1100 tramming and squaring

[rcmanchild]

Hello gentlemen,
I've been spending the last few weeks dialing in my 1100 and I've come to a crossroads. I spent a good amount of time squaring my spindle head to the column and got it about where I want it. From that point, I used my Starrett level and got the table level in the rear position. Then I took the twist out of the casting by shimming until my table maintained level throughout the entire Y travel.

At this point, I normally would expect a fairly trammed machine but I'm still off tram by .0018 over 6" in the X. Y is perfect. If I do the usual shimming of the base to correct this error, I'll induce twist into the casting.

Does anyone know a good way to tram this X issue out without loosing level or adding twist?

Any advice is much appreciated!

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[GLCarlson]

Go back a few years here and find the thread on using a jackscrew to line up the base with the column. There's also a Tormach app note about it, I think. In any case, there are several threads that go into excruciating detail. It may take some digging to find them, but they are in the forum.

Using a level is a good way to start, but it ties you to an external reference. At some point, you start chasing the external zero. This will drive you mad.

Remember: you don't care if the machine is level in an absolute sense to an external reference (the level). You only care that the column is square to the table. You are working with a local coordinate system (machine X Y Z), not one that relates to the rest of the universe. Get the local coordinate system true- X, Y, Z parallel and perpendicular- and if it's tipped 5 degrees to your shop floor, don't worry about it. To put that another way: don't try to zero out two degrees of freedom (machine zero and local gravity field zero) when you only care about one of them.

Switch to a (stiff) long sweep with a sensitive indicator held in the spindle. Tweak the base mounting nuts as needed to get flat while sweeping the table (or a ground flat plate bolted to it).

[Steve Seebold]

I must have been extremely lucky with my PCNC 1100 when I bought it. I took it out of the box, assembled the base, set the machine in it and started running.

I checked it for square and parallel and it is absolutely dead nuts perfect.

I don't do big parts on my machine, actually if I can't hold a half dozen parts in one hand, they're too big for me.

I don't do aerospace or defense work any more, I just don't want the headaches of all the paperwork Thai goes along with it.

Now, I make parts for gas powered (pump gas like a 2 cycle motorcycle) remote control boats and trucks.

Tolerances now are plus or minus "oh that's close enough".

I'm only running my machine about 8 hours a week now. I don't need to make a lot of money anymore, but I still need something to do in my retirement.

[MichaelHenry]

John Saunders did a video a couple years ago about tramming his 1100 and shows use of a jacking screw.