My plan here is to build a set of mendel parts using my mcwire and mold them so they can be cast in polyester resin. All the parts that cannot be laser cut that is. Is there a good reason no one else has done that? Say from the masters that made the first mendel? If someone ones to lend me parts it would take me about 2 weeks to complete the molds and start pouring sets, I am in US AZ. Seems like a really easy and inexpensive way to make a LOT of parts. Does anyone know or can compute the total cubic volume of all the parts? With that I can give a materials cost easily. Some drilling would still be needed but I think that is pretty reasonable, https://reprap.org/forum/read.php?148,32572,32572#msg-32572 Wed, 14 Oct 2026 21:38:33 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?148,32572,38970#msg-38970 https://reprap.org/forum/read.php?148,32572,38970#msg-38970 >inserts slid out without any resistance at all.
>A good enough result to be going on with.

Hey, this seems very nice idea.. I'll try it with my shapeways mold as well. Maybe I should also try polyester resin.]]> nite69 Casting and Moldmaking Working Group Thu, 11 Mar 2010 16:07:28 -0500 https://reprap.org/forum/read.php?148,32572,38933#msg-38933 https://reprap.org/forum/read.php?148,32572,38933#msg-38933 -------------------------------------------------------
> Polyurethane is available, but not so
> conveniently or cheaply. I've just got to take
> more care over the catalyst proportion and mix and
> fill faster, the stuff is plenty tough enough done
> properly.

For 20 bucks you can get enough Polyurethane resin to pour an entire set of Mendel parts with a 30% failure rate if you needed it. That's pretty cheap.]]> ManDrake Casting and Moldmaking Working Group Thu, 11 Mar 2010 10:19:00 -0500 https://reprap.org/forum/read.php?148,32572,38893#msg-38893 https://reprap.org/forum/read.php?148,32572,38893#msg-38893 VDX Casting and Moldmaking Working Group Thu, 11 Mar 2010 03:29:36 -0500 https://reprap.org/forum/read.php?148,32572,38885#msg-38885 https://reprap.org/forum/read.php?148,32572,38885#msg-38885
Via:
[www.smooth-on.com]

Also, here's a bit of a verbiage-dump by a guy who sells filler.
[stores.shop.ebay.co.uk]

This is also promising, but I haven't tried it:
[objects.reprap.org]]]> SebastienBailard Casting and Moldmaking Working Group Thu, 11 Mar 2010 02:41:58 -0500 https://reprap.org/forum/read.php?148,32572,38867#msg-38867 https://reprap.org/forum/read.php?148,32572,38867#msg-38867 murd Casting and Moldmaking Working Group Thu, 11 Mar 2010 00:40:15 -0500 https://reprap.org/forum/read.php?148,32572,38763#msg-38763 https://reprap.org/forum/read.php?148,32572,38763#msg-38763 Polyurethane Resin from an arts supply store. Extremely simple to work with and will set up in 15 minutes. I'm using it to test all my molds because it's so quick and easy to mix.]]> ManDrake Casting and Moldmaking Working Group Wed, 10 Mar 2010 10:49:57 -0500 https://reprap.org/forum/read.php?148,32572,38735#msg-38735 https://reprap.org/forum/read.php?148,32572,38735#msg-38735 I'll probably use food wrap as you suggest instead of the vinyl tape. Food wrap is PE. The solvents in the putty I used passed through the tape and softened its adhesive, which separated from the mold. Doesn't happen with epoxies. Another lesson learned. When I can put all this learning into practise, maybe ebay then. I wouldn't be happy if I bought today's effort myself though.]]> murd Casting and Moldmaking Working Group Wed, 10 Mar 2010 06:52:22 -0500 https://reprap.org/forum/read.php?148,32572,38708#msg-38708 https://reprap.org/forum/read.php?148,32572,38708#msg-38708
Interesting that duct tape works as a release agent for ?urethane plastic resin?. I'd just have used vaseline.

Food-type plastic wrap works well for in molds as well.

Nice bit of work, though. Going to ebay them?]]> SebastienBailard Casting and Moldmaking Working Group Wed, 10 Mar 2010 03:00:18 -0500 https://reprap.org/forum/read.php?148,32572,38688#msg-38688 https://reprap.org/forum/read.php?148,32572,38688#msg-38688 A good enough result to be going on with.]]> murd Casting and Moldmaking Working Group Tue, 09 Mar 2010 22:43:48 -0500 https://reprap.org/forum/read.php?148,32572,38672#msg-38672 https://reprap.org/forum/read.php?148,32572,38672#msg-38672 murd Casting and Moldmaking Working Group Tue, 09 Mar 2010 19:06:44 -0500 https://reprap.org/forum/read.php?148,32572,36407#msg-36407 https://reprap.org/forum/read.php?148,32572,36407#msg-36407 I think that is great but if I understand correctly it needed a bandsaw, drill press, router and presumably some jigs? I think that still has the barrier too high, it would be easier to just spend the $60 at protovantage.

People make this thing every way possible, out of many different materials. The wooden stuff is utterly great, for the millions of people with that tooling available.]]> SebastienBailard Casting and Moldmaking Working Group Wed, 17 Feb 2010 05:07:48 -0500 https://reprap.org/forum/read.php?148,32572,35523#msg-35523 https://reprap.org/forum/read.php?148,32572,35523#msg-35523 What if the parts were reformatted into arrangements of flat sheets? Cut out from, say, 12mm MDF, then glue the layers together to make the 3D part. Just print the 2D plans, glue them to the board and cut around. Relatively easy if someone can modify the design files.

So far I've got the frame vertex piece made. Editing and printing pepakura layouts works ok so far on the simpler ones.]]> Sci Casting and Moldmaking Working Group Mon, 08 Feb 2010 16:55:39 -0500 https://reprap.org/forum/read.php?148,32572,35521#msg-35521 https://reprap.org/forum/read.php?148,32572,35521#msg-35521
If you're careful you could make that block with a chisel and a hand-drill.. the bandsaw was just used for the corner cut-outs- it's the inner cut-out that's tricky without a mill/router, and the vertical 1/8" hole needs to be fairly precise]]> Triffid_Hunter Casting and Moldmaking Working Group Mon, 08 Feb 2010 16:40:29 -0500 https://reprap.org/forum/read.php?148,32572,35515#msg-35515 https://reprap.org/forum/read.php?148,32572,35515#msg-35515
I think that is great but if I understand correctly it needed a bandsaw, drill press, router and presumably some jigs? I think that still has the barrier too high, it would be easier to just spend the $60 at protovantage. I would also have some concerns about temperature (though I guess it only needs to work long enough to print a plastic extruder carriage). The barrel mounting area on my extruder gets to 400F if I have been printing a long time.]]> goinreverse Casting and Moldmaking Working Group Mon, 08 Feb 2010 15:19:14 -0500 https://reprap.org/forum/read.php?148,32572,35455#msg-35455 https://reprap.org/forum/read.php?148,32572,35455#msg-35455 wooden-mendel.blogspot.com] ;)]]> Triffid_Hunter Casting and Moldmaking Working Group Mon, 08 Feb 2010 03:46:13 -0500 https://reprap.org/forum/read.php?148,32572,35437#msg-35437 https://reprap.org/forum/read.php?148,32572,35437#msg-35437
If someone sends me the parts I promise to return twice as many or redistribute them to someone else. If anyone part is going to be sent please send the single piece mendel extruder carriage. That is the most valuable from a bootstrapping standpoint and the 'keystone' in terms of a repstrap (you need an extruder carriage to build an extruder carriage).]]> goinreverse Casting and Moldmaking Working Group Mon, 08 Feb 2010 00:44:09 -0500 https://reprap.org/forum/read.php?148,32572,34798#msg-34798 https://reprap.org/forum/read.php?148,32572,34798#msg-34798 Sci Casting and Moldmaking Working Group Tue, 02 Feb 2010 18:23:12 -0500 https://reprap.org/forum/read.php?148,32572,34723#msg-34723 https://reprap.org/forum/read.php?148,32572,34723#msg-34723 RyanGeorge Casting and Moldmaking Working Group Mon, 01 Feb 2010 22:52:18 -0500 https://reprap.org/forum/read.php?148,32572,34711#msg-34711 https://reprap.org/forum/read.php?148,32572,34711#msg-34711
Since the Mendel design appears to be over-engineered in places to account for possible printing flaws, and the positioning of the parts can be varied due to their positions on threaded bar frame, I think most of the parts can be cut from layers of 10mm and 5mm sheet material. At least for making mould masters.
There's 6 that I think would still need CNC due to the angles;

# x-carriage-lower_1off
# x-carriage-upper_1off
# y-bearing-360-inner_2off
# y-bearing-360-outer-left_1off
# y-bearing-360-outer-right_1off
# z-leadscrew-base_2off

And there's the 8-tooth gear, which I'm not sure about in the length specified. Unless you get a 30mm width belt to cut down and cut a chunk out of it before splitting. Hmm..

Will keep thinking on it. Some possibilities for the bearing and leadscrew ones, but the carriage ones.. no idea beyond CNC yet.]]> Sci Casting and Moldmaking Working Group Mon, 01 Feb 2010 19:10:15 -0500 https://reprap.org/forum/read.php?148,32572,34600#msg-34600 https://reprap.org/forum/read.php?148,32572,34600#msg-34600 The silicone will seep through any gaps in the printed parts, so you could end up with a part fused to the mould. Rough surfaces also wear the moulds out a lot faster as they provide more points the silicone can rip or split from. Plus for multi-part moulds, a rough surface would make it much harder to mate parts to each other without providing gaps for the resin to leak into. I'd rather not have to manually re-drill 72 holes. Though could be feasible if you don't mind buying unfinished parts.

Waiting to hear back from a couple of affordable-sounding CNC places.. Ultimately comes down to what's economical in time and money.]]> Sci Casting and Moldmaking Working Group Sun, 31 Jan 2010 22:49:42 -0500 https://reprap.org/forum/read.php?148,32572,34592#msg-34592 https://reprap.org/forum/read.php?148,32572,34592#msg-34592 RyanGeorge Casting and Moldmaking Working Group Sun, 31 Jan 2010 21:01:08 -0500 https://reprap.org/forum/read.php?148,32572,34511#msg-34511 https://reprap.org/forum/read.php?148,32572,34511#msg-34511
Multi-part moulds would solve some of the issues. I've made odd-shaped silicone "plugs" to place into setting PU that eliminate my need to precisely drill them out once set.
As far as the threading issue goes with the hex recesses, why not just drill out a nut and braze it a piece of smooth barstock?

From the printed parts glossary, I count 74 holes that couldn't be made by a 3-axis CNC mill. If someone could knock out one of each part on a hobby mill, think someone would consider it an even trade for getting back a full set of Mendel parts a month or two later once they'd been hand finished and replicated? The rough milled versions would be fine in any plastic, or hell even wood!

I've got mixable PU-dyes, so could make them any colour they like too, if that'd sweeten the deal? :) Got a home made degasser too, so the cast parts would be rock solid.

Failing that, anyone know someone who wouldn't charge too much for such a milling-run? And by too much, I mean less than the cost of making a mill myself.]]> Sci Casting and Moldmaking Working Group Sat, 30 Jan 2010 18:39:00 -0500 https://reprap.org/forum/read.php?148,32572,33805#msg-33805 https://reprap.org/forum/read.php?148,32572,33805#msg-33805 It would be really great if as a user you could tag a particular post or thread with a flag. For local user reference. Or to publish as a forum post in the form of links.

Yup. We need to make very clever UI changes to the forum. First, adding mailinglist capability. Second, adding "favoriting" like on metafilter.com.

This is probably a library issue.]]> SebastienBailard Casting and Moldmaking Working Group Sat, 23 Jan 2010 14:09:59 -0500 https://reprap.org/forum/read.php?148,32572,33074#msg-33074 https://reprap.org/forum/read.php?148,32572,33074#msg-33074
It would be really great if as a user you could tag a particular post or thread with a flag. For local user reference. Or to publish as a forum post in the form of links.

So a user could create lists like this in their local forum user account settings:

To do
Research this
Use this for (flashing CPU, making extruder, setting up host)
New project ideas.
Cool application links
Technical reference links .. and s on.]]> BodgeIt Casting and Moldmaking Working Group Mon, 18 Jan 2010 04:36:48 -0500 https://reprap.org/forum/read.php?148,32572,33066#msg-33066 https://reprap.org/forum/read.php?148,32572,33066#msg-33066
> ... I think we're doppelgangers. ... (:P)

There are a lot of people presenting good ideas, but over time they're buried in the shear amount of posts and difficult to undig again :S

I think we need some 'data-miners' for searching/rescuing and representing them in the wiki ...

Viktor]]> VDX Casting and Moldmaking Working Group Mon, 18 Jan 2010 03:21:37 -0500 https://reprap.org/forum/read.php?148,32572,33045#msg-33045 https://reprap.org/forum/read.php?148,32572,33045#msg-33045
Murray]]> murd Casting and Moldmaking Working Group Sun, 17 Jan 2010 19:36:46 -0500 https://reprap.org/forum/read.php?148,32572,33019#msg-33019 https://reprap.org/forum/read.php?148,32572,33019#msg-33019
... your image let me remember my post "Paperwork or sheet-cutting for 3D-molds" from two years ago - go through the atached "K1-"-jpeg's ...

With pepakura it's really easy to design fold-up-moulds out from STL-files and cut or mill the forms from thin plates ... e.g. Dibond :D

Viktor]]> VDX Casting and Moldmaking Working Group Sun, 17 Jan 2010 15:12:27 -0500 https://reprap.org/forum/read.php?148,32572,33015#msg-33015 https://reprap.org/forum/read.php?148,32572,33015#msg-33015
Wade]]> Wade Casting and Moldmaking Working Group Sun, 17 Jan 2010 14:54:18 -0500 https://reprap.org/forum/read.php?148,32572,33000#msg-33000 https://reprap.org/forum/read.php?148,32572,33000#msg-33000
Now that really is a candidate for the Wiki to join in with Sebastien on extending the Wiki to cover all build methods and ideas.

Though I'm not sure I have the ability to visualize some thing in that way to design an efficient 3 dimensional mould like that.]]> BodgeIt Casting and Moldmaking Working Group Sun, 17 Jan 2010 11:32:12 -0500 https://reprap.org/forum/read.php?148,32572,32947#msg-32947 https://reprap.org/forum/read.php?148,32572,32947#msg-32947 murd Casting and Moldmaking Working Group Sat, 16 Jan 2010 22:44:15 -0500