Extra long SQR extension for rig/desk combination?

Simucube 2
1

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:

image
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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:
https://www.simracingbay.com/wp-content/uploads/2019/04/simucubequickrelease.jpg.

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

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:
https://www.igus.co.uk/igubal/polymer-spherical-bearing?sort=3&fc=300800&inch=false&igubboresize=50

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:

image
image776×553 121 KB

I look forward to your advice.

2

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.

3

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

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4

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.

1024×579

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5

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?
https://www.igus.co.uk/igubal/polymer-spherical-bearing?sort=3&fc=300800&inch=false&igubboresize=50

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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6

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

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