27 replies to this topic

[gatormark]

Having problems soldering pinions on the Hawk 7 motors. Have heard some others say the same thing.

Anybody else having problems?

[swodem]

Exactly what is the problem?
 
Spinning pinions?
 
Are you using acid flux?
 
Tinning the shaft first?
 
Applying some flux to the inside of the pinion before heating into place?

[Zippity]

Use a Dremel disk to apply some nicks to the shaft where you are going to solder the pinion.

[slotcarone]

No different than any other motor when it comes to soldering on the pinion!!  

[Racer36]

I have used the same process for years and have never spun a pinion on a Hawk or anything else.

I rough up the shaft a bit with a fine flat file, tin it well with a hot iron, and sweat the pinion on. Don't worry about solder in the teeth, just heat it back up and spin it out on the power supply.

Hot iron is the key.

[Dominator]

Run the motor at 3 volts and sand the shaft with 220 grit sandpaper.

[glueside]

I would say the issue is not with the Hawk 7, but with the way you are applying the pinion.

[Steve Deiters]

I do a couple of things.
 
Once you cut the shaft to the proper length run the motor on your power supply and touch the end of it with a cut disc that is running. I've found that the thickness of a cutoff disc is just about the right amount to remove. Chamfer the tip of the armature shaft to provide a transitional edge. If you have a sharp straightedge it can act as a wiper when the gear is soldered on.
 
Run the motor again and with an emery board or flat file; buff the armature shaft until it is no longer "bright" or has a satin finish. Wipe to remove any residual metal dust.
 
Heat shaft and flux several times. Heat, flux, and tin the shaft several times to make sure it is completely covered in the area you wish the pinion to rest.
 
Make sure there are no burrs on the pinion and the hole is open to a degree that it would slide freely on a shaft that hasn't been prepared.
 
Put a drop or two of oil on two or three of the teeth of the pinion and roll the gear in you fingers. This will coat all the teeth of the pinion to minimize the possibility of solder flowing into the teeth of the gears.
 
Put a drop of flux in the hole of the pinion in sufficient quantity to coat the interior.
 
Place the pinion on hot soldering iron with the tapered side down. Remember heat is your friend in this case. Once you hear the flux boil off, place the motor shaft in the pinion and slide it on the motor. There may be a lot of smoke at this point as you burn off the oil on the pinion, but that's OK.
 
Assuming you cut the shaft to the proper length once it cools, you are good to go.

[Phil Hackett]

What Steve said.

[Fast Freddie]

I do one thing that isn't mentioned here. 

I do all the above, rough up the shaft, tin the shaft, and put acid flux inside the pinion bore, but when the pinion is on I rotate the pinion on the shaft with the iron tip. I get no solder on the teeth because I coat the pinion with a very light coat of synthetic oil. When the pinion is where I want it I clean the teeth with a handheld wire brush just in case. 

I have been doing it this way since the early '90s and have never spun a pinion. 

I would also recommend that you trial-fit the pinion on the shaft just to make sure it slides on easy. I had a couple of pinions that were tight and had to be "cleaned out." I use a small round file for that.

[Phil Hackett]

I do one thing that isn't mentioned here. 

I do all the above, rough up the shaft, tin the shaft, and put acid flux inside the pinion bore, but when the pinion is on I rotate the pinion on the shaft with the iron tip. I get no solder on the teeth because I coat the pinion with a very light coat of synthetic oil. When the pinion is where I want it I clean the teeth with a handheld wire brush just in case. 

I have been doing it this way since the early '90s and have never spun a pinion. 

I would also recommend that you trial-fit the pinion on the shaft just to make sure it slides on easy. I had a couple of pinions that were tight and had to be "cleaned out." I use a small round file for that.

 

I used to do a slightly different process at the end: I wouldn't care if the pinion filled with solder. I'd connect the motor to a power supply (and set the PS so the motor would immediately spin), reheat the pinion and hit the PS switch. Never had to oil the pinion and it took less time to do than oiling and brushing AND none of the "masking" oil could possibly foul the soldering joint.

[MSwiss]

I agree.

 

Don't mess with oil, and spin it out with heat and centrifugal force.

[gotboostedvr6]

After the spin I gently hit the teeth with a soft brass wire wheel on the dremel.

[Pablo]

Having problems soldering pinions on the Hawk 7 motors. Have heard some others say the same thing.

Anybody else having problems?

 

The only problems I'm having now are solder balls all over my walls and carpet, but it's not just Hawk 7 motors, it's all of them.

The worst are the S16C motors, and all my racing buddies are having the same exact problems.

 

Maybe a bad batch of solder, bad pinions, a voltage issue with my house current, not sure. Which brass wire wheel should I be using? The soft beveled, or the tapered?

 

[Samiam]

Exactly what is the problem?

A bunch of good advice. But we still don't know what the specific problem is.
 
I recently witnessed a problem with a shaft being oversized on a Hawk Retro. With some sanding/filing it was resolved. Haven't ever run into this problem myself.

[Danny Zona]

When a problem FK motor comes up I just tin the arm shaft like normal. Then I press the pinion on with my trusty Hudy pinion press. Then heat the pinion/shaft up again.

I've been doing it for a few years now.

[swodem]

A bunch of good advice. But we still don't know what the specific problem is.
 
I recently witnessed a problem with a shaft being oversized on a Hawk Retro. With some sanding/filing it was resolved. Haven't ever run into this problem myself.

Really? Sure it wasn't pinion with a small hole?

Oversized arm shafts would then need oversized bushings...

[Pablo]

I recently witnessed a problem with a shaft being oversized on a Hawk Retro. With some sanding/filing it was resolved. Haven't ever run into this problem myself.

 

You "witnessed" a problem that was "resolved".

Question: how well did the oversize shaft ride in the bushings? Kinda tight, eh?

Yet, you've never "run into this problem".   Thank goodness this is only happening in Asia and New Zealand.

Just funnin' with ya Sam

 

I had a similar problem yesterday trying to sweat solder a G7 48 pitch pinion onto a Kemtron 1.3 mm shaft.

Had the AC turned off for 3 hours, still wouldn't heat up, I'm pretty sure bad solder is the culprit.

The funny thing is, the shaft was perfectly aligned. Maybe the bushings from Kemtron are all this way.

 

[Bill from NH]

When I solder on a pinion, which isn't too often these days, I use high temp silver solder from the '70s, Stay-Clean acid flux, and my old 50w Ungar iron. I've never spun a pinion when using this combination.

I remove these pinions with an ordinary gear puller, then scrape the solder off the shaft with an X-Acto knife.

[Brian Cochrane]

If you are using an ARP pinion you never want to get any solder in the teeth area because all ARP pinions are tumbled to a smooth finish so you can get the smoothest gear mesh.

If you have to remove solder with a wire brush or an abrasive, you are not going to get maximum gear mesh.

Also when and if you need to clean or debur the bore hole on a pinion, I use the small file that is used for filing the slot of a motor brush. I put the file in the gear hole and roll the gear across my finger. I

f you're having a problem with tinning the arm shaft it might be because you have oil on the shaft. Clean the shaft with lighter fluid before trying to tin it.

[airhead]

You are all wrong, The motor has to be aligned to the north using a compass on a full moon in the month of October before the pinion will solder properly.

[Steve Deiters]

Silver solder and only silver solder. Period.

[Pablo]

 You are all wrong, The motor has to be aligned to the north using a compass on a full moon in the month of October. before the pinion will solder properly.

 

Yeah, Billy, but what if the moon isn't visible, like during the day?

[Eddie Fleming]

A few weeks ago Taylor Davis started a thread about pinions soldering or Loctite. I have soldered pinions on for years with no problems, but I bought some 680 Loctite and have used it a little. So far so good.
 
I use it the same way I solder on a pinion. Cut the shaft to length. rough up, and then clean the shaft. Make sure the pinion will slide on the shaft freely.

I use a toothpick to put a little 680 on the rough part of the shaft and inside the pinion. Slide the pinion on in one motion and let it set. 
 
Solder is quicker but this has worked so far.

[Pablo]

Wonder what happened to the OP that "heard some others say the same thing"?