Saturday, April 26, 2014

First Fiberglass Foray

Title says it all, today was my first adventure in fiber glassing.  Yesterday I picked up some supplies at Lowe's.
A quart of fiberglass resin and a pack of fiberglass cloth.  And a couple of paint stirrers, and the most important thing of all, blue nitrile gloves.  The gloves were an afterthought.  I had no idea just how sticky this afternoon was going to be, so I'm really glad I picked them up.

Start off with a pic of the resin:

I used the plastic solo cups because I already had them in hand.  I had no idea that when the resin finally kicks (chemically sets) it gets hot enough to melt the cup. 

Here's my test cup.  I used a measuring cup to add 4oz of water to the cup, then marked the level.   I also marked 8oz, just in case 4 wasn't enough.


Doing that allowed me to know how much resin I was adding to the cup, so I would know how many drops of liquid hardener to add.  The can says "for small repairs, add 10 drops to 1 ounce" and "working time will be 10-12 minutes".
For my first cup I added 4oz of resin and 36 drops of hardener.  That didn't give me time enough to use about half of the resin.
For the remaining cups I used more along the lines of 7 drops per ounce, which did give me time to use most of the resin.

Here's a shot of several pieces of cloth cut to length for the seams.

And several shots of finished seams:




 

I'll say, it's not a very pretty job, and it was pretty darn messy. I'm pretty confident that my weak seams issue will be solved with this.  I just wonder what that's going to get in the way of at a later date.  I know I can drill through it for mounting thing like the handles and the neck and tail mounts, so I'm hoping the answer to that question is not too much.

Maybe later this evening I'll get some of the work I'd planned on doing before the damage occurred.  Only 2 days lost...at least there's not currently a deadline.  Yet. :)





Thursday, April 24, 2014

Eye pics and TRAGEDY!!

Well, here's a couple of pics of starting to assemble the eyes. As I noted on The K9 Builders club forums, the A&A kit comes with both the 4 slat and the 5 slat eye patterns.

Here's a pic of setting up the eye pieces:


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I haven't decided which of the two types I want to use. I had planned on building them both, then choosing at a later date, but last night (luckily before I finished them) I realized that if I build both sets, I won't have any red material left for the control panel. That's OK, I haven't done anything that can't be undone yet.

Now, for the tragedy...late last night I came around the corner into my computer room where I'm building K9, and I kicked the $%^& out of K9's body. It wasn't where it belonged, it was sitting on the floor by the wall, because I needed the table space to work on other parts.

Everywhere you see blue tape is a seam I had to reglue.

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I've still got to reglue the side panel, hopefully I'll be able to get that done tonight.

I was already planning to reinforce most of the inside of the seams this weekend somehow, now I see that it's going to be a necessity. I'm thinking fiberglass resin and tape. Hopefully there'll be some nice pics of that before the weekend is over...

Tuesday, April 22, 2014

Hot Glue issue

FYI, the hot glue wasn't really easy to remove from the second set of ear screens. Spent a couple of hours doing that tonight...

Monday, April 21, 2014

Waiting on Amazon

So apparently , if you order from Amazon using Prime on a Thursday, and get the free 2nd day shipping option, and then try to have your delivery sent to a business that's closed on Saturday, you won't get your stuff until Tuesday :(

No worries though, some things came in today, and other things will be coming in almost every day for the rest of the week.

While I'm waiting, I decided to work on the ears some.

I started out with a 3"x2" oval created in Paint.  Printed it out, cut it out and hot glued it to my metal mesh desktop organizer thing.

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Then I cut them out using my dremel with a cutting wheel.

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Only thing is...I didn't actually measure the paper templates after printing them, so instead of a 3"x2" oval, I wound up with something about 2 5/8" x 1 3/4".

So, back to the drawing board, or actually Paint.  This time I made the oval 3.5" x 2.5", and when printed, it came out about 3.25"x 2.25".  This looks much better when compared to the first ones:

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Only thing is, this time the hot glue is being a pain to remove.

Oh, and I added some reinforcements to the inner top half of the control panel:

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That's all for today...

Friday, April 18, 2014

Shopping lists

Ok, since I've been working a little faster than I probably should have gluing all the plastic, I decided to let it cure for a couple of days, and work on my list of electronics parts.

I've got several 'extra' 12V batteries, some in particular that R2 can't use due to the shape that'll be repurposed here.

I can cross the RigRunner power distribution off the list, since I had an "extra" left over from when I changed R2's system over from Spektrum to PS2 wireless.  It also has 2 USB ports that will power the Arduino and the MP3 trigger.

Speaking of those two pieces, about 3 weeks ago, SparkFun Electronics had "Arduino day" on a Saturday, all their boards were on sale 40% off.  I picked up 2 Arduino UNOs and their MP3 trigger board.

I hit Amazon in a big way yesterday, and picked up a bunch of the parts I'm going to need.  that list included:
  • 1 right angle USB cable to use powering the Arduino
  • 1 Futaba S148 servo for the ears
  • 1 linear conversion kit for the Futaba servo
  • 1 set of servo horns for moving the ears
  • 1 set of servo linkage rods for connecting the servo to the servo horns
  • 3 12v-6v stepdown converters for powering the servos from the RigRunner
  • 1 2-channel 5V relay module for powering the antenna that will be the scanner
  • 1 12V auto audio amplifier for the sound
  • 1 set of 3.5" speakers for sound (what else would they be for?)
  • 1 PS2 controller extension cable for splitting out the signal from the wireless receiver to the Arduino

I also ordered a SaberTooth 2x25 speed controller from Dimension Engineering, having used that one in R2. Their customer service is top notch. They are very friendly and easy to work with, in the event that you ever have to contact them.

All of that stuff should be showing up next week, so I'll have plenty of new toys to play with.

Today I went shopping at the hobby store and the office supply store, and picked up the stuff to make ears with.  Brass tubing, pencil cup, that kind of thing.  Also picked up some 2mm styrene sheets, since the A&A kit doesn't come with much scrap for improvising.

My outstanding list for electronics is currently:
  • control panel light system
  • drive motors, wheels, belts, axles and such
  • servos for the head and tail
  • PS2 wireless controller/receiver
Doesn't look like much, but there's some learning and coding to go along with all the rest of that stuff.
That was one advantage of the Spektrum park flyer style setup.  All you had to do was plug the wires into the right places, make sure black and red weren't mixed up and you were ready to go.

The PS2 setup is much easier to hide though, since it's the one small controller.  It's way more fun to be anonymous and let everyone wonder who's driving, or even better let them think it's autonomous :)

Tomorrow I'll check GameStop for the controller, hopefully they'll have one and it'll be on sale since it's old tech :)

That's all for now...see you next update!




Wednesday, April 16, 2014

2 updates in 3 days. Things are actually moving pretty well with this build!

So, last night I assembled and glued the upper pieces of the body:  photo DSC02264.jpg

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I built and glued the sides first, then the back, since it had the angles and such.

As you can see, I used some packing tape in several places where strength was needed to pull some of the pieces together. That's the tape I used when I was "stretching" R2's aluminum skins around his frame. It doesn't tear, and doesn't let go by itself.

I also hit Lowe's today and bought some aluminum angle pieces. A couple of 1/16" 1/2"x3' angle pieces for the bottom side supports, which I saw another builder do, to keep the bottom of the body from flexing too much, a 1/16" 1"x3' for inside support to attach the handles to, and for neck tube support. I also picked up a 1/16" 1" square tube for the neck and some other inner support, as yet to be determined.
And, if that weren't enough, I picked up a couple of drawer pulls that look a lot like the ones in the reference photos I've been checking out. Only problem with them is that they are chrome and not brushed stainless. I'll probably look around at a couple more hardware stores before I actually use them.

This evening I decided to add some curved ribs across the top of the body, to support the top, and to assist with curving the top piece, again like I've seen another builder do.

Started off with some ABS donated by R2, from his old A&A feet. At the top is the paper template I cut out for the curve.

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And, after using the belt sander, which hasn't seen much use in several years:

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And here's the "blocks" that the ribs will sit on, to add support and make it easier to glue:

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I used small spring clamps to set the blocks, but was afraid that, being plastic, they'd wind up glued in there as well, so I removed them after a couple of minutes.

After a couple of hours, I decided it was time to add the ribs:

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And, that's all the photos for today.

Been doing some thinking about how much movement I want K9 to have, besides driving around and head up and down. I've checked out the schematic for making a moving tail and another builder's diary, and I never even considered some of the things his build can already do. Guess I need to start learning how to drive servos with my arduinos...

Monday, April 14, 2014

A New Project

Allons-y!

If that's not enough of a clue, you'll catch on shortly.

If not, Google it.

So I ordered another A&A kit from Astromech.net , the droid builder's website.  This time it's not an R2 kit.  If you don't know, A&A makes ABS plastic flatpack building kits for robots.


Here's a shot of the glue I ordered from Amazon:
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It's called Weld-on 4. The number 4 indicates that it's a liquid. They also make a Weld-on 16 that's more like a modeling glue as far as consistency, but for this build everything I read said that 4 is the way to go, because it's a liquid and it can get into the joints quickly.

Anyway, on to the production shots! Here's a pic of the lower rear piece taped and ready to be glued:  photo DSC02250.jpg

At this point I will mention that the table I'm working on is plastic. I wasn't sure how the glue would react with the table (apparently it doesn't near as I can tell) so I taped some aluminum foil together for a work surface. That's why the table is shiny.

I bought some blue painter's tape at the Wally world, since it was what was handy. Unfortunately it's "quick release" so I think maybe it doesn't stick as well as regular masking tape. Oh well, I bought two rolls of it, so it's what's getting used. You can see here that it really doesn't want to stick:
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No matter, the tape sticks long enough for the plastic "welds" to set.

Here's a shot of what the joints look like after glue and tightening the tape:

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There's going to be some sanding required, as well as some filler that'll need to be sanded too.

Here's a shot of the lower side panels glued, in the process of tape removal:  photo DSC02252.jpg

And here's a shot of all 4 lower panels after glue:

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In that last picture you can see where the glue puddles on the foil after having run down the joints.

Next up, the 4 lower panels taped together before gluing:

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Once the lower panels were taped together, I realized that there was no way I could just glue them and hope that they'd be square, so this happened:

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Hopefully that worked out. Looks like it has so far.

Also built the "control panel". Here's a shot or two. One of them shows the doubled up pieces that add strength to the thin ABS:

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That's all the pics I have for now. If you haven't figured it out already, I'm building K-9 from Doctor Who.

After the success I've had with my R2 using the PlayStation 2 wireless controller, that's the direction I'll be going with K9 as well. Almost doesn't make sense to have a controller half as big as the robot.

So far, I've picked up a couple of Arduinos from SparkFun as well as as MP3 Trigger board for sound. I already have a RigRunner 4004U power panel from West Mountain , and extra 12V batteries from R2.


I'll post more soon!