Author Topic: T-slot cutters  (Read 11912 times)

Offline steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12697
  • Central Massachusetts, USA
Re: T-slot cutters
« Reply #15 on: June 14, 2013, 10:24:06 AM »
I think everything is fine Ramon. :ThumbsUp:

Dave



PS

Back in the dim dark days when Adam played fullback for Jerusalem.........great line! :lolb:  gonna remember that one!
« Last Edit: June 14, 2013, 10:47:27 AM by steamer »
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline tel

  • Full Member
  • ****
  • Posts: 1657
  • Bathurst District, NSW, Oz.
Re: T-slot cutters
« Reply #16 on: June 14, 2013, 11:20:52 AM »
Quote
I think I may have said before - but personally I don't think theres a better satisfaction in our hobby than making a cutter and seeing it work effectively  :)

You got that right! Always a buzz!
The older I get, the better I was.
Lacerta es reptiles quisnam mos non exsisto accuso nusquam

Offline MuellerNick

  • Full Member
  • ****
  • Posts: 213
  • Germany // Outback of Munich
    • Motor-Manufaktur
Re: T-slot cutters
« Reply #17 on: June 14, 2013, 12:22:08 PM »
Quote
My nervousness has been to do with the spectre of catastrophic cutter failure in use. I've never had it before, should be OK.


You have never broken a cutter so far?!  :stickpoke:
One hour ago, I just broke a extra long 6 mm full carbide cutter. Not my first one!
The only catastrophic (at least extremely disgusting) would have been, if I wouldn't have had a spare. I'm milling a pattern (will take about 8 hours) and I want to cast it tomorrow. Otherwise, I would have had to wait 'till Monday to get a new one.


Nick

Offline jonesie

  • Full Member
  • ****
  • Posts: 127
Re: T-slot cutters
« Reply #18 on: June 14, 2013, 08:10:11 PM »
if after it is quenched oil or water and you check and a file will not cut, you know it is hard then draw it in a toaster oven at 400, got to relieve some stress, as stated in past posts this is not something for the space shuttle, some times just for a one of job, and if it works good maybe further jobs. jonesie

Offline ths

  • Full Member
  • ****
  • Posts: 1801
  • Kangaroo Valley, NSW, Australia
T-slot cutters
« Reply #19 on: June 14, 2013, 10:37:25 PM »




A couple of shots, the cutters being made, and the cutters awaiting deburring and heat treatment. I'll do what I know, harden and temper with water, maybe today. I'll keep you posted. Many thanks to all, and Ramon, thanks for another erudite treatise on another facet of this engaging pastime.

Cheers, Hugh.

Offline Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: T-slot cutters
« Reply #20 on: June 15, 2013, 01:18:24 AM »
Hugh, thanks for the shot of the VDH in use. Nice work on those T slot cutters.

Don

Offline Maryak

  • Rest In Peace
  • Full Member
  • *
  • Posts: 1818
  • Aldinga Beach South Australia
Re: T-slot cutters
« Reply #21 on: June 15, 2013, 03:55:36 AM »
Nice Cutters Hugh  :NotWorthy:

Attached is a copy of a doc I keep in my workshop folder for steel colours

Best Regards
Bob

Если вы у Тетушки были яйца, она была бы Дядюшкой

Offline ths

  • Full Member
  • ****
  • Posts: 1801
  • Kangaroo Valley, NSW, Australia
T-slot cutters
« Reply #22 on: June 15, 2013, 05:07:14 AM »
Bob, thanks for the chart, thanks to modern wonders I can keep it on the iPad for reference. Very handy indeed, but when it gets close, you've got to move quick!

Don, good to see them in action isn't it! I made the mandrel with the 3/4" bore, and subsequently bought an ER32 straight shank collet chuck to use in conjunction with it. The ML7 cross slide is too short to be able to use the 3 jaw chuck on many radial operations, this chuck makes things much more do-able, and more accurate. I am giving serious consideration to making another mandrel for the VDH, which would have an ER32 nose, foreshortening the overhang even further.

Cheers, Hugh.

Offline tel

  • Full Member
  • ****
  • Posts: 1657
  • Bathurst District, NSW, Oz.
Re: T-slot cutters
« Reply #23 on: June 15, 2013, 07:46:53 AM »
The cutters look good Hugh. but I was gonna mention earlier - an odd number of teeth seems to work a little better with 'em.
The older I get, the better I was.
Lacerta es reptiles quisnam mos non exsisto accuso nusquam

Offline steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12697
  • Central Massachusetts, USA
Re: T-slot cutters
« Reply #24 on: June 15, 2013, 09:58:56 AM »
Thanks for that Bob!   Jives with my recollections!....On the droid it will go!

Hugh....I really like the VDH......but Don likes getting me all fired up... 8)

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline ths

  • Full Member
  • ****
  • Posts: 1801
  • Kangaroo Valley, NSW, Australia
T-slot cutters
« Reply #25 on: June 15, 2013, 10:12:42 AM »
Dave, we should all like the VDH! It's a good thing, and if Don's got you fired up, then go and do it. It's not as though you've got anything else to do...

Tel, I know of the odd tooth count, but the VDH in the form I have only has a 24 hole count wheel, and 3 teeth seemed a little light. They got 8 each.

Cheers, Hugh.

Offline Don1966

  • Full Member
  • *****
  • Posts: 6817
  • Columbia, MS
Re: T-slot cutters
« Reply #26 on: June 15, 2013, 02:41:21 PM »
Hugh, I also bought the straight shank ER32 collet chuck for mind once complete. I am hoping this coming week to get back to finishing it.

Don

Offline arnoldb

  • Administrator
  • Full Member
  • *****
  • Posts: 1341
  • Windhoek, Namibia
Re: T-slot cutters
« Reply #27 on: June 15, 2013, 08:29:57 PM »
 :ThumbsUp: Good going Hugh

I've found that it's better not to de-burr home made cutters before hardening...  I tend to leave the burrs on, and once hardened, sharpen  .  If the burrs are removed, the cutting edges oxidize quite a bit in the process, and tend to end up blunt.

Once the cutter is hardened, I use a Dremel or diamond file to sharpen it; the burrs come of during the process, leaving nice and crisp cutting edges.  When using a grinding machine like the Dremel, you need to use it lightly and not let things heat up and discolour; if this happens, the hardness is lost instantly.

With silver steel cutters, heat is the enemy while cutting.  Use a low spindle speed while cutting; that prevents the cutting tips from heating up too much and softening.  Silver steel works quite well to cut cast iron; in fact, I was surprised at how well it works while making these gears; the cutter is still as sharp as when I started.

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline ths

  • Full Member
  • ****
  • Posts: 1801
  • Kangaroo Valley, NSW, Australia
T-slot cutters
« Reply #28 on: June 16, 2013, 11:41:02 AM »
Thanks for all the interest!

I did the hardening as I usually do, in the propane flame, and tempered in the kitchen oven (K was out at the time). This was a first, and Arnold, I didn't deburr. I put a piece of shiny mild steel in with the two cutters to better judge the colours, and had Bobs colour chart by my side. I let them soak for about half an hour after reaching temperature, then plunged into cold water. You can't really see the result in this photo (I didn't feel like photoshop), but the test piece corresponded well to my own and Bobs version of light straw.



So off to the lathe to see if they worked. This is the GHT rotary table, which I cast about 6 years ago, but haven't touched for a while, one of those things to get out of the way. Here is the cutter in action, followed by the finished product, although I may graduate the table in degrees.






Now the larger cutter has a different story, and as we have had a 16 year olds birthday in the family, I have no photos, so will tell you the rest tomorrow.

Offline MuellerNick

  • Full Member
  • ****
  • Posts: 213
  • Germany // Outback of Munich
    • Motor-Manufaktur
Re: T-slot cutters
« Reply #29 on: June 16, 2013, 01:13:19 PM »
Quote
I let them soak for about half an hour after reaching temperature, then plunged into cold water.


That soaking is good!
But plunging it into water after annealing is an absolutely useless step. At most, it helps to increase stress to the tool.
Let it cool down in the air. Or if you are in a hurry, cool it down with compressed air.


Nick

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal