holding a reamer in a collet

I have to say that while a floating reamer holder would probably be best. I have reamed 10's of 1000's of holes in my 31 year career as a Tool & Moldmaker with no ill affect and 98% of them or more have been done with a Albrecht drill chuck.
I see no real reason to get carried away as a hobbiest buying and building a tool that most will gain no better results from. Some simple rules for reaming, to fast of spindle speed will generally result in a under sized hole, choking up on the reamer will generally result in the hole being oversized especially at the mouth of the hole and sometimes has chatter as it enters the hole, if your reamer is 6" long hold only the last 1/2"-3/4" of it and it will float right into the hole, use a similar method for shorter smaller reamers. If you want great results drill the hole within .010"-.012" of size and then bore the 1st 1/8" of depth to within say .005" and then follow it with a reamer, the hole will be straight, in location and on size. The above would be for say any hole over 1/4", adjust accordingly if smaller.

Remember most all reamers have a chamfer'd lead that helps find the drilled hole, once the lead has it the reamer will follow the drilled hole. Heck I would worry more about the crappy foreign made reamers than I would a drill chuck or collet. YMMV
 
Charley

Unless your doing work that you figure should require the floating reamer holder, I would just go without the expense of it.

Ive reamed plenty of holes over the yrs, and never seen a need to run out and buy one. And dont plan on doing so any time soon.

When it comes down to machining, there will allways be a tool that looks good, and usefull. The thing is how many times will you really need it. Im not saying they are not use full, but in a home/hobby shop, I would just make sure your alignment is as best as you can get it.

Im sure many of us have tools in our collection that were once thought of as a must have tool, that sits collecting dust most of the time.
 
Froneck said:
A reamer is back tapered and does not cut on it's sides. So are Drills and Taps!
Click to expand...

Frank, all of my reamers, (straight fluted, hand) are parallell. As are my drill bits and taps. In fact my pipe taps are forward tapered. Adjustable reamers are also parallell to the best of my knowledge.

Cheers Phil
 
Frank;

I have yet to see a tap that cuts anywhere but on the side. You don't have to get close to see the cutting edge of each thread is on the side. Your referal to someone that put up the link to Mr. Pete, the someone was me. I put it there to help and you decided to take a shot at it. Keep it clean please.

"Billy G" :whistle:
 
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Frank is correct however his choice of words may lend to some confusion.

The back taper he is referring to (I think :thinking:) is the relief, they do not cut on the sides only at the cutting edge.
 
Reamers are generally ground with a back taper of 0.002/0.004 on the diameter per inch of flute. This prevents dragging on the side, spoiling the finish, prevents oversizing the hole because of side cutting. The down side to it is that as the reamer is sharpened, the length is shortened, bringing the diameter down due to the back taper. Granted, it isn't much, but it is part of proper tool grinding. Consult any cutter grinder or reamer sharpening handbook.
 
Ken, I should have qualified my statement with some size references. Certainly, on smaller reamers.....say, 0.1250, less back taper would be seen. On larger reamers, it's not uncommon at all to see as much as 0.0050/inch. On holes reamed with those large reamers, you can see feedlines from the corners where the actual cutting takes place.

If a reamer were truly cylindrical, it would drag on the bore, resulting in poor finish and likely oversized cutting due to buildup on the edges.

I have measured my share of reamers, and sharpened my share. There are reamers with virtually no taper, but they do not perform well.

As an aside, I have a strong preference for LH spiral RH cut reamers.
 
I gotta ask, why the preferance to LH Spiral Tony?

"Billy G" :thinking:
 
LH spiral does not tend to "self-feed", so I have better control, and spiral in general yields a rounder hole. Especially on thinner work.
 
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