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.
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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!