Matting an ER40 Collet Fixture to a Back Plate

[ddickey]

How did you hold the back plate to machine it?

The back plate was held to the spindle by D1-5 camlocks. The ER plate was not machined.

 

[ddickey]

I also want to ask about speeds and feeds in regards to cast iron. I ran my lathe in backgear, ~60 rpm I think it was, at the fastest feed rate which I can't remember what that was. My finish was poor at best but not sure what to expect from cast iron.
If anyone can direct me to some reading about machining cast or can give some opinions it would be appreciated.

 

[kd4gij]

Ok on mounting back plate to spindle. That is correct. I run cast iron around 300 rpm with carbide tooling. It eats HS steel up pretty quick.

 

[darkzero]

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.



I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.



Here's what a 6" vise looks like on another PM45 (gt40's)
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