PM935TV

[parshal]

Mark, I’m sure in a few years I’ll wish I bought a bigger one!

At the moment, I could probably fit a bigger one. We are considering moving and my wife wouldn’t be terribly happy if we had to base a purchase around a huge mill. LOL

 

[mksj]

I hear you, getting my full size knee mill moved to my new house the previous year was probably one of the biggest hurdles. I lost a lot of sleep over it, and also when I ordered a new larger lathe, it was a big very difficult getting it to the delivered to our new house at a reasonable cost. Best of luck whatever you choose.

 

[Winegrower]

Would be nice to run your same mill test on somebody’s old Bridgeport or clone. Now THAT would be interesting. To me, anyway.

 

[bakrch]

I won't/don't use a 1" twist drill on my 935!

We want to test these machines, not baby them!

I do it all the time on this 949. 3HP VFD setup for this, but you need the back gear to do it stall free.

Granted, my first choice for drilling steel is to use its bigger brother (5HP VFD), but both will get the job done just fine. Back gear not really needed for 1", but I use it anyway.

 

[davidpbest]

1" twist drill into 316 stainless or 17-4ph. I'm even willing to donate material to the both of you if needed.

The J-head on the 835 or my 935 will not power downfeed 1" into stainless without trashing the guts of the power downfeed mechanism. 3/8" is what the PM spec lists as max diameter into steel. OTOH, my RF-45 would easily drive 3/4" drill into 316 with it's more robust and advanced power downfeed system (did it many times). And to counter your other assumption, the 833 does have power downfeed and an adjustable limit stop that will disengage automatically, and is much easier to use compared to the J-head - fully documented in the user manual on the PM site. Based on my direct experience with these "baby" knee mills and the original RF-45 from Taiwan, the idea that the knee mill is always more rigid is total fallacy. I can't speak to the 833 specifically because I haven't used one, but the principals that give the RF-45 it's increased rigidity are the same, and fully discussed/documented in my attached revised write-up.

 

[wrmiller]

If I have the requirement of drilling 1" holes (or larger) on a mill, I'm sure not going to buy a 935 or smaller bench mill. That just seems stupid. But, people do what they're gonna do...

 

[bakrch]

If I have the requirement of drilling 1" holes (or larger) on a mill, I'm sure not going to buy a 935 or smaller bench mill. That just seems stupid. But, people do what they're gonna do...

It isn't stupid at all. In fact, a genuine RF-45 is even rated for drilling up to 1.5" diameter in mild steel. This is with a 1-1.5 HP motor.

My test puts RPM's at about 100, which is in the vicinity of where we believe the 833TV to be weak. It is a perfectly reasonable test. I have drilled dozens of 11/16" holes on my PM25-MV in low range into 316 and Grade 5 titanium 1.5" deep. This is with a pilot hole big enough to clear the larger drill chisel/web. No issues at all, asking a knee mill to do a little more isn't so much of a leap. This was before I had a lathe in the home shop, obviously now it is much faster to drill the same hole on a 2HP PM1236.

 

[bakrch]

Also,

 

[davidpbest]

bakrch I like the UI on your F/S app better than the FSWizard I use on my iPhone. I get the same results you do, but I like the look of yours better. What app are you using?

 

[bakrch]

bakrch I like the UI on your F/S app better than the FSWizard I use on my iPhone. I get the same results you do, but I like the look of yours better. What app are you using?

Same app just on the Android platform. I also use the paid version, not sure if that has anything to do with the difference.