DIY Seatbelt tensioner with simtools

[HoiHman]

A lot guys that have build the SFX100 are thinking about adding a seat belt tensioner to their rig.

Even though i would have prefered to use one the SFX100 servos doing the work, i have decided to order the parts servo seatbelt tensioner and will start building as soon as the parts arrive.

Parts needed:
Servos
https://hobbyking.com/de_de/turnigy...-servo-33kg-0-21sec-154g.html?___store=de_de1

Turnigy 5A (8-40v) SBEC für Lipo :
https://hobbyking.com/de_de/turnigy-5a-8-40v-sbec-for-lipo.html

Aduino uno
https://nl.aliexpress.com/premium/a...SB_20190116083039&origin=y&catId=0&isViewCP=y

Power supply:
Still need to order one, or if the specs of the servos allow it, i will use the 6v power supply of my GS-4

I will be copying the build from @Ringorian and @saxxon66 who have already a topic with complete instruction on the german forum.

https://forum.virtualracing.org/sho...ffer-100-Euro-(auch-Ohne-Motion-realisierbar)

Jochen en Micha, feel free to jump in and educate us

 

[HugoB]

Interesting thought. I wonder if I will be able to try connecting the lower belts with my tensioner once it's built. Waiting for payment request from the bloke Hugo bought off. I wonder how far away his is? @HugoB

I don’t expect mine until the last week of March. I also ordered his new g-seat panels, which are a totally unknown design to me.

Knowing nothing about how they will work, I have to trust the good reviews people are giving of his other inventions. But following his youtube videos, he is surely capable of amazing things

Following your train of thought @HoiHman , I can imagine what you mean. Maybe I can find some place to install one of SeatTime’s rails under the seat to pull on the bottom part of the harness... Let’s see how flexible this system is.

 

[HoiHman]

I think that might actually work with seat times tensioner Hugo, i would surely give it a try if possible.

 

[Steve D]

Yesterday i did a simulation and to me it feels much much more natural when the lower 2 belts are being pulled back by a tensioner instead of the 2 top ones.

The forces are immediately felt in the front your body, instead of your shoulders.

Because this is more difficult to implement, could this be the reason why most seat belt tensioners go for the tension on the shoulders?

It's really interesting you mention this Henk as I've kind of 'accidentally' achieved that with my own simple, passive set up, albeit still having my NLRv3 running alongside the SFX100 helps.

Basically, I've placed a 4mm aluminium base underneath my actuators (so it's not going anywhere and is the equivalent of fixing to the floor), to which a length of profile and eye bolts plus springs are attached. The movement of the actuators plus a little surge from the V3 applies tension to the shoulder harnesses but not too much to make things uncomfortable or result in slack occurring when that tension is momentarily relaxed. So the contact points remain. The side harnesses, (I'm using 4 point in total so no crotch strap), are fed through the apertures in the race seat and fixed to eye bolts, (no springs attached) but behind the seat rather than to the side of it. The surge of the V3, small though I've set it up to be, subsequently pulls upon the lower straps enough to apply additional tension across my hips and abdomen and simulates what I tend to feel in my Caterham when under braking. In that I'm strapped in tight from the 'get go' and the shoulder straps actually offer me zero movement, even when I'm full on the stoppers. Any additional tension in the harness, as a result of surge, tends to be felt in the lower part of the body.

What I've stumbled across isn't perfect by any means but for about £20.00 worth of bits and an old track day harness, brought back to life with a soapy wash and scrub, it certainly adds to immersion and there's probably some scope to experiment. Oddly, the first few times I used it I actually felt I had greater control of the car than usual because of how securely I was strapped in and how additional forces were being applied to my torso. Difficult to explain why but maybe a placebo effect of being wrapped up in my VR world.

 

[Stevie_007]

It's really interesting you mention this Henk as I've kind of 'accidentally' achieved that with my own simple, passive set up, albeit still having my NLRv3 running alongside the SFX100 helps.

Basically, I've placed a 4mm aluminium base underneath my actuators (so it's not going anywhere and is the equivalent of fixing to the floor), to which a length of profile and eye bolts plus springs are attached. The movement of the actuators plus a little surge from the V3 applies tension to the shoulder harnesses but not too much to make things uncomfortable or result in slack occurring when that tension is momentarily relaxed. So the contact points remain. The side harnesses, (I'm using 4 point in total so no crotch strap), are fed through the apertures in the race seat and fixed to eye bolts, (no springs attached) but behind the seat rather than to the side of it. The surge of the V3, small though I've set it up to be, subsequently pulls upon the lower straps enough to apply tension across my hips and abdomen and simulates what I tend to feel in my Caterham when under braking. In that I'm strapped in tight from the 'get go' and the shoulder straps actually offer me zero movement, even when I'm full on the stoppers. Any additional tension in the harness, as a result of surge, tends to be felt in the lower part of the body.

What I've stumbled across isn't perfect by any means but for about £20.00 worth of bits and an old track day harness, brought back to life with a soapy wash and scrub, it certainly adds to immersion and there's probably some scope to experiment. Oddly, the first few times I used it I actually felt I had greater control of the car than usual because of how securely I was strapped in and how additional forces were being applied to my torso. Difficult to explain why but maybe a placebo of being wrapped up in my VR world.

Sounds interesting Steve, any chance of some pics so have a better idea in my head

 

[anton_Chez]

My new Sparco Rev seat arrived today so I am about to mount that onto the chassis. What that means is, now with the V3 removed, I am going to be able to mount the lap belts to the chassis main rail as Steve has done. This will give me a chance to try the passive lap belt tension that you've stumbled across. I was thinking of doing exactly what you did also with the shoulder straps pseudo bolted to the floor, but I've decided to go for the active tensioner now so that's probably a waste of time and resource. I'll give some feedback once I've had some time with it.

I also ordered his new g-seat panels, which are a totally unknown design to me.

What are these G seat panels, Hugo? I actually cannot find the thread on the tensioner anymore! I'm trying to work out how to mount it once I finally get a payment request and have it built and sent out. I can't find it anywhere. i saw Seatime comment on the Pimax thread so he's alive at least! I'm sure he's busy but it doesn't make sense that the thread is now nowhere to be found. Any chance you can drop a link for that if you're able to still access it or even a link as well for the G panel stuff? I take it you make this work with a standard bucket seat, not a G Seat? Something else worth considering. If I could get some lateral G from my own seat with an additional system that would be awesome to not have to go full on with a GS-5.

I also wonder if there could be a way that we can use the acceleration forces on the shoulders with the active tensioner, with the braking effect left for the lap belts? I mean you get shoved into the seat under throttle load so having the shoulder straps pull you back into the seat could be another way to give the correct feeling.

 

[Steve D]

Sounds interesting Steve, any chance of some pics so have a better idea in my head

No problem. Will post some when I get home from work later this afternoon.

 

[anton_Chez]

Pimax coming Wednesday stand by for opinions / rage.

You're bound to get both from me.....

 

[BenKay]

How are so many people ordering / receiving the GS-5? I can't find it on their website??

 

[Mascot]

I've never had a harness on any of my sim rig setups but I'm thinking of getting one now that I've lost the surge effects of the NLMv3 and gained the SFX100. My seat is a Sparco R333 - what manner of harness would fit such a chair? I don't think there's anywhere for a dongcrusher, so it'll just be hip and shoulder straps I guess?

 

[anton_Chez]

You can grab any 4 point harness and it should do the job fine. I will give one piece of advice. If you get a cheap eBay (100 bucks AUD or so) harness, it's a knock off and although it will do the job as we are not track racing, the shoulder straps come loose on those when you are bouncing around. I'd suggest getting a proper one (300 AUD or more) and actually being satisfied with using it. There's NO point getting one that's going to continually come loose and require lap after lap re tightening. I've managed to Anthony-hack (tight ass) my way to making mine stay locked in place for the most part. I've had 2 cheap ones and will not be doing that again if I buy.

Also, you can get a 5 or 6 point harness as some are not much more expensive than their 4 point counterparts, but just not attach the 5th and 6th point. I have a 5 point and I've never used the dong smasher, although my new seat now has the allowance for it and with the active tensioner on the horizon, I might just try it out.

 

[anton_Chez]

So, I tried Steve's way of connecting the lap harness to a fixed point under the actuators........

I can't believe how tight it pulls just with pitch and brake dive..............!

I've used a slightly less elegant way of doing it just for now to test it out. I've used 2 pieces of the triple monitor mounts that I've not used since getting rid of the triples, one under each rear foot and bolted the connectors of the lap harness to it with a pan head style allen bolt and nut. Pan head is pretty flat although not perfect it's not digging a hole in my carpet just yet. Nut side facing up, the pieces are around 4-5mm thick. I wouldn't leave it that way but it was awesome to check out if you can feel a difference. A thousand times better than the springs which I've now removed and put away to never be used again..... They looked ugly, made noise and were a pain bouncing around when getting strapped in. This method is miles better, It really does pull on you pretty hard. I found it hard to drive initially but that could have also been the fact that it's 2am trying to avoid an unsuspecting VR backhander from the other half.

I'm sure once you get used to it and are not worried about noise as well, that it will blend in and actually help you to drive and modulate the pressure on the brake somewhat. I guess it depends on the car you're driving and the amount of brake dive you have dialed in and what Intensity also. I was in the Oreca in rF2 for maximum effect so I guess I had the main course pretty early on. I'm sure with a V8 supercar or GT3 the feeling would be slightly more subdued.

So, before laying out for an active tensioner, try this method first. I now want to try the shoulder harness connected the same way and see how it feels. With my new seat and harness routing through the holes in the side of the bucket (old one was like Mascot's, only holes at the top as it wasn't full bucket) I'm strapped in SO snug with both the harness and the seat playing a role in this. Can't wait for more time experimenting.

Got some mean tactile dialed in too so pretty happy with that.

 

[Mascot]

So, I tried Steve's way of connecting the lap harness to a fixed point under the actuators........

I can't believe how tight it pulls just with pitch and brake dive..............!

I've used a slightly less elegant way of doing it just for now to test it out. I've used 2 pieces of the triple monitor mounts that I've not used since getting rid of the triples, one under each rear foot and bolted the connectors of the lap harness to it with a pan head style allen bolt and nut. Pan head is pretty flat although not perfect it's not digging a hole in my carpet just yet. Nut side facing up, the pieces are around 4-5mm thick. I wouldn't leave it that way but it was awesome to check out if you can feel a difference. A thousand times better than the springs which I've now removed and put away to never be used again..... They looked ugly, made noise and were a pain bouncing around when getting strapped in. This method is miles better, It really does pull on you pretty hard. I found it hard to drive initially but that could have also been the fact that it's 2am trying to avoid an unsuspecting VR backhander from the other half.

I'm sure once you get used to it and are not worried about noise as well, that it will blend in and actually help you to drive and modulate the pressure on the brake somewhat. I guess it depends on the car you're driving and the amount of brake dive you have dialed in and what Intensity also. I was in the Oreca in rF2 for maximum effect so I guess I had the main course pretty early on. I'm sure with a V8 supercar or GT3 the feeling would be slightly more subdued.

So, before laying out for an active tensioner, try this method first. I now want to try the shoulder harness connected the same way and see how it feels. With my new seat and harness routing through the holes in the side of the bucket (old one was like Mascot's, only holes at the top as it wasn't full bucket) I'm strapped in SO snug with both the harness and the seat playing a role in this. Can't wait for more time experimenting.

Got some mean tactile dialed in too so pretty happy with that.

Sounds like a great solution - nice work, @Steve D !
I guess you need to be careful you don't choke yourself with no springs..? Is there a quick release for the harness? I guess there is in case you need to bail in a fire.

 

[Steve D]

Sounds interesting Steve, any chance of some pics so have a better idea in my head

As promised a few pics of my passive set up. It's not perfect but was silly cheap to make and certainly adds to the immersion when used in conjunction with motion. As mentioned before the V3's surge effect does a good job of tightening up the lower belts based on where I've fixed them. Might hook them up differently later so that the actuators apply the tension. Get good sustained load up across the shoulders and chest with the SFX / V3 movement combined. I have got some stronger springs on order to see if that adds anything but it might be a bit too much for my liking.

 

[anton_Chez]

That's sick. That's how I was thinking about it a while ago when trying to work out how a passive system would work with SFX-100. You HAVE to get the connection point to solid fixing that's not part of the moving chassis. So that leaves wall, floor, or a pseudo floor which is more than fine.

There is a central cam that flicks all the harnesses off when you want to get out, or if something weird happens. So you aren't trapped in there by any means.

I still think the active tension is a good idea, as you should be able to tune sway function into the harness as well giving another use for it other that just braking effects. I've mentioned other times too that you could argue its use for acceleration and leave the braking for our now newly discovered passive lap belts. There's only so much you can do with a passive system but for the time spent and investment vs effectiveness I think it's a great solution. It keeps making me change my mind about an active solution but I think the best combination would be for active shoulder straps and either passive or even just static lap belts. You get more use out of the shoulder straps, with sway, surge and brake dive all being possible.

 

[wajdi]

So, I tried Steve's way of connecting the lap harness to a fixed point under the actuators........

I can't believe how tight it pulls just with pitch and brake dive..............!

I've used a slightly less elegant way of doing it just for now to test it out. I've used 2 pieces of the triple monitor mounts that I've not used since getting rid of the triples, one under each rear foot and bolted the connectors of the lap harness to it with a pan head style allen bolt and nut. Pan head is pretty flat although not perfect it's not digging a hole in my carpet just yet. Nut side facing up, the pieces are around 4-5mm thick. I wouldn't leave it that way but it was awesome to check out if you can feel a difference. A thousand times better than the springs which I've now removed and put away to never be used again..... They looked ugly, made noise and were a pain bouncing around when getting strapped in. This method is miles better, It really does pull on you pretty hard. I found it hard to drive initially but that could have also been the fact that it's 2am trying to avoid an unsuspecting VR backhander from the other half.

I'm sure once you get used to it and are not worried about noise as well, that it will blend in and actually help you to drive and modulate the pressure on the brake somewhat. I guess it depends on the car you're driving and the amount of brake dive you have dialed in and what Intensity also. I was in the Oreca in rF2 for maximum effect so I guess I had the main course pretty early on. I'm sure with a V8 supercar or GT3 the feeling would be slightly more subdued.

So, before laying out for an active tensioner, try this method first. I now want to try the shoulder harness connected the same way and see how it feels. With my new seat and harness routing through the holes in the side of the bucket (old one was like Mascot's, only holes at the top as it wasn't full bucket) I'm strapped in SO snug with both the harness and the seat playing a role in this. Can't wait for more time experimenting.

Got some mean tactile dialed in too so pretty happy with
d

 

[anton_Chez]

G'nite

 

[wajdi]

View attachment 293859
G'nite

You have your cockpit attached very low to the actuators.

 

[Stevie_007]

As promised a few pics of my passive set up. It's not perfect but was silly cheap to make and certainly adds to the immersion when used in conjunction with motion. As mentioned before the V3's surge effect does a good job of tightening up the lower belts based on where I've fixed them. Might hook them up differently later so that the actuators apply the tension. Get good sustained load up across the shoulders and chest with the SFX / V3 movement combined. I have got some stronger springs on order to see if that adds anything but it might be a bit too much for my liking.

View attachment 293850

View attachment 293851

View attachment 293852

Really impressed I have most parts so think this could work for me

 

[HoiHman]

How are so many people ordering / receiving the GS-5? I can't find it on their website??

It's there, but.... it's not

I CAN see it but can NOT order it

 

[anton_Chez]

You have your cockpit attached very low to the actuators.

Took about 5 different methods to get it down there, too.

Try it, you'll never go high again.....