|
F908tim
Original Poster
11 posts
|
Any one work with plastics, perspex or polycarbide sheet or got a mate who does, perhaps in signmaking?
I STILL have the headlamp surrounds for the S but have not been able to find someone up on plastic sheeting to give me advice to progress. I think I need polycarbide sheet about 1.5mm to 2mm max thickness but not had any joy locating some to try out locally.
I have a picture of the headlamp cowels but it is 2.7mb and numpty does not know how to reduce the file size to post the picture as it is bigger than the 2mb image upload limit. Assistance anyone please..helps if you know what i'm talking about!
|
|
|
johnnywgk
618 posts
9 months
|
If you know how to pm it to me do that and i'll resize and post for you. hth.
|
|
|
johnnywgk
618 posts
9 months
|
Sorry, thought i was on a different forum.
If you click on reply to topic, the screen pops up where you write your post, just above that is a linky thing that says "Upload an image(Beta).
click that, then find your photo in you pc, double click it, then click forum fit.
I think that will reduce the size of your photo.
If it does'nt, dont worry, a mod will resize it for you (i think) but don't tell them i said that. hehe.
|
|
|
CNHSS1
588 posts
44 months
|
perspex is a brand name of acrylic sheet and can shatter/crack easily.
By polycarbide do you mean polycarbonate? if so its regularly used for race car windows and riot shields!!
are you making headlamp cowls for an S like those on a Griff? if so id have thought polycarbonate, vac formed over a suitable mould at 2mm should be fine. id suggest speccing a polycarbonate with a hard glazing finish (doesnt scratch as easily and doesnt yelliow with UV as badly as perspex). Word of warning, vac forming acrylic is easy, polycarbonate not so. Polycarbonate (common trade names Macrolon or Lexan) is very temp and humidity sensitive, too hot and it blisters badly, too cool and it wont form.
For mass production, the best moulds are cast from ally resin (think liquid metal) and the mould plug is heated too. Usually polycarb vac form machines have lots of individual heating elemenst to vary the heat across the sheet so you get an even 'pull' to stop getting a moulding thats paper thin in places, but barely formed in others.
If you arent making headlamp cowls and ive assumed incorrectly, ignore me lol
CNH
|
|
|
F908tim
Original Poster
11 posts
|
Hi guys,
Yep I thought it would be as easy as that too John...but no joy as the pic is 2.7MB and bigger than the 2MB file size limit set on this site. So how do I reduce it or can someone correct it if I send the jpg to them?
Yep, headlamp cowels similar to the Griff. Polycarbide is the material I had recommended but no-one around here seems to have a sample I can play with to see if it works.
Fortunately, the sheet needs to fold through only two planes rather than three and does not warp or become mis-shapen when bent over the cowel template. I hope a former or a mould will not therefor be necessary.
I was told you can 'pop it into the oven' to make it pliable...a simplification?
Anyway, sounds like I might have run into a bit of an expert! If we can get my piggin picture on the site perhaps you will have a better idea?
Anyone help me with this please?
Tim
|
Advertisement
|
|
|
johnnywgk
618 posts
9 months
|
pm it to me, i'll sort it and post it for you.
|
|
|
CNHSS1
588 posts
44 months
|
most of the materials you mention are thermo-forming, although ive not heard of polycarbide as mentioned.
often the easiest ones to thermo form over a mould in the oven (common practice for making one-off model aircraft canopies) are generally not tough enough. A stone at 70mph would destroy most.
a search for model canopy methods or a book from your local model shop may help.
get a pic up and we'll go from there.
|
|
|
F908tim
Original Poster
11 posts
|
John...You have mail.
Thanks for your help
|
|
|
johnnywgk
618 posts
9 months
|
Tim, try again using my email direct (not through PH, it dont seem to be working, in my experience, over the last few days)
|
|
|
F908tim
Original Poster
11 posts
|
Ok Johnny, three pics sent.
Cheers
|
|
|
johnnywgk
618 posts
9 months
|
|
|
F908tim
Original Poster
11 posts
|
Brilliant Johnny, thanks.
OK guys, any thoughts on the material and its fixing?
I believe these are the only set existing but if the cowels work and look good I guess others can be fabricated using these as the former.
|
|
|
CNHSS1
588 posts
44 months
|
id use 2mm polycarbonate and decent 3M scotch black double sided tape or silicone or screen bonder. Not as easy to change a light unit but neater than screws.
are the clear cowls a direct fit for a standard S type bonnet or do you need the primered headlamp bonnet shells too?
|
|
|
F908tim
Original Poster
11 posts
|
I was thinking I would leave a few 'tabs' on the transparent cowels to tuck and stick under the moulded insets...not to easy if it is 2mm thick but perhaps if the tabs were scored carefully along the fold then they would fold under ok. The insets are secured to the bonnet with a single nut & bolt fixed into the fibreglass moulds underneath.
Otherwise sourcing a correct profile strip of rubber trim to secure them in place but each side would need a different profile strip and the top edge a strip of silicone or similar as you suggest.
The insets allow you to fix and remove the entire headlamp cover to change a bulb etc. without having to disturb the transparent cowel so they would be very practical as well as look good. The chrome rings around the headlamps need removing as they do not fit flush under the profile.
I have not been able to locate some suitable transparent material to play with to see what works and what its limitations are, but your suggestion seems good. Do you have any contacts who can source some as I think I can find the rubber trims?
Pies had these before me and I think he got a bit exasperated with little progress being made before selling them onto me.
|
|
|
Griffinr
16 posts
1 month
|
If you struggle to scrounge any polycarbonate or acrylic you could try this site which does mail order. They do various types and thickness. Otherwise look for a local plastic sheet supplier who usually have a cutting service and more importantly a scrap bin!! http://www.diyplas.co.uk/
|
|
|
Gerald-TVR
2,215 posts
24 months
|
Can I suggest you get a fibreglass company like TET Moulding or Fiberon to take moulds before you attempt fitting. They could then be re-created if necessary
|
|
|
F908tim
Original Poster
11 posts
|
Have mailed the suggested company but can't find anyone local who is either interested or has polycarbonate sheeting let alone off-cuts. I don't want a 8x10 sheet of the stuff at £110 plus delivery to find it aint any good for the job. Yep, thought I would get mould of the insets made as think others would want sets if I ever get further.
|
|
|
Ceejay73
219 posts
55 months
|
Heres a linky dink to a company that supplies smaller sheets of clear polycarbonate. IMO the 2mm is what you wanna try, the bodyshells for 1/5th scale RC petrol buggies are vac formed from this stuff (that's what I was investigating when I found these guys). Maybe 1mm would be thick enough but in small sheets it's cheap enough to experiment. Anyways take a look and see if it's any help. Carl. http://www.plasticonline.co.uk/index.php?act=viewC...
|
|
|
CNHSS1
588 posts
44 months
|
Lewis & Mason Plastics in Telford will have it on the shelf, havent got their phone number here bu have it at work if google doesnt pull it up. Sure theyd have small amounts cheaply. I bought 5ft x 2t 2mm polycarbonate for about £16 iirc
edit:-
01952 210322
|
|
|
F908tim
Original Poster
11 posts
|
Thanks guys. Rang them and each is sending catalogue. RED ltd very helpful and seemed interested...sent them a few questions on polycarbonate performance...see what they say.
At least they sell small bits at sensible money!
|
|
