Search found 935 matches

by BigDumbDinosaur
Mon Jul 06, 2020 9:51 pm
Forum: General Discussion
Topic: Turning Hot Rolled Mild Steel
Replies: 3
Views: 68

Re: Turning Hot Rolled Mild Steel

Heating and quenching HRS will modify the metal's microstructure and make it denser, producing better machining properties. Carbon will precipitate to the surface as well, although the common HRS grades don't have enough carbon for heating and quenching to significantly alter the material's properti...
by BigDumbDinosaur
Mon Jul 06, 2020 9:43 pm
Forum: General Discussion
Topic: Mitutoyo mechanical digital micrometer mechanism stiff
Replies: 2
Views: 71

Re: Mitutoyo mechanical digital micrometer mechanism stiff

The only thing that has made a significant difference is to apply a drop of ATF and allow the detergents within to break down the hardened oil. You could probably clean the parts with sodium hydroxide (lye), but that offers a little risk of removing the paint in the engravings of the typical microm...
by BigDumbDinosaur
Fri Jul 03, 2020 11:08 pm
Forum: The Junk Drawer
Topic: Harold!
Replies: 30
Views: 644

Re: Harold!

Harold_V wrote:
Thu Jul 02, 2020 7:38 pm
Thanks, folks, for the good wishes.
Good to see you back. That had to be quite the experience...
by BigDumbDinosaur
Wed Jul 01, 2020 11:11 pm
Forum: The Junk Drawer
Topic: Harold!
Replies: 30
Views: 644

Re: Harold!

Very sorry to hear this. Let's hope the aftereffects are minimal and Harold is soon back "patrolling" Chaski.
by BigDumbDinosaur
Mon Jun 29, 2020 11:24 am
Forum: Welding
Topic: Old lincoln buzzbox quit
Replies: 8
Views: 390

Re: Old lincoln buzzbox quit

I bought this welder new about 30 years ago. I was welding, finished a bead and stopped to reposition the part. When I went to continue in was dead, no spark. The fan runs so I know I have power. I opened it up and everything looks good, no bad smells of burnt areas. I used an ohm meter and there a...
by BigDumbDinosaur
Sun Jun 28, 2020 8:19 pm
Forum: General Discussion
Topic: Change from 316 SS to 410 SS
Replies: 12
Views: 652

Re: Change from 316 SS to 410 SS

So would the saw coolant I mix up with an oil based mixture count as water based or oil based? What Glenn said. Water-based coolants are what they are called: coolants. They help mitigate heat buildup at the point where the cutting is going on. They do not have the lubricating properties of petrole...
by BigDumbDinosaur
Sun Jun 28, 2020 8:16 pm
Forum: General Discussion
Topic: Change from 316 SS to 410 SS
Replies: 12
Views: 652

Re: Change from 316 SS to 410 SS

GlennW wrote:
Sun Jun 28, 2020 3:31 pm
Water based.

I use Mobilmet 766 oil in my lathe flood system for stainless.
From where do you obtain the Mobilmet oil?
by BigDumbDinosaur
Sun Jun 28, 2020 12:42 am
Forum: General Discussion
Topic: Change from 316 SS to 410 SS
Replies: 12
Views: 652

Re: Change from 316 SS to 410 SS

I will try with the coolant on and off. Years ago when I was first learning how to do this stuff, I was taught that any steel alloyed with chromium should never be machined dry. I also learned from experience that water-based coolants are not as good as petroleum-based cutting oil when it comes to ...
by BigDumbDinosaur
Fri Jun 26, 2020 9:56 pm
Forum: General Discussion
Topic: Change from 316 SS to 410 SS
Replies: 12
Views: 652

Re: Change from 316 SS to 410 SS

Your customer would be so much better served to use 416 instead (assuming it meets the physical demands). I'll second what Harold said. I consider 410 to be the low rent form of the martensitic stainless alloys. The relatively low chromium content (typically around 11 percent—compare that to the 18...
by BigDumbDinosaur
Mon Jun 22, 2020 7:20 pm
Forum: Lathes
Topic: Little Machine Shop 5100 lathe - opinions?
Replies: 11
Views: 497

Re: Little Machine Shop 5100 lathe - opinions?

Does your friend work in inches or mm? That combined with whatever the machine really is would determine whether it is acceptable or not. On the plus side, it does have a quick-change tool post and appears to be in good shape. Lack of a quick-change gearbox would get annoying after a while, but it ...
by BigDumbDinosaur
Mon Jun 22, 2020 4:28 pm
Forum: Lathes
Topic: Little Machine Shop 5100 lathe - opinions?
Replies: 11
Views: 497

Re: Little Machine Shop 5100 lathe - opinions?

It says that the leadscrew is inch. Are the dials true inch? If you look at the dials, they say 0.001" 0.025mm It can't be both - one of those is wrong. 0.0250mm == 0.00098 inches. The correct ratio is 0.02540mm == 0.001 inches, which means the manufacturer must have fudged the conversion. The ques...
by BigDumbDinosaur
Sun Jun 21, 2020 7:03 pm
Forum: General Discussion
Topic: Mystery Metal
Replies: 15
Views: 1197

Re: Mystery Metal

Harold_V wrote:
Sun Jun 21, 2020 4:42 pm
Titanium is not fun to machine, in spite of the fact that it appears to machine well.
You need a shipyard-sized lathe to turn a 1" piece of titanium. :D