Expanding biceps

[ehinote2187[TK]]

Hello everyone.

 

I acquired my armor around 2 years ago, but it has been shelved for a long while. I'm now getting back to assembling it for all the fun and shenanigans that will be happening the next few years.

 

My biceps were assembled by someone else that did "typical" measurements (he just did them without measuring my biceps). They were tight then, and they're just as tight now.

 

What are some ways to expand the biceps? I've heard of using a heat gun with a towel wrapped around the bicep to expand it. I've been thinking of popping the seams and redoing them with extra plastic glued to the main pieces. Yes, I know filling them will need to happen on the seams, but I can do it.

 

What do you all think?

 

Pictures for reference:

 

 

[T-Jay[TK]]

Your biceps parts will be made of 2 halves with cover stripes at their joints.

 

Have a look inside the biceps. If there is enough material left under the cover strip, you can "open" the biceps and re-glue it with a bit more space for your arm.

 

This will of course be limited. For more, you will have to add that extra piece of plastic.

Edited May 1, 2015 by T-Jay

[TK bondservnt[501st]]

should be simple enough to use a plastic for sale sign and open the inside of the arm and add some distance.

[salamander[TK]]

These biceps were assembled using overlap joints instead of butt joining with a cover strip.  (The armor was molded to be assembled this way, and it's a kind of one-size-fits-all approach.)  To enlarge them I would cut off the molded overlap sections and then butt join the edges together, leaving a gap of about 1/4 inch on each side, and hold the pieces in place using cover strips on the inside and outside of the armor.

 

Here's how I would do that:  Assuming they were glued with E6000, use a heat gun set on Low to soften the glue, and use a knife blade to separate the parts as the glue softens.  Then (this is the scary part) use a razor knife to cut off the molded overlap parts on each piece.  Right now there's about a 5/8 inch overlap on each side, and that's what you have to cut off. You want to cut off the entire molded overlap, but no more than that.  Depending on where you make your cut, the resulting edge won't necessarily be "flat."  What I mean by this is that the outside edge might curl smoothly toward the other piece, but the inside of the bicep may have a little curl along the side so it doesn't smoothly meet the outer bicep piece.  If you can firmly glue a cover strip across both pieces, then you're good to go, but if the curl prevents the cover strip from sitting flat, you'll need to flatten it out.  You can flatten out the curl by using the heat gun on Low again -- never use High because if you overheat the ABS it can go bad very suddenly and start to warp unevenly, creating a bigger problem than the one you have.  You'll want to warm the curled edge of the bicep and then quickly sandwich it between two hard, flat surfaces.  Even better is if you can sandwich the edge of the bicep between two metal sheets and heat it while pressing down.  When the curled edge is flat, you're ready to put the two pieces together again.  (Remember, the main goal here is just to get the edges flat enough that the cover strip can be glued securely to both sides of the bicep.)

 

The cover strip on a bicep should be about 15 mm wide.  That gives you a little bit of expansion room by leaving a gap between the two edges when you glue the cover strip down.  Line up the inner and outer bicep pieces edge to edge, and then separate them a little.  You can use a wider gap than 1/4 inch if you need it, but that might make for a weaker joint.  You'll want to glue cover strips to the inside and outside of the joint for greater strength.  It's probably easier to glue the inner cover strip first, because it's easier that way to see how everything is lining up on the outside.  The inner cover strip can be wider than 15 mm if you need it to be; that gives it more surface area for the glue to hold onto.  The outer cover strip should be long enough to hide the fact that the two pieces have a slight gap between them.

 

That's my 2¢.  Other troopers may have other ideas.

[ehinote2187[TK]]

Thank you! I think I know of a way to use the folded over cover to give me more room on my biceps using the tips you gave me. I'll think about it some more, and I'll let you know how it turns out. 

 

And it was glued together with ABS adhesive. I've already separated one of my thighs because of some tweaks I have to do. It was nerve wracking, but I got it cleanly off. 

Edited May 1, 2015 by ehinote2187

[HansDC[TK]]

From looking at that first picture, it looks like you could carefully take the seams apart and use the butt joint method to reconnect with a cover strip.

 

If you manage to get the two pieces apart - you might not even have to shim cos it looks like you could get at least an inch if not more extra room. 

[ehinote2187[TK]]

I was at it today trying to get the pieces apart only to be met with the knife I was using to separate them with my hand. It got lacerated (5 stitches, yay!). Needless to say, I will be not working on much for a bit. Looks like I'll need to be getting a butcher's glove.

 

I did it all for the glory of the Empire. lol

[salamander[TK]]

Here are more detailed instructions on how I expanded my RT-Mod biceps:

 

Start with the bicep pieces.  They are molded for overlap construction, and we're going to cut off those overlaps.

 

 

Mark the inside corners of the overlaps with a pencil.  I didn't measure, I just ran a pencil down the groove.

 

 

Cut those pieces off with a razor knife (and may the Force be with you as you do this ).  Never throw away any pieces of ABS that you cut off, no matter how small.  You might need them to make a slurry later on.

 

 

Put the two halves together...

 

 

...and you can see that two problems have arisen.  1) The bicep is now football-shaped instead of roundish and we have to glue the cover strip onto the pointed ends of the football, and 2) Even if we round out those points, there is still a curl on the edges and they won't line up flat and smooth to glue a cover strip onto.

 

 

We'll fix these problems using a heat gun and sandpaper in my next post.

[salamander[TK]]

I'm working alone here and can't take photos while I'm working, but here's how I rounded out the football-shaped biceps:

 

Take a heat gun and run it like a hair dryer all over the front and back of the outer bicep piece while squeezing the open end closed a little bit in your other hand.  Keep the heat gun moving at all times and try to heat the piece evenly.  If you use the high setting, hold the heat gun at least four inches away from the plastic and be careful because on the high setting things can go bad very suddenly, especially near the edges of the piece.  As you round out the bicep piece, try fitting it onto your arm to get the curvature right.  It's okay that I'm wearing a t-shirt when I do this because I'm only working on the curvature of the bicep right now.  I'll size the bicep later.

 

 

The outer bicep piece now has the correct curvature and is round again like it should be.  Then I did the same thing with the inner bicep piece, but instead of trying to fit it on my arm, I just tried to match the edges to the finished outer bicep piece.  WARNING:  Those pointy tops of the inner bicep are the first place the plastic is going to melt.  I got careless and started to deform one of mine from heat.

 

 

Both pieces are rounded again, so the football problem is solved.  The bicep is also slightly smaller than it was originally.

 

 

But we still have the problem of that curled lip along the edge of the pieces.  The cover strip will not lie flat against the armor until we get rid of that.  If you're thinking, "I'll just sand it down," then you're a lot smarter than me.

 

 

My first thought was to soften the plastic along the edge with the heat gun and then press the edge flat between two hard, flat surfaces.  This plan did not work well at all, and this is also where I overheated the point at the top of the inner bicep and warped my armor.  It's minor and will be hidden by the cover strip, but it was a frightening omen of what I'm capable of if I'm not careful.

 

 

That's when it occurred to me that I could just sand that cusp smooth.  I used a plastic sanding block with 100 grit sandpaper.  100 grit removes ABS pretty quickly, but it will also scratch up your armor if you're not careful where you're rubbing.  You can mostly remove the scratches with 400 grit sandpaper.  After I sanded the curls down the edges lined up reasonably flat.  It's not perfect, but the cover strip will glue down over it, and that's what we want.

 

 

At this point we have made the conversion from overlap construction to butt-joint construction with a cover strip.  The next step is to enlarge the biceps and glue the two halves together, and we'll do that in my next post.

[salamander[TK]]

To enlarge the circumference of the biceps we're going to bring the two halves together as though we're butt-joining them, but then separate them with a gap to create a larger diameter, and then bridge the gap on the inside and outside to hold the two halves firmly in place.  Since the cover strips on biceps are supposed to be 15 mm wide, we can add about that much space on each side.  This pic shows the expansion gap with the inside already bridged.  Now let's start the procedure at the beginning.

 

 

The outer cover strips will be cut out from the ABS sheets Rob sent with the RT-Mod kit, but the piece that bridges the gap on the inside of the armor will be made from a For Sale sign from Lowe's or Home Depot.  This sign cost me about $9.  You can use it as is, but I didn't want all that red inside my armor.  I tried dissolving it off with rubbing alcohol but that didn't work, so I sanded it off instead.

 

 

I used 60 grit sandpaper to remove the red ink but the first round of sanding smeared the color everywhere and left the whole sign looking pink, so I did another pass with 100 grit sandpaper to make it white.  You'll definitely want an electric sander for this.  Sanding the sign created a lot of ABS dust that did not wipe easily off the sign because of static cling, but it hosed right off with water.  Altogether it probably took me an hour to get both sides completely white.  (The sanded sign is actually whiter than the armor itself.)

 

 

The cover strips on the outside are about 2 mm thick, and the For Sale sign is about 0.75 mm thick.  This thinness is a huge advantage because the sign material is nice and flexible allowing you to use a wider strip on the inside and spread glue over a large surface area to get a really good grip.  I cut my inside strip 50 mm wide.

 

 

I glued in one side using E6000 glue...

 

 

...then the other (yeah, this is the same pic we started with).

 

 

And then clamped it in place to dry.  I put some pencil marks in there to try to make the inside piece stand out a little more in the photo.

 

 

Next I'll bridge the opposite inside the same way, but before gluing on the outer cover strips I'm going to fill in that gap by cutting a thin strip of 2 mm  thick ABS (from the cover strips that I removed early on).  If I don't fill in that gap, then the outer cover strip will only be attached by a millimeter or two along each edge.  Filling in the gap means that the cover strip can have the full 15 mm of glue across the back to help hold it in place.

 

I hope this helps.  Also I should mention that I wasn't actually expanding my RT-Mod biceps, I was shrinking them -- but when I downsized the first bicep I cut off too much plastic, and then I had to enlarge it again to make it fit.

[ehinote2187[TK]]

Awesome! I got back to work today (last night actually) to try and fix my biceps. I nearly did what you did, but instead used an array of leftover ABS plastic I have to expand my biceps. Needless to say, there will be slurry/bondo/epoxy filling/painting required, but I am confident I can do that. They're now a good shape for my biceps, but I may need to reshape them just a bit for them to fit just right. They kind of look rectangle-ish right now, but I like how they fit better now.

[ehinote2187[TK]]

Progress! I have fixed my biceps a great deal. I got back to work and got them apart, chopped off the fold over joints, shaped them a bit better with a heat gun, glued in expansion pieces, filled in the seams with ABS slurry, sanded them down, and put on cover strips. They are sanded down now waiting to be painted. I may do a bit more filling with some bondo, but as of right now, it's not all bad to look at. 

 

 

 

[charlesnarles]

Wow extensive fix but worthwhile for the payoff. Before/after fit test pics will be funny

[ehinote2187[TK]]

The link I posted above is after the expanding, filling, and sanding. Yet to be painted. I'm very pleased how they turned out. I'm about to go to get some bondo and paint to start finishing it up.

 

And it wasn't so bad to me. I've built 5 proton packs before. Damn things are nearly all bondo/filler hahaha.

[ehinote2187[TK]]

Biceps are *hopefully* finished! BEHOLD!

 

 

 

 

 

 

You can see inside the shims I put in to expand them, and while I had extra slurry, I put it in all around them for extra security. 

 

What do y'all think?

[tkrestonva[TK]]

Nice work.