Hello all,

I recently purchased a Tamiya Leopard 2 1:16 and the build went smoothly for it, however when I use the elevation/depression function for the main gun the servo seems to 'twitch' or 'stutter' which causes the whole barrel to do the same thing. As you can imagine it doesn't look very good so I've investigated it as being a faulty servo. Is it worth me buying a new servo, if so, which is a decent replacement to get?
Another point being again with the elev/depress function is that I never seem to have the depression function no matter how many times I set up the dmd unit with the control sticks.

These two problems are really starting to bug me now as the rest of the model is perfect so far.

I appreciate any input you guys have, cheers!

P.S I'm using this radio kit plus the tamiya servo you get with the kit for the main gun.

http://www.modelsport.co.uk/?CallFun...on&ItemID=1968

A twitchy servo can be caused by a dirty contol pot in the servo. The output shaft is connected directly to the pot, this pot tells the control chip in the servo where it is in relation to where the servo arm is pointing. You might want to thake the sevo aprt and open the little tabs that hold the wiper plate to the back of the pot and clean it with some tuner/control cleaner. sometime just a drop of wd40 on the surface will clean it.

OK thanks for your suggestion I'll give it a go. I'll post back later on with the results.

Well I cleaned it out and it's still twitching really bad. I also forgot to add that the main gun will only elevate and depress back i.e it wont fully depress properly.

Dodgy servo or radio gear?

servo most likely. had this happen a few times in rc planes. might be a good idea to see if all the wires going into the servo plug are pushed in tight. also maybe faulty wires.

I checked over the servo wires and none of them are frayed or damaged. Would it be worth just buying a replacement servo?

yep last time i scored a futaba at the hobby store for like 12 bucks, or maybe it was a hobbico. cant remember.

I have Tamiya tanks, but not the Leo. Does it use an actual servo, or the Tamiya Gun Elevation Unit? The Tamiya unit has a clutch like the Turret Rotation Unit, and if it starts slipping, you get that infamous "rubber chicken" effect, or the gun may not move at all.

The elevation gearbox is basically a servo connected with an arm which has a ball cup connector on it moving the barrel up and down but the servo seems to weak for the mechanism as it glitches and seems unable to depress properly. Anyone willing to take a picture of there Leopard turret to make sure I havn't assembled mine incorrectly?

Thanks for the help so far.

If you have another servo plug it in to where the twitchy servo is and see if it twitches will tell you if it's the servo or other

It could be the receiver, crystal, or antenna routing.

Richard:

If it was in the receiver, crystal or antenna, wouldn't the jitter be apparent in all the servos/functions? Thats been my experience. I'd try swapping the servo first (if you can get a similar size loaner)

willo123:

Have you checked to make sure to see if its not linked to another function , as in testing it with the other items disconnected? If it disappears then, plug them back in one at a time, and when it re-appears, you may have found your source thats causing the jitter (perhaops capacitors on one of the various motors are bad?)

Also, have to checked to make sure the function isn't binding, perhaps by running it with the turret lid off?

Well I tried a different servo and the twitching stops. The main barrel now elevates and depresses but not all the way. Also the back deck clearence feature does not work either.. Any ideas anyone? Could it be a faulty DMD?

Well...

If the glitches stopped on the servo, try placing that servo in something else, and see if it glitches in that model. I've found some units just don't like certain installations.

Re: the elevation limits - perhaps your servo arm does not have enough throw, or something is binding. As I said before, watch it operate with the top off. Also look inside the turret top to see if there are any scrapes on it. This would indicate something hitting the roof, and causing the limiting.

As for the clearance issue, did you re-calibrate the DMD/MF after the swap? Trim's zero'd? Everything tickety-boo?

I don't have a Leo 2A6, so I can't suggest more...