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I too have collets, but I also purchased a 4 inch 3 jaw from little machine shop that I mostle use. Regards, John Mattis (retired mechanical engineer
I bored my 3" chuck out to 3/4". I no longer use the chuck very often, as I do most of my work with collets now.? Looks like 13/16" would work, but it looks like you would cut into the heads of the 3 little screws the hold the plastic disk in the back of the chuck.? ----- John
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I bored my 3" chuck out to 3/4". I no longer use the chuck very often, as I do most of my work with collets now.? Looks like 13/16" would work, but it looks like you would cut into the heads of the 3 little screws the hold the plastic disk in the back of the chuck.? ----- John
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You can bore the 3 inch 3 jaw out to 0/760 diameter so 3/4 inch stock will pass through John Mattis (retired Mechanical engineer)
I seem to remember some years ago someone had increased the through-bore of the standard 3" 3-jaw chuck, but I can't remember where and didn't find anything in my search.? It may have been , but that site appears to be defunct now.
I was using the lathe last night and the 5/8" bar stock I was using had trouble sliding through the chuck bore.? It was really tight.? How big can you go without causing issues?? I know the screws holding the back cover on are already close to the bore.
Mike
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Should be able to go out to say 13/16" with a boring bar. Owner of Little Machine Shop used to loan out a 13/16" reamer to ream the spindle bore.
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I seem to remember some years ago someone had increased the through-bore of the standard 3" 3-jaw chuck, but I can't remember where and didn't find anything in my search.? It may have been toolsandmods.com, but that site appears to be defunct now.
I was using the lathe last night and the 5/8" bar stock I was using had trouble sliding through the chuck bore.? It was really tight.? How big can you go without causing issues?? I know the screws holding the back cover on are already close to the bore.
Mike
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Re: Project New type of material
Do have delays in work .
Yesterday it was replacing flush valve.? Today is blood and seed for lawn .?
I hope do try a cut today.
The other is health I have stage 4 colan cancer since 2009. FYI I told in 2009 I have stage 4. The treatments makes me tired.? I have had 106 chemotherapy treatments.? Now on a new out in November 28 2023 drug call? FRUZAQLA.? I did post my wife's? deit on American Cancer so all know what did.?
Dave?
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On Thu, May 30, 2024 at 08:43 AM, Ralph Hulslander wrote:
Dave, we want to see what you do!
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Ralph
On Wed, May 29, 2024 at 11:13?PM davesmith1800 via <davesmith1= [email protected]> wrote: Thank you all for information.?
Looking forward to machining the plexiglass?
Dave?
?
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Re: Project New type of material
Dave, we want to see what you do!
Ralph
On Wed, May 29, 2024 at 11:13?PM davesmith1800 via <davesmith1= [email protected]> wrote: Thank you all for information.?
Looking forward to machining the plexiglass?
Dave?
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Re: Project New type of material
Thank you all for information.?
Looking forward to machining the plexiglass?
Dave?
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Re: Project New type of material
I've mainly turned optics from plexiglass but have a similar experience to what others have described, see:
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Re: Project New type of material
Just a advice.
One of you have big experience with Plexiglas: use super sharp tool.
I have no experience with plexiglass, however, I have now done a lot of positive cutting with this tool :
It is mostly made for internal use; however, I use it for outside cut. You can get it from 3 to 8 mm.
I have made a lot of 1 mm , 1 cm long pivots from 2 mm cheap steel in my clockmaker lathe.
The 8 mm tool fit very good in your 7x12 lathe.
And they are super sharp.?
/johannes
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I have machined a lot of plastic.? I favor HSS tools that are VERY sharp.
I also keep a diamond hand hone at the ready to further sharpen a bit after grinding, and to touch up the edge from time to time when turning.? I feel using the hone is a key to success.? It is important to have a very sharp
tool bit.
Plastics can contain a lot of impurities causing them to be somewhat abrasive and dull a tool bit faster than even cutting metal.? Sometimes the bit dulls much faster.? That will make problems as you want a very sharp tool
bit.? So, check sharpness often.
Watch out for too much speed and too much heat.? And watch out for too much feed rate or the tool bit might just dig in and jam or tear the part loose.
Did I mention that you want a very sharp tool bit?
Be careful that the tool grind shape doesn't cause stringy chips that can get caught between the face of the tool and the workpiece and mashed back onto the surface.? If this happens, they can get sort of welded back on to
the surface.? (Stringy chips are a dangerous practice in any case.)
Practice a little if you have material to spare for that.? You could also practice on something else, like cheap PVC pipe, although it probably won't behave exactly like Plexiglas.
Charles E. "Chuck" Kinzer
On Wednesday, May 29, 2024 at 11:44:29 AM PDT, davesmith1800 <davesmith1@...> wrote:
Just plexiglass rod for making game pieces from.
First time turning plexiglass?
All my life has been metals.
Any comments?
Dave?
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Re: Project New type of material
nomaly?
i? use? my? wood? late for? chek? piece? exemple
and? the wood? tools? work? very well? on plexiglase
test it? on wood? tools?
jack 47 71
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Re: Project New type of material
I have machined a lot of plastic.? I favor HSS tools that are VERY sharp.
I also keep a diamond hand hone at the ready to further sharpen a bit after grinding, and to touch up the edge from time to time when turning.? I feel using the hone is a key to success.? It is important to have a very sharp tool bit.
Plastics can contain a lot of impurities causing them to be somewhat abrasive and dull a tool bit faster than even cutting metal.? Sometimes the bit dulls much faster.? That will make problems as you want a very sharp tool bit.? So, check sharpness often.
Watch out for too much speed and too much heat.? And watch out for too much feed rate or the tool bit might just dig in and jam or tear the part loose.
Did I mention that you want a very sharp tool bit?
Be careful that the tool grind shape doesn't cause stringy chips that can get caught between the face of the tool and the workpiece and mashed back onto the surface.? If this happens, they can get sort of welded back on to the surface.? (Stringy chips are a dangerous practice in any case.)
Practice a little if you have material to spare for that.? You could also practice on something else, like cheap PVC pipe, although it probably won't behave exactly like Plexiglas.
Charles E. "Chuck" Kinzer
On Wednesday, May 29, 2024 at 11:44:29 AM PDT, davesmith1800 <davesmith1@...> wrote:
Just plexiglass rod for making game pieces from. First time turning plexiglass? All my life has been metals. Any comments?  Dave?
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Project New type of material
Just plexiglass rod for making game pieces from. First time turning plexiglass? All my life has been metals. Any comments?  Dave?
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Both my 8" HF grinder and my 6" HF grinder shake badly.? The 8" was mounted on a heavy stand and it still ran across the floor unless I loaded down it down with weight...and that was *after* truing the wheels.? During my "rebuild" I found that one end of the shaft is bent (from the factory!) about 8 thou where the wheel mounts.? I'm now trying to get that side down to under 1/2 thou like the other side.? The internal plastic fan blade was also not installed true, but that was an easy fix.
The problem with *only* squaring up the shoulders where the washers mount is that they're really thin, like 15 thou high if I remember correctly.? The tip from the Harold Hall book was to mount larger collars on the shaft to have something more substantial for the washers to rest against.? Great that you got yours smooth without having much trouble.
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Thanks for mentioning that.? I had let my sub lapse because I got tired of too many lame projects.? I may re-sub and then hit up the library.
Mike
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This was discussed in the the HSM Article I referenced.?
--?
Bruce Johnson
The less a man knows about how sausages and laws are made, the easier it is to steal his vote and give him botulism.
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On May 27, 2024, at 10:07?AM, Mark Kimball via groups.io <markkimball51@...> wrote:
It isn't absolutely necessary to use fluid in an autobalancer.? I've read some build logs that used bearing balls in a grooved disk.? Claimed to work pretty good.? The key to proper operation is to make sure the bearings can move freely in the groove.
Awhile back I bought a cheap HF grinder to make a dedicated tool grinder, based on a Harold Hall design.? I haven't made much progress on that but fully expect it will be necessary to add some kind of wheel balancing system to it.
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"If the Reeves drive ever fails on mine, I'd most likely just replace it with a 3 phase motor and VFD."
That's apparently what Shopsmith has done for their newest machines, primarily to get a larger speed range. I've been into my Shopsmith's Reeves drive a couple?of times for cleaning and lubing, and the main failure point is the belt, which you can replace (though it's not an easy job).
A weak point of the Shopmith is that many of the parts inside are made of aluminum or zinc alloys. That was because to use a Shopsmith in drill-press mode you have to lift the bed and headstock vertically, so they tried to keep the headstock as light as possible.? Logan didn't have that problem, so presumably everything inside is steel or cast iron.
Mike Taglieri?
I have an 11" Logan with a Reeves drive. It is an effective mechanical solution.
I can see why electrical solutions have replaced them. It is quite noisy for one, it also takes up a fair bit of space.
3 phase w/ VFD or a brushless motor is just a better solution, more compact, quieter, less maintenance, probably more accurate speed control and I'm guessing also cheaper.
If the Reeves drive ever fails on mine, I'd most likely just replace it with a 3 phase motor and VFD.
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It isn't absolutely necessary to use fluid in an autobalancer.? I've read some build logs that used bearing balls in a grooved disk.? Claimed to work pretty good.? The key to proper operation is to make sure the bearings can move freely in the groove.
Awhile back I bought a cheap HF grinder to make a dedicated tool grinder, based on a Harold Hall design.? I haven't made much progress on that but fully expect it will be necessary to add some kind of wheel balancing system to it.
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I bought a cheap (19.95) Harbour Freight 6"grinder that shook badly. I machined new washere and?took the armature out and squared up the shoulders that located the washers. Also made new shields from aluminum pans. Runs great and smoothly now!
On Mon, May 27, 2024 at 9:42?AM Bruce J via <bruce.desertrat= [email protected]> wrote: In the Nov/Dec 2022 issue of Home Shop Machinist, there’s an article about building a fluid-balancing washer assembly to improve grinder vibration. ?
'Build the?Slawsher: A?Balancing?Ring for Grinding Wheels by G L Carlson PH.D.?‘
I've been working on reducing the vibration in my Chinese 8" bench grinder.? Adding collars for the inner wheel flanges to rest against and making new flanges (ala Harold Hall's "Tool and Cutter Sharpening").? I was cursing having only the 1" rest, when I re-found the steady rest mod doc in the Files section.? Did not have a need for this mod until now.
Putting the rest in the mini-mill vise, with the middle slot edge aligned with the left side of the vise, it was just some up and back on the Y to give me a nice opening for my grinder shaft to fit through.? I wound up with a generous 0.885", and I could have gone even further, since I left about 1/32" on each side.? Maybe one day I'll build a larger rest with a nice flip top like many of the Myford guys have.
Mike
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--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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John Mattis
davesmith1800
GadgetBuilder
Johannes