2011 Patriot backlash help

[rdeeming]

What is your backlash of your Patriot?

I'd like to try and improve this on my machine. Especially the X axis at the moment. All I have done is tighten the threaded collar clamp and snug up the gibbs. This really helped the Y axis being at .0128 but there was not much gain in this for the X axis starting at .0146.

As it stands I have the following backlash.

X .0135
Y .0048
Z .0034

[smallblock]

Do you have the new machine with center mounted leadscrew? On the older machines with the leadscrew on the front of the machine, the X axis lash was usually related to table rock- this was often due to a warped gib strip. If you pull the gib out and get it perfectly flat, it will make a huge improvement. Your Y and Z figures look pretty reasonable and backlash compensation will take care of them.

[rdeeming]

My leadscrew is on the front of the machine. I pulled the gib strip out and it looks really good sitting on the mill table. No dykem or surface table on hand yet.

I went a tiny bit more on the collar clamps all around and now my numbers are as follows.

X .0118
Y .0024
Z .0028

Backlash compensation in Mach3 is good for positioning to drill a hole but does not help when cutting a circle. This is the main reason I started to take a hard look at dealing with the backlash after reading the Mach3 manual.

[TomB]

I had a bit of rocking with my TriPower that was not related to the gib. I don’t know how much of your machine you have taken apart but I had to take the table off to find the problem. Basically there is the table and below it a heavy casting that has the dovetails for the table and the lathe ways. I laid the table down upside down then put Dycum on the left way, the side opposite the gib. When I slide the heavy casting against the table way and inspected the result it was obvious the two sloping sides of the dovetail did not fit together well. I used a stone to take off high spots and redid the Dycum and slide. After about a dozen cycles the blue was transferring from the table to the casting fairly evenly. I tried the same approach for the heavy casting to lathe way, made some progress but not as much. Because the lathe way is so long it’s not obvious what part should be stoned.

When I put the table back together I had eliminated about half the x-axis driven table rock. In my case I believe the table top had a high spot in the dovetail that was about a 1/3 of the way down the table and that allowed the table to rock on the high point, teeter-totter style. Some place I may have described the process more fully in a thread. I’m sure I still have the pictures of how the blue transferred, but they are high resolution and I’d have to edit them down before I put them up on a public forum. Otherwise they would take ages to download.

Tom