Mills and Lathes
- Thread starter link1896
- Start date
link1896
Mr Greenfield
On my list of mods is a two part cross slide nut I can adjust to get rid of all feee play. Really annoys me at the moment, has 0.5mm free play.
Where is the slop? Thread is a LH M8 or M10.
link1896
Mr Greenfield
M8. Slop is from the pathetic half nut, I think this style you place a big bastard screw driver in the gap and twist to push the small section away. Rather agricultural
You can buy these bits fairly easily. Hare and Forbes have the same lathe with different pants on. Google has the parts diagrams. AL-51G. I think....
link1896
Mr Greenfield
Sadly they don't, they are my local shop here in Melbourne.
Mines a 1992 chinese copy of an emco compact 8, brought in by herless, now Machinery House. Aka Hare and Forbes
They were my first point of call when I stripped the feed half but. Capital Equipment around the corner from them do have some parts still. No one makes a nice cross slide nut I can easily access. Will make my own.
Mines a 1992 chinese copy of an emco compact 8, brought in by herless, now Machinery House. Aka Hare and Forbes
They were my first point of call when I stripped the feed half but. Capital Equipment around the corner from them do have some parts still. No one makes a nice cross slide nut I can easily access. Will make my own.
Hang on cross slide nut? The one I needed? I bought it from H&F.
https://www.ereplacementparts.com/nut-p-1762009.html
https://old.machineryhouse.com.au/LR944
https://www.mmtoolparts.com/store/321376-bd-920w-parts
https://www.ereplacementparts.com/nut-p-1762009.html
https://old.machineryhouse.com.au/LR944
https://www.mmtoolparts.com/store/321376-bd-920w-parts
link1896
Mr Greenfield
Needed the half nuts 4017, machinery house didn't have, assetplant did have, that's were I got them, not capital.
Machinery house's LR944 is not going to be any better then the current arrangement, I'm going to make a more elaborate two piece adjustable half nut so I can turn two cap heads to finely adjust backlash.
The cross screw must be worn, I have bugger all backlash in mine. Have fun.
SummitFever
Eats Squid
That's a fair amount of backlash, but you can never eliminate it without going to ballscrews. On a lathe cross-slide even on something like a Schaublin I always treat it as having lash. Touch off, zero your dial and away you go. Doesn't matter what the backlash is.
We're just rebuilding a little Emco Maximat V10 at the moment for small, high accuracy work. It doesn't have hardened bedways so we've been able to do all of the re-machining in house. Nice little lathe even though it's size almost makes it look like a toy. How close a copy of the Emco is the chinese variant? Can you use Emco spare parts as there's still a fair selection available from O/S.
link1896
Mr Greenfield
The tool thread quickly became distracted with talk of lathes, so I thought I'd start another thread seeing there are a few of us with them.
Here's my contribution.
Mill is a rong-fu 25, lathe is a Emco Compact 8 clone, also known these days as a 20x7 lathe, as they are quite generic out of China these days.
I bought BOTH from work for 50 bucks with tooling a decade ago so we could avoid the costs and BS of having to retrofit all the mandated safety guards, etc. plus I was the only one who knew how to use them.
I'm the process of rebuilding the lathe, she's been rather neglected. Mill will be next, its well out of square too.
Here's my contribution.
Mill is a rong-fu 25, lathe is a Emco Compact 8 clone, also known these days as a 20x7 lathe, as they are quite generic out of China these days.
I bought BOTH from work for 50 bucks with tooling a decade ago so we could avoid the costs and BS of having to retrofit all the mandated safety guards, etc. plus I was the only one who knew how to use them.
I'm the process of rebuilding the lathe, she's been rather neglected. Mill will be next, its well out of square too.
link1896
Mr Greenfield
Lathe carriage rebuilt, significantly less chatter. Found a spare cross feed nut in my parts collection, much better then the old one. Minimal backlash, about 5 degrees on the hand wheel.
Next is to align the headstock, she's rotated anti clockwise and sloping downhill. Slope adjustment will require careful and painful use of feeler gauges as shims.
Chuck is also not holding the work piece true. Probably need a new chuck. Jaws are in their correct positions and she's the best part of 0.2mm out. Will experiment with jaw locations.
Cheap Chinese lathes are cheap for a reason.
Next is to align the headstock, she's rotated anti clockwise and sloping downhill. Slope adjustment will require careful and painful use of feeler gauges as shims.
Chuck is also not holding the work piece true. Probably need a new chuck. Jaws are in their correct positions and she's the best part of 0.2mm out. Will experiment with jaw locations.
Cheap Chinese lathes are cheap for a reason.
SummitFever
Eats Squid
It' possible to redo the jaws using a die grinder or dremel mounted in the tool holder to dress the inside.
Process will involve turning a suitable sized ring to clamp in the chuck on the outside of the jaws to hold them in place when you grind the inner clamping surface.
Might need to grind the outer surfaces first.
Will be far less expensive to get a new chuck.
Process will involve turning a suitable sized ring to clamp in the chuck on the outside of the jaws to hold them in place when you grind the inner clamping surface.
Might need to grind the outer surfaces first.
Will be far less expensive to get a new chuck.
Moving posts but training wheels fell off.
link1896
Mr Greenfield
The jaws have a decent amount of free movement on the ring drive. Wondering if I can clamp something on the very inside edge of the jaws and grind them, then grind outer faces, then a ring on outer faces, then attack the remaining section on the inside faces.
Yes this is true, I wouldn't machine the outside first though.
Make the ring then machine the ID, once that is done get a piece of round Bar that you KNOW is round (grind bar if possible) then hold that and redo the outside.
If you don't have a grinder suitable to do the ID you "can" bore it with a boring bar but only "IF" it is really stable.
SummitFever
Eats Squid
Yeah. Depends on how well manufactured/consistent the chuck spiral and the inside/outside teeth of the jaws is. Typically, the ends of the insides of the jaws will be worn, so clamping a long dimensionally accurate rod in the chuck can give you an idea if its just end jaw wear or of the whole thing is dodgy. Measuring runout at a few different diameters might be first job to see how consistent the spiral is. If the chuck has spent a lot of time working around a particular diameter then all of the parts around that diameter may show wear.
Comic Book Guy
Likes Bikes and Dirt
Sorry to go off on a tangent but has any of you guys seen the Clickspring channel on youtube. Watching that guy make that skeleton clock was fascinating.
CBG.
CBG.
So to finish off the shock bleeding rig I need to modify a shock and strut cap nut to hold the guts in while bleeding but still allow air out and top up oil in. No stock apparently. Shock cap is M68x2 and strut is M60x2. I was pretty sure my old lathe was too worn to cut a decent thread but here goes. Two cuts are ok then the third or fourth was far enough out to kill the thread. Wear in the lead screw/half nut. I can get away with cutting imperial threads because I can load all the backlash in one direction but because I need to keep the drive engaged for a metric thread no go.
I chanced upon the specs for malleable iron barrel unions and lo the 40mm supposedly has an M68x2 thread joining the barrel to one half of the union. The 32mm has an M60x2. So I hit the phone and a couple of plumbing places say they have them. Get there and no, we only have brass which is different. Two, yes two, didnt even know what malleable iron was. When I explained oh you mean gal fittings. Not much call for them around here. Bit like cheddar. Anyways my standby for pneumatic stuff had a 40 but not a 32. Thead measued ok with the verniers but whether it truely is M68x2 will have to wait until I can test it in a shock.
So started machining and malleable iron is beautiful to turn, no need for lube with inserts. Bored out the guts to 49.5mm, leaving a cut to take it out to 50 and cleaned up the end to put a knurl on it and my bodged cross slide nut died. Hah, I have the new one. But the bodgy nut has damaged the cross slide screw. They dont want to play nice. Some persuation later and it is working. New screw and nut will need to be ordered. All done now and test fit today. Might be time to look for another lathe. New version of this is about $3k. Second hand bigger machine will be the go when that time comes.
@moorey TLDR, my lathe is fucked.
I chanced upon the specs for malleable iron barrel unions and lo the 40mm supposedly has an M68x2 thread joining the barrel to one half of the union. The 32mm has an M60x2. So I hit the phone and a couple of plumbing places say they have them. Get there and no, we only have brass which is different. Two, yes two, didnt even know what malleable iron was. When I explained oh you mean gal fittings. Not much call for them around here. Bit like cheddar. Anyways my standby for pneumatic stuff had a 40 but not a 32. Thead measued ok with the verniers but whether it truely is M68x2 will have to wait until I can test it in a shock.
So started machining and malleable iron is beautiful to turn, no need for lube with inserts. Bored out the guts to 49.5mm, leaving a cut to take it out to 50 and cleaned up the end to put a knurl on it and my bodged cross slide nut died. Hah, I have the new one. But the bodgy nut has damaged the cross slide screw. They dont want to play nice. Some persuation later and it is working. New screw and nut will need to be ordered. All done now and test fit today. Might be time to look for another lathe. New version of this is about $3k. Second hand bigger machine will be the go when that time comes.
@moorey TLDR, my lathe is fucked.