DIY Linear Actuator design

Hi @SeatTime hey mate mega thanks for getting me started on this project , seeing the machine go through the paces is a real Buzz , Just made the Seat mount and 1st lesson is --------frame must be stiff with little or no flex allowed , I made a hybrid wood / square metal sections just to confirm the mech dimensions and mounting points pics to follow ( its late and I have only just stopped tinkering ) platform powered up and motion seems good but potential for frame to actuator clashes so redesign of the seat mounting arrangement required but the main lesson for next version will be ...MUST BE Welded and support stiffeners where required .. the good news is that once made out of Box section tubing and welded I should have a nice ridged seat carrier may I ask what size square tubing you used now experimenting with reversing the actuator drive sequence so that the main seat support will be actuators 1=2 at the rear instead of the front as its configured now , ..
Hey @SilentChill would have loved to have used Carbon fibre rods Throughout the design but could not get the thickness ( they are typically only 1mm thick and I belive @SeatTime bonded 2 tubes internally to get something like 3-4mm for increased strength.. cheers guys oh oh forgot to ask @SeatTime could I take a look at you BFF config file as a sample for axis assignments ...

I got hold of 25/22 carbon tube from china 500mm lengths.

What about the vslot wheels ??

Cheers dude !!

Hi @SilentChill doh forgot to say I did not use the vee slot wheel in my design but seems like a doable option , I machined I square carrier for the ball nut and left about 1mm traveling gap so the will be a small amount of movement when direction is changed but not enough to impact on position accuracy , I suppose it just float above the Extrusion surface ,,HmmmmmVee slot wheels never thought of that, so nice one that man.

Yes make sure it is rigid and strong but light, or this may happen .



I still have plans to build a full carbon frame, but just too many other real car and house projects on at the moment.
As for the BFF profile, each game download has a start-up profile which you can amend to input the sizes relevant to your rig. Just follow the user manual - although I must admit it is not too intuitive. Recommend once you have loaded the relevant rig dimensions that you use the 'Easy Cue' setup once you are connected to a game to adjust the profile to your needs. I have lots of them for different games/planes/cars/race tracks etc.

hey crew another minor update , managed to swap around the actuator location so now working even better , still no load testing yet but my hybrid ( wood / metal seat mount at least allowed me to verify movement range and clash points , one downside I have noticed is the Pots that I got don't seem to be mechanically robust ( ya pays ya money ya takes your chances deal ) have noticed that they seem to split apart easily either that or my toothed belt tension is to high ( im trying to avoid slippage ) 3rd printed clip type restraint coming up me thinks . other than that things are progressing nicely would post video but youtube takes sooooo looong to process even short go pro clips , but have attached I pick of the set up before the new frame is welded..

Wow that is really high up !! What will be the height from top of your head to the floor in the highest position ?

The ceiling in my basement is only about 210cm and I'm 6ft2" I may have to dig a pit out lol

Hi @SilentChill lol yeah it took me by surprise as well but the new seat frame will drop the driver height down to a more like 700mm above the floor with the COG somewhere below the Actuator mounting Points ( at the moment the Platform height at Mid Stroke is circa 1200mm) so ceiling seemed Close .... My Latest investment saw me buy an "EVOLUOTION" Chop off saw and it paid for itselt last night as it effortlessly cut all my 25m square tube I'm using to make the new Seat Mount Frame ( at work now ) so pictures will follow later , Cheers Guys

Great progress i have a question what are you all using to bond the carbon fiber tube to the rod ends and ball screw

Hi @Justin Dail @SeatTime is the man to see about carbon fibre , I only used one piece of 20mm OD 18mm ID x 500 long on my actuators and that was mechanically fixed to my ballscrew nut adapter block , all other 5 Actuator rods were 25mm Mild steel ...but I may upgrade these later on ... Cheers

hi @wannabeaflyer2 quickie question for ya and maybe @SeatTime do you think I will be able to bond one of these into the end of my carbon tube to attach it to the platform ?? I have seen some commercial sims use UV joints in the same way so thought why don't I

Yes, depends how you 'bond' it, anything is possible .

I was going to use Teroson PU6700 as I can get hold of some cheap. The UV is 20mm and the rod ID is 22 so there will be a 1mm gap around it so hoping it will be ok after the correct preperation

For connecting ball joints to the carbon tubes, I used an inner and outer steel sleeve, with the inner sleeve bonded to the carbon tube. The inner sleeve is then drilled and taped to accept the outer sleeve when it is slipped over. The outer sleeve holds the thread for the rod ends. You could machine them, but as I don't own a lathe, just made mine with modified steel tubing and a suitable sized nut. All welded/finished as required. This enables me to change them out later if required.

Hi Guys another mini progress update , state of play , System seem reliable ref Communication with game software
May have small noise Pick ref Analog inputs ( Have used screened cables) so need to minimise that further some how
Actuator sometimes Loses Position I suspect that's why , or belt Not running true and skipping off Gear ..( Video In action required ..
New Welded Seat Frame Work in progress But now the nights are closing in its Dark by the time I get to play ( Bugger)
Movement range seems on the money
Been concentrating on FSX to see max movement range ( looks OK ) need to Quantify Working angles ..
Actuator Limit switches Work a treat (Saved some metal mangling and bank balance )
Being Deaf Noise is not an issue LOL ( The guys next door may think otherwise )
At the moment During un loaded Trials the Amp meter say less than 15 amps Drawn ( Hmmmmmm This need Checking )
so far electronics seem to be holding up fine... AMC - Sabertooth 2X32's ETC
Gonna try and download my 1st Steam Game and first car racing sim so Fingers Crossed ..
Generally Happy with the actuator construction and only a few minor enhancements to the Feedback Pot drive, seem to be required. On a whole the Belt drive is OK just minor concerns with the possible analog Noise and Maybe better quality Pots Could be required later on ..
Will post Video Soon Guys the damm GOPRO take great wide angle shots But Pain loading to You Tube even 2 minute clips ..
Cheers For hanging in there

Great news @wannabeaflyer2 can't wait for the vids

I shouldnt be too far behind you now with mine hipefully

@wannabeaflyer2 wow ! what a great simulator ! congratulation ! i am eager to watch your video.

Back again, been burning holes in metal with a vengence Lol Seat mount frame taking shape nicely , just need to redo some decidedly Dodgy welding ( er make that a lot of dodgy welding ) also as extra belt and braces ( and im gonna need it ) im reinforcing some of the Joints with Steel Plates 3" long x 3/4" wide by 0.062" strips ( 75x19.05x 1.5mm ) , got load of test pieces from work so may as well put em to use .ignore the white tape thats just how the scraped Racking material came
I'll admit its not pretty but will say once the duff wire feed on my welder was sorted the joints are starting to look more like they should ( shades of workman blaming tools LOL ( fingers crossed they hold up ) Angle grinder to the rescue ( but not removing joint metal per say) paint to follow once the Actuator Connection points have been tested and set before welding .... Cheers for looking guys

another so s video of the ol girl with lots of setting reduced for testing



Bed still there LOL but soon to be gone ...i need the space for the beast.. New frame welded and fitted pis to follow /

That's a really big girl...awesome one! What about your PSUs overloading?
I'd ordered today the first two 1605 l500mm ballcrews from china, also ordered locally a pair of 1904 l250mm leadscrews with teflon nuts for testing.

Good to see it progressing, although the power supply tripping without a passenger load is a bit of a worry. What power supply did you end up getting? Do you just have one big one?