What are you machining?

[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.

 

[Pete.]

Ah, could be. The faint band of red made me think it was steel.

 

[Hood]

Could just be the light making it look that way.
I was going to suggest cranking up the feedrate and depth of cut to get it chipping but sounds like the lathe is struggling a bit as it is so...

 

[earthman]

some switchgear for my bike build...
View attachment 199838 View attachment 199839 View attachment 199840

Very neat, what will the two buttons be used for??

 

[Kram]

It is aluminium.
Weighted it before facing 700g and after boring 400g it will be about 200g when done.

 

[Pete.]

Kram if you grind some HSS with a really steep top rake it will slice material off at 3x your current rate without stressing the motor.

 

[mtt.tr]

Kram if you grind some HSS with a really steep top rake it will slice material off at 3x your current rate without stressing the motor.

Exactly what i used earlier today. Im a fan off hss

 

[eLuSiVeMiTe]

Seems a good place to ask rather than a new thread.

Machinable plastics.
Need to make a load of adapters to standardise my extractor connection to tools.
Recommendations for materials?
Would rather leave an adapter in each tool and just plug and play

 

[Kram]

Derlin/acetal. Nice machineable plastic.
Avoid nylon. It will do what you want but its like cutting dog ****. I have bought 3kg of decent offcuts from this seller.

https://www.ebay.co.uk/itm/Acetal-plastic-offcuts-Lot-10-engineering-milling/193235091715

Do you have a pic of the hss cutter? Im not good at grinding it, doubt I can beat these sharp ground inserts.

 

[Hood]

As above but would opt for Acetal as a good bit cheaper than Delrin for basically the same thing.

 

[mtt.tr]

Derlin/acetal. Nice machineable plastic.
Avoid nylon. It will do what you want but its like cutting dog ****.

Dont mind nylon with very sharp tooling, but when it goes wrong worse than dog ****

Id go poly myself if they are one size id cast them.

 

[Hood]

I hate nylon, I used to detest it but since I got the CNC then it is just hatred of it
Cuts no problem but the stringers are immensely strong and can pull a tool out of a turret if not careful.

 

[eLuSiVeMiTe]

Dont mind nylon with very sharp tooling, but when it goes wrong worse than dog ****

Id go poly myself if they are one size id cast them.

Not that lucky. Most of the DeWalt gear is A direct fit thankfully. But need adapters for other tools to suit. Poly?

 

[roofman]

Not that lucky. Most of the DeWalt gear is A direct fit thankfully. But need adapters for other tools to suit. Poly?

what size do you need..i have some nice chunks of machinable plastic here if you need any

 

[Kram]

Also aluminim will be cheaper than decent plastics. www.ebay.co.uk/itm/Solid-Aluminium-Round-Bar-50-mm-dia-70-mm-Long-X6-Pieces-2-5-Kg-Approx/193178709763