Extra long SQR extension for rig/desk combination?

Hello. I’m currently working on a design for a compact rig (aluminium profile), probably for the SC2 Pro, which also allows me to have a normal desk when not it’s not in use.

So far this is the design I’ve come up with:

The motor is much further back than normal, so an extra long extension will be needed to reach the steering wheel.

My intention is to use the stock QR mechanism + 70mm spacer kit that comes with the motor. I think I’ve modelled that reasonably well in the above image but I could do with a confirmation of the final dimensions.

I used this diagram for the model: https://cdn.shopify.com/s/files/1/0089/4500/8736/products/simucube_2_pro_dimensions.JPG?v=1603312365
(my model doesn’t use the 8mm deep collar between the shaft and the motor, but instead has the shaft 74.5mm long instead of 66.5.

The blue part is what I think represents the wheel side part of the mechanism, parts 3 4 and 5 in this image:

The text says wheel side extension is 70mm, so this is what I think the overall dimensions are:

Can someone confirm if that’s correct or set me straight if it’s wrong?

The other part is the extended shaft and how assemble it all.

The idea is that I could bolt the shaft onto the part 5 (in the simracingbay link). I’m aware that the motor isn’t intended to take that kind of load, so my design includes a bearing (orange item in the first screenshot) which would rest on the desk, probably via a wooden block.

For the bearing, I think one of these would do:

The other end of the shaft would be attached to the wheel, and I could use the motor-side SQR to remove it and reclaim the desk.

The next hurdle is that I’m not sure what to search for because I don’t know the proper names of things.
I was inspired by this photo: Simucube 2 SQR Extension

But what are the things called? Any idea what I can search for so I can find something I can assemble (no welding)?

E.g. some sort of flange, but then what? The number of things is overwhelming, so I’ll finish with another screenshot:

I look forward to your advice.

It would be best to secure the extension to the servo via an universal joint. Otherwise, if your alignment is not perfect, you are going to wear the front motor-bearing over time and possibly break things.

Some years ago when I mated a 1m long steering shaft to my Lenze OSW servo, I used a Flaming River joint, such as this: https://www.flamingriver.com/steering-universal-joints/fr1711-3/4-inch-36x3/4-inch-36-universal-billet-joint

It means you will need to make adapters both sides though, but easy enough if you know someone with a welding shop. In the long run, use one, your servo will thank you for it.

PS: You don’t have to use the expensive stainless one I linked, they have quite a variety of couplers, mine was mild-steel and a bit cheaper.

I found two photos of how I had done mine back then, somewhere in May 2016…

A last one, should be enough to give a good idea, the part that goes on the servo hub was just an adapter plate I made and welded to the u-joint. Worked very well, bu you can also weld a short stub to a flange and bolt it to the u-joint, that will be better for the joint itself, as the welding can damage it.

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Thank you for your replies.

I don’t know any welders, although a brief search suggests there are a few small companies, possibly one-man-bands, in the area. Not sure how economical that would be when factoring in the purchase of universal joints, but I suppose that depends on how much I want it.

Do you think the spherical polymer bearings I linked to would be sufficient instead of universal joints?

The product description does say they’re ideal for compensating for misalignment.

And I’m still clueless about what else to look for. I have no knowledge of engineering.

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A spherical bearing should work too, IGUS makes high-quality stuff :wink:

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