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Medallion

PostPosted: Thu Apr 19, 2018 3:04 am
by Mobius
My uncle sent me an image of a necklace medallion that struck true with him, and he wanted a 2' diameter version of it. I was able to adapt the image into something I could cut on the CNC, and it turned out pretty sharp.

He originally wanted it cut from 1/4" aluminum plate, but that ended up being a ton of work with all the tiny details. In the end I made him 4 MDF copies (still took 3 hours each), which he intends to paint/airbrush and give to his wife.

The first two images are concept drawings I made in Fusion360. The rest are the final MDF copies, drawn and toolpath'd in V-carve Pro.

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Re: Medallion

PostPosted: Thu Apr 19, 2018 3:11 am
by ricphoto
That's really cool...like how the MDF held the edges and detail...Nice job

Re: Medallion

PostPosted: Thu Apr 19, 2018 3:43 am
by mark-s
That`s really nice....good job
mark-s

Re: Medallion

PostPosted: Thu Apr 19, 2018 4:13 pm
by rgerding
Really impressive.

Re: Medallion

PostPosted: Thu Apr 19, 2018 4:17 pm
by Leo
Love it - Nice job done well

Re: Medallion

PostPosted: Thu Apr 19, 2018 7:10 pm
by dwilli9013
Very nice. Thanks for sharing.

Re: Medallion

PostPosted: Thu Apr 19, 2018 9:35 pm
by mick40
Can you tell us what cutters you used? For MDF to hold the detail and not rip out your doing something the rest of us would like to know about. Beautiful!!!!

Mick

Re: Medallion

PostPosted: Thu Apr 19, 2018 10:31 pm
by LittleGreyMan
mick40 wrote:Can you tell us what cutters you used? For MDF to hold the detail and not rip out your doing something the rest of us would like to know about. Beautiful!!!!

Mick


Agreed!

I hate machining MDF and I am always amazed by such machining quality.

Re: Medallion

PostPosted: Sat Apr 21, 2018 2:22 am
by Mobius
mick40 wrote:Can you tell us what cutters you used? For MDF to hold the detail and not rip out your doing something the rest of us would like to know about. Beautiful!!!!

Mick


Thanks all.

I used a 1/16" tapered 3 flute EM for the detail, and a 1/4" 3 flute EM for the rest. There were 3 layers (0.5mm, 1mm, 1.5mm), done with offset pocket toolpaths.

I find the trick is in the order things are cut. The fine details on the top gears were cut first, and I skipped the clearance EM, using the 1/16" only.

The rest of the top layer and the two following layers were cut with both EMs. However, I moved the 1/16" finishing passes to the top of the list, so they all cut first and then the clearance passes cut second. Aside from minimizing toolchanges, I believe this is what let me cut fine detail without tearing.

I also hate MDF, I wish I could afford to stock HDU for something like this. It was crazy watching how fuzzy the cut would get the further into the sheet it would go (how less dense the MDF is in the middle, even in 1/4" material).

Re: Medallion

PostPosted: Sat Apr 21, 2018 4:03 am
by Xxray
Dang, looks sharp good job.
I'd spray it down a few times with clear coat, lightly sanding in between coats, to minimize absorption when finish is applied - MDF can soak up finish like a sponge.

Seems to me insulation foam board would be a great candidate for this, very cheap, holds details incredibly and easy to finish.
Downsides are, very messy to work with and very fragile.
Corian too, might be a bit of an expense though if you don't have any handy.

But looks like mdf worked out very well in this case.

Re: Medallion

PostPosted: Sat Apr 21, 2018 12:09 pm
by LittleGreyMan
Thanks for the comments.

I do agree: toolpath order is a major parameter for machining complex designs in this kind of material or in wood.

HDU or solid surfaces as Corian are much more easier to machine.

Again, incredibly sharp job with MDF.