A True "Z"

[rgbrown@itexas.net]

I needed to so a little 'tune-up' on my ShopBot. In the process I needed to true the "Z" axis with the table. I built a small 'trammel' attachment for my PC router and proceeded.

In case new owners of ShopBots are not familiar with the older tools, they were kits. As the tool evolved, the kits got better. The old cable bots took continual work to continue to use them. Cables and encoder chains would stretch or slip. The rollers used for bearings would at times bind and the steppers would loose steps. You would then change out the offending part - provided you could isolate it, re-square and recalibrate. Of course, occasionally the Z axis would get off.

The attachment is a piece of White oak with a 1/2" hole drilled in one end. An $8 Chinese dial indicator is in the other. Bandsaw kerfs allow one to secure the shafts to the wood. You rotate the tool and adjust until the shaft is square to the table.

In the picture below is also a 5/8" "Her-Saf" routher bit - it screws on the shank. I have several bits and three length shanks in this system.


Ron Brown - rgbrown@itexas.net

"In general the art of government consists in taking as much money as possible from one class of citizens to give to the other."
--Voltaire

[rgbrown@itexas.net]

1174.jpg

[gerald_d]

Ron, at last!


Have you noticed differences depending on where the car sits in the gantry? This was how we detected that our gantry needed some straightening. Consider for a moment what would happen if one of the gantry V-rollers was slightly too high/low - the gantry will have a slight twist. Point the trammel in the x-direction and run the car along the gantry to see the twist.

[rgbrown@itexas.net]

Gerald,

An excellent suggestion and observation. I will avoid the procedure until I have time to properly correct it! I'm actually quite amazed how well one of the 'old' ShopBot tools cut when one looks at the technology used on the 'originals'.

There a lot of small tools and tricks that one may transport across trades that would help one with a ShopBot. I use a 1-2-3 block quite often for set-up. I have some magnetic 'stops' that allow me to check my 'zero' when I temporally change it for a project. I guess one could make some magnetically attached 'zero stops' that would allow one to reset the "zero" at any place.

I think I have just created a new project for myself...........

Ron Brown - rgbrown@itexas.net

"In general the art of government consists in taking as much money as possible from one class of citizens to give to the other."
--Voltaire