Thread: Build Log Detailed Blaster 3 Build
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Old Dec 18, 2010, 01:29 PM
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a.k.a. Matt Nelson
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North Tustin, CA
Joined Oct 2008
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My pod layout

I'll join in the fun... here are some details on how I built-out my Blaster-3 pod. The wing/tail is pretty standard, so I'll focus on the pod in this post.

I bought a B3 as a "lateral" move from a Lighthawk-III that I sold to a friend at my field. That sale funded the B3 purchase, and I wanted to keep the additional cost to a minimum (domestic politics ), which meant using components I had in my parts bins:
Battery: NiMh, that's what I've got laying around, so that's what I'll use. I had some 2x2 stick packs, both 250 mAh and 400 mAh. I wanted to use the 400 for a little more flight time, and since I didn't have a LVA laying around, some peace of mind. No switchjack yet - just using a JST plug.

Servos: I had a few types laying around from which to choose. The method for selection basically came down to experimenting with taping the battery down on the assembled airframe, then trying various combinations of servos that would put the CG at about 85mm. I wound up with the following:
  • Flapperons: JR DS290G digitals
  • Rudder: Futaba S3114 analog
  • Elevator: JR DS188 digital
Receiver: Futaba R6106HFC. It fits really nicely tucked way back under the pod cowling. I had to buy one for this build I couldn't figure out a way to get a R617 in there, which, of course, I had laying around.
Notes on the build: I tried but just couldn't see using Vladimir's instructions for the flapperon control rods. Using his method requires fairly extreme bends/curves in the rods, and I just didn't like it. So I opted for Larry's method of cutting a couple holes in the back of the pod and running the rods mostly straight out. With the rod run straight, I opted for some heavier pushrods - in my case the heaviest stock I had was some 0.047 SS music wire. The kit didn't come with any flapperon pushrod sleeves, so I picked up a DuBro pushrod kit and used its nylon sleeves.

In the spirit of Larry's build, I made some blocks to support the flapperon pushrods behind the pod exit holes. However, I beefed mine up a bit, since it seemed like a likely item to see some damage.

Now most of you already know this, but here's a reminder: nothing sticks to nylon. With this in mind, I had to figure out a way to get the pushrods sleeves actually attached to the supports. I did two things: first was to rough-up the nylon and epoxy the assemblies together: sleeve on block, block to boom. After that cured, I applied some 1.4 oz glass over the sleeve and down onto the side of the block, then wet that out with some resin. I did a similar thing up front by the servos for the flapperon supports up there.

The end result looks pretty tough. We'll see how it holds up.

One thing to consider if you want to do the hole-in-the-pod thing: the pushrods end up EXACTLY where you want to grab the glider for javelin tosses. You have been warned.

The final result looks pretty good to me. AUW about 9.9 oz. I think the CG may be a hair forward of where I intended. I'll feel that out when I get it in the air (it's raining here in So. Cal., so I must be patient...). If the CG needs to go back, I can easily swap a 250 mAh pack in for the 400 (but I'd rather not).

One final build note: Two other areas I deviated from the instructions: I installed a "normal" launch peg. The one that came with the kit is just silly IMNSHO (). I also ditched the CF rods for the tail, and installed SS music wire in bondable teflon running down the outside of the boom. I used either 0.021" or 0.023" - I forget which one I grabbed.

Pics attached.

-matt
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