DIY SFX 150 push pull Linear Actuator

Hi Guys,

Hi Guys like Most people on this forum I decided to build my own simulator back in 2019, I took the inspiration for my design from the DOF Reality simulator, as this is a good basic design, so I modified the approach to suite my design.

I decided to go with the 3,DOF type layout, my initial design used the Simukit 400w 24v DC Motors to power the 2DOF side of the sim controlled by a sabertooth & arduino, initially this was fine in its movement and control.

Over time I became aware of play in the worm dive gear box, and I found this very annoying, I decided that I could not put up with this, so I decided to look at linear actuators for a replacement drive system.

I looked at SNC5 – 6 actuators, and as these are very expensive, I was not prepared to pay this price.

I looked at the DIY options and decided to build my own actuator based on the design at SimFeedback - SFX-100 style actuator, and this was to be a push – pull actuator and a virtually all metal construction, with a limited number of 3D printed parts.

I will get round to the specification’s in the next few days.

Hi Every One

As Promised DIY SFX 150 push pull Linear Actuator Parts & Build Listing

Parts Starting with P001

P001 Top mounting securing plate Laser cut 4mm Mild Steel.

P002 Front mounting Aluminium billet machined to 89.mm external / 46.mm center bore / width 15.mm.

P003 LMEK30UU Square Flanged Linear Ball Bushing with Rubber Seals and Resin Retainer 30x47x68mm.

P004 Aluminium Tube L 350.mm x W 89.mm x ID 75.90 x Wall 6.54.mm.

P005 Hardened hollow shaft L1771.30 / L350.mm x W 30.mm / ID 18.mm C60 Carbon Steel / Shaft coupling on rear 40 x 50.mm with ID diameter 30.mm & 28.mm.

P006 Ballscrew with Fitted Anti Backlash Ballnut RM1605-C7/ 350mm Total Length.

P007 Ballnut installed on to a 3D Printed location stabiliser.

P008 Ballnut side view.

P009 Ballnut Top view.

P010 Ballscrew Support FK12 TMT (SYK).

P011 Rear mounting Aluminium billet machined to 89.mm external / 35.mm center bore / width 15.mm.

P012 Rear MIDDILE CENTER mounting securing plate Laser cut 4mm Mild Steel.

P013 3D Printed cover motor coupling.

P014 3D Printed cover motor coupling top view.

P015 motor coupling.

P016 Rear buffer plate for protection of motor.

P017 Main rear mounting plate Laser cut 4mm Mild Steel.

P018 Motor mounting pivot brackets.

P019 Motor mounting bush.

P020 Motor mounting bush top view.



Assembly description starting with AS001

AS001 The 30.mm Linear Shaft is installed at the rear on to a custom made bush to fit the shaft on to the Ballnut, I needed to buy a second Ballnut of the same specification and this mounts on to the bush allowing the 2 parts to join together, on the shaft I needed to drill a hole, 6.mm hole through the shaft as the shaft is a grade C60 Carbon Steel this is not an easy task, the best drill for this is a, Bosch expert straight shank multi-purpose drill bit 6.mm this will dill high carbon steels although don’t try this freehand it is best to use a drill mill if possible.



AS002 The ball nut with the 3D Printed location stabiliser as it is installed in to the bush, this is retained with the M6 hex bolt through the center of the bush.

AS003 The ball nut with the 3D Printed location stabiliser installed in to the bush.

AS004 in this view it shows the ball nut with the 3D Printed location stabiliser being installed on to the main ball nut on the ball screw.

AS005 this is a rear profile showing the six threaded mounting fittings these allow the main ball nut to fit on the rear of the location stabiliser with M5 bolts.

AS006 in this picture it shows the rear Ballscrew Support FK12 with the Rear mounting Aluminium as it is installed.

AS007 A rear view of the assembly .

AS008 A rear view of the assembly and the Rear MIDDILE CENTER mounting securing plate.

AS009 rear coupling.

AS010 3D Printed cover motor coupling.

AS011 in this picture you have the main shaft with a rebound damper in between the LMEK30UU Square Flanged Linear Ball Bushing and the coupling bush.

AS012 side view of the LMEK30UU bearing and the Front mounting Aluminium billet installed.

AS013 top view rebound damper.

AS014 top view rebound damper duplicate.

AS015 Rear mounting bracket assembly to mount on to frame.


Other Parts description starting with OT001

OT001 various 3D printed parts / internal rebound damper for Support FK12 / protection cover external for LMEK30UU / rebound damper for LMEK30UU.

OT002 tension assembly rods 4 x 140.mm with 10.mm locating flange and 25.mm x 6.mm thread these go through the motor to support and locate the motor at the front and rear.

The smaller rods go through the 3D Printed cover motor coupling and locate in the Rear MIDDILE CENTER mounting securing plate this plate has 4, 6.mm threaded holes on the out side edge, 65.mm x 15.mm 6.mm thread.

OT003 4 360.mm aluminium tension rods drilled and taped to 6.mm.

Assembly description Pictures.

Parts description Pictures.

Other parts

And here is the eventual frame design for the actuators.

Good infomation, but I don't have access to a 3D printer.

I agree with you
"Over time I became aware of play in the worm dive gear box, and I found this very annoying, "

However, I'm currently looking at using steering dampers to stop the seat rocking / moving a small amount due to the play in gearbox.
Has anybody tried this ?

David, your design is fantastic. It looks professional and efficient. My own linear push pull is not nearly as good looking. Well done.

Hi Historiker
Thank you for the comment the design is not entirely my own, a lot of the designs came from other members I just copied and integrated it into one unit, and tried not to use 3D printed parts for the load bearing parts .

That is what this community is about, sharing ideas and building a better moneytrap

I do not have images of mine handy, they are simply two linier slides with a ball screw in the middle. Works great though.