F 55 frame caster forks, gearbox and motors

[wheelchairer]

So I'm trying to get some of the motors and gearboxes BM used on the BMs. So I asked a wheelchair company that fixes them

Dave did you get anywhere with sourcing these for me ?
RWD MOTOR (4 POLE) P/NO: 014827 (LEFT HAND)
RWD MOTOR (4-POLE) P/NO: 014828 (RIGHT HAND)

AMT Schamid GmbH & co kg
produziert fur
Sunrise medical GmbH & co kg
:typ: SRG410M:24P BO:12V 6/13
Sunrise part number: 101362
S NR: 107616.2222229

this reply was

Only 118945 118946 in stock sorry check if they are up to it for you.

I'm not sure where he's got these numbers from I don't have a part catalogue. Any suggestions? I just need some spare ones as I have just got down to my last spare 1.

I'm also after some F 55 frame caster forks. Can anybody make any suggestions as to where I could get them.

[steves1977uk]

Whenever I hear the name Dave, I always remember this scene from OF&H's...

Steve

[wheelchairer]

So I'm trying to get some of the motors and gearboxes BM used on the BMs. So I asked a wheelchair company that fixes them

Dave did you get anywhere with sourcing these for me ?
RWD MOTOR (4 POLE) P/NO: 014827 (LEFT HAND)
RWD MOTOR (4-POLE) P/NO: 014828 (RIGHT HAND)

AMT Schamid GmbH & co kg
produziert fur
Sunrise medical GmbH & co kg
:typ: SRG410M:24P BO:12V 6/13
Sunrise part number: 101362
S NR: 107616.2222229

this reply was

Only 118945 118946 in stock sorry check if they are up to it for you.

I'm not sure where he's got these numbers from I don't have a part catalogue. Any suggestions? I just need some spare ones as I have just got down to my last spare 1.

I'm also after some F 55 frame caster forks. Can anybody make any suggestions as to where I could get them.

According to the speed indicator on the joystick, I am getting about 9 1/2 mph. That does feel fairly accurate. So can you remember BM are these originally 8 mile-per-hour?

The guy I have been speaking to about new motors does have some, but he thinks they are only 6 mile-per-hour.

[Burgerman]

The joystick speed indicates more or less whatever you tell it to in programming. So the fact that it reads x mph just depends on how or who programmed it. It has no way to know actual speed...

The motors I used on the BM2 and BM1 chairs were always EMD 6.2mph 174 RPM PM 90 motors at 22V. So around 6.5mph with 14.4 inch tyre diameter. These were all 4 pole stock F55s motors and not AMT.

AMT motors on the BM3 were 8.5 mph marked on the casings, from sunrise, for the Groove chair. They were 224 (0R 228 I forget) RPM marked, and 45mOhm. They had less torque, than the 6.2 mph motors normally used on an F55s. And so would have been a mistake. But I was using a 150A Roboteq controller so this increased the torque back to the 120A 6.2 mph motors levels. So the extra 8.5 mph speed came for "free" without a downside.

And since I was running this at 13S lifepo4 and at 45V approx, then in reality I was getting 16mph... Which was too fast for stability really.

See https://www.wheelchairdriver.com/gopro/caster.mp4
Note that this is uphill... And because of that caster shake occurs. Do you really want this fast?

[wheelchairer]

AMT motors on the BM3 were 8.5 mph marked on the casings, from sunrise, for the Groove chair. They were 224 (0R 228 I forget) RPM marked, and 45mOhm. They had less torque, than the 6.2 mph motors normally used on an F55s. And so would have been a mistake. But I was using a 150A Roboteq controller so this increased the torque back to the 120A 6.2 mph motors levels. So the extra 8.5 mph speed came for "free" without a downside.

well that is the mistake I have made. I have put those on my BM clone.

Thanks for the information.

[Seajays]

I am doing the same thing with my BM2

[Burgerman]

I have tried many 8 and 8.5 mph motors. And at 120A they all lack the control, torque, that I want. In fact need. So if you care about that fit 4 pole 6mph motors. Doesent much matter what brand as long as they are reliable. Its not down to the motors design, but physics. No matter what you do you only have 120A to play with. For a couple of seconds. Amps = torque directly and is also directly comparable if roadspeed is a constant. Only efficiency can change that relationship. And most motors are pretty much the same. Give or take a few percent.

[Seajays]

Yes I have AMT 4 Pole 6 mph

[wheelchairer]

I have tried many 8 and 8.5 mph motors.

so which ones have you tried have the same configuration of holes so they can bolt straight onto the BM2 battery box, which presently has the 8.5 mph motors for the Sunrise groove?

Sunrise are saying that part was discontinued in 2015.

[wheelchairer]

https://www.aiosupplyworld.com/collecti ... 6700327981

[Burgerman]

Sunrise replaced them with Linix motors. So presumably they have the same bolt holes. And direct swap as long as you have an extra 2 or 3mm space between the motors and the chassis. The top plate is about 4m wider overall from memory.

[Scooterman]

And since I was running this at 13S lifepo4 and at 45V approx, then in reality I was getting 16mph... Which was too fast for stability really.

See https://www.wheelchairdriver.com/gopro/caster.mp4
Note that this is uphill... And because of that caster shake occurs. Do you really want this fast? [/quote]
Castor shake is frightening as it can lock up the front end and throw you out the chair. That nearly happened to me going downhill in a crappy NHS manual wheelchair.

But even without castor shake 16mph is way too fast for something with such short wheelbase as a powerchair. And in Blightly there are so few smooth surfaces where you can use that speed any way. Perhaps cycle ways, but even they are not smooth and they put lamp post in the middle of them! http://www.nuttycyclist.co.uk/cycling/n ... epaths.htm

[Burgerman]

Over the course of the next week or two the workmen return daily and widen the footway. Look at what a neat job they’ve made of tarmacing around the lamp post. Mind you, also look at how the tarmac has been rolled by hand, meaning that the undulations give a vibration through the bike preventing any speed above ten miles an hour. (I suppose this is in accordance with the DfT Guidelines which state “Ride at a sensible speed for the situation and ensure you can stop in time. As a general rule, if you want to cycle quickly, say in excess of 18 mph/30 kph, then you should be riding on the road.”)

You should be on the road ANYWAY. Its ilegal to ride a bike on the footway at any speed or any age. Which is what that is. It was illegal when I was a kid. Its still illegal. In spite of the fact that the cops also do it, and that they pretend that its all ok now.

[Scooterman]

And since I was running this at 13S lifepo4 and at 45V approx, then in reality I was getting 16mph... Which was too fast for stability really.

See https://www.wheelchairdriver.com/gopro/caster.mp4
Note that this is uphill... And because of that caster shake occurs. Do you really want this fast?

Castor shake is frightening as it can lock up the front end and throw you out the chair. That nearly happened to me going downhill in a crappy NHS manual wheelchair.

But even without castor shake 16mph is way too fast for something with such short wheelbase as a powerchair. And in Blightly there are so few smooth surfaces where you can use that speed any way. Perhaps cycle ways, but even they are not smooth and they put lamp post in the middle of them! http://www.nuttycyclist.co.uk/cycling/n ... epaths.htm[/quote]