning out if possible (haven't had a need to do that at work yet) or repositioning all the joystick's inductive sensors except for the forward quadrant.

I think it will also be very hard, but it depends on how the joystick data is sent to the controller. If it is actually sent just as switches, one for each quadrant, it's easy. If it's analog potentiometers or similar, then again, it's relatively easy. But if
it is encoded data then it requires having a functioning joystick and controller hooked up together to sniff teh data packets between them and figure out what is being sent for each command. Then creating a circuit or programming an MCU to recreate that data.

 

[electric_snowshoes]

I've been busy learning how to get photo resize happenin'. Real close now, lol. Getting lots of help. Slow on the understanding.

Amberwolf : Got to re-read your friends info to you & your other posts. I'll try again to borrow the matching joystick. Maybe its already a deadend?

I did not pay attention to joystick types, think I seen schematics linked on robot sites, way back when I read up on Burgerman's website & topics. Don't know if robots are using BLDC motors. I sure like Burgerman's powerchair & his efforts for the handicapped.

I would not have started this post yet had I known the photo issues. 3 days later & no photos on site.

Hour ago : Controller case has tiny torque screwheads, 2 or more sizes below T10. Allen wrench, inch & metric sizes are too large also. buy one tomorrow, charge the drill bateries just in case. Expect its an outer weather case.

Thanks for your patience & help. Back tomorrow.

 

[amberwolf]

On those little star-hole screws: Sometimes a flathead jewelry-sized screwdriver fits them perfect. Sometimes they are also "secure torx", with a little pin rising up in the center, so you have to have a tip with a hole in the center. The little flathead screwdrivers also often fit them, too. If they're in loosely you may be able to turn them by hand, but I usually have to use locking pliers to hold the screwdriver to do the turning; not so much for the leverage but because I haven't enough hand strength to grip it sometimes.

 

[electric_snowshoes]

OK, I have some photos ready, will do closeups shortly. First image has the back cover removed. The 6 controller case screws are normal T8 Torques.

Next photos will be the parts typically available from handicap charity shops. Locally I do not get the joystick control, not sure why, anyone have the same experience?

So this is a cheap source for powerful (ebike/cargo/other carts) motors that can be modified with hall sensors to run on ebike controllers, as Amberwolf has demonstrated recently with the newer version of this motor.

This quest is to adopt the motor matched controller to drive one motor, some may want both. Needs to work with ebike throttles & safety brake cutouts. This may proof difficult do to inseperatable parts inside the controller.

I suspect the scrapping of usable parts by charities is common in N. America. A solid market at fair used part prices is/may be important to charities. The parts I'm posting can be bought for $50. and less, fair (to the charity) has yet to be determined.

 

[electric_snowshoes]

Photos comtinued.
No joystick or charger. Battery & charge harness, controller & R/L motors.

 

[electric_snowshoes]

2 copies in above, one inline button, faulty operator. My added file numbers are already wonky. Sort that later.

Note the add-on ground wire set on top, someone got involved with this powerchair prior to the charity, don't look like an autherized repair. The factory controller warranty seal appears intact. Can anyone identify the logic of a ground wire?

 

[electric_snowshoes]

Drive side of the motor. Sensor modual location. Shaft is 25/32", slightly under 20mm, keyway is 3/16 x 3/16", under 5mm.

 

[electric_snowshoes]

Opened controller & ports.

 

[electric_snowshoes]

Not sure how the outer board is fastened to the housing. There is 2 'brackets' having 3 screws each, perhaps some of them attach to the aluminum housing. There is white paper/bristleboard between the bracket & board, someone trusts its insulation properties thinks the newb.

 

[amberwolf]

Observations:

So the motor is an inrunner, with magnets/rotor inside the windings/stator. Opposite of mine. Makes the rotor weigh a lot less, I suspect.

Windings are interwoven between all stator teeth, rather than just around sets of them. Not sure if that is more efficient or reduces cogging forces, or why it's done that way.

Since wheel hub goes onto shaft using keyway and locknut, you can do what I did with CrazyBike2's brushed powerchair drive and use the hub to bolt or weld sprockets to, for a chain drive, or build a wheel that you can bolt directly to the hub to mount on the shaft. SHaft was meant to hold up chair on one side so it is very strong and is supported by two bearings.

Looks like a 6FET controller, maybe 12. Be interesting to see which FETs they used, but not necessary unless you are thinking of running >24V (29V hot off charger) system.

Casing and interior design is very much like the brushed P&G controller I have here; I have not tried to operate the controller at all but it has an MCU in it that I don't know anything about, and connections for external controls/etc. that I don't have a connector for. I do have the two motors that go to it, but I'd have to make up a battery plug (looks simple enough).

I do have a Quickie joystick and the controller for it; I'll have a thread for at least pics of it at some point; dunno if I'll ever get to determining what signals it sends. But it looks like all analog stuff inside it, with LM339 comparators probably determining joystick positions and sending signals for Left, Right, FWD, REV, etc., and a pot for the throttle speed I think. If the joystick for yours is made like that one, I think you might be able to hack it to work.


Gotta run but more later.

 

[electric_snowshoes]

I have photos of the 2 boards in this controller. It is definitly brushless, I read a technical manual on this model yesterday.

I'm also getting "too big" with these images, not getting resizer screen. Going to delete all the images in Picasa & start over. A mess, as I reload the SD card. Remember the chimp & typewriter experiments in the 50's? Uncanny. lol

The features in this controller model are remarkable. Components can be added for the very handicapped such as breath controls. Another add-on controls the seat, tilt & other positions, I think leg rests too.

The manual compares 3 inhouse motors, BL equals the power of a 4 pole, but not as powerful as the heavy duty 4 pole version. No values stated, I'll look for motor ratings.

Controller heat is monitored, reduces power, called "current rollback". States the conditions that cause it.

A handheld programmer is needed to recalibrate, if controller or motors are changed. There are 99 self diagnose functions. Many settings for a lot of handicap medical conditions/limitations.

This controller may be a poor choice for hacking into a go/stop function. Perhaps useful to robotics folks? Not sure if its useful for 2 drive wheels in trikes as one wheel fights the other on side slope surfaces. Are BLDC gearless inrunner 30lb motors useful? Perhaps wind generators?



I'll get 2 more board photos up soon, Bob.

 

[electric_snowshoes]

I cannot load photo, repeat resizing, now down to 340 wide, image is 30 something KB. Results is "too big", its over the 50 kb limit. I changed the camera setting to "macro close up mode", is that my problem?

 

[amberwolf]

There's no forum file size limit I'm aware of, or at least it isn't anything as small as 30kB. I and others have uploaded files nearly half a meg (500kB) and maybe even more, that are wider than the board can display; it'll just make thumbnails for them that you click on for hte full size version. But it takes FOREVER to upload files that big, sometimes.

It doesn't matter what mode you take them with the camera; macro just has to do with the way the camera focuses on things, so it can do close-ups better.



If you could get one of those handheld programmers even for a short time, you could probably set the thing to only go forward in response to input. I doubt it has the option to ignore the second motor, but again the feedback from the first one's sensors might fool it.

2 drvie wheels on a trike would be a pretty good use for the controller, but it would be a power-waster because of the self-correction steering power as you say, since you can correct for that with the actual steering wheel/handlebar instead.


As for utility of the motor...I'm pretty sure a fair bit of weight can be shaved off depending on how it's going to be used. The whole brake assembly can come out, saving several pounds, for instance. It's not useful at vehicle speeds anyway. Might be good as a parking brake on a slope, but you can get or make latching brake handles for that, too, for your regular vehicle brakes.

It might indeed make a nice wind generator; hadn't thought of that. Be interesting to try, but we don't have enough wind here most of the time to do much, unless I make a really really big blade setup, and I think I might have trouble with the city on that one. (it's one reason I haven't tried making one yet)

 

[mettleramiel]

2 copies in above, one inline button, faulty operator. My added file numbers are already wonky. Sort that later.

Note the add-on ground wire set on top, someone got involved with this powerchair prior to the charity, don't look like an autherized repair. The factory controller warranty seal appears intact. Can anyone identify the logic of a ground wire?

That's a factory ground wire

 

[electric_snowshoes]

OK, see if the Windows xp photo resizer program works. Invacare controller boards.