Push/pull controls

[kermit]

80 $ a pop,
don`t think so ,I bought mine original cessna throttle, mixture and prop rpm including cable for only 20$+ 10$ P&P in total on Ebay.
I have put 100k slidingpods (a 3,95 euro) mounted on selfmade aluminium holders and connected it on my simkits CCU2 .
note Simkits is asking 245 euro ex VAT a piece for the same device.
And you can`t beat the original,
greetz

[No Longer Active]

80 $ a pop, don`t think so

Very much so, maybe you get them on ebay secondhand, $80 from aircraft spruce in UK at the moment!

[No Longer Active]

Ron, thanks for the drawings, so how exactly are you going to make the knobs?

Cheers,

Alex

[kermit]

Thats the charme of ebay
You can buy items on monday for 2 $ and just a few days later you have to pay double /triple for the same item

take a look at this just copy and past,
http://cgi.ebay.com/ebaymotors/Mixtu...5fPartsQ5fGear

This is 2nd hand but even that looks better then selfmades, and when you are take your time in account for making them, what will be cheaper?
I know that making your own stuff is a part of the pleasure but I like the original look.
greetz

[Ronson2k9]

You haven't seen mine yet.. hehe

I agree the actual item is always good to have for many reasons. There are times though that even if you can get the real one converting to use in FS or finding them can sometimes prove difficult. I'm always hunting though..

A note on the Throttle: You had mentioned Alex that there is a friction lock on the throttle so that ring just beyond the knob isn't for adjusting it's for locking the throttle? I didn't know that. Now I don't have to worry about getting that to adjust the throttle as I had thought it would need to do.

Now that I know the dimensions of the controls I'm going to see what I can find if doweling comes in that size or not? If not I may end up using polymer clay to make them. I'll have to make a mold first but that shouldn't be to hard. Like you I don't have a lathe so it would be hard to do on a drill press or I could try your idea.. Looks pretty promising too.

It would be cool to get the release to work for the prop and mix controls. I may have a spring loaded 'dummy' version or try to get it working as it should but then I could be going a bit over the top prototypically speaking. I know I want the fine adjust though that makes sense from a flying standpoint.

[Kerbo]

Great drawings Ron, keep up the good work. Are you measuring the real thing or just designing by guesswork? Either way they look fantastic.

I'm using cheap wooden cabinet pull knobs until I have the time to make something better.

[Ronson2k9]

Great drawings Ron, keep up the good work. Are you measuring the real thing or just designing by guesswork? Either way they look fantastic.

Well it's my best guess. First I took the drawing of the C206 MIP from the Parts manual and going on the 79mm gauge I then figured the number of pixels to the mm in my drawing which is 2.34 then I measured the diameter of the controls and divided by 2.34 that's how I came up with 30mm diameter per control. Give or take a mm. The diameter is as close as I can get. The other parts are based on good ref photos.

I got the working drawings up next. That shouldn't take to long to do should be done tomorrow.

The mixture and prop control (if on the C172) are a bit different then the 206 as there is just a thin flange over the port to the instrument panel. For some reason it's much larger on the 206. The throttle though is the same.

As you can see from this photo.
http://commons.wikimedia.org/wiki/Fi...im-control.jpg

You can't see the actual control but the flange over the MIP where the control goes through is there. It is for the mixture control BTW. Looks like this 172 is amphib float equipped from the gear button you see there. I've seen them so I know there out there if you are perhaps thinking of of going on the water yourselves.



This is the photo I'm getting all my primary data from.


Photobucket reduced the size to about 1/10 it's actual size .. If you like I can email you the full version?

This is the pit I'm building after though
http://www.airliners.net/photo/Cessn...e852b5e59ca2ff

I'm almost tempted to build the whole sim in Blender (the software I used for my drawings) but I'd rather build it for real.. hehe. It can make great drawings in 2 or 3D. It's pretty amazing software.

[Ronson2k9]

I have the working drawing complete. This is for the Prop Pitch but the same principal should work for others as well.



All measurements are a bit transitory given your equipment. The pot I used for the drawing had a total movement of 60mm which would be perfect as the total movement of the control is 75mm.

You could use a nylon bolt for the nylon rod if a rod can't be found. You would have to remove the head as you need the threads to turn within the slide holder. You could go with a cotter pin approach to connect the nylon rod to the brass tubing. Using a pin vice and small drill bit 1mm perhaps drill two holes through the tubing and rod and then run a piece of piano wire through the holes rounding it back so it doesn't snag on anything.



UHMW will work best to keep friction to near zero. That should let the nut slide when the bolt/rod is being rotated and slide easy when pulling/pushing.

The control rod should have support from inside and outside the panel so it can't move in any other direction except that of in and out.

For the C172 that may mean putting extra UHMW on all sides to the bolt then becomes the support as well. Could be a good idea in all instances so long as you can remove that later if anything needs to be replaced.

UMHW comes in many forms including tape. So you can build the holder out of wood if would like or aluminum angle lengths and tape UMHW to it. This could be preferable to screwing or trying to glue it together as UMHW is a wax it can't be glued very easily. Glues can bought but they are pretty pricey. So drilling and bolting is perhaps the best way to connect all the pieces if going with the solid UMHW material. There is the tape though so you could make the holder out of masonite (hard board) and then tape the surface where the bolt will ride. The masonite parts could be glued together with wood glue. UMHW both the solid form and tape can be bought at Lee Valley in Canada the tape is $12.00cdn a roll. There are many other contact surfaces in the simpit that could benefit from that tape (eg: yoke/rudder) making it a pretty good investment.

If you're outside Canada you can find UMHW Polyethylene mostly at woodworking supply shops. It's used in tooling and making jigs for woodworkers. It can be worked like wood (cut drilled sanded). It's best to use carbide tipped tools to work with it as that will leave a cleaner relief. It's quite rigid as well. I've never come across any that would flex in any way. So you don't need to worry about it flexing.

This pretty much concludes my tutorial. If anyone has any other thoughts or improvements feel free to pass them along.

[Kerbo]

Ron,
Could you explain how the fine adjust nut works? I can't get my head wrapped around it. It seems like the nut would need to slide for normal operation but remain fixed in order for the fine adjustment.

Thanks

[Ronson2k9]

Sure no probs.

The nut would slide back or forward as you TURN the control. The nylon rod turns as you turn the control moving the nut to one of it's extremes. So you can slide the nut back and forth by pull/pushing the control and rotating the control also moves the nut but much more slowly giving you a fine adjustment. As fine as the pot will allow of course. The guard is there to act as a wrench kind of keeping the nut from turning as it slides. The UHMW is to make sure the nut never binds on the guard.

In looking at the cotter pin option for connecting the threaded rod to the brass control rod. I should be able to find a nylon washer with sleeve as a stopper (plumbing parts section of hardware store) for both ends of the threaded rod. If not it shouldn't be hard to make one. A large enough outer and inner diameter bushing/tubing would work very well too. That could be put on the outside brass tube at the juncture between the brass & threaded rod with a cotter pin going through all 3 items at once...

At the end of the threaded rod
- stopping the nut from trying to climb off the end of the threaded rod

At the beginning of the threaded rod
- stopping the nut from trying to slide the threaded rod off the brass rod
- stopping the brass rod from coming out of the MIP.

The stopper itself can't be a nut as that would prevent the control from turning. I had thought it could have been at the beginning but remembered that. Further the stopper and cotter pin mean outer diameter has to be less then the nut to keep if from binding in the guard. Glue could be alternative if you can find one that will hold nylon to brass ?? Hence the cotter pin.. hehe

So a bill of materials would be.. (per control)

Nylon Bolt and Nut
Brass or Aluminum tubing
UHMW tape/solid pieces
100k linear slide pot
Wood or Wood Rod (doweling max dia is 1" the control calls for 1-3/16")
- I may be able to find stair stringers that are that diameter or a little bigger though?

I'm waiting for someone to come over to the house today but after I'm going to hunt down the bits.. and start putting them together.