Question about joining styrene at angles

Shaff · Post by **Shaff** » Tue Jul 06, 2010 11:38 pm

Hey guys,
I'm new to the forums, though I've been watching a reading for a few years now. Great site you have here.

On to my question, though. I'm not sure how to glue two pieces of styrene together at an angle that isn't at 90 degrees. For instance, I can create a square column no problem, because the edges of the styrene join just fine. However, what if I wanted to make a 5 sided column? At each connecting point, there would be either an over hang, or a deep seam depending on how I positioned the pieces before gluing.

Is there a tool I'm overlooking that would be able to angle the edges of the styrene I am gluing together, or would it be better to just glue the pieces as-is and then fill/sand the edges afterwords?

I hope I explained my problem correctly. Thank you, in advance.

Andrew Gorman · Post by **Andrew Gorman** » Wed Jul 07, 2010 12:00 am

Scrape the mating edges down to an approximate mating angle to get the fit most of the way there. Spending a few minutes to make a jig to hold the stock at the correct angle as you sand can save you a lot of time. Or a small tilting arbor tablesaw can cut the correct angle, or your jig can be used as a sled to cut the stock at the correct angle on a fixed bench saw. Just a few suggestions!

Johnnycrash · Post by **Johnnycrash** » Wed Jul 07, 2010 12:02 am

Yes, there is a special tool just for this kind of thing. Sandpaper.

Just sand one edge to the angle you want, and then glue it to the other sheet. Now, only sand one edge, and leave a little bit hanging over the edge. Then, once the joint has dried, sand that little edge flush. That will create the angle on the outside edge.

Make sense??

Shaff · Post by **Shaff** » Wed Jul 07, 2010 12:16 am

Geez, guys. Go to bed! It's the middle of the night here on the East coast. Ha. Very quick answers, though. Thank you. I just wanted to make sure that I wasn't missing some ancient, super secret modeling technique.

I will try both techniques out tomorrow. Thank you, Seneis! *bow*

Ziz · Post by **Ziz** » Wed Jul 07, 2010 12:55 am

Make yourself some sanding sticks. Take heavy sheet - or several thinner sheets glued together - to about 1/4" thick and cut them into strips 1/2" to 1" wide and 2 to 3" long. Doesn't have to be exact, just whatever feels comfortable.

Get some Scotch Double Sided Tape (in the yellow box/dispenser) and cover one side of a strip with tape. Stick that to a sheet of sandpaper and cut out around the strip. Make a bunch of strips for each of your various sandpaper grades.

Now when you need to miter an edge you can just run it at the proper angle against the sanding block.

tetsujin · Post by **tetsujin** » Wed Jul 07, 2010 12:24 pm

One trick I learned from the Gundam Scratch Build Manual for this sort of thing is to get a metal protractor from the hardware store (the kind with a rectangular plate with angles marked on it, and a swinging arm used to measure angles relative to the bottom edge of the plate) - attach a blade to the arm... Then set the angle you want, tighten the bolt so the arm doesn't swing around, and use it to scrape down the edge of your pla plate.

In practice, though, I usually just eyeball it and sand or scrape with a blade.

Still, precision in these kinds of mitre-joins can be very important if you're building a boxy shape with a lot of facets.

Gerry · Post by **Gerry** » Wed Jul 07, 2010 1:22 pm

you can draw it on paper... say a hexigon, then get a cheep angle-finder from Home Depot.... {3 bucks maybe}

Then set your cutter to whatever angle it says.

Post by **TER-OR** » Wed Jul 07, 2010 9:17 pm

Cut a block of wood to the angle you need. Place sandpaper on your workbench, the block on the sandpaper and your styrene on the block. Slide styrene across the block until you get your angle correct.

Wetsanding will work best, get that black 3M wet-sanding sandpaper.

Shaff · Post by **Shaff** » Wed Jul 07, 2010 11:42 pm

Lots of useful information here, guys! Thank you. I've done star wars models in the past, along with half-way completing an incredible Submarine model, but this will be my first scratch build. I particularly like the protractor idea for getting the rough cut in. The ship that I am making is shaped like a column for the most part, though it has.... well... here:http://eveart.l3ds.com/pics/Caldari/Rokh1920x1200.jpg It's a 1920x1200 image, so it's pretty large.

Anyways, I have my blueprints for it already, and I am in the process of making a wooden skeleton for it. Getting the correct angle to cut/sand it at won't be a problem. Actually cutting it to the desired angle is where I would have encountered problems. All of these ideas seem so useful. Thank you all for you tips, techniques, and advice. I'll be sure to start taking pictures once I progress farther with the model... and get a camera worth taking pictures with.

Feel free to keep giving your own solutions to the problem, though! I enjoy reading them, at the least. They'll all help me sooner or later.

Ziz · Post by **Ziz** » Thu Jul 08, 2010 8:01 am

Vageuly Sulaco-ish. Add a round engine at the back and a bunch of spikes sticking out the front...

ajmadison · Post by **ajmadison** » Thu Jul 08, 2010 10:03 am

No one mentioned one of the very best ways to ensure you get the correct angle and it provides extra strength. A bracket!! Provided the interior of whatever you're building is hidden, I'll cut a series of brackets with the desired angle. And to make sure they're all the same, I'll stack them up and sand the edges to make sure they all have the exact same angle.

If you're talking about a polygonal prism, why not cut a series of bulkheads for internal support? (Just remember to make them all smaller than the final profile by the thickness of the external skin.) You may not need the bulkheads for strength, depending upon your project, but I'm always about using every trick I can to getting good alignment. If you still need access to the inside of the structure for lighting, attaching a sub-assembly, or cutting an indentation for some important detail item, you can always cut a hole in the center of your bulkheads. In one case, the hole was used as an additional alignment aid, by sliding the bulkheads down a brass tube. The bulkheads were checked to be orthogonal to the tube, their faces aligned, then glued to the tube. The exterior was then skinned.

Shaff · Post by **Shaff** » Thu Jul 08, 2010 3:47 pm

Actually, AJmadison, I am doing something really similar to what you described. I have wooden supports every 3 inches(It's a 2' model) that make up the rough shape of the main body of the ship. They're all held in place by a wooden dowel, and cut down by 1/16th of an inch on every side to accommodate for the thickness of the styrene. However, I am lighting it and won't glue the styrene to the wood until near the end.

I have a completely different question now, however. I bought a metal ruler not too long ago and it has a "NON SLIP CORK BACKING" on the back of it, but it seems easy enough to remove it. Should I take it off? If I leave it, yeah, the ruler will stick where I want it, but there is a small gap between the paper and the actual ruler.

ajmadison · Post by **ajmadison** » Fri Jul 09, 2010 11:49 am

You bring up an excellent question. The cork does help grab the plastic so the ruler doesn't slide, but yes, the offset between the ruler and the styrene induces some error. I generally flip the ruler over for cuts, because for me, marking and cutting are separate operations. But the slipperiness of the metal directly on sheet styrene also causes problems because unless I have very firm pressure on the ruler, it slips as I make the first score.

Its probably annoying to have to swap it out regularly, but I'm thinking of trying two sided tape.

BTW, I very rarely just cut a complicated part out of sheet stock. Either I have a paper copy of what I want, which I tape to the plasticard and cut through the paper and score the sheet at the same time, using rulers, french curves, or just free handing it. Or, I have some intricate part that must fit a specific location, so I start with a specific width of sheet. Which I measure off with dividers and use the dividers to make the first score. Usually this strip is pretty rough on both ends. If its rectangular, I use my Chopper II to trim up the end. If its a specific shape or angle, I mark off and cut until the desired shape is obtained. And at this point, I'm just getting started, because then the strip is applied to the model and exact measurements are transferred to the other end.

en'til Zog · Post by **en'til Zog** » Sun Jul 11, 2010 7:02 pm

This might help.

http://www.starshipmodeler.com/basics/cj_pcg.htm - print/cut/glue

Kylwell · Post by **Kylwell** » Sun Jul 11, 2010 9:08 pm

You can also use right angle strip to build gussets to reinforce the joint.

Shaff · Post by **Shaff** » Wed Jul 14, 2010 4:00 pm

That guide was very helpful. Thank you!

Also, about the metal ruler and cutting. I found a method the other night that works fairly well. I roll two pieces of masking take to make a double-sided little roll, place then behind the cut that I will make, then flip the ruler to lay face-down on the styrene. I make sure the ruler is properly positioned for the cut before pressing it onto the tape, of course. The ruler hold pretty steady when I'm cutting, although I did keep a good bit of pressure on the ruler while doing so. This method seems to last about 3-4 cuts before the tape loses the adhesiveness and you have to re-roll two more pieces. It is fairly hassle-free, though!

BROCK UPPERCUT · Post by **BROCK UPPERCUT** » Mon Sep 06, 2010 5:36 pm

try this http://www.dickblick.com/products/dexter-mat-cutter/
or something like it , available at most art supply stores for cutting mat for pictures prints or paintings

kerick · Post by **kerick** » Fri Sep 24, 2010 7:49 pm

Shaff wrote::http://eveart.l3ds.com/pics/Caldari/Rokh1920x1200.jpg It's a 1920x1200 image, so it's pretty large.

That is an awesome and ambitous build. You are going to be cutting lots of those angles. I want to see more!

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Fri Sep 24, 2010 9:38 pm

I am a proponent of the inner frame construct.

Frame
http://www.rcgroups.com/forums/attachme ... tid=522528

Styrene
http://www.rcgroups.com/forums/attachme ... tid=269888

Frames
http://www.rcgroups.com/forums/attachme ... id=1397533

Styrene
http://www.rcgroups.com/forums/attachme ... id=1407151

.

2TALLTARY · Post by **2TALLTARY** » Wed Apr 27, 2011 5:11 pm

Yeah just use sandpaper. I use styrene a lot for my model train backgrounds. Just sand em cut em whatever. Styrene is so easy to work with. I buy a lot of styrene from http://www.iplasticsupply.com/materials ... -his-sheet Check them out if you need more styrene.

TREKKRIFFIC · Post by **TREKKRIFFIC** » Wed Apr 27, 2011 6:42 pm

Simple math tells you for a 5-sided box you would need a 54% angle measured from the plane of the styrene sheet.

AbsoluteSciFi · Post by **AbsoluteSciFi** » Sun Jun 05, 2011 9:17 am

@Umi_Ryuzuki:
Nice Work there!

@Everyone:
Making angles is not easy, at some point everyone needs to make a choice, make the cuts and bevels so precise the corners meet, or fill the crevice left behind by the corners of the styrene sheet. Both options have cons, and take time. I do a little of both.

Here is a neat tip that saves time. Sand off MORE than the angle needed for along the backside of the bevel. Then you can butt the front side seamlessly up to the next part. Fill the backside with superglue and baking soda to reinforce the seam. This will save time on finishing the outer seam, as the inside seam does not need finishing.