Tandem Tom

I bought, at McMaster Carr, the above sander. The idea is an arbor and a sanding cone the I guess should fit on the tapered section of the arbor. But for the life of me I cannot get it to go very far down the tapered section.
Has anyone had experience with these?

Andrew R Stewart 

I'll bet after Brodie's vids the cone sanding industry has seen a massive increase of sales". Andy

Iride01 

I've always thought that cones and races were hardened in such a way that the surface is harder than what underneath. So you are removing the the hard surface and exposing the softer.

Sounds like a lot of trouble to go to for the price of whatever it is you are trying to extend the life of.

Andrew R Stewart 

I believe that Tom is referring to a die grinder (think of a Dremel on steroids) bit. The arbor is a reuseable shaft that mounts in the grinder's jaws and has an arbor that the replaceable sanding cone is pressed onto. With the tapering shape of the sanding cone one can get into tight spaces and vary the fillet shapes more easily than with a cylinder shaped sanding bit. Andy

N2deep

Maybe, just maybe, a few pictures and a clear description of the tools and what your trying to accomplish would help us help you.

Iride01 

Oh, you appear to be correct.

I had to go back and read it three or four times to completely remove the idea that cones, as in cones for an axle weren't involved here.

Toward that end then is the OP certain the arbor size is the same for both. I'm not quite understanding the tapered arbor. Unless the grinding tool was made for a tapered chuck. Which would be rare to non-existent for anything hand-held from my little experience.

Andrew R Stewart 

Sorry about the poor image but I think you can see the LH and tapered arbor threading, the sanding cone has an entry hole (sort of) that one has to feel for as they wind the cone onto the arbor.

The die grinder has been one of the better tool purchases I've made over the years. I'm on my third and use it frequently. Grinding out lug, steerer and shell sockets is MUCH faster than with my Dremel. The old and second one I have stays at the bike shop with a fiber cut off disk mounted. That makes for pretty fast U lock cutting Andy (who has yet to lose their lock keys...)

Iride01 

Oh again!

I've actually used those before. I didn't even think of them. I never really cared for those type of sanding cones. I went through them like I was munching on a bag of cheese puffs. <grin>

If that is what the OP has, then if it fits on enough to not wobble when the grinder or what ever is turned on and gets to 18,000 to 20,000 rpm then all should be good. The forces of using it will seat it further on the arbor. I think the spiral twist of the arbors were longer so different size cones and other type shapes could be used.

Wear safety glasses or goggles.

jccaclimber

This is one worth giving a +1 to. A Dremel tool is the box store bicycle equivalent to a proper die grinder. Mind you they serve a purpose, and I happily have one, but it’s definitely the light version of the tool family.
Then again I call the 3 hp mill in my garage “small”.

Tandem Tom

I will post a pic tomorrow. I don't want to trudge through the snow to the barn!

Andrew R Stewart 

I use to have a lathe of the Dremel grade, an Atlas 6', the diecast Al bodied newer version. Gad it flexed a lot. Now I have a South Bend 9" which is like an almost industrial grade tool. Much like my Samson 8x30 knee lathe (in the Grizzley G0678 "family tree"). Both are serious tools but I can move them with just one friend Andy

WizardOfBoz

Bearing race grinding and polishing is done on really precise, very rigid machines. Especially for the higher tolerance classes. One can probably smooth out some rust or corrosion to improve a bad bearing, but don't think that doing so will take your corroded bearing back to grade 10 or 25. If your cup is not totally knackered, clean it up gently (If I was using a die grinder I'd probably use a brass brush) wipe out any remaining rust and dust, regrease and use new balls and cones. Won't be super, but will probably be pretty rideable and will last a bit. I did this with my Schwinn Superior - fingers crossed.

Also, there seems to be some confusion about through-hardened or case-hardened bearing races. Steel that has low carbon cannot be heat-treated to be as hard as higher carbon steels. Heat-treated high carbon steels are brittle. Tempering hardened high-carbon steel lessens its brittle nature, but also lowers the hardness a bit. One can use a lower carbon steel (more ductile, less likely to crack) steel and treat it in some way to increase it's carbon content at the surface. Then when you heat-treat the part, the surface is hard but the core is tough and you have the best of both worlds. You can also harden a case by heating it very quickly and then quenching it to just harden the surface. This avoids making the core brittle. Files are made this way (using induction heating).

Chrome bearing steels are alloys that combine very good wear properties with some toughness. They are through-hardened (at least in the sizes that bicycle bearings are made in). Most higher end bicycle bearings are, I think, chrome bearing steel. This would give you a little bet better corrosion resistance. But the point is, you probably could polish a lighly corroded bearing race to reduce that crunchy feeling, and give lower friction for a while, by polishing.

I guess one can grind bearings with a die grinder, but in all but the most desperate vintage cases - just buy a new bearing! I realize that for a PX-10, that's easier said than done, though.

BTW, back in the day my dad was VP of Sales and Marketing for DuMore, a company that made die grinders and flex shaft tools. They are useful, but having grown up in a machine-shop environment where the products had to run well and last a long time, taking a die grinder to a bearing race... ughhh. It sends shivers up my spine.

Iride01 

Just to be clear, you sort of made the assumption I did that the OP was talking about something to use on the cones of their hubs.

However we have no idea currently what the OP intends to do with this and only assume it is for their bicycle since this is a bicycle forum.

If you are just addressing my reply about cones and hardness, then thanks for the info.

WizardOfBoz

Mostly me just blathering on self-indulgently, sorry. I was trying to point out that, since most bike bearings are chrome bearinng steel, they will be through-hardened so the concern over the lost of the hard case is not operative.

Tandem Tom

OP here. The potential use is for sanding fillet brazing not sanding wheel cones.
Here are a few pics of the pieces I bought. As you can see the sanding cone will not seat any further on the arbor.
Thoughts??

Andrew R Stewart 

Tom- The amount that the cone is onto the arbor looks nearly the same as with mine. Are there issues during use?

I think I mis spoke when I said the arbor has LH threads. Andy

Tandem Tom

I'm getting severe vibration. I was using it on a HF dremel .

jccaclimber

How fast are you spinning? Those aren’t meant to be used at in the upper half of the speed range on at least name brand Dremel tools.
A lighter tool is going to have a harder time keeping vibration down as well.

Tandem Tom

I was running it at the lowest speed.

WizardOfBoz

Did the sanding roll come with the arbor? Gesswein has arbors and sanding rolls in several different sizes. Could the roll be smaller than intended for that arbor?

https://www.gesswein.com/p-3524-abra...dge-rolls.aspx

Tandem Tom

I may have solved the problem. I took the chuck apart and put it back together. Seems tp work!