Search found 15 matches

by art.h
Wed Apr 20, 2016 6:36 pm
Forum: Gunsmithing
Topic: Question on how to make this extractor.
Replies: 23
Views: 9817

Re: Question on how to make this extractor.

Before the bend was created the part would be held in a fixture on a horizontal mill with a dedicated mandrel tool set up and then a vertical plunge cut made. If quantities were small maybe just a mandrel with a single cutter with the right dia. and several plunge cuts to various depths and location...
by art.h
Mon Nov 25, 2013 6:54 pm
Forum: General Discussion
Topic: Who uses a DRO, and who doesn't..?
Replies: 24
Views: 1850

Re: Who uses a DRO, and who doesn't..?

DRO's are most useful in multiple tool operations, they give you the ability to change tools with different lengths/locations by using indicated dimensions. A poorman's CNC concept keep a cheatsheet and an established (0,0,0) for one tool part after part can be made to the same settings. This still ...
by art.h
Wed Jun 12, 2013 8:39 pm
Forum: General Discussion
Topic: measureements for dowel holes...
Replies: 15
Views: 1794

Re: measureements for dowel holes...

Using two round dowels in two round holes is automatically creating reduntant location problems. Both items are trying to locate in X axis and Y axis and acting as two absolute zeros. This can be done but it will require extreme accuracy. Most mills are not capable of this accuracy, no matter what y...
by art.h
Mon Apr 01, 2013 1:02 pm
Forum: General Discussion
Topic: New machinist student - what to buy
Replies: 16
Views: 1636

Re: New machinist student - what to buy

I taught for awhile, I agree with the waiting for the books and first assignments. Try to get instructor/s total course outline. Most instruction workshops have limited numbers of the basic instruments and expendables to get you started. Where it becomes an advantage to start aquiring equipment is w...
by art.h
Sun Mar 17, 2013 2:07 pm
Forum: General Discussion
Topic: New Project
Replies: 16
Views: 1744

Re: New Project

Bushing sleve would do the job to get it round again but I would be concerned about the new load bearing capacity created. I've seen similar repairs fail because the new intregal dia. was unable to maintain the shear load...
by art.h
Thu Mar 14, 2013 6:52 pm
Forum: General Discussion
Topic: A little humor for the train builders
Replies: 5
Views: 849

Re: A little humor for the train builders

Not much point in turning all the drive wheels to an exact diameter...
by art.h
Fri Feb 22, 2013 1:01 pm
Forum: General Discussion
Topic: What the heck is this neat little tool
Replies: 3
Views: 1445

Re: What the heck is this neat little tool

Just a wild guess, a go no-go thread gauge idetified by a production no. that was scrapped out. Someone decided to use one end ground as a punch...
by art.h
Tue Feb 12, 2013 11:24 am
Forum: General Discussion
Topic: How to Use Boron Carbide Dressing Stick?
Replies: 10
Views: 1583

Re: How to Use Boron Carbide Dressing Stick?

They have their place in the shop, rough prophiles and truing; however the corners do round out and they become inefficient. They last forever this way but as said they don't create a sharp face on the wheel. Use soft jaws in a vice and a cold chisel and hammer to chip new edges on the stick, it wor...
by art.h
Wed Feb 06, 2013 11:23 am
Forum: General Discussion
Topic: How does oil get there
Replies: 13
Views: 1383

Re: How does oil get there

I think in a lathe operation, involving single point contact, there is little lubrication involved. It is the coolant heat dispersal function that is critical. The coolant mix is about improving the evaporation temperature ie. the heat transfer ability to maintain a cutting temperature not a bonding...
by art.h
Sun Feb 03, 2013 11:13 am
Forum: Milling Machines
Topic: Fat Parallels Useful?
Replies: 12
Views: 2343

Re: Fat Parallels Useful?

Just a usefull tip, steel banding mateial cut to length and shaped liike a recurve bow will hold thin paralles solidly against both vise faces, help keep chips from getting behind parallels. It acts like a spring and keeps everthing in place during part changes.
by art.h
Thu Jan 31, 2013 11:52 am
Forum: General Discussion
Topic: Source for measuring pins?
Replies: 8
Views: 975

Re: Source for measuring pins?

My suggestion, if you can find a set, Pee D gauge set. Pitch Dia pins 3 each of a series of pins + a table of numbers which allows you to machine and measure any thread to an actual proper pitch dia.. Each set of 3 is of an equal given dia., two pins and gauge blocks works for dovetails, art.h.
by art.h
Sun Jan 27, 2013 2:50 pm
Forum: General Discussion
Topic: A Diferent Collet stop
Replies: 8
Views: 694

Re: A Diferent Collet stop

Have used them, however they have one slight weakness. If the actual slots in the collet are not equal in length-- do not depend on perfect squarness of face off when doing short length parts like .050" x .750"Dia.. The draw of the collet can cause lack of squarness, longer lengths closer to the the...