PM932 on the way

Oh, one other quick note... The angle measuring strip on the round part of the swivel adjustment is not to be used as a reference point for determining angles. As is the case for any markings of this type (be it a lathe compound or mill swivel) it's only there as a rough guideline for angle positioning. This applies to both engraved and surface label markings.

If you need to set a "good enough" angle, use a sine plate or other precision tool and adjust the tooling to match the angle.

If you need "dead on" angles, use two travel indicators (or DRO as the case may be) in the X, Y or Z direction and calculate angles by taking "Rise over Run" type measurements, combined with the appropriate math (Sine, Cosine, Tangent) to verify dead-on precision.

The engravings or labels are the last thing in the world you use to set an angle.

Ray
 
Your may be fine but to be clear there is a difference in tramming the y by shifting the column and tramming the y by shimming the head , or in the case of a Bridgeport using the nod adjustment. Shimming the column brings the column square to the table but if the head is not square with the column shimming the column does not make the head square across the entire range of the quill. Tramming the head to the column is another adjustment. In fact other users of rf 45 dovetail style columns have complained of this as well. A YouTube user hossmachine in fact has a video detailing the process talked about above. So to say it's never been spoke of with a dovetail mill like the pm932 is false. Honestly having worked with Bridgeport style mills before the lack of a nod adjustment in these mills is one of the main hanging points/concerns for me

I'll see if I can find that video

www.youtube.com/watch?v=40Q61UAnOTA

Its a smaller mill a g0704. But it demonstrates the above method
 
Thank you. Seems I could not get some to understand that shimming the column base is not the way to correct nod!

Your may be fine but to be clear there is a difference in tramming the y by shifting the column and tramming the y by shimming the head , or in the case of a Bridgeport using the nod adjustment. Shimming the column brings the column square to the table but if the head is not square with the column shimming the column does not make the head square across the entire range of the quill. Tramming the head to the column is another adjustment. In fact other users of rf 45 dovetail style columns have complained of this as well. A YouTube user hossmachine in fact has a video detailing the process talked about above. So to say it's never been spoke of with a dovetail mill like the pm932 is false. Honestly having worked with Bridgeport style mills before the lack of a nod adjustment in these mills is one of the main hanging points/concerns for me

I'll see if I can find that video

www.youtube.com/watch?v=40Q61UAnOTA

Its a smaller mill a g0704. But it demonstrates the above method
 
Holy cow... the video is Exactly what I have been saying all along... In all that discussion (which the fellow did a very nice job of) there is no mention of head nod. He did not apply any leverage bars anywhere and apply forces to demonstrate that columns bend under force.

Those little tabs he installed are only a fine tuning mechanism to adjust head swing and is exactly equivalent to the push/pull fine tuning adjustment I mentioned a couple posts ago. Those little tabs will need to be removed if you decide to swing the head for a special purpose cut. And finally, when he trams the table, he uses shims on the column.

In that video, when he checks the Y tram to the column, his machine was perfect -and he suggest no method of correction if it weren't -because none is needed. The reason is because that is the same angle that get's adjusted when you put shims in the front or back of the column.


What is this head nod issue?

Ray
 
I am well aware that the tabs he uses are for tramming in the x direction. I would say that is completely obvious and really is not what we are talking about here at all.

I am not saying that there is a well known "nod issue" as you seem to think I, and p500, are. But the idea that they are all perfect is kind of absurd. My main point was that there is a difference between squaring the column to the table and squaring the head to the column. My concern is that you are entirely reliant on how well the sliding surface of the head is ground parallel with the column ways and there is no method of adjusting since there is no built in nod adjustment.

That said, maybe it is never an issue as you claim.

Brian

- - - Updated - - -

Also, let me add that I am no trying to disparage precision matthews and this issue is not only in their mills. There are discussions of similar issues with clausing 8520s and millrite machines that also lack nod adjustment.

b
 
If the head is not aligned to the column in the Y direction then, the only thing that is impacted is linearity in the quill travel -which is a travel of about 4" (can't remember exact amount of travel). In this particular case, there are many other factors involved having much greater impact. The quill lock is not set when the quill is used for drilling -this means the quill moves around a little -and it does but much less so than a drill press. BTW, you never perform mill cutting operations without the quill lock engaged. Also, you avoid at all cost doing any milling with the quill extended beyond an inch or so -it's just common sense.


Anyhow, I'm not the kind of guy who claims that any manufactured product is perfect -that's not a reasonable expectation. I am the kind of guy whose attention is drawn to bold font letters saying "Serious Design Flaw"... I also get concerned when people start filing down their new machines before they know how they perform and my eyebrows raise when people tell me that dial indicators deflect when leverage bars are applied to mill columns.... The machine is what it is and it's very good at that. On machines that have head nod adjustment, you cannot adjust the column. These are design trade offs... not design flaws.

About 30 people have been emailing and PMing non-stop ever since this topic arose. It all could be avoided if people post things clearly and in perspective. ... If I bought a Carera GT and the motor wouldn't peg the speedometer, I'd want my money back. I know that my Toyota Tacoma won't go up to the 140 MPH that's on the speedo and I see no point in trying to find out if it can.

Ray



I am well aware that the tabs he uses are for tramming in the x direction. I would say that is completely obvious and really is not what we are talking about here at all.

I am not saying that there is a well known "nod issue" as you seem to think I, and p500, are. But the idea that they are all perfect is kind of absurd. My main point was that there is a difference between squaring the column to the table and squaring the head to the column. My concern is that you are entirely reliant on how well the sliding surface of the head is ground parallel with the column ways and there is no method of adjusting since there is no built in nod adjustment.

That said, maybe it is never an issue as you claim.

Brian

- - - Updated - - -

Also, let me add that I am no trying to disparage precision matthews and this issue is not only in their mills. There are discussions of similar issues with clausing 8520s and millrite machines that also lack nod adjustment.

b
 
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