Author Topic: Making indexable tooling  (Read 5069 times)

Offline Chuck in E. TN

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Making indexable tooling
« on: July 09, 2011, 07:48:30 AM »
I have decided to try making a couple of indexable tools for my current project. I want to make a 90° Countersink, and a 60° dovetail cutter. I will follow Bob Warfields’ write up on the dovetail cutter, and Chris Heapys’ write up on the countersink.

Bob’s Dovetail cutter http://www.cnccookbook.com/MTMillDovetail.htm

Chris’s countersink  http://www.astronomiainumbria.org/advanced_internet_files/meccanica/easyweb.easynet.co.uk/_chrish/csknotes.htm

I have been researching/studying insert info and have chosen TCMT inserts for both.
What I can’t find is the screw size information for holding the insert on the tool.
Where do you find this info? Do I have to buy the insert and determine the screw from that, or is there a chart or reference for insert mounting screws?
Any other input?  Examples of tools you’ve made?
I have a bit of O1 ½” drill rod (silver steel) to work with, or would regular steel shafting work?

Chuck in E. TN
Chuck in E. TN
Famous TN last words: "Hey ya'll, watch this..."
MicroMark 7x14, HF X2 mill, Green 4x6 saw. Harbor Freight 170A mig

Offline Lew_Merrick_PE

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Re: Making indexable tooling
« Reply #1 on: July 09, 2011, 11:13:35 AM »
Chuck,

Just saying "TCMT insert" does not tell the whole story -- we need a size.  The Enco, MSC, or other major industrial supply catalog will have a table of insert values that will list some of the clamp screw sizes for various inserts.  I find it easier to look up a holder for the insert as they will have a "replacement clamp screw" reference that should tell you what you need to know.  The thing to remember is that most of the "new" (call it post-1990) inserts are based on metric screws which means that the countersink angle is 90° rather than 82° and that getting this right is critical to proper operation.  (You really do not want to know how I "learned" this.)  Be sure to buy the strongest grade of screw you can as these puppies take a lot of load.

Offline DaveH

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Re: Making indexable tooling
« Reply #2 on: July 09, 2011, 12:08:24 PM »
Chuck,

Iscar in thier Ecat gives screw sizes.
Such as this:
http://www.iscar.com/Ecat/item.asp/app/86/mapp/IS/fnum/961/GFSTYP/M/tool/T/cat/3601812/lang/EN

Might help.

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)