I think I've got all the tools I need and I've started makeing more progress on my key to time project. I decided to start a new thread to try and keep my momentum up and I'll try to add pictures and updates over the comeing days.
My current goal is to have all the parts made out of foam before the 20th as that is when my vacation ends.
I've also gotten my first order of casting materials to make a mold. Once I've got the pieces made I'll need to do up mold boxes.
I would also like to appologize to Exilea as I won't probly get very far with more acrlic key parts untill I'm done with this. I have a bad habbit of not finishing these kinds of projects so I want to devote my energy to one thing at a time.
So here are my first pictures. A couple of my work place as untidy as it is and one pic of each of the two parts I have finished. I posted pics of the smaller piece earlyer but wanted to re-do it for a better finish on the cut faces as my new cutting tools cut much smoother.
Here's the mock up for the hardes cut so far. It's a notch out of the corner. This is the pieces I had done up in acrylic.
It is based upon the 6inch theory from the boards so the end result should be a full 6x6x6 cube.
Two more pieces down and two to go. I have enough done to do a quick tape together test fit. I'll have those pics in a bit, I must have missed them when I uploaded them. It's not 100% so I might need to re-do once pieces but the others are close enough that I think some putty and sanding should bring them into line.
Hey that is an awesome idea. I was thinking also that the use of peperakura, its basically paper modeling. I know several members of the RPF have used it to build helmets, you feed the measurements into I think its a website to get the dimensions and scale, you then print out the image and fold it 3-D into the shape, its all numbered sides. Once you have done that you can give it a coat of resin and fiberglass to harden it up and get a starting point for a master mold. As I said I have seen several helmets made in this fashion and it worked out brilliantly. Any one else heard of this method?
Finished one more pieces, almost done with the first bit I think. I started work on the last one but do to a minor mis-calculation I botched that one and will need to do it later this evening.
I also put them together for an almost done test fit and I am fairly pleased with the result. I haven't decided yet if I think it's too big though. It looks rather large. There are quite a few gap issues that don't show up in the pic but I am hopefull I can fix most of them when I move on to part 2, putty and sanding.
I also have not entirely decided about the detector holes. Mostly likely I'll wuss out and not put those in but it is still an option at this point in time.
If you think you can pull it off, i would definitely try to put the Tracer holes in it. I was wondering the other day how hard that would be to put those in without messing up the progress so far. Let me know how that goes!
I finished up the last piece today. Sadly it contained one of the harder cuts, took me three trys to get it right pft. Here's the finished cube with todays sponsor Squirt for size referance.
Still not sure if I can fix all the gaps but I'll give my best.
Sadly I think it would be best to use two of those wire scroll tables for best results. One set up for strait cuts and one set up for 45 degree cuts. This would greatly reduce any variation in cut angle from adjustment.
So now on the to the next step, puttying up all the parts and slowly mating together all of the internal angles.
Very slowly. After running into the two pieces that needed re-doing I've been going over the overall fit of the other pieces and I'm not real happy with it. Not convinced that I can fix it with putty and sanding.
So, the good news.
I have decided to finish one of the pieces all the way through to completion, I'm shooting for some time later this month. If it turns out well then I am going to start re-fabbing pices one by one fitting them to each previous pieces. Hopefully I'll be able to maintain a decent fit with this method.
I've never done anything like this before so everything is a bit of hit or miss. I've got some vacation comeing up in September so more progress should manifest then.
I tride my first attempt at mold makeing. It was definately a learning experiance and I needed to use up the mold rubber before it went bad.
I ordered a product called Oomoo from Smooth-On. It is an inbetween product that is an easy mix of 1 to 1 but still has all the possitive properties of a latex mold rubber.
Saddly I did not have enough to fill my mold box so it will have to be re-done but I can definately do things better the second time around. There was some seapage up under the part that led to a corner getting broken off during de-molding but that was easily fixed. A few stains but other wise flawless release with no release agents or prep work of any note.
If anyone is looking to make any molds of their projects I definately recomend this product.
Mold box V1 too big
Mold Box V2 still too big
Mold Box v3 still too big but close, went ahead with pour.
Finished mold, drys shiny but it is ready for de-mold
Time for de-mold!
Finished, though unuseable, mold. I was quite impressed with the level of detail.
Now to order two more kits of Oomoo and try again!
Both companies also have some great tutorial videos as well. You can find them on their site or on Youtube with a tap plastic search or smooth on search.
For the lazy people like me I suggest the Oomoo for molds that you don't need to last a long time and Tap-plastics silicone mold rubber for molds that will have the longest use life. Neither require pre-mold or pre-casting preperation of the parts like the cheaper polyurethain rubbers.
The Tap Silicone is harder to mix and is best used with a digital scale as it's ratio is different. 10 to 1 if I recall correctly. It also needs poured differently use the 'bombs away' method described in taps video unless you have the bucks to shell out for a vacum chamber. I may try this stuff next but Oomoo is just so much simpler.
You can also see that the standard Oomoo kit that I purchased will go quite a ways if you arn't doing something as large as key pieces. For screwdrivers and keys and what not one kit could do quite a few molds. It is best to get mulitples ready if you have them since no mold rubber has any apreciable shelf life once the seal is opened. It's pretty much use it or lose it.
Lastly, Tap has a clear plyester resin that I am going to try to make my parts our of in the end. But they also have dies and colors to tint that product. It could easly be used for scredriver lenses or any other clear or transusanct colored pieces.
This is a link to the clear casting plastic but it is available off the shelf at Michels craft store in the 16 and 32oz size cans so you don't have to wait for or pay for shipping.
Post by meantimebob on Aug 30, 2008 21:12:34 GMT 1
Fascinating thread this.
If I can just make a suggestion, you may find that such a large rubber mold with relatively thin walls may flex when you try to use it and some of the the flat planes around the outside will be bowed. A simple solution to this is when the rubber has gone off, remove the cardboard wall but, before removing the plug object, put a plaster and scrim jacket around the mold. That will hold everything in place nicely.
Hope that helps. Looking forward to seeing this project, great work so far!
I've been testing the clear plastic for the final product by doing some crafty embedment items. I'm haveing a bit of a bubble issue but oddly I'm hopeing that I can use a foodsaver vacuum packer off ebay as a poor mans vacum degasing chamber. This stuff smells pretty strongly like testores plastic modle glue while cureing but it cures hard and very clear and is the stuff I can get off the shelf down at Michaels craft store.
I have also found that Smooth-on now carries a clear compound for home use as well but it dosen't cure hard, it stays the consistancy of stiff rubber. This isn't the final stiffness I'm necesarily looking for but cures very clear as well and may be a good alternative. It would also be much easyer to add detector holes to the finished piece if I so decide to try that out.
Here are the items I embeded while I wait for the funds to order up more Oomoo for the re-mold of my first piece.
P.S. Meantimebob - Thanks for the tip. Once I get the mold made I"m going to cast the first piece in plaster of paris. I should know then if there is going to be any bowing issues and only be out a couple bucks.
Here are the options I've found on line for casting clear items.
Cast'n Craft polyester clear resin which I used above. This is actually a very easy to use product, is the cheapest of the other options by weight, and the heat out-put appears to be very manageable by amount of hardener added without effecting the final product. Can be purchased off the shelf at Michaels
Encapso k is probably the simplest product with a 1 to 1 mix ration but is a little spendy if you are doing a large casting and doesn't cure hard. Has to be ordered on line.
Easy Cast clear casting epoxy also cures hard and is a 1 to 1 mix ration. After e-mailing the company they advised against doing very large blocks of this material as it produces more heat than the polyester resin. I headed that advice and have not tried this product. This is also available off the shelf at Michaels however.
Crystal Clear urethane from Smooth-on looks amazing but is for industrial use only and sounds horribly toxic requiring special preparation and equipment. On line only.
ArtMolds AquaClear Resin and Por-A-Kast Clear Casting Resin can both be found at www.DickBlick.com but are quite expensive. These may end up being the best long term option for the do-it-yourselfer as they are UV resistant unlike the cast n'craft or easy cast options. On line only.
Lastly, when I inquired about the Cast'n Craft and easy cast it was recommended that if I wanted something UV stable and clear to consider having an acrylic casting made at a foundry. I looked around on the Internet and only found one that ever responded to my emails was www.meisnerart.com. He seemed to think it would simplest to machine the parts but I couldn't get my 3d models into a usable cad file format and never finished getting a quote.
Coloring - For other projects that mite require a spot of color both Tap Plastics and Smooth-On offer Opaque and Translucent pigments to color their clear products. This could be used for making colored lenses for LEDs and such with the proper mold.
Wow I talk a lot. Sorry guys.
Last Edit: Sept 12, 2008 19:02:57 GMT 1 by Darksyde
Post by meantimebob on Sept 13, 2008 1:39:40 GMT 1
Glad you thought my tip was useful. Testing it with plaster first is a great idea.
Those embedded tests worked well. As for the air bubbles, once you've mixed the stuff and before you pour into the mold, sit the mixing pot on a vibrating surface (washing machine on final spin would do) so that the bubbles rise to the surface in the pot and you can blow on them to be rid of them. Then pour very carefully and blow on any further bubbles that rise up.
So for those embedded tests, what were the molds made of? I've found that using resin in rubber molds tends to leave it slighty sticky unless it remains in the mold for a very long time. Maybe your stuff will be fine though, hope it is, I want to see this great project completed.
I haven't used anything else with the stuff yet so I don't know if it will stay sticky against the Oomoo like you mentioned so I may have to test that next as well. If it is just the very outside that stays sticky then the resin spray I ordered to finish the botoms will probly work as well to set the out side and let me sand and polish. Only time will tell.
Well. Attempt # 2 is cureing as I type. I didn't make the mold box quite as much to fit as last time and I regret doing so. I pretty much came up just a hair short on mold rubber even with 3 kits. Some times short cuts just aren't worth it. Live and learn I guess. I added some small blocks and fillers while the mix was still wet to try and help out. The botom of the mold will be a funny shape but I think it got up over the master part high enough for a good mold. I'll just have to wait and see what it looks like after I crack it open.
My last minute fixes seem to have worked and that is a much better thing than I suspected. My master took much more damage this time around than last time. Not sure if I can fix it so here's to hopeing my castings come out right heh.
I have pulled everything apart and just need to do a little more clean up and I should be ready for my first poor of plaster of paris some time in the near future. I'm still pretty far away from a finished part as I see it but I'm slowly getting closer.
Oh, and I spiled a little of the mold rubber on my newspaper I had down and discoved that it picks up ink realy realy well also heh.
Got my plaster casting out today. Came of the mold like a charm. It has some serface bubble defects but i'm not doing anything important so no worries with one. Everything seems to be up to an acceptable quality so the next thing to do is clean up my mold, rub down some mold release and mix up some clear polyester resin. The end of Piece #1 is in site.