DIY G-Seat Prototype #3 – Bigger belts, pulleys, thinking about Argon drives

By March 3, 2020 March 5th, 2020 G-Seat, Sim Rig

Any of the works related to “@steely’s G-Seat” is Copyright 2020, Rowan Hick released under the Creative commons license Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) . Read here for more details of what you can and can’t do, along with my intent.

Getting back from a short break, a package that I’d been waiting on from Aliexpress showed up – proving all of China wasn’t shut down. Very excited I unpacked it and immediately put the HTD5M pulleys next to the HTD3M, such a difference..

HTD5M left, HTD3M right

Dinner rolls around, quickly dispatch that and get into the job of making them fit. I needed to drill new grub screw holes in the main shaft and figure out which belt to use. Eventually settled on the 420 (ordered a 410,420 and 425) and put two idler pulleys in.

Already starting to see some areas I needed to improve, we’ll get to that, this was a just “can I get the belt/pulley system to hold together” gig. The good, great news is yes !

It’s alive !

I did 2x 30min runs, playing with various settings. First run I did right at the end getting one tooth to skip – but I think an amount of flex and loose idler pulley bolt contributed to it. I tightened it all up and tried again.

Over 6 months with this futzing on and off, and with a full height seat flap, full intensity / max movement, in a corner running a DD wheel, pushing against the seat flap – I couldn’t manage to break it.

One very happy camper

Observations and refinements

We’re not finished yet by any stretch. This was an important milestone but there’s much (much) more refinement needed.

1. Heat build up / gearbox ratios

The drive was getting hot, with a capital H. While I never got an overtorque alarm the drive casing got up to 59 degrees after half an hour. That’s warm. More than likely because I’m using more torque than I need to – the gearbox ratio needs to change. Currently it’s 4:1 with the pulleys adding an additional 2:1 final drive, total 8:1.. so I could go to around 16:1 I think total. Update: ordered 2x 7:1 gearboxes

57.4 C on the Servo casing, got up to 59.5

2. Flex

Everything’s moving ! Just see the video… the idler pulleys are moving, and the main shaft is bending. Mostly to be expected. So I need to make a capture plate to hold the idlers where they should be, also a pillow bearing half way along the main shaft.

Update: found and fixed some lose grub screws

3. Moving the idler position/slots

Not quite right where they are. Also debating whether I want to elongate the motor mounting slots so I can use proper gates belts – they only come in certain size increments, whereas the Chinese belts are more flexible. I have a feeling true Gates belts will hold up longer.

4. 3D printed arm.. showing stress fracture and moving

I’d bodgied up a simple 3d arm months ago, now it’s showing – a stress fracture is appearing where the locating pin/screw is and it’s also rotating +/- 5deg or so as a result – not good for ultimate fidelity and pretty quickly is going to fail.

5. Lots of tuning to be had in SimFeedback

I need to play with this – I started out with one curve in the way the lateral G’s were applied, changed to an inverted curve and it completely changed the feeling of the lateral G’s. I suspect I’ve got a few hours of settings tweaks till I find what works.

6. Been investigating Argon drives

With all these AASD units I’ve got boxes everywhere. So I *have* been investigating using Argon drives to both keep foot print small and the ultimate silent solution. In theory it’s possible, they are *very* costly little units compared to our AASD drivers, but it’s possible. Have worked out *roughly* how to get it all wired up and exchanging emails with Granity.
(note this is by no means saying the drives will work with SimFeedback, just a theory at this point in time!)

7. This thing is almost terrifying

After playing around with some more settings; and being braver on movement, I decided to go round Bathurst. Oh boy. Oh boy. Oh boy ! It’s (a) awesome and (b) terrifying – the panel when you hit a wall is quite violent, so I’ll need to turn the max speed down.

What’s awesome? You start noticing things about when the car either loads up or unloads that aren’t immediately apparent on screen or via the wheel, or via the platform.

Stay tuned..


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