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Diamond in the rough?
- Thread starter DavidR8
- Start date
- Joined
- Oct 16, 2019
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- 6,576
Counting down the days till my lathe arrives! Arrival -six days!
- Joined
- Oct 11, 2016
- Messages
- 3,857
@SLK001 I only said it is harder to do in a QCTP. I use the 4-way for what it's good at, the QCTP a lot, and the Armstrong under the conditions noted above. Each using it's strengths.
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- Oct 16, 2019
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Well rats. I picked up the QCTP and it’s a piston style.
I wanted a wedge-style post. The picture and description were a bit vague so I took a chance.
Easy to return so no big deal.
Scouting for a wedge-style post now.
Sent from my iPhone using Tapatalk
I wanted a wedge-style post. The picture and description were a bit vague so I took a chance.
Easy to return so no big deal.
Scouting for a wedge-style post now.
Sent from my iPhone using Tapatalk
- Joined
- Jul 8, 2018
- Messages
- 880
Lantern toolposts also hold REAL BIG tools, the ones whose shank won't fit in the QCTP holders. My Logan came with a BXA, and I have used a lantern toolpost for CXA-sized knurling tools and parting tools. Both types of tool benefit from the extra rigidity, though whether it comes from the larger tool or the lantern I cannot say.
Machinist's Workshop from early this year (Vol 29, No 5) has an article Getting the Most out of your Lantern Toolpost that is really worth a read.
- Joined
- Aug 3, 2017
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- 2,437
Fwiw, I've had both and actually preferred the Piston tool post over wedge. My BXA on my Logan was a piston style. My new lathe has a CA which I bought a wedge type, and I find loading the tool holder much more finnicky. The wedge has enough play in it that it jams when loading the holder, but the Piston loads easy every time.
I have yet to notice any accuracy difference or advantage to the wedge style.
- Joined
- Oct 16, 2019
- Messages
- 6,576
That’s interesting. I did a bunch of research and it seemed the opinions tended toward the wedge style being more repeatable.
I have a wedge style on my mini lathe but obviously it seems minuscule loads as compared to an A, B or C size post.
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Just bought a BXA piston style for my lathe
Fixed income played a part but most of the comments quoted not much of a difference for hobby machinists
I suppose as most tools you can get a lemon
Being retired thought I have lots of time to shim tool height but It gets a little tedious
So far I love it going to order more holders
No matter which one you go with when you make the nut from the plate they supply make it
a T nut(some videos show just mill it to fit the slot)
I tapped 2 holes in compound to fit screws so it does'nt slide when adjusting
Only 3 more days then the Diamond in the rough arrives
Congrads on you purchase
Fixed income played a part but most of the comments quoted not much of a difference for hobby machinists
I suppose as most tools you can get a lemon
Being retired thought I have lots of time to shim tool height but It gets a little tedious
So far I love it going to order more holders
No matter which one you go with when you make the nut from the plate they supply make it
a T nut(some videos show just mill it to fit the slot)
I tapped 2 holes in compound to fit screws so it does'nt slide when adjusting
Only 3 more days then the Diamond in the rough arrives
Congrads on you purchase
- Joined
- Oct 11, 2016
- Messages
- 3,857
So I have a piston AXA, a piston style BXA (both offshore) and a wedge Aloris BXA (bought on a day of weakness) Here's the dope: My AXA repeats really well and holds firmly enough on a 12X37 lathe with a 1.5 HP motor. The BXA: not so much on my 14X40 with 3HP motor. It seems to really depend on the maker and your luck with offshore tool posts. The Aloris, of course is rock solid. I have no plans to buy a CXA for my 15X60 7.5HP lathe. I will be using its 4-way tool post. I'll make an adapter for my dinky #1 Armstrong to use on the 15" If I feel a moment of weaknss, I'll make a shoe for the Aloris BXA to use on the 15".
David: There should be no rush to buy a QCTP for your South Bend. Yes, they are more convenient, but my mentor used his SB 9A with only a lantern for 40 years and did very good work. He held to close tolerances and even turned large items on it. If you can't find 1/4" square HSS tools I can send you some, already sharpened.
Another point of view: The piston ones theoretically aren't as good as the wedge style. I think it matters more about the quality of manufacture of the tool post more. A poor wedge tool post will be sticky and won't repeat worth anything. A piston poorly fitted isn't as rigid, and will also have repeatability problems. That said, repeatability is overrated. You want rigid.
For those who violently object: All I'm saying that there is no rush. His lathe will work fine with what he has. Time enough to save for a nice QCTP post... A lot of good skill development can be done with his Armstrong.
David: There should be no rush to buy a QCTP for your South Bend. Yes, they are more convenient, but my mentor used his SB 9A with only a lantern for 40 years and did very good work. He held to close tolerances and even turned large items on it. If you can't find 1/4" square HSS tools I can send you some, already sharpened.
Another point of view: The piston ones theoretically aren't as good as the wedge style. I think it matters more about the quality of manufacture of the tool post more. A poor wedge tool post will be sticky and won't repeat worth anything. A piston poorly fitted isn't as rigid, and will also have repeatability problems. That said, repeatability is overrated. You want rigid.
For those who violently object: All I'm saying that there is no rush. His lathe will work fine with what he has. Time enough to save for a nice QCTP post... A lot of good skill development can be done with his Armstrong.