|Project by drobertson||posted 10-12-2015 02:35 AM||1221 views||5 times favorited||5 comments|
This is a project for a friend who makes Kaleidoscopes.
One of his biggest challenges is making clean cuts on the very expensive first surface mirrors used in his scopes. After a little brainstorming we came up with this design for a cutting table that will hopefully simplify his process a bit.
The table surface is a piece of corian we got cheap from a counter top guy we met. It was the leftover piece from a sink placement. This gave us an extremely hard and flat surface to work with. It also glues great using 2 part epoxy.
The corian was mounted on a bit of 3/4 ply and trued up on all sides. A cutoff strip from the corian was epoxied to the base as a stop/base for the glass being cut.
Dadoes were cut down each side and t-slots were added as a way to lock down the cutting guide. I highly recommend Orange Aluminum if you are looking for t-slot aluminum. They are the best price I have found and their products are great. Note – that was in no way a paid endorsement, I just like them.
I have been doing a lot of jigs with t-slots lately and sorted out what seems to be a good way of mounting them. T-slots work best when their top surface is exactly level with the jig it is being mounted on. Regrettably I have just never been good enough to get that exactly right with a dado blade. Instead I just cut a dado slot that is slightly deeper than the t-slot. Tape goes on each end of the slot and I pour enough 2 part epoxy into the slot to fill the bottom and go a bit higher than where I expect the t-slot to sit.
I mount stop blocks on the top of the t-slot with a bit of wax paper under them. This t-slot assembly is then pushed down into the epoxy. The epoxy pushes up the sides a bit, but it mostly comes up through the screw holes in the bottom of the aluminum and settles into the deep base of the t-slot. The stop blocks that are mounted on the t-slot ride right on top of the jig surface, perfectly aligning the aluminum.
The epoxy holds this setup amazingly well. I tested a small section of t-slot glued with epoxy to a bit of scrap wood. After mounting it in a vice I wedged a iron rod in it and attempted to pry it off in a little test to destruction. The rod ended up bending and the aluminum strips on the top broke away, but the epoxy never failed. i consider that a success.
The new table has a cutting guide made of some scrap Sapele I had around. There is a measuring tape on both sides that is offset to accommodate the cutting tool width. The idea is to make it easy to adjust for different size cuts.
On the back there is a breaker bar made of Sapele and some piano hinges. The two parts of the breaker bar are cut at a small angle, allowing the breaker bar to push the glass down and snap it along the score line.
A bit of scrap walnut went on as trim and all the wood was given a light coat of poly. The result is what we have in the pictures.
We did some tests today and it worked like a charm. It was easy to set up and we cut two sheets of mirrors down to size without a single chip or flare in the glass. Overall we are pretty happy with the results.
I do have some ideas for improvements, but for now it is a working cutting table.