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- Apr 30, 2015
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I think I'm going to keep putting off buying any after reading this thread LOL I don't need to drive myself crazy that badly
-M
-M
Actually - they are just so very useful - especially for woodwork! Plonk two together in the right way, and you can rule 1, 2 , 3, 4, 5 and even 6. Stand it up against your circular saw blade, and adjust away. Guide a drill into a frame - dead square. I suppose there is no harm in clamping one into an angle-iron or box section weld. You don't get much else made to the precision, that works like a gauge block + handy parallel thingy that you can bolt down, all for about £20 for two of them!I think I'm going to keep putting off buying any after reading this thread LOL I don't need to drive myself crazy that badly
-M
Thanks very much RJ. The thought had crossed my mind that it would be unlikely that I would be the only one on the case of 1-2-3 blocks in this context, and sure enough, you folk have wrung it out in a thread more than a year ago.My approach to the Asian 1-2-3- block fault was to simply turn and thread some special studs with 3/8-16 threads on one end aqnd 5/16-18 threads on the other. A few minutes of turning and single point threading per stud.
Leggos for Machinists
Well, not quite. About a year ago, I purchased five pairs of 1-2-3 blocks to go with the pair I already had. My intent was to use them for machining setups, etc. As mny of us already knew, although the Asian blocks have 3/8"-16 threaded holes on the 2 x 3 face, all the through holes are bored...www.hobby-machinist.com
an M6 would be a good deal stronger than a #10. I dislike our imperial thread sizes and use metric hardware where practical. Mixing the two bothers me. A lot. Some strange OCD thing im sure.Making the hole is surely possible with a carbide drill or milling cutter. We can make holes in glass and stone! Spinning an aluminum rod in 80 grit slurry would do it, and leave the aluminum rod more or less intact! Making the holes is a reasonably fraught exercise unless one takes care, but I think the holes is a reasonably straightforward task.
This assumes we settle for the ready-made slightly less than 3/8" holes, which is sensible. We don't want any more work than necessary!
The bushing you suggest is to be glued in with Loctite, and at the same time we adopt a smaller screw that will have an OD that will fit through the (apparently) 0.355" diameter holes. So far - so good.
Given that I am looking at 9mm holes (some 9.01mm, others up to 9.04mm), and thinking M6 bolts, and I don't actually know what is #10 screw, please forgive. Looking at tables for UNC, a 5/16 x 18 screw leaves only 0.03125 each side. A 1/4" x 20 leaves 0.0625 each side, which seems to me to be "enough".
So, is the recipe to get some 3/8 x 16 (maybe not very hard), cut to make a slug, ends faced to make a counterbore bottom when in place. Loctite 638 into the existing threads, and drill out and tap to (say 1/4" or M6)? That could work! Does one make the entire bushing first, or drill and tap when it is glued in place?
Not OCD. I have lathe(s) which are relentlessly imperial. I have had to get used to the series of sizes 1/4, 3/8,7/16, 1/2. Sure, I can convert, and the digital caliper has a little button that does it for me.an M6 would be a good deal stronger than a #10. I dislike our imperial thread sizes and use metric hardware where practical. Mixing the two bothers me. A lot. Some strange OCD thing im sure.
I can understand the (French?) South Bend has an imperial threading lead screw, but I take it that the ACME screw on the cross slide has a metric pitch. How far does one turn advance, and how many divisions around the dial? Your lathe may have been produced "converted", or had a conversion done at some stage unless you had it from new.My South Bend Lathe was made in France and is metric on all the dials which suits me well. Unfortunately it was made with an imperial lead-screw so while i only single point metric threads i am unable to disengage the half-nut. Were Whitworth lathes produced?
I apologize for the thread diversion. I had never thought about this to anything like the level of your questions. This lathe was made in the 1970s and is weird. I like it actually. One revolution of the handwheel reads at 10mm (diametrical measure). The cross-slide moves about 0.197”. Thanks for putting those thoughts in my head. I like that stuff.I can understand the (French?) South Bend has an imperial threading lead screw, but I take it that the ACME screw on the cross slide has a metric pitch. How far does one turn advance, and how many divisions around the dial? Your lathe may have been produced "converted", or had a conversion done at some stage unless you had it from new.
I ask this because I am seriously considering "converting" mine, by giving it a 2mm advance ACME screw.
Re: Whitworth threads. The only difference to regular threads is to grind the tool angle to 55° instead of 60°.
Whitworths use TPI for thread pitches, just like any other imperial thread.