March 11, 2015

New Cross Slide

Since I only have one of the original taig cross slides, but want both a cross slide and compound on the mini lathe, I had to make a new cross slide from scratch.  Also, since the little ballscrews I'm using are right-handed, rather than left-handed like cross feed leadscrews normally are, the whole system has to be rethought a bit.  To get the correct motion, the handwheel that moves the cross slide will be fixed to the cross slide, rather than the carriage.  Basically the same way compounds are normally set up.

As with most projects, I started out with a nice brick of aluminum.  The original cross slide is on top for reference:

It's significantly bigger than the original for a couple reasons.  First, by mounting the handwheel on the cross slide, you lose travel distance towards the spindle, since the hand wheel would collide with the carriage.  Also, I just wanted a bit more travel than a stock Taig has.

Why isn't it steel, or better yet, cast iron?  Well, aluminum was good enough for Taig... I may try hard-anodizing it like the original to improve its wear resistance.  Also I don't have any cast iron bricks lying around.

I faced the brick to size, and cut a strip of brass to make a gib from.  The bar I cut from had some nasty internal stresses, so the piece warped like crazy when I slit it off.  I was able to machine it down to size and get rid of the warp, though:

Here's the squarely-milled jib and cross slide.  A few holes were drilled and tapped to fix the two together, and then I milled the dovetails:

Preparing to mill the dovetails:

Turned out pretty nicely.  Tapped holes along the side were added for adjusting the gib.

I lapped the surface the same way as last time to get it to slide smoothly:

Next episode, I'll be adding the ballscrew and hand wheel to the cross slide.

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