feet

New parts, feet getting done and some more stuff done..

I know ..

I’ve been lazy, not updating this here properly!

Good thing is, I’ve been building!

I’ve narrowed my search for glue down to really 3 candidates that I’m using for different tasks. Yes, the “remover” is actually used as glue. It’s a nail polish remover that consists of nearly 90% Ethyl Acetate, which is a strong solvent that melts styrene, thus welding the plastic together!

Very volatile, sets very quick, then needs 24 hours to harden, but a joy to work with!

The thin needle is standard polystyrene cement, not as fluent, not as quick setting, and with a needle applicator that allows me to squeeze some extra glue into small crevices!

Finally, the standard superglue. Used for anything where I need something setting fast, or for gluing resin parts to styrene!

Since the Ethyl Acetate chemical is not really healthy to breathe in, I decided after a day of testing to invest in my health and get myself a proper mask. In this baby, I don’t even smell the thing.

Last thing I want from my hobby is health issues due to breathing too many fumes from glue!

 

Anyway, so what have I actually accomplished?

Well, the legs are now *nearly* done. I need a tiny metal insert, that Sigge is kindly providing to me, hopefully this weekend, and after that I can skin them fully, and then my droid’s legs are 100% DONE!

They are partially skinned now, as you can see in this picture:

Skinned the sides, sanded them down, and now the main part of the leg is ready to be skinned. Then the tiny pieces under the shoulder needs to wait for a tiny piece of aluminium.. =)

While waiting, I’ve started work, and made quite a good way into making the center foot. I attached my resin half-moon’s which are both screwed and glued, and then I realized that I had actually purchased the full plates in resin some months ago, and these half-moons were actually planned to just be half-moons on the outer feet!

Oh well, more spare parts to sell to someone else. Starting to get a few of those!

The foot needs to sit and harden overnight, and then the top pieces sanded down to match the angles. After that, It’s “only” the bottom parts left!

The inside of the foot is complete with mounting plates for 2 double casters. They run smooth and should be quite shock absorbant. I’ve used quite a bit of styrene inside the foot, but since R2 is going to be top heavy, I don’t really think this will be a problem.

I also designed a quick and easy (and sturdy) way to be able to have the main foot detachable. My idea is to have both legs and center foot detachable for easier transport.

I’ll jot up a design tomorrow if I have time, and see if my new CNC friend can make them for me! They should be quite simple, though.

Speaking of Aluminium, these arrived today:

Long awaited, all the way from Australia comes these machined logic surrounds, which will fit nicely into my dome, that should arrive any day now.

Apart from that, I also received and soldered together what might possibly be the controller for my R2 unit. Cheap and simple, and allows for a few servos and/or signals to be controlled from a PS2 compatible controller.

Since I have an Arduino Uno, I’m also hoping that I can use the receiver part in this, and program the Arduino to actually interpret the buttons pressed, and thus allowing me more control with combining buttons pressed on the PS2 controller!

All in all, a good build day, even though it was quite short for me.
Tomorrow, I’m hoping to get some more skin on the legs or possibly finish the center foot!
nite all!
//Micke
By |2016-12-06T00:02:00+01:00January 9th, 2012|R2-D2|Comments Off on New parts, feet getting done and some more stuff done..
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Nail polish remover, center foot and more sanding!

So: After emptying several tubes of model kit glue, with various results, I got back on trying to find the raw chemical, Ethyl Acetate, to glue together my droid.

You can find the actual chemical, the only issue is you need to buy it in bulk!

So, after emailing, calling and finding out ore about it, I stumbled across something.

Seems my girlfriends nail polish remover consists mainly of … you guessed it: Ethyl Acetate!

I have called the company to see how much concentration of this it’s actually in the bottle, but a competing brand (no pic, sorry) (Gripen Remover for you Swedes) consists of 80-90% of Ethyl Acetate.

So, silly as it may sound, I tried gluing a few pieces of styrene together with nail polish remover… and it actually works!

I’ve used the “other” brand, since I know the concentration in that one, until I get word from the company about the concentration in the bottle pictures above.

I also cut out all my pieces for the center foot, and started gluing it together. Not with glue, though. I glued it with nail polish remover.

My initial thoughts is that it is very volatile, you need to work FAST, and you need to soak a bit into the plastic, then keep it hard pressed together for some time, and most importantly: leave it over night to harden. The joint doesn’t get stiff and firm until after 24 hours.

So far, so good!

Oh, apart from that, I’ve got a few hours worth of sanding ahead of me. Got to sand both motor holders, parts of the center foot, the second leg, and chamfer like mad for the foot shells!

Good thing it’s a long weekend coming along!

 

//Micke

By |2016-12-06T00:02:02+01:00January 5th, 2012|R2-D2|Comments Off on Nail polish remover, center foot and more sanding!
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Some new years building progress…

So, since I’ve had a lot of time on my hands during the new years, I’ve managed to get quite a bit done!

I took a few trips to the hardware store and picked up more polystyrene cement, as well as some needed tools and a huge lot of nuts and bolts and washers. At least enough for me to attach battery boxes, the motors to the main feet and all that.

I took the first leg i finished outside and spent 10 minutes with my mouse sander on it, to get all unsmooth edges and uneven bits done and dealt with, and the end result was really nice and smooth.

In addition to that, I routed cables through the leg, and made sure my shoulder hubs fit well into the shoulder, with a magnetic lock.

Here’s the sanded leg with cables running through the leg and proper cable attachments mounted. This leg only needs a small amount of sanding on the marked, red edge before it is ready for skinning.

I decided to add a caster to the main foot as well, as the big wheel is really off center, and I wanted to make sure the foot was nice and level. I may not need this, but at least I have the option of trying this. With the system with the motor holders, and the feet only being shells, I should be able to just switch the feet around to the other leg, should I like to have the caster in the front or in the back. Having the caster in front will cause more impacts, but it will allow me to run the droid backwards through doors if I need to.

Here’s the final foot motor holder, mounted and ready! Seems sturdy and stable, and I can’t wait to get the robot to a point where I can actually have a robot that can move! =)

Apart from that, I also went back to my HP’s and made small white caps to cover the bottle caps out of 1mm styrene. This looks way nicer than the previous temp solution of using paper as a diffuser.

I am starting to get the hang of working with styrene, and using the first leg as a template, I used it to mark and cut out the parts for the second leg.

I even managed to get some time gluing half the leg together.. My plans are to have it completed by tomorrow, and thus having both legs ready, construction wise. Skinning is definitely needed, but that will be for later!

I also have plans for a magnetic lock for the shoulder horseshoes, but I’ll have plenty of time to put that into action before skinning the legs!

So at this point, I’ve got all skins cut out, fixed lights for my hp’s, got one leg done and the second halfway there… and one motor holder done!

//Micke

By |2016-12-06T00:02:03+01:00January 1st, 2012|R2-D2|Comments Off on Some new years building progress…
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