2DOF Build log - Status: Construction Begun

Oh, ok. Blackpill is generally a f401 or F411. Bluepill (F1), although technically capable is much different from F4 chips (and more expensive) so it does make more sense to develop on that platform. Odd because back when i was looking, the EMC development was abandoned. Got a link to the blackpill one then?

he was using his facebook more to post things, I started to follow it.
https://www.facebook.com/ebolz.magy

As i already have some buepill for other things, i will not buy black just for this, i will wait to test when it releases for f4.

you are very active in the forum and understand a lot from what i see, a while ago i bought a nema34 (hybrid) to make a DD, based on another project i saw, using arduino uno to convert the pulses + stm32 to mmos. I ended up selling the kit, but I want to go back to the project again, I'm thinking of opening a post here on the forum, if you are interested in the project too, we can evolve the idea, what do you think?

I dont mind helping where i can but im not likely to build another one for myself any time soon.

Interesting reading ebolz posts - It appears he is developing EMC -M3 on a stm32f103 based black pill. There is a reasonable chance it will run on bluepill i would have thought.

Edit: Read more and as suspected the bluepill should work but may require a mod for the usb resistors (normal). I have all 3 of those boards in my toy box. Can test for you.

the emc page was kind of abandoned, I was posting more stuff.



I will open a new post on the project with nema 34 hybrid, with what I already have, will have more interested. I'm not very satisfied with my current my1020, and I'm looking to get back to the hybrid servo project

So there has been a lot more progress on the sim - It's all moving now but I have not posted that just yet. This weekend I have been working on a new shifter. The one in my profile pic was built just over 10 years ago now (wow i'm old) but I wanted to re-vamp it.

Key things were to make it smaller and lighter, both of which i achieved. The top parts are 3d printed for the moment but these will be subbed for Carbon Fibre. The bottom bits are 3d printed. This time I have also used bearings in the vertical arm pivot points.

The new one is about 1/4 size and weight of the original one. Hooked up to a pro micro at the moment to make it into a joystick.

Few more things to go - Add sequential mod and add a reverse button. I always kept reverse as a manual button before because you pretty much never use it and it keeps the H pattern good for 6 gears.

Also want to replace the spring with a smaller one and shorten the overall shaft. Probably replace the top collet with the gear knob itself too.

Now I just have to work out a way to mount it!

It looks like the file on your thingiverse for this wheel hub is different from the one here, it's missing the nut holes on the back along with the holes for the gear, will you upload the new file any time soon?

That should not be a problem. I will say though that I ended up scrapping the captive gear, favouring a grub screw from either side and I made it out of aluminium. I just found that the gear was not secure enough on the shaft and it always had some movement.

Oh, you mean the one on the Thingiverse? The horizontal screw holes for the flats for the spanner?

Yeah, sorry I didn't realize that was the version up there. I would give preference to that design as i think it will hold up better over time.

The problem with the other version is that the gear did not fit firmly on the shaft and you had to rely on friction from the M8 nut to stop it from moving but once you dial up the force, it will develop a wobble. It's only a few degrees but annoying. This design resolves that but you rely more on the grub screws than the M8 as if you overtighten it, it will just pull through a printed part.

attached is the older STL if you want to still have a crack at it...

Hey, I understand now. Thank you for explaining, I thought the one on there was an old design, my inexperienced brain thought the nut would be superior in strength. Alas, my plan was not to print it anyway, I just needed some reference photos for measurements, I was thinking of combining the two methods, having the gear and the horizontal screws. I don't have any money for machining, but I was thinking of using some metal plates and tubes/pipes, welded together to get the shape of the design. It will be hard to find the right dimensions, worse case I could maybe get a rod/shaft and dill it myself to get the right dimensions. Instead of screwing the gear, I was thinking of welding it to the plate.

Why not 3d print? Going by your profile, there is a makerspace that looks close to you with 3d printers.

Because of price and accessibility due to covid. I could get a service to print it for me, is it strong enough? I could consider it, but even you went for metal

Happy to print and send to you if you want, it would only take a couple of weeks to get to you. Printed at 100% infill it should be fine.

Hi,
You use mainboard from wheelhair?
Did You change some in it, becouse I ignore this board by supose there is soft start and brake during rotation change. If there is direct speed movement I will dont have to wait for boards from china till new Year

Yes and no - It was highly modified and the microcontroller was replaced with an arduino running a modified version of SMC code (0-128-255 rather than 0-255 with direction). Doing it again, I would not use the wheelchair controller because i had to compromise. Essentially I was just driving the H bridges directly and the cabling was nice but it was more hassle than it was worth. Just stick with normal H bridge devices.

All clear, thx for respond

Wait what, are you sure? For free? I'll pm you