sillyness

My Feedback: (25)

I need to remove some SWB servo arms from some 8611 servos. These are the older arms, not the double-loc arms. I've heard you can use a gear puller to get them off.

Where do I find a gear puller that would work? I don't even know what type of store to start looking in.

Thanks.

bigbri

My Feedback: (287)

I used a screwdriver....very little effort needed to remove arms
B-

Tired Old Man

My Feedback: (1)

Places that specialize in RC cars often carry gear pullers for their products. It may not hurt to try making something that's just the size you need for the job. Shouldn't be too hard, just perplexing.

sillyness

My Feedback: (25)

A screwdriver won't work on these... they are VERY tight... almost welded. I'd crack the case.

I'll look around at Sears and such... see what I can find. There's a place that has RC car stuff about 45 minutes from here... I'll give 'em a call.

xtreem3d

My Feedback: (1)

what about the gear puller they make for pulling gears off electric motors like the gws's.
steve

Futurase

My Feedback: (10)

Please keep us updated as I have some AirWild arms on JR 8411's and I don't care if the screws fell out in flight there is ZERO chance of the ams coming off. I had to use the screw that holds them on, to pull them on with. The splines lined up perfect, just you could only push them about half way down. They ain't ever slipping off though that is for sure. I hear of guys using loctite, silicone and all kinds of tricks to hold theirs on. No need for that on Airwild arms and JR 8411's[sm=stupid.gif]

I think a plasma cutter might get mine off.

Norman Ross Jr.

mvigod

I have some aluminum arms on some 8411's that a plasma cutter might not even work on! If anybody finds a good gear puller or something to solve this problem I'm buying it. I am subscribing to this thread to see what everyone comes up with.

sillyness

My Feedback: (25)

Wow... when I saw you posted on here I though I was getting yelled at for putting this in the wrong forum

Tired Old Man

My Feedback: (1)

[sm=lol.gif]LOL.

I'm interested in the cure for this dilemma as well. Let us know what you find.

Ken Bryant

My Feedback: (10)

An idea

1. the center screw needs to be installed. Do not tighten it just leave about 1/8" gap between it and the surface of the arm. This screw will get backed out as you make progress.
2. get a stiff peice of metal (small wrench, hard steel of some kind) This metal needs to be the same length at least as to where you can grip it on the side of the servo.
3. Optional; grind at the center of the above metal so it sits on the screw head without sliding.
4. Using 2 pairs of pliers squeeze the control arm and the metal rod/bar together. As the arm begins to move loosen the servo screw.

For single sided servo arms it's going to be tough but it can be done. Also might require the assistance of a freind
Same as above but use a screwdriver stuck under the rounded short end. With a little cordinated effort you and a friend will be successful.

Use a little WD 40 on the servo prior to attempting this, it should help.

This will work the same as a puller and allows for the use of local items around the house.

Hope this idea helps some one.

RCP57

My Feedback: (25)

A very tiny amount of anti-sieze applied with a q-tip to the servo arm and spline will prevent this from happening. Oil will do nothing in the long term to prevent seizing, it will just dry up.

mvigod

Where does one purchase anti-seize? never heard of it even.

also what if the horn is so tight you have to force it on in the first place?

Tired Old Man

My Feedback: (1)

You can get anti-sieze at any local auto parts store. If the horn is that tight, and they often are, the anti sieze compound should still help to prevent metal to metal bonding through corrosion since the metals are disimilar.

I never thought of using that stuff on servos, but that's the kind of situation it's designed for, so why not?

mstroh3961

My Feedback: (4)

You might give this a try. Place the servo in the freezer to shrink the metal parts, after an hour take them out and touch a clean soldering iron:no solder on the tip: to the side of the arm. the aluminum will expand and come loose of the still cold shaft. I have not used this method on servo arms yet, but it works like a charm on other items. If you have two irons that may work better.

bobknudsen

My Feedback: (4)

Hi Guys,

I have had this problem ever since I bought one of the original Hangar 9 330's and used their hardware kit with the gold servo arms on 8411 servos. Maybe somebody has a better way, but this does work. I always replace the servo screw with a 3 mm by 3/8's allyn screw, because they work better for sucking down the arms. To get them off I put in a 3 mm by 1/2 inch allyn bolt so I can use all the threads in the hole and still have the arm able to pop off. You can go to any discount tool store and buy the cheapest puller they make--it costs about $4. This gets to be kind of a juggling act, you will see if you try this. Put the two legs of the puller through a water-hose clamp and on each side of the servo arm while lining up the puller pin, tighten the water hose clamp so that it holds the puller arms against the sides of the servo arm on each side of the screw. Once you tighten up the hose clamp, if you have the puller pin lined up over the allyn bolt, it will pull the arms up easily.

Big Bob

Ken Bryant

My Feedback: (10)

After thinking about this over night I have to agree with mstroh3961. The freeze and heat method will probably work the best and be the least damaging. The advantage is that if there is any locktite that has been used the heat should take care of it too.
I think the metal gear on the servo is a different metal alloy and may not expand as much as the aluminum arm.

OK you guys with stuck servo arms start trying these ideas out and tell us which worked best.

sillyness

My Feedback: (25)

Geesh... freezing, soldering irons, and chemicals that may disolve gear lube on $100 servos... you guys are making me nervous!!!

Banker

My Feedback: (10)

Try this:

1) Put the servo arm in a vise such that the servo is free wheeling.
2) Put a 3MM x 8 in the servo
3) Put your 2.5MM allen head screw drive in it
4) Lightly tap in the screw drive unilt the arm backs off.
5) Works every time.

Cheers!

CAPtain232

My Feedback: (40)

I have been in the mechanical maintenance business all my life. As mentioned above, many times I have done the freeze and heat method with VERY GOOD RESULTS. I think the one problem here is the size of the parts we are dealing with. The small size may not allow the parts to expand and contract enough..... HOWEVER, I do think this would be the first thing to try.

If that alone does not work as well as you would like, I would use the freeze and heat method in conjunction with a small puller. As someone else mentioned, you would be best off to find a bolt that is long enough to be fully threaded into the servo and have enough room to pull the arm off.

DO NOT put a puller on it without something else threaded into the servo output shaft. You will most likely damage the threads making it hard to get the screw restarted.

If in the future you decide to use anti seize on the arms, BE VERY CAREFUL..... This is messy stuff. A little bit goes a very very long way.

mstroh3961

My Feedback: (4)

The object is to heat only the arm! aluminum will expand much faster the the output shaft.

Antique

My Feedback: (4)

Haven't tried it but there are really cheap battery cable pullers at Checker Auto..You might have to do a little grinding on the arms to make them smaller, the size is about right..Put a screw in the hole to keep from damaging the threads....

sillyness

My Feedback: (25)

Got my servo arms without damaging threads, splines, or servo arm. Didn't use chems or heat/cold.

Takes 2 people. It's similar to Ken Bryant's idea with a little modification.

1. Threaded a 3mm screw into the servo that almost bottemed out and left about 1/8" of free threads above the servo arm.
2. Took a pair of wire strippers and closed the biggest hole around the servo splines without actually gripping them... idea is just to get underneath the servo arm where it mates with the splines.
3. Placed a thin screw driver across the screw head and parallel with the wire strippers.
4. Had wife hold this assembly together.
5. Used 2 pairs of pliers and squeezed the screw driver and the wire strippers together.
6. Arm popped off with no damage to arm or splines.... worked great!!! The whole idea is that the strippers hold the servo arm still while you are pushing the screw (and servo) out of the arm.

Hope this works for others!

tail strike

My Feedback: (1)

Go to auto parts store get a puller for removing the cable from the battery terminal. May work


Re: When you do spins start high!

mglavin

My Feedback: (31)

These pullers should work, the secret is they need to be SMALL with the abiltiy to fit under the servo arm and between the servo case. I don't think there is anything available that will grab the arm itself, at least a half arm a double arm maybe.

http://www.walthers.com/exec/productinfo/230-220

http://www.internettrains.com/norshorlinpu.html