Thanks very much for that calculation. Using the same formula, the gear ratio on my yoke is 12:1, based on the 4:1 gear ratio provided by the Banebots gearbox and the 3:1 gear ratio provided by the timing belts connecting a 72-tooth pulley to a 24-tooth pulley in each axis. The overall gear ratio of my yoke is thus significantly lower than that provided by the original Sidewinder 2. Replacing the 4:1 gearbox with a more aggressive version would reverse that; for example, an 11:1 gearbox linked to a 3:1 gear ratio between the two pulleys would raise the ratio to 33:1. Based on measurements cited elsewhere, I believe this would exceed the force provided by the Brunner yoke. Whether or not this arrangement would be viable I cannot say with confidence. I may be lured into spending another $150 or so on new gearboxes to find out, but before doing so I’d want to think more deeply than I have up until now about the “ideal” amount of force to aim for. The Brunner yoke provides one standard of comparison. Does anyone else have a solid, well-reasoned answer to the question, “How much force should a force feedback yoke provide?”
Hi Don, thank you for completing this project and providing all the information to build it. You did a fantastic job.
I am new to Force Feedback and DIY builds, I am currently using the original SideWinder Force Feedback 2 with XPForce but eventually I would like to use a Force Feedback Yoke for GA airplanes and possibly in the future a control column for airliners (like Boeing 737 style).
I did a bit of google research and reviewed different projects and that’s how I found out about yours.
Regarding your question above:
“How much force should a force feedback yoke provide?”
As you have indicated Brunner Yokes could be used as a reference. I can see they have a range of Peak Force depending the model of the yoke:
Brunner - cls-e-ng-yoke
Peak Force
Pitch: 40 N / 9 lb-ft
Roll: 1.7 Nm / 1.3 lb-ft
Brunner - cls-e-mk-ii-yoke
Peak Force
Pitch: 110N / 24.7 lbs
Roll: 6Nm / 4.43 lb-ft
Brunner - cls-b-ng-yoke
Peak Force
Pitch: 190 N / 42 lbs
Roll: 11 Nm / 8 lb-ft
Brunner - cls-p-yoke
Peak Force
Pitch: 750 N / 169 lbs
Roll: 35 Nm / 26 lb-ft
So it seems that Brunner top of the range Full Flight Simulator LEVEL-D yokes have higher forces.
Then looking at some of the DIY projects I came across I found these values being quoted (please refer to references below):
[1] Roland van Roy - simprojects.nl
Quoted Force
Elevator/Pitch: 61.5N which is around 6.2kgf (~13 lbf)
Roll: not listed (or I did not find it)
For the elevator, I had used a high quality DC servo motor. Spec of the (second hand) motor that I used: (Glentek GM2340-15) glentek . com / glentek/dcsel.aspx
Power: 150W, 0.133Nm/A, rated current : 2.5A, DC resistance 2.8 Ohms (actually I measured 4.2 ohm). Of course you can use other types, but the torque smoothness needs to be checked carefully. At 3A, this motor produces 0.40Nm. with a shaft diameter of 13mm, a wire wound over the shaft will produce a pulling force of 61.5N which is around 6.2kgf. This value is OK for most normal light GA force loading.
On his project Roland also makes reference to (history . nasa . gov/monograph12/ch15.htm#148) which could be useful to determine the right amount of force.
[3] Creator: Don (WarmBugle376586)
Quoted Force
Elevator/Pitch: not measured
Roll: 0.9Nm (~0.22 lbf - ~0.1 kgf)
I measured a torque of 0.9N-m on the bank axis with my yoke, using the. 4:1 gearbox. Unfortunately, I don’t have a similar measurement for the pitch axis force handy, but it seems to be in the same ballpark.
[5] Ian at BFF Simulation Force and Motion - bffsimulation . com
Quoted Force
Elevator/Pitch: 9 kgf (~88N - ~20 lbf)
Aileron/Roll: 4.25 kgf (~41N - ~9 lbf)
The force levels produced are also much higher than on conventional FFB joysticks. The default system set up will produce single handed aileron control forces up to 4.25 kgf (~9 lbf) and elevator forces up to 9 kgf (~20 lbf).
Larger forces can be generated but would require the transmission ratios to be increased.
[6] Creator: Tim (Hackaday) - https:// hackaday. io/project/184668-flight-simulator-force-feedback-yoke
Quoted Force
Elevator/Pitch: 8 lbs (~35N - ~3.6 kgs)
Aileron/Roll: 4 lbs (~17.8N - ~1.8 kgs)
Pitch axis:
Range = 10 inches
Max force = 8 lbs
Roll axis:
Range = 180 deg
Max force = 4 lbs
I am not an engineer or real life pilot so I cannot really say how much force should be provided by a force feedback yoke but looking at all the above values possibly something similar to the ones quoted by Ian at BFF Simulation Force and Motion seem strong enough:
Elevator/Pitch: 9 kgf (~88N - ~20 lbf)
Aileron/Roll: 4.25 kgf (~41N - ~9 lbf)
However, I suspect it is not possible to obtain those forces using the original SideWinder motors.
In fact, Roland at simprojects.nl used a modified SideWinder board to obtain a 3A current to power more powerfule DC servo motors (not the original Sidewinder motors) and doing that he achieved an Elevator/Pitch 61.5N which is close to 88N from Ian at BFF.
So, I guess if you use the Banebots 11:1 gearbox you should definitely get more force.
From what I understand you did not use the resistor mod describe here (https : // www . xsimulator .net/community/threads/diy-force-feedback-flight-yoke.12944/#post-194679) to double the power of the motor so I wonder what kind of force you would get that modification? Have you thought to try it out?
Also Tom (T R Para - see reference [4] below), in his posts mentions a SideWinder board mod to discrete mosfets (not sure if this increases power too) https: //www. xsimulator. net/community/threads/diy-force-feedback-flight-yoke.12944/page-3#post-219555 so maybe this could also help to get more power.
I am trying to figure out which Force Feedback Yoke to build so I hope this information proves to be useful.
Probably someone more knowledgeable than me can combine all the information and details from different projects and create the ultimate DIY Force Feedback Yoke at a fraction of the cost of the Brunner yokes.
Don let us know if you manage to implement any modifications which produce stronger force for your hybrid force feedback yoke.
Once again, well done for completing and sharing this project.
Dan
References:
@WarmBugle376586 to add to my previous reply, it seems I found a post from Jay providing his measurements for the FFB Yoke V1
Quoted Force
Elevator/Pitch: 1.8kg
Roll: 0.94Nm
https:// www. aerofly. com/community/forum/index.php?thread/8474-3d-printed-force-feedback-yoke/&postID=42327#post42327
I took ordinary digital scale, tip it on it’s side, reset the reading and then pushed it against the yoke until it overcame it’s force and started moving it. The yoke was set (via FS Force) to push the pitch axis all the way out with maximum force. At this point the reading was about 1.8kg.
With the Roll axis, I put the scale under one side of the yoke, applied max force (in FS Force) towards the scale and again slowly moved the scale up until the yoke started rotating. Here we have reading about 0.6kg.
According to online torque calculator (using Force x Lever Arm Length formula) the torque = 0.94Nm.
Dan,
Many thanks for your kind words and, especially, for your incredibly comprehensive answer to the question of how much force should a force-feedback yoke produce. Really splendid.
Regarding the various alternative approaches to obtain greater forces, I am pretty sure I’m going to limit my effort to getting a bigger Banebots gearbox, and even with that don’t have a target date. I’ve been working on the instruments using MobiFlight and 3D printing, and it’s taken me quite some time. Any further improvements to the yoke will have to wait for that process to be finished.
I briefly considered going with a fundamentally different approach like the one involving a bigger motor, but gave up the idea as not being within my skillset.
Likewise, I also admired the approach in which the MOSFETS are upgraded to double the current, but having worked with those tiny surface-mounted components for many hours while trying to rescue my first Sidewinder control board, which I somehow managed to short out or otherwise destroy, I had to admit that it’s a job for young people with steadier hands and sharper eyes than mine. The thought of putting my (second) existing board at risk by swapping out the MOSFETS and resisters is frankly terrifying, with visions of sleepless nights, ruined equipment, and a murderous glint in the eye of my very patient wife.
But I will indeed report the results of upgrading the gearboxes, if and when I get around to it.
Thanks again,
Don
Hi Don,
First of all, I’d just like to say thank you for the highly detailed information and resources you’ve provided in your build. It looks fantastic and I’d be delighted to hear if you’ve made any progress since June? It’s this post that inspired me to build my own so I’m just slowly sourcing the materials.
I’ve managed to get myself a MS FFB 2 from ebay for £65. I was wondering, do you know the rated speed of the 550 motors? I haven’t taken it apart but was curious if it was marked on the motors? This would help with gear ratio and torque calculations I would think. Also, re the gearboxes, I took your advice and got myself some higher ratio gearboxes for improved torque, but I went the aliexpress route, and got a couple of 14:1 550 motor gear boxes from there.
I notice you used different size pulleys for the pitch element (72 teeth and 24 teeth), where as the VR flightsim example seemed to use same size pulleys. Did you find you needed more torque?
Also, was there a specific reason for the 40/61 gear ratio for the potentiometer?
Thanks again,
Rae
I know that this post has not been updated for a while but I found this project online and would like to try to DIY my own. I’m finding it difficult to find the Banebots gearbox in Europe and I don’t really understand what’s the requirements.
I measured the gears on the FFB2 motor and it looks like it’s 16mm in diameter but I cannot find anything online on that size. Am I searching it wrong?
If anyone could point me to the exact gearbox I need to get (and the size) that would be great. Ideally on a 12:1 ratio or similar. Thanks!