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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.? |
Re: Project New type of material
¿ªÔÆÌåÓý
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
From: [email protected] <[email protected]> on behalf of Charles Kinzer <ckinzer@...>
Sent: Wednesday, May 29, 2024 1:17 PM To: [email protected] <[email protected]> Subject: Re: [7x12MiniLathe] 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? |
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? |
Re: Fixed steady rest
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. |
Re: Fixed steady rest
¿ªÔÆÌåÓýThis 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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Re: speed control
"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? On Sun, May 26, 2024, 10:06 AM Aaron Woods via <awoods550=[email protected]> wrote: I have an 11" Logan with a Reeves drive. It is an effective mechanical solution. |
Re: Fixed steady rest
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. |
Re: Fixed steady rest
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:
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Re: Fixed steady rest
¿ªÔÆÌåÓýIn 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.?¡®
--? Bruce Johnson "Wherever you go, there you are." B. Banzai, PhD |
Re: Motor swaps?
He some facts on most motors.?
A 2 speed cooler motor is two motors one is 1725 and the other is 1140 different horse power different torque? Industry motors that two speed is one changing the poles from 4 to 8 pole. Typically 1725 to 840 rpm same torque. They have made motors outside this rule but are uncommon. DC motors are typically the same torque for most of speed range.? The low cost may not be same torque like vacuum cleaners? Dave? |
Re: Motor swaps?
I have the older Consews on my CNC and grinder:
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On 5/26/2024 11:20 AM, BuffaloJohn via groups.io wrote:
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Re: Motor swaps?
ok
I undestend? now but? it is probaly? low power? about une qaurter? hp pr one? haft? at max I also a astronomer? and? we? control? oour? telescope? whit? stepping? moteor? from? washing machine very powerfull? the? tork? is? at? is? max? all? time? whit? this? kind? of motor? also? be? able? to? use? it? as? a? diverder?? you ca control? your late? at about? 22 step? per? turn? easyly? and? more? also jack 47 71 |
Re: Motor swaps?
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On Sun, May 26, 2024 at 8:15?AM Jacques Savard via <jacquessavard=[email protected]> wrote: On Sun, May 26, 2024 at 07:52 AM, Ralph Hulslander wrote: --
Buffalo John |
Re: Motor swaps?
Jacques, . It is a Brushless sewing machine motor. Ralph On Sun, May 26, 2024 at 11:15?AM Jacques Savard via <jacquessavard=[email protected]> wrote: On Sun, May 26, 2024 at 07:52 AM, Ralph Hulslander wrote: |
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