I don’t go into the unit most Mondays now; using the day for paperwork, accounts, mail and other assorted admin type work. But today I had a few things to do, so went in. The centre was like a ghost town. Not a soul about all day. This is never a good thing…unless you want peace and quiet that it is.
I took a photo of a job last week and forgot to post it here. The turned item is a 17″ clock bezel which required turning on both sides. Not the simplest of tasks at the best of times. But even more difficult when the client decides that it requires altering due to a design change…how do you remount a 17″ delicate bezel to re-turn a section of it? Cole jaws too small, jam chuck wasteful at this size, and nothing to pick up the center from…humm
The massive chuck on the big lathe of course! I changed the jaws set and picked up the internal straight edge using the outside of the jaws as reference. Bingo!
I recently bought a Gast pump on eBay to make a vacuum chucking system with, and had got so far but still had a leak on the bearing. This morning I went down to my local Marine supplies place and had a chat about fittings and bearings. “No problem” was the response. £12 later and all the bits and pieces were gathered.
A 3/8 hose connector fitted snuggly into the bearing and was fixed with araldite, a recess was turned into the existing aluminium hand wheel on the lathe (I rarely use the hand wheel) and the bearing glued in the same way. A rubber washer fits between hand wheel and the headstock just to be certain of maintaining vacuum pressure. A vacuum chuck was made up of layers of MDF, sealed, and mounted on a board with one of the M33 nuts detailed in an earlier post. The whole thing was sealed again, and has since been over-painted to ensure the air-tightness of the whole rig. This first chuck has a ring of flat rubber as the seal between chuck and workpiece, but the next will have a split rubber hose, and I’ll compare results later.
And once set up a trial run was called for. I mounted another piece of 18mm MDF and made the back plate for a second vacuum chuck using the M33 nut again, sealed in with araldite.
I haven’t got the vacuum gauge and dust filter inline yet, it should be delivered tomorrow, but the system works a treat and even with a couple of heavy and aggressive cuts to test the hold, all was well. It should prove a real boon overall. Even better as I managed to get all the hose fittings and hoses from my Father-In-Law for nothing! My Mother-in-law may not like him hoarding “rubbish”, but I do!
And it does go to prove that they really do come in useful one day…