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"Jupiter 1" Cutting wheel in a pencil sharpener

 

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Hi Roy
I did what you told me.
After a lot of pictures and Trigonometry?calculation, I decided to make the fine cut 30 deg. in my mill.
A set up in a homemade jig and I did the fine cut.
The result was very good.?
Then I discovered the pencils use different type of wood.


Johannes Lavoll
Mexico







From:[email protected] <[email protected]> on behalf of Roy via groups.io <roylowenthal@...>
Sent:?Tuesday, July 30, 2024 5:28 PM
To:[email protected] <[email protected]>
Subject:?Re: [7x12MiniLathe] "Jupiter 1" Cutting wheel
?
Yup! By sharpening the B face, you'll restore the chip clearance that's been abraded away from normal wear.
?
It'd probably be worth the nuisance of making some type of guide to keep the same relief angle on all the teeth.
?
Roy
 

The cutter was designed so you can flip it over when one side is dull. Are you going to do something different on the other side? Did you ever find out what kind of threads the missing screws where? I liked your idea of using a slightly oversized dowel threaded into the hole to find the pitch of the thread. Paul M
 

Most pencils are made of cedar - here's a link with more details:
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?< . >
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Cedar being a relatively soft wood, you may need to make the cutter sharper than an end mill leaves it. From my woodworking experience, a little hand honing can work wonders. You can probably reduce honing time by cheating a bit by honing at a slightly different angle, creating a small honed surface at the tip of the milled surface.
?
Roy
 

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Hi Paul and other for feedback.
My Jupiter 1 pencil sharpener has only a cut edge on one side. I think another model has on both sides.
As I have measured it, I think all screws are in inches, the cutting axle is in Left Hand 1/2-20.

A technical question: is -20 tpi a UNF or UNC? ?

I asked you about this inch system . As I understand, there have always been 12 inches in one foot.
However, the length of a foot has varied during time and country. Hamburg, as city, had their own length of a foot long time ago.
Pls correct me.

Pencil wood: I tested my sharpener with both BIC and STAEDTLER, both HB, however, the cutoff stuff was big differently.
One looks like wood. The other was some generic or composite wood.
But the pencils became sharp.

I saw in EBay? an original sparepart cutting disk: EUR 150

I have taken a lot of pictures: maybe I will make a short view in YouTube ?

Johannes Lavoll
Mexico




From: [email protected] <[email protected]> on behalf of paul mcclintic via groups.io <cannontandem@...>
Sent: Thursday, August 15, 2024 5:11 AM
To: [email protected] <[email protected]>
Subject: Re: [7x12MiniLathe] "Jupiter 1" Cutting wheel in a pencil sharpener
?
The cutter was designed so you can flip it over when one side is dull. Are you going to do something different on the other side? Did you ever find out what kind of threads the missing screws where? I liked your idea of using a slightly oversized dowel threaded into the hole to find the pitch of the thread. Paul M
 

Have you thought of using something like Cerrosafe to take a casting of the threads to better determine the threads? Just a thought and not sure that is what you were trying to do.
Ron
 

Roy,
Thanks for mentioning Cerosafe!
I had forgotten about this method!
Dick
 

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??? SO is Cerosafe strong enough to pour into a threaded hole & then cut a slot & unscrew it ? Do ya have to use some kind of release agent ? From what little reading I just did ( wikipedia ) , Sounds like some interesting stuff . I've seen & heard of Cerokote but not Cerosafe , same family ?

thanks

animal

On 8/16/24 7:11 AM, OldToolmaker via groups.io wrote:

Roy,
Thanks for mentioning Cerosafe!
I had forgotten about this method!
Dick
 

From their site, it initially shrinks, then expands a little after it solidifies:
?
?< >
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Other thing, 1/2"-20 is a UNF thread, relatively easy to find, although LH stuff is less common, therefore pricier.
?
Roy
 

Cerrosafe should be strong enough though I have never tried it like that. I have used it making chamber casts in firearms. Depending on the application, there may be enough "sprue" left over to turn the casting out. Cerrosafe shrinks for a short period of time after cooling which should allow it to be easily removed/screwed out. Do not leave it in to long and follow the instructions as after a period of time it will expand. It is also reusable, just remelt it. Be careful using it in areas that are extremely sensitive due to heat getting the metal into other areas and not being able to get it out easily. I did something like that in a lever gun receiver.
 

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This is yet another variation of a fusible alloy?which is manufactured by Cerrobend and other smelters.? And yes it is pretty strong and can be brittle.? ?An AI search disclosed that Cerrobend “is?a metal alloy made of bismuth, lead, tin, and cadmium?that is also known as Wood's metal, Lipowitz's alloy, Bendalloy, Pewtalloy, and MCP 158. ?It's a eutectic alloy with a low melting point of 158° F (70° C), which is 54° F below the boiling point of water.? Cerrobend is useful in many industries because of its low melting point and controlled shrinkage, including: Soldering, Making custom metal parts, Anchoring bushings in drill jigs, Cores for spinning, Tube-bending filler, X-ray and electron radiotherapy shielding blocks?.”

·??????? ?

“Cerrobend is easy and relatively safe to handle, flows freely when molten, and slightly expands after solidifying in a tube to create a snug fit and accurate bends.?It can also be reused without significant loss or deterioration if handled properly.?However, Cerrobend's fumes and skin exposure are toxic, so it's important to take precautions when using it,.?“

We used to use it to make custom shielding blocks for high energy radiation therapy of cancer patients.? A hot-wire pantograph-like ?device was used to cut out molds for the shields from Styrofoam slabs, and the resulting openings then filled with the molten alloy and left to solidify.? When the patient finished their several-week-long course of therapy, the shield blocks were re-melted in a heavy duty temperature-controlled “coffee maker” and the metal reused.?

?

Jerry F.

?

From: [email protected] [mailto:[email protected]] On Behalf Of mike allen
Sent: Friday, August 16, 2024 11:44 AM
To: [email protected]
Subject: Re: [7x12MiniLathe] "Jupiter 1" Cutting wheel in a pencil sharpener

?

??? SO is Cerosafe strong enough to pour into a threaded hole & then cut a slot & unscrew it ? Do ya have to use some kind of release agent ? From what little reading I just did ( wikipedia ) , Sounds like some interesting stuff . I've seen & heard of Cerokote but not Cerosafe , same family ?

thanks

animal

On 8/16/24 7:11 AM, OldToolmaker via groups.io wrote:

Roy,

Thanks for mentioning Cerosafe!

I had forgotten about this method!

Dick

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