I hate reamers!

[orionstarman]

Trying to ream 3/16" dowel holes. Put a .187" reamer in a .187 ER25 collet holder. Checked it with an indicator. Over .01" run out. Give it a tap and check again. Still .01 run out but now it's on the other side. Tap and check, tap and check, over and over again. Finally I think I have just right and run the part...check the holes...over size. I know, I know I should have run a test piece. But, after fighting with this friggin reamer for over half an hour I just wanted to get it done. Now I have to do it over again. I hate reamers!

Why is it such a pain in the butt to get a reamer to run true. There has got to be a better/faster way. I mean this is the way it was done 25 and 50 years ago.

Has any body here used a floating reamer holder? Are they worth the money? What other tricks are there to get a reamer running true?

Thanks

[kwhizz]

Sounds like your collet assy has seen better days.......But.......To help yourself out........when you get a new reamer......take it and put it in a lathe or reversing drill press and run it backwards and using a medium fine India stone.....gently stone the transition area from the lead-in chamfer to the reamer diameter........what you are doing is lightly "Dulling" the actual part of the reamer that does the cutting..........now the reamer will not have a tendency to cut where it wants , but to follow the hole and "Actually" Ream rather than "Cut"...........

Ken

[Chuck Reamer]

That is why they make .001" under size reamers they even call them dowel pin reamers. I have a little trick that you can maybe use to solve your problems.

Take a ball bearing of something roundish and larger than your hole, place it over the hole and give it a whack with a hammer. This should peen the edges in a little bit and should hold your dowel pin no problem.

[Belding]

There is no way you should be getting that much runout in an ER collet. Where are you measuring this? If you are measuring this right where the shank of the reamer comes out of the collet, you have a bad collet holder or collet. Try an indicator on the internal taper of the collet holder. If you are measuring this further down on the reamer, it is justified. As long as the reamer is concentric with the machine spindle where it is mounted in it, you should get accurately sized holes.

zac

[HuFlungDung]

Clip the collet into the nut first. The collet should hang from the nut. Do not simply stick the collet into the taper and screw the nut on over top because the retention clip inside the nut is eccentric and will severely skew the collet.

[Mike Stevenson]

Is the reamer bent? Put it on a surface plate and roll it. You will immediately see if the shank is straight or not.

[Andre' B]

That is why I have a few good boring heads and a selection of bars.
When you only have one hole that needs to be the right size is not a time to be second guessing reamers.

I have never seen a reamed hole that was really round anyway.

[bugzpulverizer]

Hang out your reamer a little farther then you have it now. Drill a smaller diameter hole to ream. This will force reamer to follow hole. Also the stoning suggestion is a great one.

[Mike Stevenson]

orionstarman,

Are you reaming this hole into Aluminum?

[orionstarman]

Originally Posted by Mike Stevenson orionstarman, Are you reaming this hole into Aluminum?

A2 tool steel.

[orionstarman]

I don't know if our 3/16" collets are bad or not. I'll have to take time tomorrow to check them out. Like I have nothing else to do. I do know that one of the .1870" reamers was bent. A coworker said to me "bend it back", yeah right, in the scrap hopper it went. I feel enough pressure trying to get parts made and out the door with out having to fight with the tools I'm using.

[donnelson]

chuck your reamer in a spin fixture on the flutes and spin the shank true to the flutes