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Trefoil Knot Mold

Posted: Wed May 28, 2014 4:20 am
by Toby
Edit 7/19/14: The mold now has commercial value to me. Sorry, no more details!

Re: Trefoil Knot Mold

Posted: Wed May 28, 2014 5:05 am
by jimc
lookin good and nice job so far.

Re: Trefoil Knot Mold

Posted: Wed May 28, 2014 9:48 am
by rgproduct.com
Great project.

If you need any advice regarding large real moulds/castings/layups for production etc please ask.

http://rgproduct.com/?page_id=533

http://rgproduct.com/?page_id=594


R

Re: Trefoil Knot Mold

Posted: Thu May 29, 2014 5:41 am
by Toby
Edit 7/19/14: See first post.

Re: Trefoil Knot Mold

Posted: Thu May 29, 2014 11:23 am
by rgproduct.com
A thought, does your fan need finer aiming? If it is blowing filament extrusion off then maybe it is aimed a smidgen too high?

I have seen those printed cowls that aim more tightly below the print head.

Do they help?

Wrong printer but identical item:

http://www.thingiverse.com/thing:34863

http://www.thingiverse.com/thing:69327

Right printer, more complex:

http://www.thingiverse.com/thing:344950

complex and right printer:

http://www.thingiverse.com/thing:264899

...and possibly the best 404 page ever: http://www.thingiverse.com/thing:153654



R

Re: Trefoil Knot Mold

Posted: Thu May 29, 2014 12:15 pm
by Toby
A fan duct may work, unfortunately the only one of those that is designed for the M2 with the stock makergear extruder is also the one that has no pictures of an actual print. Not a good sign...

The idea came up recently to design a fan duct for the M2 as a challenge for this group. I have it kicking around in the back of my mind but nothing more than that yet.

About casting questions... have you ever cast ceramic? If you can picture this trefoil knot mold I'm making, would it be possible to cast with it in ceramic? I'm thinking I'll run into problems with the ceramic shrinking in the mold while it dries. It won't have anywhere to go without cracking. I don't think slip casting a shell will work because the plastic mold won't behave the same way a plaster mold does. So it would have to be a solid cast. But I have zero experience and am just guessing from what I've read.

So far I've been casting in something called Permastone (from Activa in the US), which is a plaster mix but very strong. It has practically no shrinkage so it works in these kind of molds. Do you know of any ceramic slip that won't shrink ?

Re: Trefoil Knot Mold

Posted: Thu May 29, 2014 12:42 pm
by rgproduct.com
Yes, I have...

http://rgproduct.com/?page_id=1411

I use a Jesmonite type polymer gypsum. Or a version of it for my speakers on a rotation moulder i made. They come out stunning and finished as per website photos.

www.rgproduct.com

It is like cold cast ceramics.

Why not just print the shape in clay filament?

R

Re: Trefoil Knot Mold

Posted: Thu May 29, 2014 1:56 pm
by Toby
I just had time to glance through your web page. Looks like a great story about the speakers and I'll go back and read it more later. How do you intend to use your M2 in your work?
rgproduct.com wrote:Why not just print the shape in clay filament?
Biggest reason is that it will take upwards of 30-40 hours (my guess) and when it's all done, you have just one. With a re-usable mold, you print once and then can make multiple copies, in different materials. Chocolate trefoils anyone?

Also I don't know how well those new filaments work in practice, or what damage they might do to my M2.

Re: Trefoil Knot Mold

Posted: Sat May 31, 2014 7:41 am
by Toby
Edit 7/19/14: See first post.

Re: Trefoil Knot Mold

Posted: Sun Jun 01, 2014 8:07 am
by Toby
Edit 7/19/14: See first post.