-
Scam Alert. Members are reminded to NOT send money to buy anything. Don't buy things remote and have it shipped - go get it yourself, pay in person, and take your equipment with you. Scammers have burned people on this forum. Urgency, secrecy, excuses, selling for friend, newish members, FUD, are RED FLAGS. A video conference call is not adequate assurance. Face to face interactions are required. Please report suspicions to the forum admins. Stay Safe - anyone can get scammed.
Clarkson Mk2 Tool and Cutter Grinder
- Thread starter thestelster
- Start date
That's how mine works. I have one that has a grinding / machinist vise on it, one with a drill press vise, and one regular plate. I don't use the one for the drill press. I should re-purpose it.
Hi Peter,
Norton 38A60KVBE 4" ALOX 60grit
Yeah, I was kinda surprised it came out so well.
Yes, that's exactly right.
Story of my life! Good looking results though.
I've taken to sparking out on it just like a SG and get that sort of finish. Several passes back and forth, no stoning necessary! I like doing various threading bits this way. Set up seems easier, put a square to the work and tool bit.
Last edited:
Yes, that's exactly what I did.
And I think I'm hoing to get a 2" sine vise. The 3" I used was rather awkward to position on the table.
I made the threaded section of the part with the new HSS 55° cutter I made. Used the 3-wire method to hit the pitch diameter, using this calculator:
www.cgtk.co.uk
But......
CGTK - Three-Wire Screw Measurement
But......
Attachments
.....it doesn't fit, WTF!! I remeasured and checked, well, sure enough, its not 3/16"-32BSF, it's actually 3BA.
BA (British Associaton) threads are an old thread standard for smaller screws.
en.m.wikipedia.org
3BA is 4.1mm x 0.73 in metric
or 0.161"-34.5 tpi and BA threads are 47.5°.
Well, fortunately for me, I have a BA tap and die set!!
Once I tuned the threaded section down to 0.162"; and 32tpi is very close to 34.5tpi, it had left enough material to make it proper. And it fits!!
I lucked out this time.
BA (British Associaton) threads are an old thread standard for smaller screws.
British Association screw threads - Wikipedia
3BA is 4.1mm x 0.73 in metric
or 0.161"-34.5 tpi and BA threads are 47.5°.
Well, fortunately for me, I have a BA tap and die set!!
Once I tuned the threaded section down to 0.162"; and 32tpi is very close to 34.5tpi, it had left enough material to make it proper. And it fits!!
I lucked out this time.
Attachments
I wanted to thread as close to the shoulder as possible, so I wasn't sure how wide to cut the relief, so I didn't bother 'til after. I set my carriage stop indicator so the zero (the point I had to disengage the half-nuts) had the tool about 0.010" before crashing into the shoulder. Of course I went slow and practiced a couple timesVery cool tap and die set! Luv it!
So what's with the flaky thread relief the first time around? I always thought you should cut the relief first............
Glad to see that you are human after all!
And my usual grooving inserts were too wide so I had to make a thinner one, 0.045", from hss.
And yes, to err is human. And I find I'm making more mistakes as I get older, but I'm getting better at fixing the mistakes!!
You know, I was about ready to start machining the rest of the part, which is going to take several hours, and then I have to harden it. And then I said to myself, "I hope this material is really 4140". I started to second guess myself. So I took a piece of the same material, turned a portion of it down to 1/4" diameter and heated it with a propane torch for 15 minutes, then quenched in ATF.
Cooled it off, and tested it. A file skates right across. Thank goodness.
Can you imagine spending all that time on a part, and then realizing its junk. And nothing to have been learned from it other than, mark your metal as soon as you get it.
Cooled it off, and tested it. A file skates right across. Thank goodness.
Can you imagine spending all that time on a part, and then realizing its junk. And nothing to have been learned from it other than, mark your metal as soon as you get it.
No imagination required, I DO IT all the time.
I have been saving kingpins from trucks with the intention of making some R8 tooling. I grabbed one the other night and started roughing out the 0.9495 end. Perfectly on size in all dimensions. When i got to the taper, i realized i grabbed the smaller dia pin off the bench, and it wasn't going to be large enough to work. Needed 1.25", only had 1.10". Doh!
