DIY 2DOF home build

Yeah I definitely will bring the base back to at least in line with the seat when it's fully reclined in motion. Also thinking of bolt on/off extension arms for further balance. This makes the unit take up less space when not in use.

60mm ctc lever is pretty long, id suggest 40mm ctc, unless you have plenty of torque to move them. Like 60:1 boxes on motors

Cheers bsft,
My motors are 200W ones from Motion dynamics, I'm pretty sure I bought the 60:1 drive box but I went back to the site and they only state the RPM now. So now I'm unsure of what I have. I'll drill a hole at 40 in case 60 struggles.

Are you sure the Conveyor style bearing's will be able to support all that weight ? those roller bearing's are not exactly meant to take that much weight on their Own. I would suggest you look into Caster's that are meant to take 2-300lbs by themselves, You Traction loss motor will also thank you in the end allowing that much smoother operation.

FWIW i can push my traction loss side to side with my pinky finger and next to zero effort. here are the Castor's i used. There rated for 300lbs a pop

Cheers guys, I have the hollow shaft which means it's the 25:1, so 40mm it is.
I have Lemcol 25mm ball transfer units which are rated to 45Kg each (L1753). I have four of them so it should be fine, I've made skates out of them in the workshop before
I chose these units because they are slim line (31mm height) and simplistic but most importantly I already had them.

They came from an old project that I stopped part way through because of costs. I tried making an Omni directional treadmill, the concept worked but the cost would have been over $5000 to build.

Design


First stage partially assembled (everything hand made, except for bearings)



I actually got a treadmill motor and thinned out the driveshaft and belt which I then placed under the rollers. It worked beautifully and I actually fully completed one section (no pics, imagine that section full of rollers) but when I calculated what I had spent it would come to $400 per section, times that by 16 sections. Then some schmuck made what I had in mind (different concept same outcome) for about $2000 it was no longer viable to continue building it. The ball transfer units was just a part of my initial design concept that never went ahead.

Interesting, Like anything DIY its Infinity moddable, so worst case you can change it at a later date.

I look forward to seeing your updates in the coming weeks/months.

Had some time to get the bottom frame started. Firstly was welding practice.
My first rig while strong, looked like a dogs breakfast and was a rushed effort. I only have about 1.5 solid hours of tinkering time per night
so I tend to try and get as much done in one sitting which is really a bad way to go about it. So I chopped up about 40 pieces of metal into inch cubes and welded them all
together to get my technique right.

Old welds:



New welds:




Whilst not perfect, I don't feel the need to grind them back to hide them.

Two piece bottom frame with castor mounts welded in, they are different sizes because I've had to make my own swivel. I'd originally chopped up the metal to make
a mount for a 155mm x 155mm 150kg chair swivel that Bunnings list in their catalog but after going into three different stores none of them had it. So I bought a heavy duty wheel castor and cut/welded it to another plate.



Got my flex couplers in the mail, obvious chinese ripoff is obvious as they don't quite fit the shafts they say they do. ID on the couplers are listed as 6mm and 12mm but I've measured with calipers 5.8mm and 11.7.
So I'll drill them out to the correct ID and all shall be sweet.

Good work nice bit of stick welding there and i do like the grumpy old
Man mug too

Cheers guys,
I'm certainly a grumpy old man tonight, my 3 year old daughter has decided that she doesn't want the soup that was made for her and that she wants "something else". I think someone is going to bed hungry.

The ball transfer units (the fancy name) are rated to 45kg each. So that's a capacity to move 180kg, the proof will be in the pudding as they say.

she will eat the soup when she will be seated on your dynamic sim!

Urg, I Still fear that those ball roller's are a mistake. Imo there's a high likely hood they will provide too much friction and not allow the frames to smoothly ride on each other. But by all means, Prove us wrong. Lol

Those pedals look incredible! Outstanding job on them and everything else. I'm not only impressed, I'm inspirered. Very nice job, can't wait to see them in action.

Progress is messy


Control box (almost complete)

Well, no bingo. Went through SMC3 tutorial, i can see feedback from pots and thats about as far as its got. No motor movement .
Lights on the motomonster outputs do nothing. Just incase anyone else has this issue my hardware is arduino mega2560 and using a motomonster per motor.
I've checked, double checked and tripple checked my wiring.

Hi , In your management software you know move the axes manually?

Very good work!
Will pedals and gear cutting tools is what?