- Thread starter Kram
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Kram
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Ive changed to a new 12mm chinese endmill, as I have no spare travel to drop work down. I am very suprised - its an open slot but it was quite happy 2mm deep cut, full width and moving fast, even happy 1mm deep climb milling. Im sure it will be worse with vertical raised higher.
I need a vice with a smaller bottom jaw, 30mm seems OTT, im sure 15mm would be adequate!? Ill get some csk bolts then I can drop another 10mm.
Dcal
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Today I machined another tipping wheel for the bead roller.
I have an earlier version that I welded and then machined (because I didn't have a big enough lump of bar) and that works fine.
This is for a mate but I might make one for myself as well.
It's made from a bit of tie-bar that came out of a harbour wall we were demolishing, I'm sure 20 years ago.
It was too big to fit in my 3 jaw and I should have put it in the little 4 jaw but instead I tack welded a bit of bar to it and mounted it in the chuck that way.
When I machined the first side down I was able to turn it and mount it in the chuck then use a parting tool to cut the bar off.
It didn't like it and broke the parting tool tip.
The heat affected zone was a hard as the hobs so there must be a bit of carbon in the bar.
This is good (I think) as I might have a go at hardening the whole thing.
The bar had hardened to a fair depth and was still hard 3mm in.
The rest went fine and I did clock it in the 4 jaw to finish off the other side.
Very simple thing but I'm quite pleased with it as it's about the level my machining skills have reached.
Has anyone any idea what grade steel a 70 year old 3 inch tie-bar would be made from?
I have an earlier version that I welded and then machined (because I didn't have a big enough lump of bar) and that works fine.
This is for a mate but I might make one for myself as well.
It's made from a bit of tie-bar that came out of a harbour wall we were demolishing, I'm sure 20 years ago.
It was too big to fit in my 3 jaw and I should have put it in the little 4 jaw but instead I tack welded a bit of bar to it and mounted it in the chuck that way.
When I machined the first side down I was able to turn it and mount it in the chuck then use a parting tool to cut the bar off.
It didn't like it and broke the parting tool tip.
The heat affected zone was a hard as the hobs so there must be a bit of carbon in the bar.
This is good (I think) as I might have a go at hardening the whole thing.
The bar had hardened to a fair depth and was still hard 3mm in.
The rest went fine and I did clock it in the 4 jaw to finish off the other side.
Very simple thing but I'm quite pleased with it as it's about the level my machining skills have reached.
Has anyone any idea what grade steel a 70 year old 3 inch tie-bar would be made from?
Wrought iron!
zx9
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Nice tip @Hopefuldave I will be using the tailstock for a bit more rigidity next time I am torturing the Drummond.
doubleboost
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2 post hoist legs boring out worn threads to accept drip in feet
New power quill doing a splendid job
Woody.v8
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Balls! looks almost finished too, Gutting when that happens.
Well thats going in the bin. I made several mistakes. The biggest was I engaged the dial at two, where as the rest of cuts were at one.
I'll get some practise on scrap before I try this again..
doubleboost
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Do the thread first
Agroshield
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I know your pain. A sharpie is good for marking thread dial numbers you need to use. A Post-it note is good for obscuring things you don't want to use.
Make some overlays for the TDI, possibly held on by magnets, that are pitch-specific and only have the useful numbers on.
Little known fact: Rick Wakeman used to do screwcutting as practice for playing two keyboards at once.
Hood
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Well thats going in the bin. I made several mistakes. The biggest was I engaged the dial at two, where as the rest of cuts were at one.
I'll get some practise on scrap before I try this again..
Is it a metric leadscrew on the lathe? If not then it may be that you should keep the halfnuts engaged until the thread is complete.
zx9
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Well thats going in the bin. I made several mistakes. The biggest was I engaged the dial at two, where as the rest of cuts were at one.
I'll get some practise on scrap before I try this again..
It is an absolute pain in the rump when that happens, fortunately I have never done quite that much work before before making a pigs ear of it. (yet)
As per @Hood above, it may not be the right way to go about it but it works. If like me you have a screw on chuck and are worried about running the lathe backwards, don't be too concerned, the tool is withdrawn using the cross slide for the reverse part so accidentally unscrewing the chuck at moderate speed is very unlikely.
On my to do list is an adjustable stop for the cross slide to make the process easier, no doubt I will remember half way through roughing out the next item I need to thread.
Shox Dr
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Well thats going in the bin. I made several mistakes. The biggest was I engaged the dial at two, where as the rest of cuts were at one.
I'll get some practise on scrap before I try this again..
Feel your pain. Had the same happen to me a while back. Now I choose a number on the thread dial and stick with it. Takes longer as you always have to wait for it come round. Better than trashing the part though.
Dr.Al
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I tend to do this too - always engage at number 1 as it stops me being a prat. Having said that, I've got a non-screwed chuck so I tend to thread with the spindle running backwards and the tool upside down. As that gives a lot more time to disengage the half-nuts, I can run the lathe a lot faster than I would with a normal orientation tool (no risk of crashing into the work piece) so I don't have to wait as long for the thread dial to turn.
