Windshield Vents

[Hank Jarrett]

Re: Windshield Vents

I sure don't mind taking them over to the plastics guy and seeing what he would want to make new ones. Generally the cost is mostly making the mold. Once that is done, he can pop them out in whatever numbers you want. I will see what he wants for the "non-recurring" cost and the individual "piece part" cost. The more who want them the more we can spread the mold cost out. Just like the interior placards.
If he doesn't want to take it on I can send you the pieces back. If we DO do it, the original pieces may not be worth getting back once they have been used to make a mold.
Hank

[Buell Powell]

Re: Windshield Vents

Hank,
That sounds fine-I will mail them to you-keep them as long as you need to and if they don't make it back thats OK.--With Jim we have 3 people interested-hopefully there will be enough to make it practical but if not the vista vents are a good replacement--especially for those of us with the swing out windows--they just aren't very practical for ventilation.
Thanks

[Hank Jarrett]

Re: Windshield Vents

May take a couple of days, but I will get them down to the plastics shop the week I get them. Do you still have my address?
Hank

[Buell Powell]

Re: Windshield Vents

Yes-I do and I will mail the vents Tuesday--

[bashibazouk]

Re: Windshield Vents

PETG does have low UV resistance. A vacuum forming table is pretty easy to build. Just a board with a hole in it for an adapter that will fit on your shop vac, a foam rubber seal around the outside that will match a couple of frames like small screen window frames. You clamp a piece of plastic between these with binder clips, put it in the oven, heat it until it sags, put it over your buck on the forming table and suck it down with the shop vac. The buck on such a simple part would probably be easiest to carve out of wood.

http://www.instructables.com/id/Make-a-good,-cheap,-upgradeable-sheet-plastic-vacu/

CAB or cellulose acetate butyrate sheet would be ideal, but it's pretty expensive in big sheets. A little reading reveals that Lexan and other plastics are vacuum-formable but are ofter hygroscopic which means they need to be dried in an oven for a long period of time or the moisture in the plastic will vaporize and cause bubbles or pits. There's a great resource here:

http://tinyurl.com/formech

Probably acrylic would be easiest and cheapest:

http://www.usplastic.com/catalog/item.aspx?itemid=23554&catid=442

[Hank Jarrett]

Re: Windshield Vents

Josh,
I am kind of expecting they will recommend Acrylic and just make multiple copies of the mold. They can pull a bunch at one time and maybe get the cost down to the point where everyone who wants a set can get an extra set to replace them when they yellow or crack. Sometimes it is less expensive to go with the cheaper stuff and throw it away when it wears out than pay a fortune for the good stuff (OK, so how many Harbor Freight tools do YOU have?)
It will be interesting to see which way the cost numbers fall out, two PolyCarbs or 10 Acrylics?
Hank

[bashibazouk]

Re: Windshield Vents

It seems to me like this is another part that could be easily and CHEAPLY made in the shop. No outsourcing required. Just me talking. Looking at the photo of the original, I can't decide whether there is a missing piece or not. Seems like there ought to be a way to shut off the air altogether.

[Hank Jarrett]

Re: Windshield Vents

I am thinking it must have been a set of pieces to that when you rotate it so the opening is faced aft it is closed off. When it is pointed down rain would be kept out but it would only be half open to ventilate. I will need to look at it to figure out how you turned it. Time to get the jewelers loop out to look at the photos again.
Hank

[bashibazouk]

Re: Windshield Vents

Anyone have a higher-resolution version of this picture?

[bashibazouk]

Re: Windshield Vents

Hey! I found this on the Alliance Memory site!! Hooray!

[Hank Jarrett]

Re: Windshield Vents

You DO know that first picture is up-side-down! That is the sissy strap hanging behind it (which I have been looking all over for a picture of! THANK YOU!!!)
'Looks like to me there are actually TWO of the "scoops" facing opposite ways riveted together with a space between them the thickness of the windscreen. There are 6 rivets and 2 screws and knobs. Too bad there is no way to shut it completely in really cold weather.
It also looks like VERY thin material that probably COULD be home vacuum formed.
Hank

[M Towsley]

Re: Windshield Vents

Josh,

You have already proven your worth. If anyone could do this, you could. Probably in your sleep!

[cvavon]

Re: Windshield Vents

Hank and josh if you turn the scoop so the wind gos past the opening it could draw a vacuum and help pull the heat off the floor witch is something tcraft needs

[Hank Jarrett]

Re: Windshield Vents

It is going to be fun to experiment with. At the location by the leading edge on the windscreen it is in a high pressure zone close to the leading edge stagnation point. It could even have air flowing in when turned backwards there! Where it would be REALLY nice is down on the boot cowl to suck air out or blow air in around your feet. When I rebuilt the front of the 41 I insulated the boot cowl and put upholstery in. Looks really nice and keeps the warm where you want it and the cool where you want it, but there is only the cabin heat outlet to stir the air around.
Hank

[cvavon]

Re: Windshield Vents

Hank i have vents on the boot cowl of my 40 and they work well