Sheared screw of rear axle on Kirby Classic 1CR

[superocd]

I recently acquired a 1CR and had done my usual disassembly and cleaning. When reassembling the machine, one of the screws that holds the rear axle to the motor shell sheared off, almost flush with the hole. Common sense says to use an extractor but this is a real small screw and I've already checked, the smallest extractor still is almost as big as the diameter of this screw. Am I screwed (no pun intended)? I'm not sure if I feel comfortable drilling out the screw, being that aluminum is a pretty soft metal and it's entirely possible to make a wrong move and ruin the extrusion that the hole sits in.

Also, off topic ~ This is the very first time I've washed/submerged an armature and field. Always wiped down with a rag dampened with rubbing alcohol but this motor was filthy and smelly. Washed it in Tide liquid and hot water -- didn't scrub but rather swished it around after a soak for a few minutes. Rinsed well and fully dried of course. Bearings were going to be replaced anyway so I didn't care too much about them. Anyone else wash motors? This machine was FILLED with dust and dog hair, even inside the motor. Smelled like it too. Now even the field and armature look and smell new. Was I wrong to do this?

 

[huskyvacs]

RE: the motor

you never wash any motors that have cardboard or cotton/asbestos...whatever insulator material on the field coil, for obvious reasons, it will decay and expose the motor to a short. Also some chemicals can melt down the shellac coating on the windings which is also not good.

Fan collectors mostly agree on mineral spirits and gentle brushing. Must use non-chlorinated solvents.

Not sure how or what to use to rebuild the insulators on the windings. Friction tape maybe.

 

[rowdy141]

Is the tip of the screw visible on the inside of the housing? If so, pliers/Mole grips might grip the tip. It's a lot of work to dismantle it all again, but it may save you a lot of grief.

A very fine drill bit (sewing needle size) in a Dremel will work, with care. Be sure to limit the depth it can travel, so you don't go too deep and into the housing. You don't need to drill out the entire screw, just enough to get another tool in there.

Try cutting a slot into what's left of the screw. So a small, flat screwdriver will fit.

Try WD-40, Penetrating oil, or heating & cooling, to help free-up the bond between housing and screw.

Try watchmaker/clockmaker tool suppliers for an even smaller Screw-extractor? They must exist.

Can you spin your smallest screw-extractor in a drill, to file it thinner/narrower while still retaining a cutting edge?
You only need it to work once.

 

[kirbyklekter]

I had the same thing happen to my 1-cr classic about 20 years ago. Back then I didn't even know about extractors, so I took the chance and drilled it out, knowing I had a source for a replacement axle if I botched it up. I used a smaller bit on the drill because I didn't want to strip out the threads. Lucked out! The shank (?) of the old screw basically crumbled from the stress I put on it earlier while trying an impact screw driver.

Are you going to replace those bearings on the motor BEFORE running it? I was thinking that with the few minutes you had soaked the motor that the bearings might have taken on some liquid, and soapy liquid at that. If they did I would imagine that when up to speed they could send that liquid back out under pressure and mess up your clean motor plus as you know, water in the motor,not good.

I've not used Tide for cleaning motors but I wouldn't think it was too strong as to do any damage to the varnish coating on the windings,so that's good. Plus if you had any cleaning odors left after cleaning, I'd rather smell Tide than some chemical solvent! Good luck with the axle.

 

[superocd]

There isn't a way to access the screw from inside the motor shell, the hole doesn't go that deep to pass through into the shell. Even if there was, fitting my hand back there let alone a hand with a tool wouldn't work. I've tried some needlenose pliers to no avail, there is probably less than half a mm of screw beyond the surface. Doesn't look like I could easily get a Dremel in that recess. I might have to drill this out with a VERY steady hand, and redo the threads, and hope that the bit (titanium) is able to take out the screw and not wander. Part of me wants to take this to a machine shop but I'm not sure they'd even bother with something so trivial.

As for the motor, when I powered it on before taking the entire machine apart, it had obvious bearing noise, so I was going to replace them with the newer, sealed style anyway.

I was worried about the varnish on the windings dissolving, but a vac shop owner told me that he's washed dirty motors in Tide before, with a good rinse, and never had an issue. I've also heard of people running their motors through the dishwasher, that's something I'd never do because I'd never allow something so dirty in my machine unless I had a dishwasher in my garage strictly for that purpose. We'll see when I have the machine together, so fingers crossed. I think it will be fine. The motor looks so clean it could pass as brand new, compared to the motors I just surface-cleaned with alcohol and a rag.

 

[kirbyclassiciii]

superocd

You need part no. 102069 as your new rear axle shaft, and two 102269 screws (#6 x 5/8").

~Ben

 

[madman]

I look at it this way. If you sheared the screw by (over)tightening it, the screw is not stuck. It's just sitting there loosely. Some patience and gumption will get it out. Drilling is a last resort for this situation. You will only make it worse, or damage the hole. Just baby it out. I'd try poking it with a safety pin. If it's stubborn, try a VERY sharp pointed punch, and GENTLY tap it in a counterclockwise direction. Chances are good you can just unscrew it.

Unless, for example, you cross-threaded it, then drilling it out is the way to go.

Extractors suck. They're tapered. The very act of jamming it in the screw expands the screw and makes it even MORE stuck. Unless you had a significant amount of screw sticking out of the hole. But in that case, you wouldn't need an extractor! They're a moot point if you ask me.

 

[texaskirbyguy]

Just stumbled onto this thread...
Did you get the screw out?

If not, and there is still a small stub left, try diagonal cutters.
Crunch down on the cutters to where it starts cutting the screw, then turn while under pressure.
I have gotten many broke screws out this way.

If this is not so be a restored museum piece, you could drill a new hole in the axle and shell and use a different screw and maybe a nut also.

Let us know how the motor turns out - never heard of anyone washing one. I use dry brushes and then a damp cloth at the end. Takes a while but works well.