julianthegypsy
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I've had a hell of a job setting it up for some reason, when its bang on it doesn't want to cut, so I lowered it a bit and now it cuts but leaves a big pip. I'll try bringing it up a tad.
- Thread starter jordan1
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I've had a hell of a job setting it up for some reason, when its bang on it doesn't want to cut, so I lowered it a bit and now it cuts but leaves a big pip. I'll try bringing it up a tad.
Lawnmowerboy
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Is it a quick change tool post or the one with 3 bolts and shims? Quick change have the small locking screw that stops at the bottom and clamps up with the little cam arrangement. Having it too low is more likely for the tool to grab (not a nice experience!)
If it was chattering then this is quite common and not enough angle on the cutting edge.
If it was chattering then this is quite common and not enough angle on the cutting edge.
julianthegypsy
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I have two toolposts on the cross-slide, which is lever operated, and six tool stations on the capstan. One toolpost is adjusted by sliding a wedge and the other by shimming. The parting tool is on the wedge adjusted posted at the moment.
If you have some flex going on somewhere, its easier to part with a parting tool below centre height. If you position it above centre, and it snags the tool is dragged downwards into the workpiece causing horrible things to happen as it jams. Below centre height and it snags and deflects away saving it sometimes.
The idea is absolutely spot on...
I'd face off after it as a extra op if I had to, unless your making 100's of the same thing and the extra cycle time ends up costing you money (running a capstan...).
julianthegypsy
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I do plan to make hundreds, but facing off would take seconds, parting tool on one side of the slide and facing tool on the other. I need to play with it, and probably get a better parting tool than the rdg carbide. I don't like it anyway, it's 4mm wide, which I think is way too much.
brightspark
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make your own then out of a tct saw blade. its verry thin and cuts a treat
Lawnmowerboy
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Then braze a lump of carbide to it?
We have ice cream tubs of old tips at work that come out the CNCs. If you need any then PM me
They're well useable but need a bit of a grind maybe
We have ice cream tubs of old tips at work that come out the CNCs. If you need any then PM me
They're well useable but need a bit of a grind maybe
Shox Dr
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Rear facing upside down, is supposed to give good results
julianthegypsy
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Upside down means the pressure would be on the adjusting screws which wouldn't be as solid unfortunately. The lathe has instant forward and reverse so it can go any way. Adjustedit a bit today and it was a bit better, 7.5mm carbide drill went straight in afterwards as someone suggested it would, with no centre drill, but parting was still so slow! I wouldn't mind trying some tips brazed on to something. I have a good iscar tool but the holder is too thick to fit in my toolpost and I can't see a way of milling it off. The only thing I could think of would be to weld a piece of 12mm square on the side but I imagine that would have to be toolsteel too with special electrodes?
Told you it would works with hss as well.
Check the part off blade is not lifting.
julianthegypsy
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Not using a blade, it's a solid tool with a 4mm carbide tip. Would an hss blade work ok? I have an iscar tool with a replaceable tip but it won't fit in the toolpost!
Meanwhile, back on topic, the centredrill doesn't seem to be an advantage in this case! I might use it to chamfer the hole afterwards though, I have a spare station!
Meanwhile, back on topic, the centredrill doesn't seem to be an advantage in this case! I might use it to chamfer the hole afterwards though, I have a spare station!
Could and probably is lifting Julian.
As you say on centre it dont cut, whats probably happening is its lifting above centre so rubbing.
Any part tool should be on or fractionally under centre.
Small holes 1 to 4mm i usually do centre drill first, its less to actually drill with the drill and comes in to its own on harder steels.
Bigger drills 6mm and above certainly 28mm plough straight in. Works good even at 8" depth at 12mm dia.
As you say on centre it dont cut, whats probably happening is its lifting above centre so rubbing.
Any part tool should be on or fractionally under centre.
Small holes 1 to 4mm i usually do centre drill first, its less to actually drill with the drill and comes in to its own on harder steels.
Bigger drills 6mm and above certainly 28mm plough straight in. Works good even at 8" depth at 12mm dia.
graffian
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I don't use carbide for parting and I part using power feed.
I am using an upside down tool on a rear toolpost, it's an
eclipse HSS parting blade they work OK.
julianthegypsy
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Are you cutting stainless? I don't have power feed, my cross-slide is lever operated. If an hss blade will cut at a reasonable speed I will buy one, but I can't afford expensive experiments!
julianthegypsy
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Thanks. That means upside down on a rear posted it should be a bit above centre, right?
