Thanks guys for the info. On another thread, The book 'Machine Tool Reconditioning and the Art of Hand Scraping' was mentioned. I bought it and I feel it was worth every penny of the $100+ I spent. The chapter on gib contruction and fitting alone was worth the price, imo.
Connelly, the author, spends many pages telling you how to make your own precision straight edges, parallels, and gauges. A very inspiring book. With the knowledge presented in this book, one can make many of the precision items, which are out of the price range of a hobbyist or small businessman.
Mcgyver, I would not recommend the machinerepair.com site to anyone. If my memory of the date is correct, in the spring of 2004, I sent a check for the video and book he advertises. The products were never sent. Several emails from me were never answered. Mike, or whoever runs this business, had it together enough to take my check to the bank and cash it before I could cancel it, however. I have been stuck for years on the issue of scraping until hearing about the Connelly book from you guys. Stay away from machinerepair.com!!
In order to recondition the lathe I have and build a cnc gantry mill, I would like to have a 4 foot long precision parallel/straight edge. Using this tool and a precision level, I think I will be able to get very accurate alignment of the ways of any mill or lathe.
I would like to try and make one myself out of a 49" long steel 'I' beam that I bought for $15. It is about 3" tall and 2" wide. In order to reenforce it, I want to 'cold weld,' with 'jb weld' or some other tough epoxy, vertical braces and diagonal braces. Once the braces are cut and glued in, I will have the beam ground on all four sides at a grinding company. Then, using a 30" on-the-diagonal surface plate that I have, I will touch up it's accuracy by hand scraping.
I am also thinking of beefing up the top and bottom surfaces with gray iron or steel plates, which would be cold welded to the beam using epoxy. I would then have it ground.
Do you think this will be stable enough to hold its accuracy? My feeling is that welding the braces by normal means will induce warping and stresses into the beam, making it very inaccurate. But I am wondering what differences in room temperature will do to the way epoxy pastes expand and contract. Maybe that will also make it very inaccurate.
Any thoughts?  |