Ye Olde Rocket Forum - Rock-A-Chute Mark II Nose Cone

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- - Rock-A-Chute Mark II Nose Cone (http://www.oldrocketforum.com/showthread.php?t=18498)

Quote:

Originally Posted by John Brohm

The model pictured below I built and presented as a gift to Carl and Miss Sheryl, for all their help over the years. Remembered fondly, missed badly.

I'm sure both Carl and Sheryl appreciated the gesture as well as the craftsmanship that went into that model. Sure looked nice!

Quote:

Originally Posted by BEC

Is that 1.15 inches the long ones or the short ones? They alternate at two different lengths, 5 of each, around the circumference.

I sure get that “smaller than we remember” bit!

Thanks for the catch. I couldn't see that, mine is still in the package and I didn't think to rotate it.

That was the short ones at 1.15" , the long ones are just a scosh over 1.49" so I'm gonna say 1.5" for the long ones.

Be sure to read this thread: https://forums.rocketshoppe.com/sho...=mark+important

Also, does anyone know if the Quest Museum is still accessible anywhere? There were great photos not just of Leeds Sweete but also Sterling Atomic crayon sharpeners being used as Mark II nosecones.

Quote:

Originally Posted by sandman

I have an original Lead's Crayon Sharpener so I measured the ridges.

They are 1.27mm or 0.05" wide and 0.50mm, or 0.02" high.

Very subtle ridges.

It would be a easier to see if I took it out of the package...but I do want to do that. :rolleyes:

The only place it says "leads" is on the bottom. It says, "A Leads Sweete Product".

Do you have a measurement on the exact height? Thanks!
-Jack

Quote:

Originally Posted by BEC

I agree. That picture is lousy, and the pictures I have of another Mark II (taken at NSL 2013) don't show the ribs very well either.

I can try (if I remember) to get a better-focused picture of the one in the MoF next time I'm up there. I have a much better camera in my phone now than I did that December 2010 day when I took the pictures you have.

John Brohm, who is very detail oriented, wrote an article for a club newsletter detailing how to make the balsa Semroc reproduction nose cone that comes in the Mark II retro-retro kit look much more correct. It contains much detail about number, length and spacing, and is attached. I got it from him in another Mark II thread on here (more just below).

I've done a couple of Mark IIs this way, using 1/32nd basswood as the strips, and it is easy to overdo it. The ribs on the actual sharpener are not that prominent....

Added: Here are some pictures from a Mark II thread on here:

https://www.oldrocketforum.com/show...90&postcount=47
https://www.oldrocketforum.com/show...65&postcount=53
https://www.oldrocketforum.com/show...21&postcount=64
https://www.oldrocketforum.com/show...29&postcount=70

Heck, why not just cruise the entire thread for yourself. LOTS of pictures of both the actual crayon sharpeners and John Brohm's reproduction idea....

I've updated the design based on the input from those with the numbers, which helps a lot. Thanks to everyone for your help. Take a look at the design and let me know what you think. If I need to I will go back and create a third version.

That second picture on the thingiverse link looks MUCH better. I'm glad we were able to flush out some real dimensions for you.

Quote:

Originally Posted by Jack Hydrazine

Do you have a measurement on the exact height? Thanks!
-Jack

Jack, I get 2.03" without the removable bottom that's for clean out the crayon shavings.

It is a crayon sharpener after all.

Thanks for the info!

Quote:

Originally Posted by Jack Hydrazine

If the sharpener pic was a little closer and more in focus and taken from a another angle it would helped to figure out exactly how to design it. I've looked online for other pictures, but they were out of their packaging and too far away and if up close they were in their packaging.

In the photo it's difficult to say what the exact dims are of any part of it. I inferred everything from knowing the OD of the airframe tubing and gave it my best shot.

I'd love to hold it in my hands and actually measure it and get some good photos of it.

my sharpener is in storage somewhere, but note that there is a slight "flare" at the bottom (and possibly a circumferal ridge at the very bottom, but that I'm not sure if it is part of the shell or the base.

Quote:

Originally Posted by Gus

I've got the Stine-Carlisle letters, and a couple of other documents on SoAR's links/resources page. I've got the old MMI photos scattered on my disk drive but not on the web. I don't remember what else was there.