Search found 210 matches

by choprboy
Tue Jun 11, 2019 4:01 pm
Forum: General Discussion
Topic: Worn pulleys/ additive metal
Replies: 10
Views: 339

Re: Worn pulleys/ additive metal

You mean plasma spray/metal spray? Using a plasma or acetylene torch to blow fine metal particles onto the part, which melt in the stream and then adhere to the part surface. Used for buildup of shafts/etc. https://youtu.be/X43SJakLTA8?t=1263 Having had to repeatedly place pulleys that continually g...
by choprboy
Sun Jun 09, 2019 3:14 pm
Forum: General Discussion
Topic: Large motors and soft start
Replies: 30
Views: 827

Re: Large motors and soft start

Harold, I agree with the others, a star-delta (or wye-delta) starter would seem to fit the bill. The star connection reduces the effective voltage across each motor winding by ~40%, which reduces the starting current by ~66%. Do you know the actual fuse installed in the service? Thermal fuse blow ch...
by choprboy
Sat May 04, 2019 12:08 pm
Forum: General Discussion
Topic: UP Bigboy 4014 first steam and whistle
Replies: 5
Views: 575

Re: UP Bigboy 4014 first steam and whistle

A longer video with 4014 first trip in the yard and out to CO.
https://www.youtube.com/watch?v=RR7Q27cIEvo
by choprboy
Mon Apr 22, 2019 12:18 am
Forum: General Discussion
Topic: Mounting an INVERTER
Replies: 12
Views: 1802

Re: Mounting an INVERTER

Can an inverter be mounted directly to a motor? On something like a Rockwell vertical mill, where you might have a drum switch mounted directly to the motor junction box. Could an inverter be mounted on the same position? On the motor.. no, there isn't much structure to mount to. On the machine bod...
by choprboy
Fri Apr 12, 2019 3:12 pm
Forum: General Discussion
Topic: Small Diameter Slitting Saw
Replies: 13
Views: 1996

Re: Small Diameter Slitting Saw

MSC has some 3/4"x0.040", but they are pricy. McMaster has some 3/4"x3/64" (0.047") as well. Micromark has some for Dremels/ertc that are 3/4"x0.15". I would have thought LittleMachineShop would have some, but they only seems to have a handful of larger sizes now... 1/2"D is pretty small. I may have...
by choprboy
Thu Apr 04, 2019 11:00 pm
Forum: Milling Machines
Topic: Rockwell Vertical Mill 21-100
Replies: 8
Views: 1131

Re: Rockwell Vertical Mill 21-100

Yes... After a few years of using mine, I find one of the biggest drawbacks to the 21-100 is the lack of a lower speed range. I find I never go more than 2400 rpm, but even the lowest 370 rpm is frightful when trying to do a large fly cut or bore a 4" hole.
by choprboy
Thu Apr 04, 2019 10:54 pm
Forum: Milling Machines
Topic: Rockwell Vertical Mill 21-100
Replies: 8
Views: 1131

Re: Rockwell Vertical Mill 21-100

I don't know if they are taller, but yes apparently there are two versions, one with a flanged column and one with a flared column. I *think* the flanged where the earliest, production ran thru a couple versions of the Delta/Rockwell company from the late 50's to early 80s, but I don't really know m...
by choprboy
Wed Apr 03, 2019 9:44 pm
Forum: Milling Machines
Topic: Rockwell Vertical Mill 21-100
Replies: 8
Views: 1131

Re: Rockwell Vertical Mill 21-100

Are you sure it is not DO-6372 (Dee-Ohh)? Delta/Rockwell serial number format apparently varied by manufacturing plant. a DO prefix would seem to indicate a 1967 Tupelo. Do you have the original motor on the mill? It may give you some additional information. See: http://wiki.vintagemachinery.org/Del...
by choprboy
Sat Mar 09, 2019 4:56 pm
Forum: General Discussion
Topic: Spinning bearings with air
Replies: 11
Views: 1109

Re: Spinning bearings with air

The street wisdom is "never spin bearing with compressed air" Why? I would guess that the reason is that you are blowing contamination into, and oil/grease out of, the bearing race, thereby shorting the life of a new bearing about to be installed. But yeah, cleaning an old gritty bearing I don't th...
by choprboy
Sun Mar 03, 2019 4:27 pm
Forum: Welding
Topic: welding unistrut
Replies: 4
Views: 958

Re: welding unistrut

I've welded a bunch of unistrut for various frames (microwave radio/tower/building brackets/cable trays/etc.). The zinc and yellow can be welded directly, but even with grinding it is not a pretty weld (unless you grind way back), do to zinc contamination. The yellow is zinc-chromate, so its pretty ...
by choprboy
Thu Feb 21, 2019 10:43 pm
Forum: General Discussion
Topic: Mysterious "1/2 Axis" Displayed on DRO
Replies: 13
Views: 2390

Re: Mysterious "1/2 Axis" Displayed on DRO

Well... the above link is dead as the site changed its layout... but if you had gone to the site and click Support->Manuals->Accessories you would find it:
http://www.atrump.com/support/92-suppor ... nload.html

Or... search "Griffin GF800 dro" on Google and it is now the first link.
by choprboy
Mon Jan 21, 2019 10:42 pm
Forum: Milling Machines
Topic: What is this CAT40 tool?
Replies: 13
Views: 2736

Re: What is this CAT40 tool?

Basing on what I have plans to make out of a morse taper stub... someone's custom spade drill bit holder? The screws being the alignment pins and the large hole for a set screw to lock it in place?