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Sculpting more Rahm Kota armor

Koda Vonnor

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I cut a slightly oversize elbow guard from 2mm Sintra, then took a silicone rubber mold of it on the flat, then poured a urethane rubber model using ReoFlex-40 from Smooth-On. I used an old plastic sheet that I think was for covering a bowl in the microwave and tack-glued it inside the gauntlet assembly with a bit sticking out the elbow end. I wanted a semi-rigid form that would extend the conical curvature beyond the end. I lined up the rubber model and glued it to the plastic sheet, sealing the edges with superglue.


The plan is to mask off the elbow end inside the cone and pour a Hydrocal mold over the rubber elbow guard model. That will give me a smooth mandrel to use for heat-forming the Sintra elbow guard. This will ensure that the curvature exactly matches the inside of the gauntlet at the elbow end.


The top and side edges of the guard will have 1mm raised edging. The bottom (wrist end) edge will be riveted to a curved strip of galvanized steel, cut from a piece of duct-work. The steel strip will have two squares of Sintra spaced out and rivited. The forearm plate will have mating sintra squares spaced to the gaps in the steel strip assembly, each with a super magnet embedded in it, as well as raised keys that mate with the edging on the main assembly. The whole thing should snap into place like a row of teeth.


Stay tuned.






I told you the gauntlets were the hardest element of this costume. :P


~ Vonnor

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Masked it off at both ends.

Poured in Hydrocal.

Pulled out a mandrel.


The Sintra production elbow guard will be heat-formed to shape in that little depression. The cross-hairs transferred from the soft model are a free bonus.







~ Vonnor

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After much trial and error, with no trial and success, attempting to heat-form a Sintra elbow guard, I decided to go with what I know. Taking advantage of the dry mid-70s temps with no sun or wind, I built a 4-layer fiberglass elbow guard.


In the process I discovered an interesting thing. Before I laid in the cloth I was worried about releasing the production cast from the mold, so I sealed the hell out of the plaster, then used some auto paste wax on the mold and polished it up a bit. Not only did the casting release easily, the no-gelcoat back surface was dry as a bone with no tackiness. The wax in the mold reacted just like wax in the resin allowing it to fully cure. I added a couple layers of Bondo icing and sanded it down while in the mold to be sure of the surface curvature.


The contour came out perfect with very little gap . Still missing the edge trim at this point but wanted to test fit the assembly for scaling. The fiberglass material is going to work better for riveting to the galvanized steel plate in the magnetic closure system.


It's starting to look like something.


Come back soon.








~ Vonnor

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I added the edge trim to the elbow guard, and took a first cut at the gauntlet closure. I added alignment blocks to the rear of the forearm plate and a strip of galvanized steel to the elbow guard. The square spacers were milled out to hold the magnets. Unfortunately, I accidentally drilled through the center spacer and out the other side. The pix have a nice Photoshop patch over the hole, but I'll have to fill the real one with a fiberglass/bondo plug or else re-do the part. I'm kinda leaning toward the latter as it is rather thick and heavy with its 6-layers of glass. Four or five layers would have been good, and left a bit more flex in the part


The magnets are N52 pull-weight, which is on the better side of the more common N42s, but with just the two (the center one in the pix is fake) it didn't pull against the backing plate as well as I'd hoped. I may end up using 0.75" Dia. instead of 0.5" shown, and just ream out the slot a bit more. The forearm guard will cover the ream-age anyway. Also, the 0.25 thickness is a bit too much as well. I can get 0.20 without epoxy coating and try those.


The glue I used for the metal to plastic bond is LocTite Pro-Line Fast-Grab Premium 8X construction adhesive. Absolutely wicked bond. Gotta clamp it for a few hours though.


After the glue dried I just had to try the thing on. With the neoprene wrist seal under it, the assembly holds pretty tight, maybe too tight. Also it will have to hold 1cm higher on the forearm, and with the TFU1 Kota shirt on it resists any rotation. I'll have to keep the fabric light and the sleeves tight under the gauntlets.


Stay tuned.








~ Vonnor

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Today I did a rough sculpt of the wrist clip. The photos show I need to adjust the alignment a bit, as well as smooth out the edges and contours. I ended up being off a little on scaling and relative positioning of the forearm plate. It should have been about 0.25" longer and extend by the same amount more toward the hand. It's funny there was just no way to get it perfect without the wrist clip, but the entire assembly had to be completed before the clip could be sculpted. Catch-22. :oops:


The end result is the wrist clip is a bit shorter end-to-end than it should be, but I'll live with it rather than redo a whole new forearm plate and mounting.


Most of the finish shaping and fitting will be done on the hard model. Will also be able to measure the symmetry and can always re-do the sculpt if corrections are needed. :)


It slowly rolls forward.








~ Vonnor

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Back from NYCC and back on the project.


Since I had to do the clay sculpt directly on the production gauntlet parts, this was by far the most difficult to wall-off and mold. I painted a few layers of Smooth-on Rebound 40, trimmed the edges a bit then used a contour guide to cut out cardboard for walling off the perimeter. Carefully added Hydrocal White plaster in half sections, with vasoline applied to the seams in between halves.


I will stuff some Bondo and glass inside to get a rigid model to work with. I can finally visualize how the piece will be worn and removed. The design is quite remarkable for a CG model. I'll show more detail on what I'm talking about after I take the casting. Also, the palm-side cutout will be done on the rigid model.


More to come.


http://i107.photobucket.com/albums/m305 ... ces221.png

http://i107.photobucket.com/albums/m305 ... ces223.png

http://i107.photobucket.com/albums/m305 ... ces224.png

http://i107.photobucket.com/albums/m305 ... ces222.png

http://i107.photobucket.com/albums/m305 ... ces220.png


(Links only - the new board does not allow 1K wide pix. :( )


~ Vonnor

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I laid in some fiberglass yesterday. Thick Rondo coat then 7-8 layers of cloth glass strips then another thick Rondo. I added 2-3 more layers on the wrist side for reinforcement since I will be doing the rectangle cutout. It's fugly for sure, but very solid. Symmetry isn't perfect but I can shape it a lot on the next phase. It won't be worn anyway, just a hard model for taking a shell mold. I have some super strong urethane resin I will use to pour the production piece.


Oh and now that I can examine it closely, I realize I'm going to have to sculpt a second one of these for the right gauntlet. I was hoping to use only one and just pour two from the same mold, but to lay flat against the end of the main assembly the sculpt picked up a very small amount of skew twist. This one will not lay flat on the right assembly. Oh well, practice practice practice. :)


http://i107.photobucket.com/albums/m305 ... ces227.png

http://i107.photobucket.com/albums/m305 ... ces229.png

http://i107.photobucket.com/albums/m305 ... ces226.png


~ Vonnor

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First, I had to be able to put the one-piece wrist clip on and take it off. It is a VERY tight fit and will be a bit tighter before the production piece is cast. As you can see I will have to squeeze it on before the glove, then pull the glove cuff up under the clip. With just the padding afforded by the glove, it is moderately comfortable. It may take a prolonged period of elevation to get it off after a long troop, but I will pay that price for accuracy. The clip will also support the main assembly and keep it from encroaching on the hand guard.


Still just a first round of smoothing and shaping. It will have more Bondo filler and surface spread before it's ready for molding/casting, but so far I'm very happy with the results.


Apologies for the unfocused shots. I was using a remote shutter with my right hand, and neither hand is as steady as a few years ago.


More as it comes along.


http://i107.photobucket.com/albums/m305 ... ces230.png

http://i107.photobucket.com/albums/m305 ... ces232.png

http://i107.photobucket.com/albums/m305 ... ces233.png

http://i107.photobucket.com/albums/m305 ... ces234.png

http://i107.photobucket.com/albums/m305 ... ces236.png

http://i107.photobucket.com/albums/m305 ... ces237.png

http://i107.photobucket.com/albums/m305 ... ces238.png

http://i107.photobucket.com/albums/m305 ... ces239.png

http://i107.photobucket.com/albums/m305 ... ces240.png

http://i107.photobucket.com/albums/m305 ... ces241.png


~ Vonnor

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Good afternoon dearest Bill,

I write to inform that this thread has been shared on our
FaceBook page's Friday Flagship Forum Feature (03.07.2015) as a fine example of the depth and variety offered by our users on The Flagship Eclipse forum.

Thank you for sharing your inspiration with our community.


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NOTE: As it appears now that larger size images are allowed in this forum, I would like to catch up my project documentation from where I left off. Most of these posts were copied verbatim from the Rebel Legion forums.


Thanks very much, Maestro! I am honored.



1st: Learn how to make the part.

2nd: Make the part.

Yesterday I smoothed the surface and shaped the contours on the left wrist clip. After cutting the join-notches and clamping it to the main assembly, several issues were noticeable.

On the sculpt, I left the semi-circle cutout a bit small, so that the alignment might be adjusted left or right if necessary. I mistakenly ground out it's alignment based an attempted self-symmetry for the part, rather than waiting until I had it clamped in place, so you can see it does not line up with the semi-circle cutout on the forearm plate. Also as you can see in the last photo, the palm-side rectangle cutout is not aligned with the center line of the main assembly, as it should be. The skew of the whole thing rather threw me off during the sculpt. Look closely at the handle of the clamp, and the jaws. The centers of those should both be lining up with each other and with the reference vertical.

Lastly, notice the gap between the forearm plate and the wrist clip. It is very inconsistent, as are the surface flush lines between the two parts.

This is just another lesson. I will re-do this sculpt, but this time I will take care to pre-mark center lines and guide-points, and measure the alignment off the entire assembly rather than just the one piece.


~ Vonnor

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I wedged the left vambrace back on to the armature and cut a rough clay sculpt for the wrist-clip redeaux. I took more time to form the clip in alignment with the main assembly as opposed to the armature. The spacing came out much better both from the forearm plate and from the hand guard. This will still need to be shaved down some before taking a mold, but all in all it is much better than the first attempt.


More coming soon.

~ Vonnor

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I trimmed a lot of bulk off the sculpt, and did some surface smoothing. It's not perfect but will be easy to fix on the rigid model. I am much happier with the alignment, spacing, symmetry and contours compared to the last attempt. I coated it with clear spray acrylic to help keep the mold clean. If the unopened Rebound-40 on my closet shelf is still viable after 10 months I will paint the rubber mold liner on there tomorrow.


~ Vonnor

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Started with one ounce (half oz each parts A and B) of Rebound-40 from Smooth-On and painted a thin coat over the clay sculpt. After about 45min this was followed by a 2nd layer of Rebound-40 (2oz total) with 2 drops of Thi-Vex silicone rubber thickener. Then a final coat of thickened rubber after about 30min.

Later today I will under-cut the edges as best I can and wall it off for a Hydro-Cal plaster mold shell. I'll have to do that in two pieces or it won't come off the "ARM"ature.


~ Vonnor

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Walling off the rubber mold so a plaster shell can be poured over it. It doesn't have to be pretty, just mostly waterproof. I use corrugated cardboard sprayed lightly with clear coat. I brushed the armature with Vaseline where  it was plaster on plaster before the pour. The other half of the mold shell will be completed tomorrow, then just have to wait for nice weather to lay up the fiberglass rigid model.


~ Vonnor

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I shaped, trimmed and primed the wrist clip hard model, then carefully notched the mounting grooves into the palm-side flap. It came out much better than the previous attempt. It still needs some minor contour corrections, but it will definitely work. The rectangular cutout will be added next.

The production piece will be cast in high-strength urethane and will be attached to the main assembly using a cap screw and a threaded aluminum backing plate. The screw will be visible and not be true to the CG reference, but will be necessary for real-life wear. The torque is likely to be too much for magnets at that mount point.


~ Vonnor

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Doing a lot this weekend. So far I've modified a new pair of gloves (the last pair had irremediable issues), stripped the cracked silver paint off the right hand-guard and re-primed it, and adjusted the edge thickness of the wrist-clip. I also added an epoxy putty back-fill that was pressed into the main assembly at the closure point to imprint the contours of the edge strips into the reverse of the wrist-clip. This locks the clip into position and prevents any lateral movement. The production piece will have a hex-screw backed by an aluminum clamp that will take the place of the green temporary clamps shown in the photos. The clamp will not be visible when worn, only the hex-screw. That is a necessary deviation from referential accuracy (one of two total in this build - more on number 2 later) to insure a rock-solid assembly.

The gloves have a 1.5" Velcro closure strap that goes all the way around the wrist. This not only allows for a very snug fit, but nicely pads the wrist-clip from digging into my skin. The edge of the clip digs tightly into the padded closure strap and holds the entire gauntlet assembly from slipping down onto my hand to interfere with the hand-plate.

It's all working much better than I anticipated so far. :D

More stuff tomorrow.


~ Vonnor

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I filled all the tiny flaws with plastic putty, primed and sanded it with 800grit wet. I back-filled the whole thing with oil clay, then sprayed a clear-coat over it. When that dries I'll attempt to make a rubber block mold for pouring the production piece. The wolverine grooves are to help it get a purchase on the padded glove closure around the wrist. The tracks cut in the top of the tab will mate with the edge trim on the main assembly.


~ Vonnor

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The lower half of the wrist clip rigid model was carefully masked off with clay, then a mold box was put up around it. The contours of the piece made it a major challenge to determine the split point between mold halves. As long as the halves can separate, and the air bubbles can escape during the pour, it's all good. The little gems are the registry keys to insure a perfect join, and the little straws on either side of the pour hole will let the air out as the resin goes in. I ordered some OOMOO25 for this mold. The pencil line is the approximate fill level. A half-inch plaster slab will top it all off.


~ Vonnor

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I poured the top half of the mold and capped it with a 1/2" plaster slab, then cleaned all the filler clay off the bottom half. I had to pull the rigid model completely off the rubber to do this, then re-seat the model to the mold and flip it all over. After shaping the pour-hole and spraying Ease-Release 200 over everything, I poured the bottom half of the mold and the plaster cap. I had some issues where the 2nd half of the mold stuck to the 1st half in a couple spots. This was due to my grabbing the mold and oscillating it to help get the model to sit tightly in place for the 2nd half mold pour. My fingers rubbed off most of the mold-release at those spots causing the new rubber to stick to the old. Luckily it was in places that don't effect the casting. Today I will microscopically pick all the debris out of the mold using double-sided tape, then bake the mold halves for a couple hours. If the TASK® 9 in my closet is still viable I'll attempt a casting this afternoon.


~ Vonnor

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Here is the rough casting. There were a good number of air bubbles throughout the piece, mostly on the edges. After de-flashing and sanding, many were exposed. I don't think it's bad enough to scrap the casting. but I did fill them all with PC-11 Epoxy Paste. That stuff is fantastic as a filler, but it does take 12-24hrs to dry (depending on temperature).


More after the filler dries.

~ Vonnor

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Now that the left gauntlet assembly is complete, the right gauntlet build begins. I expect this to go much faster than the first one, for two reasons.

Less trial and error: Lots of mistakes were made and lessons learned on the left arm assembly, so I already know how to build each element. Less time trying to figure out how to build the piece. I can just build it.

Less unnecessary pre-production detailing: Most of the parts do not need detailing on the intermediate steps. For example, I did not bother to square up the edges of these cross straps, since I have to finish-sand the fiberglass production straps anyway. Why do it twice? This was repeated many times while building the left gauntlet.

I hope to get these in a mold tomorrow, and cast the fiberglass straps on Tuesday or Wednesday this week. I am also going to do the final painting on all the finished armor parts so far, with the dark iron metallic coat ready for scratch-weathering.

Onward it rolls.


~ Vonnor

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Armor parts so far (L to R):

Right shoulder bell
Left gauntlet assembly
Right hand guard (weathered test casting in front)
Left hand guard
Left wrist clip
Left elbow guard
Left forearm plate

All have a thin even coat of Rustoleum metallic Soft Flat Iron except the Left hand guard and Left elbow guard. Those were coated with Rustoleum Oil Rubbed Bronze as a test, but are too brown for the tone I was looking for. They will be sanded down and re-spritzed with the Iron color. The bronze tone will work much better for the final low-light dirt on all the pieces.

The Left shoulder bell will get the Soft Iron coat tomorrow. I ran out of paint before I could hit it.

Note my Kitchen Witch and her escort in the BG. ;)


24 total armor parts to this costume (counting gauntlet cross-straps individually). 12 are completed. I consider it a milestone.

~ Vonnor

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