A behind the scenes look at film and television Prop making peppered with everything else creative we do!
When I lent my services to a collegue who was working on a film about 12 years ago, I was introduced to the world of cnc. I remember watching this huge machining centre milling out a slab of mdf and turning it into a fantastic set of gears. I knew that it would have taken me hours to achieve the same thing with traditional power tools. I decided then that I would invest in a cnc router for my own business Oxenham Design. At that time I could turn on a computer, but even to check email seemed like a crazy set of operations. I persevered and learned every piece of relevant software I could get my hands on. I am now fortunate enough to be using Vectric's ASPIREsoftware, and Techno cnc routers, which has helped us to create some amazing projects, both in part, or in full. I thought that this blog would be a great place to share "behind the scenes" adventures with the software, materials and equipment we use, as well as the projects we build.
The other portions of the bear job were the internal plates that would hold the tube and vacuum motor.
Because the model was added to after I imported it into Aspire, all the work from this point will be done totally in Aspire. I pulled 2 cross sections from the model, these 2 sections will make up the front half of the plates that will sandwich the tube that holds the fluff. The distances were already figured out based on the blower motor and stuffer tube set-up.
This was the result of combining the front and back cross sections into a top and bottom plate. The 1/4 arches will get glued to the plates to make a ring that will lock the tube to the plates.
The plan is that the internal mechanics will get assembled separately, then inserted into the final painted machine halves.
The company asked if we were interested in painting the bear to save them time. Styrene is a bit of a different animal when it comes to paint. A lot of paint doesn't adhere in the long run, resulting in flaking off in a couple of weeks, if not sooner. We use an industrial ABS styrene lacquer. It chemically eats into the styrene, and is sand-able in less than ten minutes if you put the part in front of a fan. I decided for the prototype that he would look better if the face was a few shades lighter than the rest of the bear.
Here's the final paint job with the graphics applied. I used the vectors from Aspire to create the final shapes for the sticker graphics. The graphics were colored and drawn in Corel, and printed by our friends at Autotrim in Lindsay, ON.
And with that, the little guy left the shop to have his insides jammed in, and get stuffed into a box bound for Orlando!
I'm looking forward to doing the next characters in the near future, especially after conquering all the unknowns now!
8)
JWO
Our Internet has been pretty sketchy all week, trying to upload images and blog has been VERY frustrating. A lot of unsaved changes, etc. But I'm trying again!
I spent an awful lot of time staring at this view, slab after slab after slab. The whole project was toolpathed with a 1/2" ballnose cutter. 40% stepover on the roughing pass, and 8% stepover on the finishing passes. Again, I ran 2 finishing passes and limited the second, 90 degree pass, to just the edges. All in all, it was a total of 22 hours machine time to get the front and back molds, including the mating plates.
One by one, slowly, the parts started to appear. I removed a lot of the inside of each slab, not only for weight, but to allow easier access for drilling the small vacuum holes that will be required in various places around the mold.
When all the dust had settled around our Techno cnc, this was the final result. I think it came out great! He's pretty cute I think. We were fairly luck in the fact that we didn't have to do any cleanup on him. The company we're making it for is prepping the mold. Even better. No sanding for us!
I was able to drop by the customers fabrication shop the next day to see the final pull. Looks great!
The back of the machine pulled equally as well. You can see the various recesses that will accommodate the internal mechanics of the machine. It will be exciting to model the other characters required for the whole job later!
8)
JWO
While we were working on wrapping up the Zelfs job, we were also right in the middle of our Build a Bear machine prototype.
We were working with another company on building the prototype, so it wasn't totally our job from start to finish. This machine will be a 3' tall portable machine, that can easily be transported from one event to another. If you aren't familiar with Teddy Mountain, basically you buy a stuffed animal skin, and stuff it yourself with the fluff, and add all kinds of accesories like hats and clothes. This machine will get used to blow the fluff inside the empty skins.
The project started with a lot of meetings regarding everything that needed to be incorporated into the molds. We were supplied a set of castors, a telescoping suitcase style handle assembly, and the dimensions for the mechanics. The other big part was the shipping box that it needed to fit into. The size of the box was already determined at 2'X2'X36" tall. Apparently this is the most practical size for 'product to skid' ratio for shipping, as they get 8 cartons to a skid. I spent some time modeling the bear character above for the initial concept approval. With lots of back and forth emails, the front got signed off on.
The other slight complication to the build is that they want multiple different characters over time. BUT, they want to use the same backs for every machine. So ultimately, they only want to have 1 mold for each new character fabricated. A large task, but still quite solvable! I didn't quite now how at first, but I knew the answer would come while I worked away on the 3d model! I won't bore you to much with the initial 3d modeling in Hexagon!
With all the modeling finished in Hex, I brought the 3d model into Aspire. This is where I'll do the stuff that's too tricky to do in Hex. Aspire does an amazing job at adding the much needed draft angle that will be required to vacuum form the shells. You'll also notice I left the curved "tube" inside the bear. Once the piece is vac-formed, this will get trimmed out, and should fit the actual tube that's going in the chest perfectly.
I also punched in all the places that would get the final decals on the finished part. The reason for the punched in areas, is to help protect the graphics from getting caught and peeled off over time. It was way faster to do this sort of thing in Aspire, then any other software. The other addition done in Aspire, was the 2 bottom tabs that will counter-act the 5 degree draft angle on the whole model. These will let the machine stand straight up, without rocking back and forth. I added these as a separate component, so they wouldn't be affected by applying the draft on the imported model.
Once everything that was needed was added to the model, I sliced it up into 3" slabs. I'll be machining this from 4 pieces of 3" thick MDF. I didn't actually have to laminate these slabs up, the company that hired us supplied all the slabs at the size I requested them. NICE!
The material got delivered slightly over the 3" thickness the model was sliced to. This actually suits me fine, as I can mill off the difference for a perfect slab thickness. I also ran a second finishing pass at 90 degrees to the first one, but limited the toolpath to just the very edges. This saved a total of 10 hours machine time, versus wastefully cutting nothing at the top of the slab during the second pass! All of the slabs were rough and finished passed with an extra long 1/2" ball nose cutter. As I don't have a tool-changer (What's that Techno cnc? Why sure, I would LOVE an automatic tool changer:)
I try to keep my tool changes to a minimum whenever I can, so using the same cutter for both tasks, as it saves me the work of changing out the cutter.
8)
JWO
