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

 

[anton_Chez]

Do you like a seatbelt system like this?

Of course! But that looks pretty involved and dare I say, expensive.

 

[dedraro]

Of course! But that looks pretty involved and dare I say, expensive.

Expensive with the scn6 for sure, but with a decent gearmotor like this:
https://simukit.com/moteurs/9-moteur-120w.html
Controlled not necessarily with a sabertooth even only with a ibt2, that for these motors are good enough, then we would have to create a system that would replace the linear movement of scn6, which I think we can do with rails and linear bearings.

However, mine are just ideas, there is a lot to work on, but I keep you updated if I proceed with the project.

 

[Ringorian]

I Had one build before with the 120 w Motors From simukit . You need gears, Potentiometer, psu , ... No thanks but yeah, it works

 

[sebna]

I fell in love with this seatbelt tension system

When I have finished the SFX-100 build, I will try to do something similar, I do not know yet whether with scn or geared motors, what makes me doubt about a scn6 is the noise ... and the cost
Do you like a seatbelt system like this?

Uhh, I like his system a lot! Both motion and tensioner . Too complicated for me but me like it a lot.

 

[sebna]

BTW - those are the cheapest high quality with most recent design I have found in the EU.

https://www.rennsportshop.com/de-to...k-6-Punkt-Gurt-Tourenwagen-FIA-8853-2016.html

Beltenick is Taiwanese OEM producer for all top brands like Sparco, Sabelt etc... those are Sabelt with different logotype...

If you pay attention. Most of the links provided previously lead to incomplete sets with certain straps missing (for tightening or releasing of belts - in most cases straps for both of those functions are missing or old carbiner technology or from heavier materials).

If ultimate quality and weight is not important you can find sets on ebay for 60-75% of that price but the link above is pretty damn good price for the quality and selection.

And here is the link to factory catalogue: http://www.beltenick-trp.com/content.php?uid=9

I have done the research recently when was buying for myself so I thought I will share my findings

Edit:
When I was buying there was a promo and they were going fot 89 euro. Still 120 is great and hard to beat price.

Cheers

 

[HoiHman]

@sebna, those seatbelt look great for that price.

Currently i have a 4 point harness and i'm thinking about a 6 points, but... how does 6 point actually work?

-Do you always need to use the lower belts or can you leave them off also ?
-How do you get in a 6 point harness? (4 point is quite some work already)
-How does it feel in the "personal area" ?

 

[sebna]

@sebna, those seatbelt look great for that price.

Currently i have a 4 point harness and i'm thinking about a 6 points, but... how does 6 point actually work?

-Do you always need to use the lower belts or can you leave them off also ?
-How do you get in a 6 point harness? (4 point is quite some work already)
-How does it feel in the "personal area" ?

Hi Henk,

To address 1st question:
The one I linked have to be used in 6 point configuration. The submerge straps are fixed to camlock and cannot be detached.

I think this design can be used as 4 point if wanted https://rrs-direct.com/store/harnai...5.html?___store=english&___from_store=english however you would need to confirm it with them.

The difference is in the way the submerge are connecting. Both are Beltenick but the other link is branded RRS.

The harness from my previous post should be more gentle on our manhood due to "T" design which more evenly distributes the belts and causes less strain but it is really hard to be sure until one tries.

The 2nd question:
It takes me a about 30 - 45 seconds to strap myself (at least this is how it feels like lol, never timed myself).

How I do it? When I unstrap myself I leave all straps laid down this way that when I get back to seat next time it is all ready and in place to just click in 4 top ends to camlock (which already holds bottom ones) and quite often I do not have to tighten belts as they are ok from last use.

My bucket seats "helps" a bit with managing of the straps when not in use. I utilize the halo openings for storing of top straps when not in use and then it is easy and quick to get them when I get in into the seat.

And the last:
I am fine but I am used to it at the same time (I used to use 6 point of same design in my project car). The good news is that 6 point should be more comfy then 5 point and also there is two ways to route the submerge straps with one being usually more comfortable then the more common way. However I am using the standard way and I am fine with it (the less common way, but still fully correct, to connect the submerge straps is to connect them to same point as waist straps and to sit on them so to route them under your heaps this way you keep them most far away from private area as possible - it is really best to try both routing methods and decide which works best - with the less common method you do not need the bottom opening in the bucket seat at all).

If you are not sure and you cannot be if you have no tried 6 point before probably better would be to buy the ones which will allow you not to use the submerge straps in case it is too uncomfortable or to be prepared to return them if you do not like them under distant sales law available to us in EU.

At the same time we do not really simulate real breaking Gs in our simulators so the pressure on our private parts is not that big and also you can make the bottom straps a bit more loose then rest of them to give yourself more space in that area . It will not affect general performance of the harness for our needs.

It is all about adjusting the straps until it is comfortable or comfortable enough and it can take few attempts (days) before you get it the way you like it.

I would highly recommend to buy additional shoulder pads no matter what.

Also you have 14 days to return it if you cannot make it work for yourself.

EDIT:

Probably 6 point is the way to go with belt tensioner because anti-submerge straps will be allowing the tensioner to strap you more securely rather then letting it pull the whole harness assembly upwards like it would probably happen with 4-point.

 

[HoiHman]

Thanks Seb, for the great and well explained answer.

I'm going to try to use the passive seat belt tensioner first with my current 4-point harness. Because my rig is not permanent and therefore things like keyboard, gloves and mouse all have to be placed within reach when i put the rig in my office.

I've had a lot getting in and out the seat when finding they were just out reach when strapped in

So i'm not sure i want to complicate getting and out even further. Thanks for the link of the RRS harness, that might be an option.

 

[sebna]

Thanks Seb, for the great and well explained answer.

I'm going to try to use the passive seat belt tensioner first with my current 4-point harness. Because my rig is not permanent and therefore things like keyboard, gloves and mouse all have to be placed within reach when i put the rig in my office.

I've had a lot getting in and out the seat when finding they were just out reach when strapped in

So i'm not sure i want to complicate getting and out even further. Thanks for the link of the RRS harness, that might be an option.

You welcome Henk.

I of course read about you change of plans as to using the passive one first and then I forgot all about it in the heat of writing of the reply

Just coming back for a second to the time it takes me to strap myself. If we include putting on gloves and steering wheel then it is more like 2-3 minutes all together I would imagine. I start with gloves then with steering wheel in my hand I sit into the rig, lock the wheel to QR and then do harness after which I am stuck in the rig and cannot reach anything anymore other then simulator controls (I cannot even reach the keyboard which I have mounted to the rig). My wife is having a good laugh at me at this stage

The RRS have also great selection but it is considerably more expensive (other then the Black I linked which is at promo price ATM). Just be sure to email them if this harness can be used in 4-point config as I am not sure. Also if you look at the pictures of this black RRS harness I have linked you will see it is a bit confusing as picture of harness shows there is no "T" design on the submerge straps but next slide with, kind of, technical drawing shows a "T" design . I am pretty sure it has no "T" but it is yet another thing worth confirming (if it has "T" most likley you will not be able to use it as 4 point as it would be same product as I use just with a different branding).

Cheers

 

[HoiHman]

Guys i need some help with the specs for springs needed for the passive seat belt tensioner. There are so many options available and i have really no idea what to buy for this project.

I ordered a couple of these trampoline springs, but they were way to stiff. 160mm 3mm thickness

So guys that already have installed springs on their passive seat belt tensioner, can you tell me what to look for:

- Length
- Diameter of the entire spring
- Diameter of the steel windings
- Spring constant (Nm/mm)


That would be great

Thanks

 

[saxxon66]

Guys i need some help with the specs for springs needed for the passive seat belt tensioner. There are so many options available and i have really no idea what to buy for this project.

I ordered a couple of these trampoline springs, but they were way to stiff. 160mm 3mm thickness

So guys that already have installed springs on their passive seat belt tensioner, can you tell me what to look for:

- Length
- Diameter of the entire spring
- Diameter of the steel windings
- Spring constant (Nm/mm)


That would be great

Thanks

I cannot help you with the specs of a Springs but here is a good source for this stuff

https://www.federnshop.com/de/

They are very inexpensive and can help you regarding technical questions on the phone.

 

[asteroulis]

I do think that springs have ratings , so you could be able to calculate at which extension in mm's you'll get what force applied. So if you measure the max height during braking you'll be able to see what kind of force you are asking from the springs.

 

[anton_Chez]

I pretty much went to the store, picked up a few that I thought might do the job, and went with it. I had one that was pretty stiff and I thought that wouldn't make much of a difference at all. It would have just been like bolting to the profile. So I got a couple that I could physically pull apart with my fingers a decent amount and went with that one. The length I can't remember why I chose that one. I think it was the stiffness that I prioritised and just went with one that was a decent length to suit. Mine are maybe 100mm long? Perhaps a touch more.

 

[HoiHman]

Thanks @asteroulis, @anton_Chez and @saxxon66 for you replies. The problem is that i have no idea where to start.

I wish there was a local store where i pickup a set. Online shopping looks that will be a lot of trial and error.

I was hoping for somebody who has them installed could give me the right specs.

 

[Mascot]

Thanks @asteroulis, @anton_Chez and @saxxon66 for you replies. The problem is that i have no idea where to start.

I wish there was a local store where i pickup a set. Online shopping looks that will be a lot of trial and error.

I was hoping for somebody who has them installed could give me the right specs.

Is there something that acts like a spring, but with adjustable tension? That might be a better bet.

 

[Stevie_007]

Guys i need some help with the specs for springs needed for the passive seat belt tensioner. There are so many options available and i have really no idea what to buy for this project.

I ordered a couple of these trampoline springs, but they were way to stiff. 160mm 3mm thickness

So guys that already have installed springs on their passive seat belt tensioner, can you tell me what to look for:

- Length
- Diameter of the entire spring
- Diameter of the steel windings
- Spring constant (Nm/mm)


That would be great

Thanks

Henk, ive ordered various of different size springs from ebay ill keep you posted on my findings

 

[anton_Chez]

I don't even know what they are. They had a sticker on them when I bought them but I took that off when I installed them. I don't know how much info was on there that would have allowed you to order from somewhere else something similar. I guess we'll never know!

 

[sebna]

BTW if you look at the page 27 of this manual they explain the idea of alternative mounting of anti-submerge straps for 6-point harness. It is usually more comfortable method for us men

https://www.tillett.co.uk/shop/documents/downloads/seat-belt-fitting-information-2012.pdf

Cheers

 

[Mascot]

I guess another option might be to have a row of several springs that you can add or remove to adjust tension, just like Charles Atlas used to do with his old-skool chest expander. I obviously only ever used it with all five intact, so I have to take others word on this.

 

[Stevie_007]

I guess another option might be to have a row of several springs that you can add or remove to adjust tension, just like Charles Atlas used to do with his old-skool chest expander. I obviously only ever used it with all five intact, so I have to take others word on this.

thats a good idea actually got me thinking now - thera-band tubing