Question for those using a Steering Damper on controls

[helisim8]

I have been using a modified Logitech 3D Pro joystick that I separated the throttle and yaw pots to make DIY heli collective, anti-torque pedals and extended cyclic. I have about 100 hours with them on the sim, but just recently added the motorcycle steering damper to the pedals.

 

The resistance force seems fine, but there is a lot of "stiction," or resistance to small reversing movements. I have applied some Danco silicone grease for o-rings, and it works great for about 20-30 minutes before the o-rings wipe it off the shaft and I need to re-apply the silicone grease.

 

Have you done something to permanently solve this issue, or do the o-rings just "wear in" with time? I only have about three hours use so far since adding the steering damper. Thanks.

[FragBum]

I see you've been busy too, nice setup you got there... :thumbup:

 

Nah it's all part of your regular helicopter scheduled maintenance. :P

 

But should be good for more than 20 minutes.

 

How much travel of the steering damper are you using, I've tried to use pretty much the full travel with good mechanical advantage.

 

I've added a little lubricant grease to the shaft both ends AKA petroleum jelly. The seals seem to bed in after some use. The steering damper on my collective has been in service for maybe 100s of hours and feels good the damper on my pedals has only been in service for maybe 20 hours and is still bedding in.

[helisim8]

Hi FragBum,

 

Thank you for your response. I’m only using about half of the travel. I could change the attachment point to get full travel, but would lose mechanical advantage.

 

Do you still have to add the petroleum jelly on your collective steering damper, or does it not need lubricant after the seals wear in? Thanks.

[FragBum]

 

Do you still have to add the petroleum jelly on your collective steering damper, or does it not need lubricant after the seals wear in? Thanks.

 

Well yes but it's more of a case of cleaning the shaft nothing fancy just a wipe over with a tissue to clean any accumulated dust a such off and just a small amount periodically, the petroleum jelly was what I had to hand that was not bearing grease, that black stuff spreads everywhere.

 

The other grease I have used is so called water proof grease that you would use if you overhauled a tap (faucet??)

 

When I say periodic it's like months AKA maybe 100's of hours I clean them including the ones in my cyclic maybe more often then I need to but.

 

Gotta say it should get better as you go.

[FragBum]

What are the pivot points for the pedals at the bottom, sleeve bush or roller bearing? Having the resistance of the damper will load those pivot points and if just sleeve bush bearing may need some lube.

[helisim8]

There are ball bearings or spherical rod ends at all the pivot points. The unit was very free before adding the damper. Which was actually the reason for adding the damper as the pedals would not hold there place and flop freely.

 

Do the RC car shocks you used for the cyclic have the same "stiction" effect? I need to find a solution for adding resistance to the cyclic as well. I am trying to simulate the feel of Robinson R22 controls which are not hydraulically assisted as in the R44 you fly. I have only .8hr in a R44 and 1.1hr in a R22, so need some more flight time for calibration soon.

 

I feel like the resistance of the steering damper is good, and also nice that it is adjustable, but the "stiction" would be unacceptable on the cyclic. Maybe I have to try the rotary dampers that others have mentioned. I'm eventually probably going to have to build another cyclic and collective with dampers for resistance and either better pots or try the Hall effect sensors.

[FragBum]

There are ball bearings or spherical rod ends at all the pivot points. The unit was very free before adding the damper. Which was actually the reason for adding the damper as the pedals would not hold there place and flop freely.

 

I meant where the the sections with the foot bars pivot, the reason I mention it is because when I put the damper on the collective the pivot point was just aluminium sleeve and the force of the the damper took it's toll so I added roller bearings, but as the sleeve bearing failed stiction became a problem.

 

Do the RC car shocks you used for the cyclic have the same "stiction" effect? I need to find a solution for adding resistance to the cyclic as well. I am trying to simulate the feel of Robinson R22 controls which are not hydraulically assisted as in the R44 you fly. I have only .8hr in a R44 and 1.1hr in a R22, so need some more flight time for calibration soon.

 

You gotta do the research right. :thumbup: :D

 

Hopefully I'll get another couple of hours latter this year. Yeah. :D

 

 

Okay yes initially they do for a bit hence the grease on the shaft, however all that is needed on start up is just do a few figure 8's just like I'm supposed to with the cyclic and viola, the cyclic is smooth and stays put when I need to do stuff with KBD or mouse. The dampers just give some resistance to movement and it really is just a slight force in the required direction.

 

I'm looking for slightly larger ones maybe 1/10 scale and maybe better quality for my next iteration of the cyclic.

 

I feel like the resistance of the steering damper is good, and also nice that it is adjustable, but the "stiction" would be unacceptable on the cyclic. Maybe I have to try the rotary dampers that others have mentioned. I'm eventually probably going to have to build another cyclic and collective with dampers for resistance and either better pots or try the Hall effect sensors.

 

That stiction should disappear really it should, although maybe using more of it's travel with good mechanical advantage could help. :thumbup:

 

Part of the start up checklist in the R44 is to turn the hydraulics off and do that figure 8 movement with the cyclic to check for binding etc and it feels sort of clunky without hydraulic assist. Whats the cyclic like in R22?

 

 

The difference between (good quality) pots and HALL effects is the amount of angular travel required you kinda have to gear up for a pot to get as much rotation as possible and gear down for the Halls only about ~20-something deg rotation. Also with the UGN3503 the output range is 0.83V to about 4.3V so I have to change the DCS inputs to slider and use dead zone and saturation to bring the input to full scale range easy to do in DCS control settings and it stays linear you can then add user curves or curvature to apply some nonlinear transfer function if needed.

[helisim8]

Yes, I have flanged ball bearings on either side of the square aluminum tubing "stalks" that the foot bars are connected to for the pivots. I may try connecting the damper further up the stalks to use more of the travel, even at the expense of the mechanical advantage. Perhaps that may make the stiction less noticeable.

 

I have so little time in the real helicopters, I almost don't remember what the cyclic feels like, only that there is more resistance than my Logitech 3D Pro without centering spring. My .8 hr in the R44 was an intro flight where the instructor never really took his hands or feet off the controls, so I felt a lot of resistance, even if it had hydraulics. The R22 doesn't feel clunky at all. It was smooth, with a fair amount of resistance like in a car steering wheel, and a small zone around where the stick was where there was less resistance. Not slop, though.

 

I need some more time in the R22 to get a better feel to compare with the sim controls. I know right now that I'm not even close on the cyclic and collective that I have. Not even sure I'm close with the pedals, but at least I have some resistance now.

 

Interesting information about the Hall sensors, I have to say that I'm probably more comfortable dealing with mechanical stuff than electronic stuff. So I'll have to think and learn more about the Hall sensors versus gearing pots.

 

I'm coming to the sim world from RC helicopters, and I can see that this is an entirely separate hobby on its own. I got started because I thought the simulator would be a good way to build muscle memory to fly a full size helicopter, and way less expensive.

[Thadiun Okona]

Use real damping grease. Nyogel 767a is not like anything you can buy at any hardware store (I've been making damping mechanisms and exploring greases for this purpose since 2012) and makes mechanical damping mechanisms work nearly as well as real hydraulic ones.

 

 

 

One of the things that make it very different form other greases is the lack of stiction under these conditions, despite being really heavy stuff. Breakout force is no different feeling than the kinematic stroke and it doesn't evaporate away the way normal greases do.

[helisim8]

Use real damping grease. Nyogel 767a is not like anything you can buy at any hardware store (I've been making damping mechanisms and exploring greases for this purpose since 2012) and makes mechanical damping mechanisms work nearly as well as real hydraulic ones.

 

One of the things that make it very different form other greases is the lack of stiction under these conditions, despite being really heavy stuff. Breakout force is no different feeling than the kinematic stroke and it doesn't evaporate away the way normal greases do.

 

 

Thank you for your reply. I have heard of Nyogel 767a being used for sliding contact surfaces. Are you saying it works well on hydraulic shaft stiction too? My problem is the o-ring seals around the hydraulic shaft wiping away the silicone grease. I am looking for something that stays on the shaft longer or maybe gets impregnated into the o-ring seals if you think Nyogel 767a will help.

[FragBum]

Looking at the picture my thinking and this is just an idea, would be to turn the damper around so the shaft rod end attaches the stalk piece. This also gets it out of you foot space. :)

 

Maybe some 3 or 4mm * 40mm aluminium angle going vertical and mounted along the section where the rod end currently attaches, with height enough to put a bolt through a couple of nuts and hang the damper so it's aligned reasonably both ends and in both planes.

 

I've kinda sketched it on paper if you want.

 

Thinking about the leverage my pedals are about 130mm above pivot point and the damper connection point is about 65mm below but I do have the advantage of almost the full travel of the damper so I can just dial in what resistance I want.

 

This is what I was thinking.

 

Edited March 12, 2019 by FragBum
Add pic and typo

[helisim8]

Thanks for the sketch. Now you have me wondering if my geometry is all wrong. Part of the problem is my foot rests below the pivot point so the round bar is lower on the stalk to reach the ball of my foot, but if I move the bar up, it also increases the overall pedal travel. Did you happen to measure the actual pedal travel in the R44? I have to do that the next time I fly the R22.

 

Otherwise, I think I will try moving the damper attachment point to get the full range of damper travel as you mentioned, try to maintain the mechanical advantage, and maybe add a floor board to raise my foot rest. Thanks for your ideas.

[FragBum]

R22 plus and minus 2.9 inches of travel. ;)

 

Robinson R22 Maint manual see 10-13

 

The geometry will also effect the rotational travel of the pot, so you will need to experiment with that if you want to have the travel about the same. Although torque reaction will not be the same as in real life.

 

Oh BTW my wife commented about how your pedals a like all shiny and neat looking,.. :cry: :lol:

[helisim8]

Tell your wife, "Thank you."

 

Thanks for the link to the R22 Maintenance Manual. Lots of good information there! Hmmm, I think I need to find some time for a re-do on this. I'll see what I can do.

[Thadiun Okona]

Thank you for your reply. I have heard of Nyogel 767a being used for sliding contact surfaces. Are you saying it works well on hydraulic shaft stiction too? My problem is the o-ring seals around the hydraulic shaft wiping away the silicone grease. I am looking for something that stays on the shaft longer or maybe gets impregnated into the o-ring seals if you think Nyogel 767a will help.

 

 

 

 

Hehe, no not to put in the hydraulic damper, to use instead of one or to supplement it so that you can run the hydraulic at minimum resistance.

 

 

I have one of those hydraulic dampers, and also make adjustable tension friction rub joints and the quality of the kinematics of a generous amount of surface area is actually better than the hydraulic damper.

 

 

 

I assumed my damper was a lemon, so did some homework and bought some synthetic 10 weight motorcycle fork oil after reading up on motorcycle forums. Mine also has sticktion, that gets worse with higher resistance. I'm hoping the bleed/refill makes it start behaving, otherwise I'm sticking with my mechanical dampers.

 

 

 

Here's an album of a positioning joystick I made for MWO in 2012 https://imgur.com/a/ixi64. Towards the middle of the album is a breakdown of the simple friction joints. I used it emulating absolute mouse, and it was totally viable playing against kbm warriors, due to the precision of the damping and Nyogel made it from from good to great.

[helisim8]

Here's an album of a positioning joystick I made for MWO in 2012 https://imgur.com/a/ixi64. Towards the middle of the album is a breakdown of the simple friction joints. I used it emulating absolute mouse, and it was totally viable playing against kbm warriors, due to the precision of the damping and Nyogel made it from from good to great.

 

Nice work on your joystick!

 

Thanks for the clarification. Have you ever used the flat disc rotary dampers? I am wondering if those are a commercial version of the kind of dampers you make yourself. Wondering if there would be less stiction with those than the hydraulic damper.

Edited March 13, 2019 by helisim8

[TomVR]

On 3/13/2019 at 5:27 AM, Thadiun Okona said:

 

 

 

 

Hehe, no not to put in the hydraulic damper, to use instead of one or to supplement it so that you can run the hydraulic at minimum resistance.

 

 

I have one of those hydraulic dampers, and also make adjustable tension friction rub joints and the quality of the kinematics of a generous amount of surface area is actually better than the hydraulic damper.

 

 

 

I assumed my damper was a lemon, so did some homework and bought some synthetic 10 weight motorcycle fork oil after reading up on motorcycle forums. Mine also has sticktion, that gets worse with higher resistance. I'm hoping the bleed/refill makes it start behaving, otherwise I'm sticking with my mechanical dampers.

 

 

 

Here's an album of a positioning joystick I made for MWO in 2012 https://imgur.com/a/ixi64. Towards the middle of the album is a breakdown of the simple friction joints. I used it emulating absolute mouse, and it was totally viable playing against kbm warriors, due to the precision of the damping and Nyogel made it from from good to great.

The stiction thing is hit or miss, I have one damper thats perfect, finger tip movement, and another two from the same seller bought a month later that are basically friction brakes, useless garbage.

I am looking to get them serviced somewhere, maybe they need new oil.