D.E.P.S. problem, need ideas.
 

I installed the DEPS system in my Temptation. I was doing the final install on my gear yesterday and when I put the dual pushrods back in they were very tight and hard to move. I tried to clean out the ends where they exit the fuse because I though that this is the only place where anything could have changed but they are still tight? Anyone have any suggestions?
thanks, Tom

RE: D.E.P.S. problem, need ideas.
 

Tom,

If you read Troys original article about the D.E.P.S. system you'll see the original tubes
were not plastic like on the Central Hobbies version , but Teflon tubes which were a lot
more forgiving if they needed to be curved. The push rods get very stiff to move if the
plastic tubes are curved any amount at all , they need to be very straight. The only thing
I can think to try at this point is maybe spraying the carbon rods with some automotive
silicone spray to make them slicker.
I've tried both versions and prefer the Teflon , although the plastic is easier to attach
to the ladder because it's stiffer. If you wrap the Teflon too tight it will crush.

tommy s

RE: D.E.P.S. problem, need ideas.
 

The odd part of this is, I installed it and tried it before I did anything to the fuse, like paint or glue in the vert tail post, and it worked fine. I'm stumped. I have a large MK bellcrank I may end up using.
[sm=tired.gif]

RE: D.E.P.S. problem, need ideas.
 

Sand the rods. I took them down to about .065 with 320 grit finishing with 600 wet.
I then filled the support tubes with graphite lube using a piece fuel tubing between the bottle and support.

(The graphite lube is a dry powder lubricate available at most hardware stores for about $4.00 a bottle)

RE: D.E.P.S. problem, need ideas.
 

Sorry Wrong post......

RE: D.E.P.S. problem, need ideas.
 

Sorry guys posted from my buddies account. He was logged in on my machine earlier today.

Tom,

Use a long metal 2-56 pushrod to plunger the tubes and remove any paint or filler material. Any extra stuff in there will cause it to bind up.

Next is remove the purshods from the tube guides and look at them to see if they have any ridges and or smooth on the surface. I have seen some that have some small ridge activity going on. Use some like 320grit paper and sand the ridges. Just roll the rods in your fingers not to sand the dia down...just to remove the ridges nd make it a smooth surface. This has not been a problem on any of my installs but thinking about the ridges if the plastic guides are bending at all this could be a cause for the binding.

If you have the ends glued on already its an easy remove...Just heat the ends and the epoxy-JB Weld or whatever will come soften and you can pull the ends right off. Then slide them out through the front of the fuse.

Next is look at your connection up front where the 2 rods come together. Is it binding here at the "Y".

Is it binding as it attaches to yours servo wheel. Meaning is there any bending to get to the servo connection. I make sure to have my elevator servo and elevator control horns mounted when installing the system. This makes for a straight shot. If was free before and is not free now....something changed.

Next is look to some lubricants. I would look at the silicone spray...I have seen some teflon spray that could work. Another really good thing to try is Rain X....I have used this to lube antenna tubes.

Don't scrap the idea....You just need to work with it a little.

For what its worth I have had the same experience with both the plastic tubes and the Teflon tubes. I like each one for a given reason. The Plastic ones are more critical on the bending....But the Teflon ones are worse when attaching to the balsa sticks. Basically you have to get it to be a straight line If it bends then it can bind up. I have the Plastic ones in my Supremes' that I flew last year and still flying and they are smooth.


I think a little surface clean up on the rods themselves, some plunger work, and some Rain X might be the best solution to try. Apply the RainX to the rods and let it dry before installing them in the tube guides.


Good Luck with it. And let us know how it comes out.

Troy

RE: D.E.P.S. problem, need ideas.
 

OK will give those ideas a shot tomorrow and see what happens.
thanks

RE: D.E.P.S. problem, need ideas.
 

Too bad Tom, wished we would have spoken earlier. Depending on how you glued the teflon tubes in place, I can see where this could be a problem. The teflon used is thin and flimsy, and will collapse a little as the glue cures. I suspect that's what happened in your case

This system is easy to do if you take a pair of carbon rods from CST Sales cat #T515-4, make your ladder setup from these and install it. Theyare carbon hollow rods with a .116" ID. The teflon guider tubes will slip fit inside these, and will just float inside the carbon tubes. No need for any binder material other than front and back, just to keep the teflon tube from sliding around.

The teflon tube can be installed after the plane is done, with the carbon rod or a steel rod for support while inserting the tube. Then complete the deps setup normally.

There is variety of carbon tubes available at CST. Resist the temptation to get the smaller carbon tube that will just fit the solid carbon rod. In a high vibration environment, carbon against carbon will wear the system out prematurely. Definitely use the teflon tubing because Teflon is soft and will absorb alot of the punishment, yet slippery enough to never cause any problem. This set-up will weigh in at around 40 grams or less depending on how long one makes the carbon tubes and how crazy one gets with the ladder.

MattK

RE: D.E.P.S. problem, need ideas.
 

I think you are right Matt, I think it was the glue curing that crimped the tubes because it was working fine before I pulled out the rods and glued it all.
Tom

RE: D.E.P.S. problem, need ideas.
 

I tried to make sure the D.E.P.S. tubes were straight. I lightly lashed them to 1/4" balsa sticks with thread. One of my tubes ended up having more drag than the other tube. In the end, I replaced the CF rod with 0.060" dia rod. Now the system works well. I like the idea of buying Troy's original teflon tubes from CST.

On my next plane, I'll probably go back with pull-pull cables on elevator.

Steve

RE: D.E.P.S. problem, need ideas.
 

The lightest system around is pull-pull. It also has some issues as all actuation system do, but these can be overcome with some forethought. I still have teflon coated Kevlar cable for sale if anyone is interested. Contact me directly at [email protected]

MattK

RE: D.E.P.S. problem, need ideas.
 

I was just finished putting tubes (teflon) in my Temptation and everything was working great before I connected the carbon rods at the servo end. When I connected the carbon rods, I used too much CA, and it ran down the carbon rods. Result was binding in the teflon tubes. I cleaned up the rods and everything works great. Next time. I will lean the assembly toward the servo end while applying CA to the carbon rod joint.

RE: D.E.P.S. problem, need ideas.
 

What sort of glue would work well for glueing the sleeves to the 1/4 sq. ladder, after it's been wrapped with thread to avoid this possible 'crimping' of the sleeves? I'm about to try this setup for the first time and have the parts on order from central hobbies. MTK's setup with the larger rods for the 'ladder' seems like a good one....

RE: D.E.P.S. problem, need ideas.
 

I just hooked up the elvators to my DEPS and it works well. I took some very light 1/4 inch square sticks and used a dremel with a router bit and cut a groove in them so that the tubing fit in flush with the stick. I then wrapped with thread and hit with thin CA. The groove holds the tube in place and gets it out of the way at the exits. It is still plenty strong with the grooves cut in the sticks. I supported it in four places and tied the stick together in four places. It is a tight setup. There is absolutely no slop except for what is in your servo.

RE: D.E.P.S. problem, need ideas.
 

When I install servo lead tubes and antenna tubes I usually use canopy glue , probably
would work well on the D.E.P.S. also , doesn't seem to shrink much.

tommy s