#131
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That came out great.
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Marcus aka. Gojeep Victoria, Australia http://willyshotrod.com Invention is a combination of brains and materials. The more brains you use, the less materials you need. |
#132
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Steve said: "The Lexan will nest like above. Fastened with counter sunk flat head machine screws with a 1" black painted perimeter border on the inside of the Lexan."
From experience with mating Acrylic Canopies to aircraft, to avoid complications, it is good to allow room for the differential expansion. What many builders miss is the overall "growth" along a line of fasteners. I make a hole much bigger than the fastener and use a dimpled flat washer to hold the window in place - allowing for expansion. I suspect this car is going to see the outdoors. Does the Lexan tolerate the heat-expansion forces very well? mjb
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Marc |
#133
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Thanks guys for the kind words. ---- Just to let you know there was a lot of head scratching associated with this project. Skintkarter mentioned having a similar job coming up soon. Hope some of these ideas are helpful for you guys to make your jobs a little easier.
Marc Bouget Thank for your input. I have made the holes larger but never knew if there was a spec size for a given size machine screw in the aircraft industry.Do you know of any reference material? ---- I do have an inch pound screw driver and was also wondering about torque specs for machine screws for poly carbonate to metal to allow expansion and contraction movement as you mentioned. No mar scratch resistant ploy carbonate is more or less the standard of the drag car industry and stands up very well. Lexan windows that have shape to them need to be formed in an oven so when fit there is no tension pulled in when screwed down. Tension well cause stress cracks to show up in fairly short order. ------- QKiss
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Steve Kioukis Sometimes your mind is stretched out of shape by a new idea never to go back to its original form. Last edited by qkiss; 07-08-2017 at 11:26 PM. |
#134
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Recently saw a neat solution by one of of 'god' fabricators and racers here. He runs a ahem - whisper... rumoured 900hp BMW E34 3.5ltr sedan in the BMW Open Class series here. To streamline his car when fitting up the polycarboate/lexan rear screen and bring the 'glass' up flush with the body, he has attached a bandsawn strip of black plastic (not sure what flavour) about 12mm thick, to the existing window apperture flange. Strip is attached to the flange with 3/16 or so pop rivets, counterbored into the strip to give a flush surface for the glass. The glass is then attached to said strip using plastic countersunk screws, drilled and tapped into the strip. Nice, neat and clever. Screws are black plastic so blend into the black mounting strip. I should have taken a photo, but hopefully you get the idea. All seems to stay in place as he spanks the super rich brigade with their $300k-$500k E46 5.0ltr Dinan engined beasts at 250kph over the start finish line... He is not a popular chap in some quarters...
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Richard "I know nothing. I from Barcelona" (Manuel - Fawlty Towers) Link to our racecar project https://www.facebook.com/pages/Elan-...ab=public&view |
#135
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Im just reading this and I couldnt stop, read all the pages in one sitting. Very impressive work. Cant wait to see more.
One thing that I have never seen/heard was the use of stainless to tack the aluminum window channels. Can you explain this more? I take it as you sandwich the aluminum between the SS then actually run a tack on the stainless and its just enough to penetrate to the aluminum to basically spot weld the aluminum together?
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Cody Lunning |
#136
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Door window frame
What was the thickness of the metal used for the window frame? 3003H14?
Fred26t
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Fred26T |
#137
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Marc Bouget Thank for your input. I have made the holes larger but never knew if there was a spec size for a given size machine screw in the aircraft industry.Do you know of any reference material? ---- I do have an inch pound screw driver and was also wondering about torque specs for machine screws for poly carbonate to metal to allow expansion and contraction movement as you mentioned. No mar scratch resistant ploy carbonate is more or less the standard of the drag car industry and stands up very well. Lexan windows that have shape to them need to be formed in an oven so when fit there is no tension pulled in when screwed down. Tension well cause stress cracks to show up in fairly short order. ------- QKiss [/QUOTE] Polycarbonate is damaged by exposure to oils and will start crazing. The hole size isn't related to fastener size, it's determined by length of a line of fasteners in conjunction with the cooefficient of expansion for the poly. I forgot to mention that the dimpled washer is supported by an aluminum spacer made from tubing. The spacer is related to fastener size, of course. I will see if I can copy the details from a drawing I have. mjb
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Marc |
#138
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Quote:
https://www.youtube.com/watch?v=gcgC3V3mkcw
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John |
#139
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Ah I was under the impression he was tacking with his tig welder. Misunderstood
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Cody Lunning |
#140
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The material used is .040 5052 ----- 3003-h14 would work also. This is a race car and weight is a big consideration and mounted to fiberglass doors.If it were a street car with steel doors the material of choice would have been steel. Material size is also mentioned in post #125.
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Steve Kioukis Sometimes your mind is stretched out of shape by a new idea never to go back to its original form. |
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