I ave seen the jaws "fixed" bt externally clamping on a ring then run s grinder up the inside of the jaws, BUT, Mr Bravo, I do like your method, do I spy a counterbalance weight?
I ave seen the jaws "fixed" bt externally clamping on a ring then run s grinder up the inside of the jaws, BUT, Mr Bravo, I do like your method, do I spy a counterbalance weight?
No counterweight needed. Chuck will only turn 75rpm whilst grinding
Brilliant stuff - watching with mucho anticipacione!
+1. I barely understand and am completely in awe - so if you told me Gandalf had fixed it I would believe you, but, as impressed as I am with the actual machining I am even more impressed with the lateral thinking that brings you to the design.
So started to cobble up a way of grinding the jaws Made an adaptor to fit a small grinding wheel to a long shaft bench grinder Took off the toolpost ,mounted the grinder and covered up the bed Grinding speed was on the slow side at 3000rpm but by spinning the chuck in the opposite direction at 75rpm it became use able Multiple small cuts with the power feed engaged got the job done,with frequent stops for the grinder to cool down. After the first go at this,it was a lot better,but not perfect. I took the chuck off, cleaned it again thoroughly. Did find one slight burr internally that I stoned off. Reassembled and reground the jaws again.
End result? 0,01mm run out that is repeatable. It’s better than when it was new. Well worth the two days of messing about 😊
I ave seen the jaws "fixed" bt externally clamping on a ring then run s grinder up the inside of the jaws, BUT, Mr Bravo, I do like your method, do I spy a counterbalance weight?
Externally clamping on a ring is a waste of time as it loads the jaws in the wrong direction. After grinding ,the clamping concentricity will be worse than before. If you want to test the theory, clamp a bit of round bar in soft jaws, remachine the outside of the jaws to suit a hollow , internally machined bit of thick wall tube. Clamp the tube internally with your freshly machined soft jaws…..don’t bother fetching anything to measure the run out,it will be clearly visible,even without your glasses on 🤣🤣
You should be ragged, tagged, debagged and left with a tingling aargh sole for admitting to owning such filth. 🙄🤣🤣Quickest way to stuff up the slide ways on a good lathe…. If you can’t turn a precision size finish, you won’t grind one with a tool post grinder either
You should be ragged, tagged, debagged and left with a tingling aargh sole for admitting to owning such filth. 🙄🤣🤣Quickest way to stuff up the slide ways on a good lathe…. If you can’t turn a precision size finish, you won’t grind one with a tool post grinder either
It is used as a milling attachment with a speed controller, it was made up as an easy option to drill some small holes in a shaft at 30degs...... I have never used a grinder on a lathe, done plenty of cast iron tho, which, as you know nearly as bad.
I ave seen the jaws "fixed" bt externally clamping on a ring then run s grinder up the inside of the jaws, BUT, Mr Bravo, I do like your method, do I spy a counterbalance weight?
No counterweight needed. Chuck will only turn 75rpm whilst grinding
counterbalance weight from a Lift, not a counter balance weight for turning
You should be ragged, tagged, debagged and left with a tingling aargh sole for admitting to owning such filth. 🙄🤣🤣Quickest way to stuff up the slide ways on a good lathe…. If you can’t turn a precision size finish, you won’t grind one with a tool post grinder either
It is used as a milling attachment with a speed controller, it was made up as an easy option to drill some small holes in a shaft at 30degs...... I have never used a grinder on a lathe, done plenty of cast iron tho, which, as you know nearly as bad.
The one thing I never liked about this lathe was the toolpost. I seemed to spend more time looking for shims to pack tools up with and get them on centre,than anything else. So I started looking for a better set up. In the meantime I had 100 three inch diameter shafts to make. Plan was to face, chamfer and centredrill them in the big lathe, and finish them off in the Cnc. So, 40 years after it was supplied new, the rear toolpost came out the wax coating
Wax off Fitted to the lathe temporarily,it transformed that job
It was around about now,that a very annoying fault developed where the lathe would seemingly randomly trip the circuit breaker. . Normally just on or after switching the machine on so that the motor was running but the clutch wasn’t not engaged,but occasionally whilst you were actually turning. It didn’t really seem to follow a pattern apart from it seemed to be worse the day after alot of use. Checked all sorts of things,but nothing really apparent showed up.
I also started looking for a quick change tool post. I didn’t want a Dixon type as I think they are totally overrated,so I started looking for a big Multifix C. Swiss made, they are the dogs danglies especially on a big lathe. Extremely rigid and repeat consistently. . Managed to find the tool post 😃 …but the holders were going to prove very difficult to source and for a very recent world event issue…..
There are loads of Cheap Chinese knock offs. Unfortunately most are not manufactured the same way as the originals and do not repeat well…They use cheap steel of the wrong grade and, unlike the originals, are not hardened.
The Multifix C type toolpost I have is an original one made in Switzerland. It’s the second biggest one they made and so isn’t that common place. Multifix themselves have been bought out or taken over a couple of times. So, the search for toolholders started. Whilst there are some original ones for sale on Fleabay, they have been there for years as they are special application, basically redundant these days and totally over priced. I did manage to find a new boring tool holder at a reasonable price
From a lot of research, I found out that there are a couple of companies in the U.K. and in Europe selling these holders. All non original, but a very high quality Chinese copy. Manufactured from the correct steel with the splines Wire EDM machined in and hardened. So, I started enquiries. Of course they won’t actually admit they are Chinese made,but neither would they prove otherwise. They all evidently came from the same factory. So ,with more digging I found out where. Create tools…😃
Very good reviews, apparently excellent service,and a really good website. The Lady to speak to is Nina. She gets back to you within 24 hrs and will handle all your enquiries. Not a single negative comment to be found about her or the Company. So I pinged over an email and waited….
