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Gluing Polycap on Plastic


dyowelb

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I don't know of any glue which sticks polycaps in the sense of being a solvent for polythene. Trying to stick a polycap directly to styrene or ABS by applying glue to the mating surfaces simmply doesn't work because the glue doesn't affect the polycap at all and any flexing of the part causes it to break away.

The only way I know how to do it is to use either CA or epoxy adhesive and encase the polycap, not so much sticking it in position as caging it. If the glue bonds to the styrene and surrounds the polycap it remains in place because there is no direction in which it can get free, but even then the join won't stand much pressure before something gives and the polycap escapes once more. The only surefire way is to build a styrene enclosure around the polycap to trap it in place but if you don't have room for this there is not much else you can do.

Spelling edit.

Edited by Mechmaster
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yeah..i think i have no choice but to remove the polycap and make the legs static. as for the styrene solution i don't have enought room. i guess i'll have to build a 'knee' out of styrene...

here's the pix of the legs to give you more idea

post-3-1071524099_thumb.jpg

Edited by dyowelb
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Have you considered ball joints or even ratchet joints like the Yamato 1/48s? I have no idea where one can find the latter though.

The model should be light enough that plastic ball joints would be able to hold the positions you want. Plus you get some extra posing possibilities.

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Have you considered ball joints or even ratchet joints like the Yamato 1/48s? I have no idea where one can find the latter though.

The model should be light enough that plastic ball joints would be able to hold the positions you want. Plus you get some extra posing possibilities.

They also make polycaps that have a slot in them to mount a mating component like the gundam MG kits. Then you would only have to glue some type of nub on the lowwer half of the leg. If you need a couple, I can mail some too you. I have extra from a few of my kits

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Have you considered ball joints or even ratchet joints like the Yamato 1/48s? I have no idea where one can find the latter though.

i did...i'm planning to use ball joints where the thigh and the pelvis meets...

They also make polycaps that have a slot in them to mount a mating component like the gundam MG kits. Then you would only have to glue some type of nub on the lowwer half of the leg. If you need a couple, I can mail some too you. I have extra from a few of my kits

sure....that'll be great ...i need all the help/material i can use for this one...

thanks,

dyowelb

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dyowelb,

I can get wave joints here (2.34 a bag) or the Kotobukiya joints (2.00 a bag) as referenced by Andy Wacht's Legioss custom writeup. I just picked up a few sets to modify my Legioss. Other sizes are available.

If you can't find any in the states, I'll send you some for the price of the joints, envelope and stamps. But shipping might be ~ 5-8 USD from here. I have to double check.

Good luck on your project.

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HI

I'm in the process of customizing my SD and I'm having trouble gluing a polycap on plastic. I'm using Testor Model Cement. The part is too small to put any extra styrene.

Do I need a special glue/cement? Any tip???

thanks,

dyowelb

Crazy Glue will glue just about anything togeather, and dries hella quick.

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All you need is a WAVE 'L' joint and some putty. And you'll be set.

I must agree with that. The best way to fix them is embedding them with putty, but be sure to use a hard one!

Cianoacrylate glue ("super-glue") would also help.

HLJ has lots of Kotobukiya poly caps references, in different sizes & colours. Prices range from 200 to 300 Yen:

http://www.hlj.com/scripts/hljlist.cgi?Ser...Poly+Unit&Dis=2

Aaaargh, if I had known it before... :blink:

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thank guys....but i might stick with the styren knee for now since it;s the best solution for. but i might use and 'L' joints on elbow and balljoints on thigh.

by the way, how big is a 1/72 hase battroid head??? height x width x depth???

thanks,

dyowelb

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A Hasegawa Battroid head is about 2cm long, about as tall, and maybe around 12-14mm wide.

I don't quite understand how you're going to get mobility from this joint. It seems like, hinged or not, there'll be no place for it to move. But here's what you need to know to mount a polycap:

First off, you can not glue polycaps to anything. They're too flexible. If you super glue them to something, and then they flex a bit, the super glue will pop right off. What you need to do is encase them such that they can't go anywhere.

There are two simple and effective ways of doing this: the first is to mount the polycap using Bondo (a polyester putty used for auto body work - it's cheap and very useful). Bondo is great for all kinds of custom-fitting work, too. The second is to mix up super glue with talcum powder to make a putty. This super glue/talc mixture (SGT) bonds as well as super glue but is more resilient and workable - it won't hold a bond to a polycap, either, but it will create a solid, durable grip around it.

I'm still trying to figure out just what you're trying to do. It looks like what you've got is a polycap that's already installed in the top part of the leg, and you want to hook it up to the lower part of the leg. Really, the best way to do that is to mount a peg in the lower leg and have it go through the polycap. I don't know if that's possible with the way you've got it set up, though.

Probably the simplest solution is an off-the-shelf type of thing. Somebody suggested Wave L-Joint: I think thos would be too large for this application. Wave T-Shaft or Kotobukiya Mecha Joint might be a better choice:

http://www.hlj.com/scripts/hljpage.cgi?WAVOP-291

http://www.hlj.com/scripts/hljpage.cgi?KBYD-109G

The Wave part is also available domestically from Gundamshop.com if you're in the US. Both are basically the same thing, though the Kotobukiya one is a bit larger and stronger: the middle is a box with two hinge joints, and there's a long peg coming out from each end. Bury the pegs in Bondo and it's installed.

You might also want to check out Peter Savin's work on his Hi-Zack. He does a lot with Bondo - most of the stuff he shows is cosmetic stuff but there's some real nice work with aftermarket polycaps, too. He really knows his stuff.

http://models4you.whoadude.com/

He seems to be a big fan of the Kotobukiya T Joint:

http://www.hlj.com/scripts/hljpage.cgi?KBYD-103B

It's a nice general-purpose joint which could be very useful for the installation you're doing (where the top part of the leg appears to have some kind of horizontal peg going through the polycap, and the bottom of the leg has nothing) - you could trim a T joint to the right length and mount it in the upper leg as-is, and then you'd have a long peg extending down from that joint which you could then Bondo into the lower leg. If the peg in the upper leg is the right size, that is. (Check the measurements. Kotobukiya's site, linked from the HLJ pages, has great technical drawings of their parts with measurements.) For this particular installation it could be the easiest way to go, if the fit is right. In general the T joints are a bit more work to use than things like the Mecha Joint, but they're incredibly versatile.

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tetsujin,

thanks for the infos...

I don't quite understand how you're going to get mobility from this joint. It seems like, hinged or not, there'll be no place for it to move.

i'm trying to improve the kit and get rid of the stiff looking robot. if everything fails i will mod it to be in static position and reposition everything that i can.

I'm still trying to figure out just what you're trying to do. It looks like what you've got is a polycap that's already installed in the top part of the leg, and you want to hook it up to the lower part of the leg.

the pieces are not yet glued together so i can still removed the polycap. i'm in the process on test fitting everything and trying to find ways to approach this problem.

can anyone post a bigger pix of these L and T joints??

thansk,

dyowelb

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