Need Advice: Die Grinder Bits

[ProTex]

My current die grinder is a Craftsman 1/4" pneumatic. I realize some of you might suggest I upgrade my die grinder before I buy accessories.
So be it.
Here is what I need to do. I need to remove a steering stem from a vintage Honda motorcycle and replace it with a newer Kawasaki stem. The s.o.p is to grind down the weld on the bottom of the stem and press it out; do the same to the donor stem and press it into the Honda clamp.
The stem and the clamps are made of steel. I need to buy some (I assume carbide bits) to grind away the welds so that I can press the stem out from each triple clamp.
I spent a couple hours this afternoon "grinding" away with the set of stones that came with my die grinder. There has to be a better way.
My question to you guys is can you suggest a type or source of the grinding bit(s) I need? I realize they will not be inexpensive, so no Harbor Freight/Northern Tool ****, please.
I'll attempt to post some pics of what I'm talking about. Perhaps pics can better explain than my typing.
Here is an unmolested steering stem:

Here is the area that needs grounded and pressed:

Here is what I accomplished this afternoon using the grinding stones that came with my d-g:

Obviously photography is NOT my strong suit.
Thanks for your replies/suggestions.
Jim

 

[slicktoptt]

I use carbide bits from eastwood for porting work and like them a lot...so much in fact, I own both the short and long kit that they offer. Could probably find some for a little less money if you looked but you probably only need a couple of bits not the entire kits.

Good luck

 

[A_Pmech]

Pro,

Do you have an electric angle grinder, in say, a 4 1/2" size. It's a 1-minute job with an angle grinder if it's just a "keep put" bead with minimal penetration.

I wouldn't use a die grinder except by last resort. They're a finishing tool originally designed for touching up and polishing die sets after heat treating. Die grinding points aren't very aggressive.

Hopefully, the weld doesn't penetrate too deeply into the base metal of the triple, otherwise it will have to be machined out.

Since you quoted SOP, I assume this is a previously documented modification for your motorcycle?

 

[jdcompman]

Like stated above, it looks like your easiest bet is to simply go at it with either an angle grinder or a cutoff wheel. with the cutoff wheel you can very accurately grind away the weld without cutting all the way through the stem. I think a die grinder with any type of bit is going to take FOREVER!!

 

[ProTex]

Only that it's been done before; just not by me.
It is quite common to replace steering stems with ones from modern bikes so that you can implement modern suspension components.

 

[ears]

I would use an angle grinder as well. If you need good die grinder bits go to a local welding supply they will have everything you need. Carbide burrs are much more agressive than the stones as well.

 

[alex71]

You have a point if you're talking about the OP's die grinder, but generally speaking I disagree. There are plenty of industrial die grinders out there that offer very high material removal rates with a carbide bur. At the same time, you have more control and less fatigue from a small, lightweight tool (compared to an angle grinder, especially an electric one).

Just about all products, .5 HP and over from Cooper, Sioux, Atlas-Copco, IR (industrial line), Chicago Pneumatic (industrial line), and TC Service, fall into that category. Conversely, just about anything else is a toy.

Pro,

Do you have an electric angle grinder, in say, a 4 1/2" size. It's a 1-minute job with an angle grinder if it's just a "keep put" bead with minimal penetration.

I wouldn't use a die grinder except by last resort. They're a finishing tool originally designed for touching up and polishing die sets after heat treating. Die grinding points aren't very aggressive.

Hopefully, the weld doesn't penetrate too deeply into the base metal of the triple, otherwise it will have to be machined out.

Since you quoted SOP, I assume this is a previously documented modification for your motorcycle?

 

[alex71]

Here's a nice set of carbide burs for a good price. Unless you use them constantly, or abuse them (don't let them bounce around inside a bore!) they will last you a good long time.

http://www.tools-plus.com/astro-pne...dium=feed&utm_source=froogle&utm_term=AST2181

 

[A_Pmech]

Pro:

Slick and Alex both make good points about the use of carbide burrs. I didn't mention them as I have no experience using them in your application, working though a weld bead. Especially a bead that probably contains parent metal from what is probably 4140 shafting and therefore prone to "hard spots" in the weld HAZ.

However, it is a good idea and worth a shot!

What bike are you upgrading? I assume the new forks are larger in diameter, thus the need for the triple mod?



Alex:

I was referring to the OP's mini, and the fact that they were originally used for tool and die finishing and touch-up. As you stated, there are far more capable die grinders out there than the prolific "minis". The big electrics are quite something, I'm told. I've never had a chance to use one. I should have mentioned that.

 

[alex71]

Now look what you made me do... post more pics of the straight grinder drawer in my toolbox. These are all pneumatic. I've used the electric ones and while powerful, they're too bulky. An industrial pneumatic grinder will have as much power (if you have the compressor to run it) and is much easier to handle.

The sioux in the second pic puts out 1.5 HP, and is the king (of what I have, anyway) of material removal, as long as you can get the body to fit. its on the bulky side for an air grinder. The dotco is much smaller and easier to handle and not far behind on power...

The atlas copco in the top left of the first pic puts out 1.2 HP, and is basically unstallable. if you lean on it too hard it will either destroy whatever material is next to the drum or destroy the drum itself. Nice slow 12K RPM grinder. Nice thing about these is the shaft has a suspension, so there is never any bounce, and no vibration.... Just have to hold on tight when you first press the trigger down so it doesn't jump out of your hand.

I could describe the pros and cons (not many here) of every one, but who wants to listen?

 

[Stick Figure]

I have the Matco 1HP model grinder, and w/ a decent carbide tip, it would be through that weld very quick. I would probably knock down what i could get to w/ the angle grinder though, it removes material quicker, but you can't get in quite as tight of an area.

Most of my bits have come from grainger, but i know the welding supply stores, as well as the tool trucks usually have a good variety. The other trick i have learned is to keep the bits lubricated in "tap magic" or a similar cutting oil for steel/stainless and in WD40 for aluminum.

 

[SpiderGearsMan]

powerhouse and atd have real long ones for cylinder head porting

 

[A_Pmech]

Now look what you made me do... post more pics of the straight grinder drawer in my toolbox.

Nice collection!

I could describe the pros and cons (not many here) of every one, but who wants to listen?

I'm all ears.

I have, or have used Sioux and Dotco aircraft tools such as rivet guns and squeezers, Kett's saws, routers, drills, shavers, countersinkers, etc. All top-of-the-line stuff! I've used some old IR and CP stuff as well, but none of the "new brand" stuff.

Are these Ebay finds, or do you have a better source?

 

[stock z/28]

Hi guys,

I have a bunch O f high dollar die grinders as well. I think I like the composite IRs the best, but I like electric die grinders a lot, it saves on my electric bill.

I prefer the large body Milwaukee's but I use a lot of the smaller Milwaukees as well.

Dewalts and the old B&D industrial are also great. I use the larger ones on a heavy duty speed control for port work.


As far as bits go I scrounge about all I can find cheap. Obviously it takes a quite different bur for aluminum as it would for steel.


For "cutting" wilds in two I generally prefer a small diameter, thin abrasive wheel.


Jeff