How to manufacture a new chuck backplate for the lathe! Basic guide for turning a new taper adaptor
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- Опубликовано: 2 окт 2024
- A new addition to the workshop lathe, in this video we look at machining a new backplate adaptor to take replace the old three jaw chuck for a shiny new one. By modifying and reusing the old spindle nose adaptor we are able to manufacture a new adaptor plate to mount the new three jaw to the lathe. Bit of turning, drilling and tapping. What more could you ask for?
I just did this exact same job, on an L0. I did not need a spacer, my mount was larger and flat so i machined it directly to the chuck. By some miracle i got it to .0005 on the chuck drum, but the test shaft was about .0025 off center. I guess that will have to do for now.
Got to be happy with that! I certainly would be. I’m very tempted to re-visit this, I could machine something round in the four jaw, grab the bar with the three and machine the spigot. Would just mean re-machining the adapter. Lots of other more pressing things to do unfortunately so a couple of thou will be good enough for now…
I made up a new back plate for my Round Head Triumph exactly the same way, but I had a new Pratt chuck, it still had .002" run out. I machined the spigot slightly undersized and using a rubber mallet knocked it true to about 5 tens. The ground bar runs out by about a thousand and a half 2" from the chuck. I don't think a 3 jaw will do any better, I don't have a 4 jaw, so it's what I make do with.
That’s another reassuring comment about runout. I’m not unhappy it’s 3 thou, I would have preferred it to be a little less though… great idea about the spigot, maybe I’ll have to do that, but you’d have thought a quality chuck would be better from the factory… I had considered grinding the jaws too but as I’ve a 4 jaw I don’t think there’s value in that. Again, appreciate the comment and support 👍
The method you used is a common way to mount a 3 jaw chuck to get it as true as a GripTrue chuck that has adjustable features etc......you can use this method for the oldest crappiest worn out chuck and it will work wonders.....ask me how I know as I have 60 years in the machine shop.
One thing that will relegate a 3 jaw chuck to the scrap heap is bell mouthing where the jaws are worn in the body slots and no amount or grinding will make them run true, usually they have a waggle and it varies to the diam of the workpiece.
Please forgive me for saying this,
I know you mean well trying to express the situation you are expressing
But please try to speak a little bit slow and try to form your words a little bit cleaner for English,
Your dialect if that is what one calls it,
Has a tendency to slur or make it a little bit awkward for myself and maybe a few others to catch what you are saying, I enjoyed the video
Thank you for taking the time to comment. All constructive feedback welcomed, I do acknowledge I get a little carried away sometimes, that is a byproduct of the local twang unfortunately. My recording equipment isn’t the best either so that isn’t helping. You aren’t the only person to have difficulty catching everything so I will try to speak a little more coherently in the future. Appreciate the support 👍
This Old Tony's hands with the correct accent!?
Hardly the legend that is Old Tony but the folk of Yorkshire have always got something at babble on about! Really appreciate the comment and support, stay tuned for more content as there’s plenty on the way!
@@theyorkshirefabshop8776 It's not babble - it's simply telling those not fortunate enough to be born in Yorkshire how they should understand the world...
I enjoyed watching your video and found it interesting, you explained the process you adopted to complete the work very well. I am looking forward to seeing other videos that you have made, regards Gary
Thank you for the feedback Gary, very glad to hear you found it interesting. Watch out for more like this coming soon, appreciate the comment and support 👍
As others have mentioned, a loose fit spigot by 5 or 6 thou will allow you to have a "bump true" chuck, sounds like a bodge but it is really quite acceptable, a poor man's grip-tru.
Thanks for the suggestion. I had been thinking about this recently and what I’m more tempted to do is machine the back of the chuck. I’d clock a ground bar to tenths in the 4 jaw, then grab the bar with the three jaw and take a couple of thou off the face and out of the spigot. That would true the chuck. I have been using the three jaw recently and the couple of thou run-out really hasn’t been noticeable so I’m just leaving it at the moment!
Definitely. I did the same with my Pratt 3 jaw on the Boxford. I hardly use a 4 jaw anymore as I’m able to bump the chuck a few thou to get it running true. I made a back plate today however instead of directly transferring the chuck screw holes, I used the circle function of the DRO on the mill to drill the mounting holes.
I like your content but there are too many adverts so I won't be coming back
Thanks for the positive feedback. Unfortunately adverts aren’t something i can do anything about, we have got google to thank for those… there didn’t used to be ads on small channels because they don’t receive any money but now there are.
Greats videos, man! Picking up a lot from them. Cheers from Sweden.
Thank you for the positive feedback, glad to hear your enjoying them!
really enjoying your channel, cheers from the US......Paul
Thank you for the feedback Paul, glad to hear you are enjoying the content 👍
.003... that's about what I would expect from a new chuck... it's fine
Thanks for the comment! That’s good to hear, I haven’t got anything else to compare it to so it’s reassuring to know it’s Steere abouts. Four jaw for a little more accuracy anyway
Junk yard
This week mounting a new 250 d6 , 4 jaw ,on my minitor d360... same issue with backplate.. so I will make from stock...
Good luck, if you’ve got a pre machined spindle nose adapter like I had then that will make things easier. I also have a 4 jaw I want to mount but it will need a new spindle nose adapter making so that will be a little more involved!
Or213 mm
this looks like a Clausing Lathe.......I have a 6913 that unfortunately has
met the end of its life, really enjoyed this video.....Paul
This particular model is a very local to me British Woodhouse and Mitchell (although were also made under the Town Woodhouse name) manufactured in Brighouse, West Yorkshire. Nice machine in its day but not very popular with the hobbiests so prices are low.
Nothing is ever totally past it, although machines can easily be written off if the work required vastly outweighs the added value of the machine in new working condition…
Hi mate, have just done a couple of chucks to back plates recently, pretty much did what you did, although could only measure with a digital caliper, just got near and kept tickling the ridge till I got a tight fit. I had the same runout like you, with one chuck of indeterminate make, although made in Poland, and was newer. But the old Pratt Burnard chuck was bang on in concentricity with the backplate. It clocked about half thou on a test bar. , but I doubt if that repeats! (I have screw on 1 1/2" x 8tpi) For dead accurate work, I use collets, or 4 jaw. But 3 jaw is good enough for most jobs, after all you turn to make it true. nice work though, enjoy your presentation, cheers, Dave
Digital calipers are as good as anything these days, you’d have easily been within a thou no doubt. That particular chuck wasn’t a cheap Chinese product, which is why I was slightly disappointed about the run-out. I have contemplated holding a ground bar in the 4 jaw, clocking true, then clamp the 3 jaw backwards onto the bar with a view to machining the spigot location, but that would negate the current good fit and mean I’d have to remachine the back plate. Not out of the question, just maybe unnecessary. With a thousand other things lined up it falls quite low on the list of priorities!
Thank you for the words of encouragement, it’s highly appreciated! 👍
Does your lathe have coolant?
It doesn’t unfortunately, I have considered fitting a standalone system for the slower HSS work. Maybe I could build a system in the future? Thankfully carbide tooling is much more resilient to heat so doesn’t generally need it.
my old clausing lathe has the same spindle as yours you need to fabricate the correct spanner wrench and stop beating on the machine like that
Don’t worry, it is on my list of things to do! The problem I have is the previous owners of this lathe have also done this for many years resulting in damage to the locking nut which may be too excessive to allow the proper seating of a c-spanner. Removal of this would involve disassembly of the spindle which I am unlikely to get round to…