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-   -   Making your own screen. What thickness Perspex to use ?? (http://www.horizonsunlimited.com/hubb/tech/making-your-own-screen-what-49662)

*Touring Ted* 14 Apr 2010 15:20

Making your own screen. What thickness Perspex to use ??
 
Hey all

I'm going to make my own screen but before I buy the perspex, I was wondering what thickness to buy.

Im just going to bolt it to the top fairing with no support arms.

From what other have said, If it's too thick, it will put more strain on the bolts and be harder to shape and be too stiff but too thin and it will bend/flap/crack etc !!

All advice welcome :thumbup1:

djorob 14 Apr 2010 21:32

Screen
 
Hi.
made a screen a few years back with some tinted plastic I recycled from work.
It was around 4-5 mm thick and I was able to shape it with careful use of a hot air gun.
Getting too close with it burned the surface but luckily I found this out on a test sheet.
Not sure exacly what type of transparent plastic it was but the thickness worked well.
Dave

CaptTeach 15 Apr 2010 05:40

For cars 1/4in for the windsheild and 1/8 for the side pieces seems to work fine if you are using Lexan, add a 1/16th for Plexi. I have not made one for a bike yet but will be doing one soon for a Crotch Rocket I traded for - the one on my Harley is about 3/16 but not sure of the material. Shaping the Lexan is pretty easy with a heatgun and if you hold the heat below the piece you can tell when its about to go soft. If you dont need a very big piece I would check with a local supplier to see if they have any 'drops' or cut off pieces from a past project

Big Yellow Tractor 15 Apr 2010 09:16

3 Attachment(s)
Ted,

How big a screen do you need ?

Does it need to be clear ?

On my naked road bike, a small fly-screen upped the comfy cruise speed by 20mph.

I have made a screen blank from epoxy-fibreglass for my Dr. Zed and will trim it to fit the existing light surround. I've just stuck it on with some tape so you can get a (really) rough idea.

If you don't need a really tall screen, a bit of pretty thin polyprop would do the trick. It will take up the curve of your headlight surround when you fix it and will have some flexibility when you dump the bike.

The third pic is the bike I might build if I won the lottery

BYT

*Touring Ted* 15 Apr 2010 10:22

Cheers for the replies... Nice looking screen that tractor ! Just the right height too.

Ebay is full of perpex off-cuts so im going to pick up a 4mm 450x300 piece. £5 to the door. Can't complain !

Now I need to find a heat gun

tomhughes209 16 Apr 2010 17:23

Hey Ted

Finished the screen on my KLR before I set off for my test run around Europe.

Went for 6inches above the KLR stock screen - I'd say that gives about an overall 11 inch screen. Used clear, 5mm perspex. Cut the shape based on a card outline and stuck it straight into the oven. 110 degrees for 8-10 minutes and its as mouldable as you like.

Try to add a top lip if you can - its a pain trying to bend a lip and the convex curve on your own if you're using the oven. If you use a heat gun it could end up taking forever, as you don't want to apply too much heat to one area else the perspex will blister.

I'll stick a picture up when i can find one.

T

tomhughes209 16 Apr 2010 17:47

1 Attachment(s)
there... amazing what you can do with a spare evening, a hack saw and some plumbing washers.

oldbmw 16 Apr 2010 19:53

1 Attachment(s)
Quote:

Originally Posted by *Touring Ted* (Post 285284)
Cheers for the replies... Nice looking screen that tractor ! Just the right height too.

Ebay is full of perpex off-cuts so im going to pick up a 4mm 450x300 piece. £5 to the door. Can't complain !

Now I need to find a heat gun

Think you will find a decent hair dryer will work fine.
Now just to please me. When it is all done, install some car trim beading along the outer edge. This could save you considerable discomfort in the event of an unexpected halt :) You don't really want to be riding with your head just above a guillotine.

PS, I got the Panasonic camera yesterday, it is brilliant. See reduced image from 3.5mb to 50k taken at about 150 yards.

Andysr6 16 Apr 2010 23:28

Hi, i have made numerous screens / headlight protectors over the years. i normally use 4mm perspex and for large curves i heat the whole piece in an oven then form it around something that shape. For smaller areas heat that section under the grill until it gets floppy and bend to shape (wear gloves).
Drilling the holes requires great care as they will crack easily. Andy B

grumpy 17 Apr 2010 01:20

I have made few screens for my xt660x, these two pictures are the latest, the first has its base behind the headlight surround, the second has the base in front of the surround, with the base behind I get a sort of forward suction effect to my jacket, with the base in front of the surround, with a gap of a three quarters of an inch there is no suction. The screen is quarter inch thick perspex, which drills well and cuts easily with a jig saw, finishing the edge with a belt sander, bending is done with a hot air gun.

http://i1014.photobucket.com/albums/...swan/001-1.jpg

grumpy 17 Apr 2010 01:24

this is the only way to get the second photo on
http://i1014.photobucket.com/albums/...n1swan/002.jpg

*Touring Ted* 13 May 2010 09:02

I'm just about to plonk it in the oven.....

Iv put in on foil on a large baking tray.


As for drilling !! Do you recommend a drilling it fast or slowly ???

Would melting through be a better idea ?? (Screwdriver and blowtorch method) and then cleaning the hole up with the drill !

Capo Sakke 13 May 2010 09:25

I used 2mm polycarbonate made shape with cardboard template saw with jigsaw and just bend it and bolt it with three M 5 with large washers and that's the result. :confused1:

http://kuvablogi.com/nayta/prev/img2563621.jpg

Works fine and it's strong and durable :thumbup1:

*Touring Ted* 13 May 2010 10:41

Well...

That wasn't fun !! LOL.

I got it all maluable and shaped it around my BBQ gas bottle. The problem is that i need to bend it in the middle too so it will sit more upright when bolted to my front cowl. When I bent it, it deformed at the bend. It's not pretty but it's just as strong.

Heating in the oven then shaping by hand just doesn't give you enough time to shape it as it cools VERY FAST !! I had to use the heat gun which makes it hard to do large adjustments...

You get about 10 seconds to shape it before it becomes stiff again.

Anyway, it's on the bike now and does the job. It's not going to win any prizes for style but it only cost £5 in total !!

http://i600.photobucket.com/albums/t...m/DSC02841.jpg

TBC....

Trichelia 28 Jun 2010 17:57

Hi all, I attached a visor to my xt this weekend. Bought it off ebay, think it was from an old cb400.

I took the bike to 60mph to see how it faired, it was noisy. I then adjusted the angle of the screen making it slightly more vertical and this improved the level of noise however I am still unhappy with my efforts.

The top of the screen takes me to nose/ eye height with my helmet obviously collecting the full brunt of the airflow off the screen. I have left a slight gap between the headlight cowling and the bottom of the screen, as I saw some beemers like that so it must be for a good reason.:smartass:

- is it better to have the screen take you below the helmet, or above. Above would surely make for a very unstable odd looking structure ?

- would a perm screen be better than a screen one can remove. I wasnt happy riding the bike through slow traffic though, the screen gave some very odd depth of field distortions - or should the screen just be shorter so you look above it? - any clever ideas ??

- Should the screen be flush with the headlight cowling ?


Cheers

-


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