What are you machining?

[eLuSiVeMiTe]

Going on from your wanted thread...can i ask what are you making of fixing with stepped pullys?

Lathe. New motor and pulleys.
https://www.mig-welding.co.uk/forum/threads/new-motor-and-vfd.95777/page-2#post-1444458

 

[Kram]

Rough atttempt at a pulley. Started cutting right side angle by compound and the rest is rough.

Problem being, without a tool angled under 38? degrees, wont have clearance enough to sweep the bottom. Should I start with a square groove tool to full depth, and then cut the angles, until they intersect?

 

[ronan]

Rough atttempt at a pulley. Started cutting right side angle by compound and the rest is rough.

Problem being, without a tool angled under 38? degrees, wont have clearance enough to sweep the bottom. Should I start with a square groove tool to full depth, and then cut the angles, until they intersect?

Yes, i always plunge with a parting off tool, get the bulk of the material out of the way and give yourself a bit of room to work.

 

[Hood]

I would grind up an HSS form tool for that. Same profile on both sides as the pulley groove but narrower.

 

[mtt.tr]

Have 4 poly bushes to make, not the most pleasing material but its do able.

First job was to make an arbor and clamp its against the Chuck jaws, its damn grippy.

 

[mtt.tr]

Just to make some stainless sleeves and its done. Hopefully Only an hour left

 

[slim_boy_fat]

Just to make some stainless sleeves and its done. Hopefully Only an hour left

You going to knit a jumper? .

 

[mtt.tr]

You going to knit a jumper? .

Horrible bloody stuff.

 

[Hood]

Horrible bloody stuff.

I have only ever machined it once and thought it was quite nice to machine, maybe a different grade or something. I used a DNMG insert but it was actually a HSS insert, polished and very sharp with a positive rake.

 

[Ton-up]

Easy to machine if you slice it rather than turn it.

 

[mtt.tr]

I have only ever machined it once and thought it was quite nice to machine, maybe a different grade or something. I used a DNMG insert but it was actually a HSS insert, polished and very sharp with a positive rake.

If im honest this stuff was pretty easy, just ground a hss blank very positive rake finsh was good. I have machined softer poly and that really is awful as it just doesn't want to come away.

I also find deep depth of cut high speed infeed and fast spindle speed using stabbing moves forces the poly to break away from it self, continuous cuts it get pushed along in a complete ring

Oh and wood spade drills are the nuts for drilling it


Its more akin to wood turning.

 

[Kram]

Pulley done, other than the keyway.

Too big

1:1.

 

[ronan]

You can do the keyway on the lathe too if you don't have broaches and a press. Using the carriage like a shaper.

 

[Maker]

You can do the keyway on the lathe too if you don't have broaches and a press. Using the carriage like a shaper.

I've tried that once, I found it worked much better using the more rigid rear toolpost, tightening the gibs on the compound would have probably helped too.

 

[Kram]

Bored out the 180 pulley to 65mm, cast iron powder everywhere! It is now 1.7kg, must have been atleast 2kg before.
Any idea what the max speed would be for a large CI pulley like this?

Also got two of these tiny DTI holders.

 

[Hood]

Cast Iron lathe chucks of that dia will be rated for 2-2500rpm I would think, so a pulley would be at least that as it is not under anything like the same forces.

 

[Pete.]

I'd happily spin that up to 4000rpm or even more. Wouldn't stand near it the first time though.

 

[Kram]

Started on the 125mm pulley blank. Waiting for lathe motor to cool down a bit. Did try to holesaw the centre 57mm but no torque, so I have bored it out 63mm so far, going for 81.5mm.
Much swarf, would go well on a tree!

 

[Pete.]

Dunno where you got that piece of steel but going by the finish and the swarf it looks like a bloody nice piece of material. No wonder why your motor is cooking.

 

[Hood]

I thought it was Aluminium.