Windshield Vents

[Hank Jarrett]

Re: Windshield Vents

Charles, I like it. I would have thought it would be lower on the boot cowl to blow air around the feet but that would be almost impossible to reach to adjust. Can you reach it there to turn it?
Hank

[cvavon]

Re: Windshield Vents

Hank yes it's easy to reach from there and the opposite side can be gotten to from left side also chuck also do you need a wheel

[Hank Jarrett]

Re: Windshield Vents

I have got to get out to the barn and make sure which wheel I still have so I can get a match for it. Over 100* this morning in the hangar working on the 41. May take a couple of days to get in the barn to check the 45 (different location and my boss wants me to actually do some work tomorrow).
I had a gallon paint can with some UV dope (silver) in it at the hangar. Only had about 1" in the bottom and got so hot the lid blew off! It's TOO DARNED HOT!!
Hank

[cvavon]

Re: Windshield Vents

Hank i have a person that has a plane down for a bad wheel and needs one to get back flying let me know soon as he will take both but only needs one did you look at the photos on for sail post also eric will take them so you spoke first but need to know SOON!!! chuck

[Hank Jarrett]

Re: Windshield Vents

The 45 won't be flying for a LOOOONG time so if someone needs one to get airborne they should get it. Another will come up in the (probably) years I spend rebuilding the 45.
If someone has a non-flight worthy one I can use for rolling around let me know. In the Navy we used to coat the damaged areas on wheels with poly sulphide sealant and assemble them with a non airworthy tire. We used them for years for ground transport. You could NEVER get them apart and we painted them bright red so one wouldn't end up on a flying plane. Really handy things to have around.
Hank

[bashibazouk]

Re: Windshield Vents

Back to the vents....

Any speculation about the diameter of the mounting hole? 2-1/2 or 3"?

Just a guess.

[Hank Jarrett]

Re: Windshield Vents

I will measure them when I get the parts and make a drawing to post. That way everyone will have the same size.
Hank

[Hank Jarrett]

Re: Windshield Vents

Buell,
I got the vents and they are either Byuterate or Acetate sheet. Either way it is an OLD material and has shrunken pretty bad. I have already done a drawing of what I think the original size and shape probably was and a contour form drawing for the plug to make the scoop part. I think if we made them from Plexi we could probably form them with a wood plunge die and a couple of of pieces of of MDF heating the plastic with a tile gun. We might get a few small bubbles that way, but for the vent they wouldn't show anyway. The plastic is REALLY thin and I would probably go up one size just to keep the vent from breaking if someone was fooling with it. From the looks of the molding marks on the plastic I think these things may have been made in the factory the same way I plan to do it. Do you still have the plastic piece it was mounted in? Knowing the exact size of the hole in the windscreen would tell me if I estimated the shrinkage right.
I am going to try and make a die and form and see how they come out. I tried to take the parts to the plastics company but they closed early Friday (MAN, I hate taking off from work and the place closes early! Glad I was of anyway to take my wife to the airport).
I really like the design and look of it with one exception, there is no way to totally shut it off like the later versions in cold weather. I couldn't see any way to close it of from the pieces you sent.
Hank

[Buell Powell]

Re: Windshield Vents

Hank,
Those are the only pieces I have. It sounds like you have already figured a workable plan. I haven't tried forming plexiglass except for making a windshield for a model boat by bending a piece of tin can the shape I wanted and cutting out a piece of 1/16" plexiglass and placing it in an oven and heating until it drooped over it. I had thought about making a form for an oversize piece to lay on and one to place on top with a weight and pins so it would slide down as the piece softens with heat ,then trimming the diameter. I wonder if cutting a slit for the scoop opening would make it form easier? I don't have any idea if it would have worked and not sure how I was going to make the forms though. Wonder if the old original forms are still with the factory inventory?

[Hank Jarrett]

Re: Windshield Vents

From the pieces you sent there were10 holes drilled in the plastic, 8 at 45* apart around the edge and two at the end of the curved slot for the eventual opening. I could still see where the holes for the slot were drilled and the slot cut in the part that stayed flat. When the scoop is pressed into the plastic the cut marks at the edge were stretched. In the middle of the scoop part the edge was trimmed and was smooth.
All I needed was a good jewelers loupe and a bit of manufacturing archeology. ;-)
If I'm right I should be able to make a duplicate with a bit better material than the original. I drew it up so we could take a current windscreen and just cut a new hole taking out the holes and slip this one in. It comes within 1/16" of what I figure the original was dimensioned.
Hank

[jim cooper]

Re: Windshield Vents

speaking of vents....my last t craft, the one the hangar collapsed on, had them at knee level on the side of the airplane, controlled by a little knob. VERY nice! Current one does not have any. But....windows slide open very well and don't rattle. JC

[Hank Jarrett]

Re: Windshield Vents

I took the parts to the plastics manufacturer and their price seemed VERY high to me. The little rings alone were going to run over $8 to $10 each and they wouldn't even guess the cost of making the pressed parts till they took a longer look at it. I showed them my idea on how they probably made them originally (they didn't go for complex processes back then) and they gave me some Lexan and Plexi to try it. I get the feeling they thought "that just might work" but didn't want to test it themselves. When you have a building full of complex machines for things like this it is hard to accept all you might need is a couple of blocks of wood and a tile gun.
I have to get the engine built up for the 41, but I will try and make the parts for the mold and die at the same time.
I will post pictures of the process either way. If it doesn't work maybe someone in the tribe will see where I made a mistake.
Hank

I think I already have a MUCH simpler way to make the rings with a router table and a couple of blocks of wood.

[bashibazouk]

Re: Windshield Vents

Two words, Hank. "Vacuum forming." See previous post. If you try to press the hot plastic into a mold with a die, I think you're going to get surface distortion and defects. A simple buck carved out of a chunk of wood and placed on a piece of pegboard on a box hooked to a shop vac will do the job.