Showroom Blame73's 2DOF Seat Mover

Nice solution! It's an m8 the one you're using too?
Did you buy the bike cranks online?

PS. I see you're using it for the traction loss, a 17cm crank I suppose

I'm a former downhiller so this crank was lying around...it's from a dh bike. The diameter of the axle is not the same, so I had to use spacer.

PS: M8 screws

I haven't found the bike cranks in my town (and 15-17 cm. are too much anyway), so I'm building something like this from @Meawto and @noorbeast

I did that, sheared the bolts, it was a mess....you really need to have the cranks so they squeeze and not just rely on the pin

And now what are you using? I fear common bolts could break, maybe a steel shaft...

Try using grade 8 bolts. Grade 5 bolts deform and then sheer. Grade 8 bolts will take on more stress before they sheer and don’t deform much.

sketches for motors holder and levers to wormdrive gearboxes


worm drive scheme

Waiting for the levers to be done I built an Arcade box


Now it's time to start all over again.


Joined top and bottom tie rod ends


New fuses


The new levers! Beautiful!!


Bended some aluminium (1.5 cm stripes) to hold the potentiometers


A bolt for the coupler


With the coupler


To be continued...

How did you fix that bolt to the motor shaft? Epoxy? Is it perfectly centred? If not, once start turning it will describe an eccentric movement and will be difficult for the pots handle it.

Drilling the shaft while the motor is turning is a Great way to ensure its 100% bang on. Also Some of the solid shafts have a start to a hole already there, so its just a matter of drilling out to the proper size....Tho it appears the motor's Blames got required Very precisely drilling of the shaft to get his feedback bolt in place. Its more than doable and There's a good reason we Run Flex Couplers. To help remove that wee bit of wobble to the shaft.

I Threaded my Motor shaft and inserted a Cut down m6 bolt. It appears Blame might have used epoxy, but im Not sure if he threaded the shaft or not.



LOL upon CLOSER inspection......Blame, did you glue the Flat of a Flat head screw to the shaft ?

I have also 3d printed jigs before to align by holes in the shaft if you have a printer handy

The shafts have a clear center (concentric circles), and flat screws also have it.
Loctite for metals.
Perfectly aligned, it doesn't make any ellictic movement (and there's a flexible coupler anyway). I tried this way before drilling the shaft and it works.

You won't move it even with an hammer! I applied a lot of strenght trying to move it, but I haven't been able to, seems to be soldered

Good to know!! Nice solution anyways

part two

found motors holder and placed in position. left motor


and right


PSUs, fuses, electronic box w/ USB hub



Let me introduce you v. 2.0 of my Seat Mover!
With Simtools 2.0 and the new motors it's nowhere near the previous version (simtools 1.3 and wiper motors)!!

That little movements of little degrees you won't never feel with wipers are now there, making me discover new bumps in tracks I thought I already knew)




Decent photos (not taken with a poor camera phone) and a video to follow

What do you prefer, long bars to the seat shoulders as before with wipers or this new design with short arms under the seat? Why have you changed your design?

I changed just because with the new 60:1 I don't need long bars anymore (and I avoid my 2yo daughter to hang there... she thought were there to be pushed and pulled).
With high torque you don't HAVE TO, as with wipers where a longer lever is essential

One JRK wasn't working anymore, the one I fixed last month. I thought it was the usb port again, so I removed it from the box, attached to the PC to check it and it was working as it should.
Turned out it was the USB hub, just its port, that was broken... hmmm, better than byuing a new JRK...
Replaced the USB hub, ok, PC sees it but no power... PSU's gone!

So, I had the hub and the PSU broken.
Question: could the hub have damaged the PSU (but not the JRK) or vice-versa?

I noticed some stuttering with the wireless mouse I got in the same hub, but I thought it was the battery of the mouse that had to be replaced, but thinking about it again, could have been the HUB that was sayin' goodbye. Can really a hub break the PSU??

Nice and clean design with small lever

@Avenga76 I've read on another thread that a graph like mine (below) is because of underdamped response, so I should add more D or lower the P.


My PID now is 0.5 - 0 - 0.5 what do you suggest me doing?
Thanks!

Less P, add a little bit of I,

It looks like you've got way too much P, and too much D. I don't know if the JRK config is the same as other PID loops, but usually Kp and Kd shouldn't be even close to equal. Try lowering D by a lot, lowering P by a little bit, and adding a small amount of I. Also for best accuracy, are you sitting in the seat when you're tuning it?