Commander's Challenge

[flyingemt]

All,

My Wing Commander has thrown me a challenge and I could really use some help. Please see the attached image. What I need to do is create an MPC or two MPC's to replicate this bullet and the breech in the center of the arrowhead. The bullet needs to be rounded and the breech should be invertly rounded as to match up.

I am prepared to compensate anyone for their time if they can assist.

Please let me know...

Flying....

[Smoken D]

Cool plaque, is it for the 303rd down at Whiteman?

[ladjr]

I would try to scan. Do you have the scan attachment

[bergerud]

Here are some raw materials to work with. Made using 3d tool rail sweeps.

[eelamb]

Nice work Dan

[flyingemt]

Smokin, actually it is from 303rd. However the "Wing King" has some ideas for some plaques and has asked me to look into all this.

Dan, thank you sooooo much. My 3d knowledge is less than minimal, lol. Please let me know what I can do to repay you.

Mike

[bergerud]

Dan, thank you sooooo much. My 3d knowledge is less than minimal, lol. Please let me know what I can do to repay you.

Mike

My pleasure. The riffling was interesting. If you need the stuff tweaked, let me know. I gave you .png so you can edit.

[flyingemt]

My pleasure. The riffling was interesting. If you need the stuff tweaked, let me know. I gave you .png so you can edit.

Dan,

Sent you an email, is it possible to remove the round to create the entire breech? The casing is 1.75" in diameter.

Mike

[bergerud]

Do you mean you want just the shell without the bullet so it can be inverted?

[bergerud]

Here is the shell truncated.

[Smoken D]

A few things I made for the 303rd at Whiteman. A really bunch of great guys except when they use my place to lock on:roll:

[flyingemt]

Dan,

I'm sorry, what I meant was, take the entire round, shell too, and create the entire breech cutaway. Am I describing this correctly?

[bergerud]

I am not sure what you mean. The bullet has to be carved separate, does it not?

[bergerud]

Here is what I would do. I made it all as big as I could assuming you have Designer 1.187.

[flyingemt]

Here is what I would do. I made it all as big as I could assuming you have Designer 1.187.

Dan, absolutely PERFECT!!! I owe you a bottle of choice....

Thanks again!!


Mike

[bergerud]

I hope it works out. Double check everything - untested!

[flyingemt]

Dan, I'm not the brightest bulb in the box, but how do you do the bullet double sided like your pattern? Just flip the board?

[bergerud]

Dan, I'm not the brightest bulb in the box, but how do you do the bullet double sided like your pattern? Just flip the board?

Yes, just flip the board. The machine will carve the back of the board first and then ask you to flip the board over. The thickness of the board is important and that it has clean square sides.

You might look at: http://www.carvewright.com/assets/tips/CarveWrightTips_and_Tricks_Sept09.pdf

[bergerud]

Here another bullet with a thicker rim. want2b says the rim chips out.

[want2b]

Here another bullet with a thicker rim. want2b says the rim chips out.

Made a tenative run and the base looks great, hope to get time for a complete run today. Will post pic of result.
Many thanks,

Rick H.

[want2b]

The first pic is of the earlier MPC done in poplar, second pic is of second MPC done in some southern pine I had just for a trial. 1st one really had bad fuzzies and I did a lot of cleanup on it, base minimal thickness & chipped. Second one surprised me being pine and was fairly clean, only cleaup was some hand sanding w/240. Did a quick paint job just to get an idea of the finished product. Hope to get time to do one in maple soon.
Again, many thanks to bergerud for sharing his abilities & time.

Rick H

[bergerud]

You are welcome. That looks great.

[flyingemt]

Dan, Want2b,

I did this in maple. I'm seeing pitting only on the right side. Any thoughts or is this just the grain of the wood?

See below...


67210672116721367212

[bergerud]

That looks to me more like something was moving. Either the wood or the bit. Make sure the rollers on the truck and the spindle are tight. That cannot just be the wood.

[flyingemt]

Dan,

I checked the spindle and the truck both. No movement with either.

[bergerud]

Could the wood have been moving during the carve? Tabs not big enough?

[flyingemt]

Could the wood have been moving during the carve? Tabs not big enough?

Negative on the tabs, I set for one side only since using maple. Result post carve was a solid 1/16" perimeter, and then cut bit for the cutout.

[bergerud]

Well I am about out of guesses! Dull bit against the grain is all I have left.

[chief2007]

What was the bit optimization? Also did you carve it at best or optimal carve quality?

[flyingemt]

What was the bit optimization? Also did you carve it at best or optimal carve quality?

Chief, yes, did at optimal. 2+ hrs...

[James RS]

To me it looks to be the grain of the wood at the creation of the curve




Dan, Want2b,

I did this in maple. I'm seeing pitting only on the right side. Any thoughts or is this just the grain of the wood?

See below...


67210672116721367212

[unitedcases]

I have seen some patterns do that before. Is it something that sanded out fairly easy?

[SteveNelson46]

Was the pattern created by importing from a picture?

[bergerud]

Was the pattern created by importing from a picture?

I made the pattern in Designer with rail sweep.

[RogerB]

Was there any curly or figure to the wood? That will do it some time's.

[flyingemt]

No curly, perfect piece of maple.

The pitting in the pictures is even after sanding. So it was extensive pitting..

[bergerud]

Flyingemt now has the rotary jig and so could try the bullet as a rotary carve. I used the original curve to make a rotary pattern. I am not sure it will be exactly the right diameter. I have not carved it. Anyway, here it is: (Designer 2.0 file)

[flyingemt]

Dan,

Diameter is only .02 off and not worried about that. I need to ask a favor though. Can you extend the length to 11.5" and round the tip of the bullet just a hair more. I got to 99% and it snapped at the right side. Other than that, PERFECT!!

See attached..... the chromed one is an actual casing with an aluminum round, so you get the visual sir.74428744297443074431

Mike

[bergerud]

I do not know if this is what you want. If you double click on the board, you can edit the curve yourself. Have you tried that?

[flyingemt]

Dan,

Can you alter the breech.mpc to reflect a casing diameter of 1.875" ? The one previous was great, now I need to lay a real round in one.

Please let me know.....

Mike

[bergerud]

The depth of the carving was 0.8. I think I made it as big as possible for the 0.8 carving depth limit. To scale the diameter to 1.875, the carving depth would need to scale to 0.9375. Do you have Designer 3 or Designer 1.187?

[flyingemt]

Designer 3 sir...

[bergerud]

Ok, see if this works. Fitting a real shell may require some extra tweaking. I think I would carve a test piece of MDF on normal first.

[flyingemt]

Copy, will do sir and advise....