Est. 1998 — 27 years of woodworking knowledge
Creating my own longworth chuck
Mike Schwing
I'm fortunate to have access to millions of dollars worth of tools where I teach woodturning, so I decided to build my own Longworth Chuck and took some pics and videos along the way. Mine is made from 1/2" aluminum I cut on our waterjet and powder coated in our own ovens. It works well, but have a vac chuck system on the way. Here's an album of the creation. (yes I can make these for you, we'd have to talk)
https://goo.gl/photos/SeqbCTtrngCFvWhL7
Re: Creating my own longworth chuck
Dick Coers
You made a longsworth but bought a vacuum chuck? Surprising!
Re: Creating my own longworth chuck
Mike Schwing
Yes. I'm not the only person using our lathes, so I built the Longworth for shop/community use. I've been using it as well, but I'm remembering my vacuum chuck fondly from years ago and admit it is a better solution than the Longworth.
Re: Creating my own longworth chuck
John lucas
A.longworth will.hold bowls.with hoes.and cracks, a vacuum.chuck.wont.
Re: Creating my own longworth chuck
Mike Schwing
Thats why I'll have both John. I most definitely prefer the vac chuck over the Longworth. Both have their place.
What I meant
Dick Coers
What I meant is if you have access to a million dollars worth of machinery, and the capability to make a longworth, a vacuum chuck should be an incredibly simple task to make. Not that one is preferred over the other.
Re: Creating my own longworth chuck
John K Jordan
No fair. You have access to nice toys for cutting things.
JKJ
Re: Creating my own longworth chuck
Mike Schwing
I do. Let me know what you need.
Re: What I meant
Mike Schwing
Gotcha. Yes the drums are easy to make, and with an industrial supply of compressed air I'm thinking of using the vac generator from Grizzly at http://www.grizzly.com/products/Stick-Fast-Vacuum-Generator/T1168 . Anyone have any experience with this thing?
BTW, here's the shop in which I work. I took these pics when I first started there.
https://imgur.com/gallery/l8wnk
Venturi vacuum generator
John K Jordan
I don't have experience with that (I use a pump), but I do know some are quieter than others. A gentleman at our club, John Tarpley, has some experience and brought one for a infusion stabilization demo and I could barely hear it. I could check my notes for the brand or give him a call if you'd like.
Joe Woodworker has some information both on vacuum chucks, pumps, and venturi generators. I put a link to his vacuum chucking page in another thread yesterday, but here is is again along with a page on venturi generators.
https://www.joewoodworker.com/veneering/vacuumchucking.htm
https://www.joewoodworker.com/veneering/v2-about.htm
The venturi info concerns vacuum presses but Joe says it will work fine with a vacuum chuck. If not also use for a vacuum press all the extra hardware to monitor and maintain pressure could be eliminated.
JKJ
Re: Venturi vacuum generator
Mike Schwing
Thanks John. Joe actually lives pretty near me and I've bought veneer stuff from him.
Re:Be CAREFUL
Don Evans
The ONLY time I have been hurt on a wood lathe was back in the 80's when we didn't have all the 4 jaw scroll chucks and a lot of other things available today.
I was trying to find a way to finish the bottom of things on the lathe instead of off the lathe. I saw an article in Fine Woodworking for what would be referred to today as a form of cole jaws. So I said that should work, and I made it.
First time using it, BAM! Lot of blood from my head was running to the floor.
It would have work fine had it used some form of rubber grippers like the ones sold now, but instead used wooden ones, which broke or one of them did and that is what nailed me.
I swore right then that I'm not gonna make my own tools and now days there is no reason too. Too much well made things out there to do the job.
But that's just me! With my now 40+ more years of experience I would not have made the mistake I did then.
So good luck with that.....
Don
Re:Be CAREFUL
John K Jordan
Also, a report in the last year or so said someone was injured when a home-made longworth chuck came apart. I didn't find out if it was due to poor construction, too high a speed, violent turning, ???
Re:Be CAREFUL
mikeee12345
What could possibly go wrong when you build a home built tool that rotates at 3500 rpms on a lathe? Too many of these home built projects are made with sub-standard materials that have the potential to fail when materials used in the construction of the tool come apart under load. Some of these tools work fine at lower speeds but once you reach the higher rpm's the reliability and safety of the tool goes out the window. A more experienced turner usually knows these limitations, whereas a new turner may have missed the warnings from the owners manual or tutoring from a professional or club demonstration.
Re:Be CAREFUL
Don Evans
Here is what happened in my case. Remember this was in the early 80s, the lathe was a 1956 Delta. Variable speed? What is that?
It had and still has a Faraday motor on it from the 1940's Unbelievable torque, within about 1/3rd of a second it was at full speed. I had the belt set for it's slowest. I was using a machinist chuck on it which held onto the home built coles but one of the hold down gave way and BAM!
This lathe has been in storage for many years but I turn a lot on it with no problems other than that one.
Then came the Nova 3000 which I also liked but I still wanted the Oneway 2436 which came next, it's just so much better made there is no comparison, I more than likely would have gotten a Robust had they been available at that time.
Don
Re:Be CAREFUL
Mike Schwing
Thank you John. I can assure the readership that anyone who saw my Longworth chuck would consider it professional grade. It never goes above 600 RPM, and if I'm SUPER invested in the piece I also wrap the whole bowl/chuck in shrink wrap to ensure further that it won't go flying off on that last little cut of the remaining nub. (TBH I usually sand that nub away as it is prone to a catch) It has so much energy behind it though that it will unscrew itself if I don't use a set screw on the spindle, and the brake on the lathe will go bonkers and need a reset period if I turn the speed down to 0 at once rather than slowly bring it down. The only mod I would do if I made another is put finger holes on the backside plate as well.
The future
John K Jordan
>>> I can assure the readership that anyone who saw my Longworth chuck would consider it professional grade.
I can believe that, based on your photos! Perhaps the one that came apart was made of plywood or something and operated without wisdom.
Some day we'll have bluetooth chucks and such that can communicate with the lathe and limit the speed to that 600 rpm or whatever. This lathe will also detect out of balance blanks and either limit speed or activate internal counterbalancing. It will detect the inertial mass and adjust the acceleration/deceleration accordingly so my ornament finial will stop quicker than that 30 lb bowl blank. Digital indexing and auto advance. Push-button micro adjustments on the banjo/tailstock with CNC control for attached rotary tools. Rapid rewind and ejection from tailstock with auto advance for threading, etc. And an automatic sharpening port on the headstock - insert working end of tool for a programmed perfect grind and mirror honing in seconds.
JKJ