Showing posts with label Astromech. Show all posts
Showing posts with label Astromech. Show all posts

Friday, June 26, 2009

Ankle time

My legs are actually complete but I forgot to take a photo. This one was near completion. I tend to keep some of the paper templates stuck on until near the end, for drilling guides etc....




Okay, so these pieces of .125" (3mm for those of you without freedom of speech) styrene will become a legitimate ankle.
By the way, I have got a few jabs for my dislike of that communist metric system, but I have to say I am protecting the best interests of America here. After all, the commies also tried to get americans to embrace the Decabet. This was a metric system version of the alphabet. In the Decabet, the first four letters, A, B, C, and D remain the same. The letters E and F are combined into one character, Г. For example, the word "eagle" would be spelled "ГaglГ" and would be pronounced, "Ee-fag-lef" The letters G, H, and I would become one letter, "GHI" and the letters L, M, N, and O would become "LMNO", pronounced "Elemenoh", as in, "Please lmnopen the door."
Lastly, the so-called "trash letters" (P through Z) would be combined into a single letter, so an ordinary "stop" sign would look like an incomprehensible mess of letters all squashed together. For example, the word 'alphabet' would be spelled A-LMNO-PQRSTUVWXYZ-GHI-A-B-EF-PQRSTUVWXYZ. We don't want that in these United States.


Dave labeled the four pieces I'm gluing together in the next picture "MAO", which PROVES the aussie commitment to Maoism. The ankle axis hole is not yet drilled but the cable access hole was drilled to 3/4" with a Freud forstner bit. I mean, I say Freud forstner but it is easier to remember it as Fred Flintstone. In the original soviet plans, the hole was supposed to be 20mm.
I did drill a 3mm hole (with an actual liberated 3mm drill bit) on the axis so I could align all pieces with a nail.

The whole thing got glued to the MALS parts and a nail is used in the 3mm hole for alignment. I was a bit surprised to find out that the diametre of my nails is indeed 3mm.


Now I glued the parts marked MAS. These parts had to be chamfered. I suggest looking to Bjoern Giesler's blog for a good way to practice chamfering. Chamfering will be the most annoying thing you'll do in this build and there is a lot of it. It never ends up the way you want, but it gets close enough that you can fix things where needed.


Next, the part labeled MALB goes up against the MALS block. Be sure you drilled a 5/8" hole so the copper pipe (or if you are extremely lucky, a towel rail as in the plans) can go through. Observe the chamfers on the MAP1 uprights and add those. Add MAB and the 2 MAP2 pieces.

When I checked the top edge, some edges were not the right height. I got them flat with the bastard file. When cutting thick styrene, sometimes the edges have a bit of diagonal flashing. I try to always file those before gluing.
I'm missing a few photos but here's the end product. I skinned the sides with .020 styrene (0.5mm for those of you learning Russian as a second language).
I haven't blogged in a few days mostly because I wanted to have photos to go with what I write. But so far I have the skinned body, two shoulder hubs, the legs and the ankle. I might have a bit more going on but I'll do another update this weekend. It's hard to do anything when the baby needs attention, though. ;-)

Saturday, June 6, 2009

Building the Dave Everett styrene droid


Alright, this is my first post on blogspot, I mean, I say it's the first but it probably won't be because I'll probably delete it and make another one...if I don't like it. Ok, why am I doing this? Well, right now is not a good time to be building a wood or metal droid in my apartment. I live in a small apartment with my wife and baby and can't install a full woodworking shop.
I have started from Dave Everett's plans. The first thing I did was to have the frame and skin plans printed at fullsize at Kinko's on Wilshire, near Staples. This was not cheap, at $4.50 a page. However, at one page from the end their printer ran out of paper and so they restarted the job. Kinkos let me keep the extra pages so I ended up with two sets each minus one page. Pure luck!
At that point my wife was already getting angry. I had spent money on printing the pages, so she wanted to make sure I wasn't going to waste any resources. The following morning I drove to Gavrieli Plastics in North Hollywood and purchased two sheets of 3mm (.125) styrene and one sheet of 1mm (.040) styrene. I can't quite remember how much I paid, I posted it on the R2 Builders club group but their search function isn't helpful right now. I do know I paid a bit more than if I had used http://www.indplastic.com/ which is what many folks recommend. Next time I build a droid I will buy directly from them because 1) they're cheaper and 2) shipping is free when you get to $125 in purchases. All I know is I damaged my 1mm sheet while loading the thing in the car and had to buy another one. I spent nearly $100 because I ended up getting 2 sheets 3mm, 2 sheets 1mm, one pint of Weld-On 16, and an applicator bottle ($5, overpriced, but it looks just like Dave's).

I found out soon that I bought the wrong Weld-On. I was supposed to have bought Weld-On 3, which is the most fluid. Apparently one of the other PDFs mentioned Weld-On 16 and I had that in my head. Argh!

The next expenses came entirely from tools. I went to Dick Blick on Beverly and Poinsettia and bought an Olfa L-1 Heavy Duty Cutter with Ratchet Wheel as recommended by Dave in the tutorial. I also bought a circle cutter tool from X-acto that turned out to be completely useless in the long run. It's a small thing called a "compass cutter". Do not buy, you won't get anything out of it. Blick had no P-cutter in stock, I don't think they regularly stock it. So I ordered from Amazon.com. The P-800 HD Plastic/Laminate Cutter came a few days later and I love it for cutting styrene sheeting. It won't cut circles but it is actually straighter/better than the L1. The problem is it creates a wide groove, so you cannot use it on parts that are drawn joined together on the paper, because it will eat a little of the next piece. The P-800 also hasn't come with extra blades, but so far I haven't needed any. I did however run through several blades on the L-1 already, so I am glad I bought extras.



Now here comes the big issue I have with Dave's otherwise impeccable plans: Dave uses that communist metric measuring system. His measurements are in millimetres. This makes getting certain tools and hardware much more expensive and annoying. We'll come back to this, right now let's look at the tools he recommends:

1) Trimmer router and plunge bit. Dave has the Ryobi TR50A, the A in the end is for "Australia", the British colony Dave hails from. ;-) I bought the Factory-Reconditioned Ryobi ZRTR45K Laminate Trimmer Kit. It was a lot cheaper than the Makita 3707FC Fixed Base Laminate Trimmer with LED Light that others have mentioned. One thing to consider is that Harbor Freight sells a much cheaper (in more ways than one) router, but the nearest HF store is too far for me. I purchased a 1/4" straight bit and a 3mm straight bit.

2) Olfa utility knife. Again, I got both the L-1 and t he P-800 HD.

3) Steel ruler. Dave's rulers use the communist metric system. He mentions his 1m, 30cm, 60cm and 150mm rulers, which make no sense in more advanced countries. So I got a 30 inch AlumiCutter ruler which is made specifically for cutting. The backing isn't cheap cork and doesn't slide while cutting. This I bought at Blick. While there I also bought the Alvin CUTTING MAT GRN/BLK 18x24 which has proven indispensable!


4) Set squares. Does it bother anyone else that set squares are triangles? Got two of them at Home Depot.

5) Styrene needle applicator bottle. That cost me $5 at Gavrieli. Way overpriced, but I didn't feel like looking around.

6) Drill bits. This part is annoying. Dave says to buy all these communist metric system bits. ;-)
They are:

3mm drill bit- I bought the Precision Twist 2ACO 3.00 Mm Metric Cobalt Drill 135 Deg NAS 907 33mm Flute 61mm Length

4-12mm Step drill bit - I bought the Irwin 11102 Unibit2M 4-Millimeter to 12-Millimeter by 1/4-Inch Shank Step Drill Bit

12-20mm Step drill bit - could not find
3mm countersink - could not find
8mm countersink - could not find
And later on a 17/64 drill bit. I got the Precision Twist NAS 907 Cobalt Steel 17/64" Drill 118 Degree 2 7/8" Flute 4 1/8" Overall Length

7) Digital Calipers - I bought this one:8" Digital Caliper Stainless Steel LCD Measuring Tool - with Fraction Display

There are other tools listed on the plans. They aren't "Immediate" tools but eventually you'll need them. One of those is a drill press. I tried one of those Craftsman Drill Press Stands that converts a regular drill into a drill press. BIG mistake. It was a dud, it didn't work well and nearly destroyed my $90 Skil cordless drill. I will buy a real drill press next month.

I got a 2x4 folding table from Staples for $30 on sale. This can be folded and stored out of wife's sight daily. I then sprayed my plans with Elmer's Craftbond 11-Ounce Spray Glue, allowed to dry for a minute and glued them to the styrene. I have had mixed results with this glue, but it does a good temporary bond. Only problem is if it pools up, then the bond is permanent and messy, so you need to spray lightly. The other alternative is some overpriced 3M repositionable thing which costs like $15.

It's important to note that at this point I had no router. The only thing I could possibly do was cut the straight cuts. So that first night I cut all the straight pieces in the frames plans out of 3mm styrene.

The second night I cut all the skins from the 1mm styrene, except for the round cuts.

A few days later the router arrived. I went to Home Depot and got a 3/4" thick 2'x4' sheet of MDF. I made a 1-1/2" hole in it with a holesaw bit and mounted the plastic underside of the router on it. I can clamp this onto my folding table with 4 C-clamps for stability.

Now here is the problem: this tool can make your wife extremely angry because it is the messiest part of the deal. In order to appease my wife's protests I promised to buy her a new vaccuum cleaner. But I also had to Dexterise my work area in our tiny apartment with lots of sheet plastic. Even with all this the styrene granules flew everywhere.

Anyway, Dave explains wisely that you should start with the outer cuts so as to not lose the centre of your piece. I thought I was smart enough and that I would keep that advice in mind. It seems I didn't. You see, I was doing rough cuts and final cuts, and didn't stop to think there are no rough cuts for the internal dimensions! I solved the problem by crossbracing the second ring which I had stupided earlier and centering the ring on the crossbrace. Lesson learned.

I cut most of the circular pieces, not all. Wife was getting too angry and I had to stop. It occurred to me that I should have bought a cordless router instead because then I could've done this outside on the street! Dang...

It's Saturday and I need to go buy the Weld-On 3 on Monday. So no work will be done this weekend. All the straight pieces are cut. Now I need to get the gluing going. I'll get around to it Monday.
I just realised I DO know how much I spent at Gavrieli Plastics. I checked my ever-shrinking bank balance and the record shows I spent $92.88 for 2 of the 3mm sheets and 1 of the 1mm sheets. I then stupided the 1mm sheet, walked back in and bought another one, plus the Weld-on 16 ($7) and applicator bottle ($5 overpriced thing) for $27.03. I can't solve for X in this equation but I can tell I spent far too much. I also realised I'm very afraid to check my bank balance, but I'm even more afraid of my wife checking it.