Best approach for tramming nod on PM-728VT

[Christianstark]

There are several videos on you tube about their benefits, and even how to make your own. We have the tools to make our own tools.

 

[6061T6]

I got mine from saundersmachineworks — they make one in 6061 for PM728 which is inexpensive.
For production, they have a 4041 hardened version too.

 

[svideo]

I got mine from saundersmachineworks — they make one in 6061 for PM728 which is inexpensive.
For production, they have a 4041 hardened version too.

Oh that's a great starting place, I have gotten so much value from John's YouTube channel that I have zero hesitation in supporting his business. The fact that they have something made specifically for my mill is icing on the cake!

There are several videos on you tube about their benefits, and even how to make your own. We have the tools to make our own tools.

Now that I know these things exist, YT is my next stop to learn more. Thanks to everyone in the thread for teaching me!

 

[6061T6]

If you are at the stage where you can make your own fixture plate, you certainly have better equipment than the PM728 and are far more skilled too. They are not easy to make to the level of accuracy you can buy them at -- especially at the price they are sold for.

One thing a lot of people get intimidated by is anodizing -- you can certainly buy a 6061 plate and anodize it at home for very low cost. While I didn't do that, I am set up for it. It is far easier than people think.

 

[addertooth]

Oh wow @6061T6 - I never knew fixture plates were a thing (told y`all I'm a newb ) and I can see immediately how this could help me out. There are, of course, a zillion options in the market to choose from. Do you have any experience with a solution you like that would be suitable to a PM bench mill?

If the goal is to JUST mount a vise, you can always make your own Fixture plate which registers with the T-Slots on your table as well. This way you start out super close, You can even put in some grub screws (at 45 degrees) which bear against the side of the T-Slots to nail down alignment very quickly.

 

[Genghis6400]

@davidpbest
After reading your post I went and check to see if my 728vt mill column is ”Tilted” and sure enough it is!! There is almost a .003” off within 3 inches!! there’s also the “Nod” situation… in the Y axis there is at least more than .007”-.008” off within 7 inches. I got this mill earlier this year but have not use it yet, just been taking it slowly to set up it properly. Would be super grateful to receive any advise from you regarding the procedure to remedy this.

 

[davidpbest]

@davidpbest
After reading your post I went and check to see if my 728vt mill column is ”Tilted” and sure enough it is!! There is almost a .003” off within 3 inches!! there’s also the “Nod” situation… in the Y axis there is at least more than .007”-.008” off within 7 inches. I got this mill earlier this year but have not use it yet, just been taking it slowly to set up it properly. Would be super grateful to receive any advise from you regarding the procedure to remedy this.

I will DM you about this - don't want to hijack the OP's thread.

 

[svideo]

I will DM you about this - don't want to hijack the OP's thread.

@davidpbest Man I learn so much about how this stuff works from reading your posts, I would be thrilled if you shared more about how best to approach this here with all of us!

Current status: 1 thou out in the Y axis over 6". If I put a 1 thou shim between the headstock and column, it's out a thou in the other direction. What this suggests is that I might do better with a half-thou shim, but I'm not finding anything that thin available in brass. I do find steel and stainless, but I don't think using steel shims on that steel surface is a great idea, and am concerned about reactivity if I used aluminium.

 

[davidpbest]

I’m glad my posts are helpful and thanks for the feedback. It’s often hard to know if my contributions are useful, so thanks for the comment.

You may be guilty of overthinking the material compatibility issues with steel and aluminum shim stock. But . . . .

Brass is too soft and brittle to be used in 0.0005” shins.

Little Machine Shop sells limited compression plastic shim stock in thicknesses from 0.0005 to 0.005”. They are sold individually or in a set with several sizes.
Also available through Amazon as a set.

Stainless shim stock is available in 0.0005” thickness in small quantity on eBay.

Cigarette wrapping papers are typically 0.0003” to 0.0006” thickness with variations in thickness and compressibility among brands.

Before you shim the head, make sure the quill and head movement are co-linear as described in my video. Also, 0.0005” would not be difficult to scrape in if you have the tools and interest

 

[Cletus]

It’s often hard to know if my contributions are useful

@davidpbest "Useful" is such an underestimation!