Measureing 5 flute reamers

[lmcollins]

I want to measure some 5 flute reamers. Somewhere on this forum there is supposed to be someone who makes a block (105 degrees) which enables you to do this.

A new special mic costs about $150.00. I was thinking the block would be much cheaper, since I have standard mics up to 5 inches. I've searched and cannot find the info.

HELP!

[scb]

FWIW rather than go thru all the convulsions to measure odd fluted reamers, I just ream a hole with it in a piece of material (usually CRS) then measure the hole with pin gages.

[Tokarev]

360/5*2=144
(180-144)/2=18
1/cos(18)=1.0515 - this is a coefficient for multiplication of the chord measured between 2 furthest cutting edges X.
X*1.0515=D - this is your reamer's diameter

[lmcollins]

Ok guys. I should have been more specific.

These are my throating reamers. When I chamber some calibers I throat separately. If I had a scrap barrel I'd use it and my plug gages. I admit I hadn't thought of that. I can make about a bore sized hole, and then use the plug gages.

As to the math: I'll have to think about that. I took trig about 64/65 i.e. 1964/65. I used to be able to use someone's mic's in an industril setting for a minute or two. The reamers ar older Clymers 5 degree throats, and who knows what over bore diamiter they used to make them. Everyone now tries for .001 over bullet diamiter. That's what I'd like to have to set up cast bullet rifles with a 3 degree included angle.

The reamers have a lefthand twist, and are righthand cut - so I don't know if the trig solution would workout correctly. I will have to investigate it.

I don't think they would re-grind them, and a new reamer would cost about $50.00 a piece.
Probably charge me that much to re-grind them - just setup cost.

I might have to send an email to Dave Manson.

[andremajic]

Dave Manson will sharpen other peoples reamers. He charges 60.00 bucks. Give him a call.

[Pepe Ray]

A P.M. for Imcollins follows.

[M-Tecs]

I believe you would need 108 degree v-blocks for this to work. The reamers having a left-hand twist a right-hand cut doesn’t affect the trig.

108 degree v-blocks aren’t cheap and that only gets you two points of a three point measurement. You could do I with a 108 degree v-block, a mic and a gage pin the size of the bore you intent to cut or you could order a v-anvil mic. http://www.mytoolstore.com/starrett/483.html for $555.49 or you could do as suggested and just drill a hole in a piece of scrape aluminum or steel to the pilot size of your throating reamer than ream and measure the bore size.

Its quick and simple and it is something I would recommend you do for every new reamer you purchase. Some reamers cut oversize or leave a poor surface finish. That’s not something I want to discover in a $300.00 barrel blank.

[Pepe Ray]

Ken has the "V" blocks for sale.

Send a P.M. to 45Nut

[Pepe Ray]

Whoops!!
I'm sorry, I think---

Is Ken still out on sick leave?
If so , PM to me please.
Pepe Ray

[lmcollins]

I understand that the spiral flutes wouldn't effect the trig, but it does make it harder to measure perpendicular to the axis of the reamer correctly.

Note: I want to work to the 001.

FYI: I called Manson this afternoon and ordered a new .264 throater. It will have their standard 1.5 degree angle, and runs .265 in freebore. I inquired about their .284 throaters, and the standard throater is .285 in freebore, and has a 2.5 degree angle.

I talked to "Clyde" at Manson's, and he went out into the shop and checked the prints that they "make to" to give me these figures. You should all take note of them.

Note: I will try to get the time tonight to checkout a test drilled-and-reamed hole in something. I have plug gages. I admit that hadn't occoured to me. "Duh" on me.

All of these ablution are inportant for those of us who want to do gunsmithing work for shooting cast bullets. Or just plain accuracy work.

Frankly: if someone just wants "cheap" do not bother me. It takes as long to do a good rebarrel job with a quality blank as it does an Adams and Bennet. YOU are more likely to get junk. I wouldn't bother to do it for myself. Why should I bother for you?

[Casting Timmy]

Could you put the reamer in your lathe and zero a dial indicator on the shaft you can measure and then use the dial indicator to measure the radius of each cutting portion of the reamer? Double your readings and take an average and you should have a good guess of the diameter.

[Red River Rick]

Could you put the reamer in your lathe and zero a dial indicator on the shaft you can measure and then use the dial indicator to measure the radius of each cutting portion of the reamer? Double your readings and take an average and you should have a good guess of the diameter.

That's the best one yet! :Bright idea:

Good for you Casting Timmy.

:drinks:
RRR