- Joined
- Feb 1, 2015
- Messages
- 10,093
A 5/16-18 bolt will thread about 1-1/2 turns into an M8 1.25mm nut. An M8 1.25mm bolt will thread about 1 turn into a 5/16-18 nut.
-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Thread issue with QCTP adapter on 10x22 lathe?
- Thread starter Frank O
- Start date
That sounds consistent with what I saw using the bolt/nut ends of the 5/16-18 thread-checker with the Grizz post, Grizz handle and LMS hollow bolt.
Well, that's really interesting. I don't know how close the G0602 is to the G0516/Sieg C6, but they appear to be roughly similar.
The QCTP that I bought from LMS sometime back, but didn't around to mounting right away, was this one:
https://littlemachineshop.com/products/product_view.php?ProductID=2280
At the time, LMS said I'd either have to modify the tool post sled (topmost part of the compound) on my G0516, or use this replacement sled:
https://littlemachineshop.com/products/product_view.php?ProductID=3787
Dewbane, when you put the Aloris QCTP on your G0602, did the Aloris mounting stud fit right into your stock Grizz sled? I'm not clear on what issues caused LMS to tell me I couldn't put their AXA QCTP on my stock Grizz sled, but instead I'd have to buy a replacement sled. (The other option, the hollow bolt, didn't come along until later.) I'm just wondering if buying an Aloris mounting stud to use with my Grizz sled and LMS QCTP would be a solution for my situation.
- Joined
- Feb 1, 2015
- Messages
- 10,093
Ok, looking at the manual, you don't have a slot for a tee nut. You would either need to use the adapter or drill and tap the compound for the AXA stud. If it were my lathe, I would opt for the second, assuming there is enough meat in the compound and with the understanding the I will have modified my lathe.
Yes, I can see from the G0602 manual that it has a tee nut that the tool post screws onto. This isn't on the G0516.
If I were going to drill/tap the compound for the AXA stud, I'd have to look at the compound's thickness to see if it seems meaty enough. As for modifying the lathe, usually when making changes to equipment I try to keep it to stuff I can undo. Though to be honest I can't really say why, because I never undo anything and virtually never sell gear.
If I went with the replacement sled (this replaces what the Grizz manual calls the "cutter rest carriage"), I'd have to (in order of complexity):
1) Transfer over a gib adjusted by three screws on the front face of the compound. Probably easy.
2) Transfer a ball oil port from the Grizz compound to the replacement sled. Have no idea what's involved with this. Is it a press fit, and can you release it by pushing with something like a small screwdriver from the inside?
3) Figure out what looks like a beefy shim of some kind on the end of the keystone channel
3) Drill/tap two holes for the hold-down screws for the compound's feed screw. Doable, but since virtually all my work so far has been with aluminum, nontrivial.
- Joined
- Feb 1, 2015
- Messages
- 10,093
The reason that I would drill and tap is that the M8 stud is pretty light. Even if it didn't break or strip, it will stretch under load and cause lack of rigidity.
It sounds like your replacement sled is nowhere near plug and play. The ball oilers can be driven out from the back side. I moved one and repaired another on my 602. I would just buy replacements from Grizzly. Since you will be making new holes for them, you can buy them from McMaster Carr as well.
It sounds like your replacement sled is nowhere near plug and play. The ball oilers can be driven out from the back side. I moved one and repaired another on my 602. I would just buy replacements from Grizzly. Since you will be making new holes for them, you can buy them from McMaster Carr as well.
- Joined
- Apr 27, 2016
- Messages
- 57
If you can't find a solution with your present stud to work with that adapter stud then suggest doing what RJSakowski suggested. I've done the same thing and was admittedly nervous altering it but it worked out well and I should have done it sooner. You'll never really have a need to revert back to the old set-up.
Looking at pics of your compound rest on that model, it appears you'll have plenty of thickness/meat to thread into and be solid. While this is not the best video to recommend, its at least an example of someone doing the exact same thing you would need to do and will give you a better idea what it entails, it doesn't look difficult at all. Just need to make a flat surface, drill a perpendicular hole and thread.
- Joined
- Mar 2, 2018
- Messages
- 232
I understand your fear of making irreversible mods to your machine, but if you turn out like me, it won't be the last time. I've added more hold down studs to my compound, compound gib locks, and something else that escapes me at the moment. Drilling and tapping an expensive machine is a scary proposition, but if you take your time and be careful, well, I did it, and if you're the kind of person who even shelled out the cash for a lathe in the first place, I think you can handle it too. The nice thing about Grizzly stuff is they carry a lot of parts for a long time. Worst case, you screw it up and shell out for some parts.
Speaking of which, I will just throw out a random warning. It's really easy to find yourself focusing on the work instead of the markings on the tailstock on a g0602. I was drilling the center hole for a series of bushings I was turning, and I got greedy and tried to go deep enough to bore out one more. I unscrewed the tailstock spindle, and the Jacobs chuck started spinning violently. It wrecked the threads on both parts, which proved beyond my skill to fix. I ordered new parts, waited what felt like forever, and when I finally got it put back together and got back to work on the project, I immediately did it all again! Argh! I haven't worked out a good way to address that design flaw yet, but it's on the list of planned future mods.
Speaking of which, I will just throw out a random warning. It's really easy to find yourself focusing on the work instead of the markings on the tailstock on a g0602. I was drilling the center hole for a series of bushings I was turning, and I got greedy and tried to go deep enough to bore out one more. I unscrewed the tailstock spindle, and the Jacobs chuck started spinning violently. It wrecked the threads on both parts, which proved beyond my skill to fix. I ordered new parts, waited what felt like forever, and when I finally got it put back together and got back to work on the project, I immediately did it all again! Argh! I haven't worked out a good way to address that design flaw yet, but it's on the list of planned future mods.
Thanks! That indeed is pretty much my exact situation. The only thing I wish is that he said and/or showed more about how he made the cut to flatten the piece, and also drilling out the hole (particularly how he got it lined up).
Here's an interesting discovery.
In the back of the drawer where my LMS AXA QCTP was sitting for about four years, there was also one of LMS's adapters for the compound rest that I must have bought at the same time. A couple of shots of the adapter placed below the Grizz compound rest:
And here is the LMS AXA QCTP mounted by its 9/16-18 bolt onto the adapter:
The most interesting thing is that, although LMS said two holes would have to be drilled/tapped for the M5-0.8 hold-down screws for the carriage handwheel, as you can see in the second picture the holes are already there. As it turns out, the holes are tapped.
So, it's looking pretty close to bolt-on. I need to install an oil cup, the gib that runs the length of the rest, and the three screws that adjust the gib. Then screw the existing carriage handwheel onto the end, and it's done. I thought I'd order a new oil cup, gib and screws from Grizzly since they're like a dollar each.
Yes, the QCTP is an import, but I figure it will serve me fine as I work on learning with it.
Thanks for all the advice from everyone -- looking pretty easy from here on out.
In the back of the drawer where my LMS AXA QCTP was sitting for about four years, there was also one of LMS's adapters for the compound rest that I must have bought at the same time. A couple of shots of the adapter placed below the Grizz compound rest:
And here is the LMS AXA QCTP mounted by its 9/16-18 bolt onto the adapter:
The most interesting thing is that, although LMS said two holes would have to be drilled/tapped for the M5-0.8 hold-down screws for the carriage handwheel, as you can see in the second picture the holes are already there. As it turns out, the holes are tapped.
So, it's looking pretty close to bolt-on. I need to install an oil cup, the gib that runs the length of the rest, and the three screws that adjust the gib. Then screw the existing carriage handwheel onto the end, and it's done. I thought I'd order a new oil cup, gib and screws from Grizzly since they're like a dollar each.
Yes, the QCTP is an import, but I figure it will serve me fine as I work on learning with it.
Thanks for all the advice from everyone -- looking pretty easy from here on out.