Help on mechanical, telescopic cylinder.

[Ian (the norwegian)]

Hiya folks.

How are y´all? :)

I'm at the moment building a Tamiya Scania r620 with a dumper box.
I need a telescopic lift cynilnder for the dump box. Here in Europe this cylinder are usually placed under the box, about 1/3 of the way back.
I know there are a hydraulic cylinder from Leimbach that could fit, even if it is a bit short, but I have seen a mechanical cylinder somewhere. Telescopic.

Does anyone here have an idea how this is made? I've been thinking for a while but can´t find a useful sollution to the telescopic part...

Have a nice one.

Ian.

[fhhhstix]

You could do a single stage ram easy enough just attache a threaded rod to a gear motor and put a threaded insert in a tube to simulate the rod and put it all down inside a tube and put a cap on the end with a hole for the rod. A telescoping cylinder would be much harder as you would need stages of threaded rod and it would be pretty sloppy by the time it is fully extended and when each stage reached the next and started turning it out there is the possibility of it locking up as it hits the stops and then it would not be able to come back down.

Travis

[fhhhstix]

Talk to russisloud he has built some and here is a link to his vendor section. The Bone Yard (http://www.rctruckandconstruction.com/forumdisplay.php?f=62)

Travis

[Lil Giants]

Are you Ian in the same area of Norway as Ole (vforce)? He's using a nifty electric screw drive from Carson (I can't find the product listing on Carson's site) that gives a smooth realistic lift speed from bottom to top & back again. It's quite powerful too.

There really is no comparison for scale hydraulics for dumpers and Scale Art makes a nice telescope hyd system. I haven't tried one myself yet, but maybe someday.

http://www.scaleart.com/produkte/bauteile/hydraulik.htm

The Wedico telescope has been working good me, use one in each of three trks.

[Finster]

Hi,

I agree with the others that a long telescopic screw drive might be difficult to produce and have it function well. Here is a link to another forum where a gentlemen built an awesome bridge-layer tank with some short mechanical telescopic cylinders. Maybe his methods will work. I hope this helps. http://www.rcpanzer.de/apboard/thread.php?id=12739

[JAMMER]

They do have long telescoping screw hoist and it works off of plate under the hoist that turns the screw I have seen them but can't remember were. Ed

[Rebekah_harper]

if you are thinking of the cylinder for bulk tippers that are mounted at the end then If you have the time then you could do the following.

you will need a number of metal tubes. then thread the tubes but no need to do the widests. then you will need to get nuts the will screw on each of the tubes.

the nuts will have to be welded onto the end of the tubes and grinded down to the size of the tube you attached to . you will need to put a stopper on either end so that it doesn't come appart once assembled.

at the bottom you can use 2 bevel gears to turn the outer tube and as the hinge of the assembly. this allows you the have the motor separate from the main body and hidden so that is look nice and neat.

I think it will require some experimenting but this would be the way.

the only other way would to use a metal cable to push into a cylinder. this cable could only be the length of the whole trailer but this could be enough. use a feeding mechanism to push it in. It could be anything that is abit flexible. and house it in a long tube along the trailer chassis.

eg. Many moons ago there was a toy that had a long plastic pull rack. this was so that when you pull it fast it would then spin a fly wheel. then the car would just zoom off.

hope that this might give you a good idea.

Becky