Some time ago I posted a request for help in figuring out how to eliminate the laborious deburring problem when drilling a series of holes through one inch aluminum tubing for a telescoping operation.
Here's what I ended up doing and it is working!
The finished product is telescopic tubing assembly for use as a cargo catch in the back of a pickup or SUV ww.cargocatch.com . We start with a five foot piece of one inch, .050" wall tubing which allows a standard 7/8 OD tube to slide nicely. To make the assembly fully adjustable we drill 16 holes, one inch apart and insert a push button stop on the inner tube. This allows the user to buy a universal kit and make it fit almost any vehicle.
My problem was that in drilling the holes through the one wall of the tubing left a lot of burr on the inside requiring painstaking deburring with standard deburring tools making calloused hands and short tempers.
The solution: I ordered a 3' long 7/8 drill rod from McMaster Carr and a 3' long 3/8 thick by 1.75 wide cold rolled steel, cut two chunks from the barstock, drilled to accept the 7/8" drill rod and sandwiched it all between the flat stock so it can slide under a standard drill press or even hand held drill for production. Then I got hold of a drill bit recommended by McMaster that is supposed to be great for leaving very little bur.
It worked! What little burr is left after drilling is removed when I twist the finished part making the mandrel act as a shear for the little burrs that remain. A quick blast of air before loading the next piece of tubing and drilling the 16 holes, and voila! Cut time from 7 minutes to less than one minute for a total cost of less than $50 and a few hours of work on the mill drill.
If he pays a local $15 an hour to apprentice, his cost per unit is now two bits a piece and the best quote he got from any of the local shops was $2.00 per piece with a setup charge of over $100 each run.
I'm celebrating with a shot of Herradura Tequila in a snifter and letting the aroma sooth me into a meditative state of being.
Cheers from ChulaJuana Wayne