Does this sound like a good process?

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Does this sound like a good process?

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quinn	q quinn posted 7 Years Ago HOT Topic Details
q Group: Forum Members Posts: 155, Visits: 992	I already posted about my carbon fiber helicopter boom, for that I decided I'll bite the bullet and do alloy molds. I also need a carbon fiber helicopter canopy. Similar shape to a football but a bit bigger and open at the back, I'll attach a pic of one. It will have pretty thin wall thickness, generally they are about a half mm, maybe .6 or .7. So only a couple layers of weave. I will be making my own design on fusion 360 and milling the plug on my cnc. The process that makes the most sense to me is milling each plug half (mold will be split down the middle lengthwise, right and left half) out of mdf or foam, spraying it with layers of duratec primer, sand and polish, then attach each plug half to a flat sheet of melamine or some other rigid plastic to create base for mold flanges and proceed to make fiberglass mold halves from that. I would prefer to skip the plug stage and go straight to milling the molds, but it just doesn't seem to work out as well as making fiberglass molds from a plug. From the female molds I will vacuum bag a carbon fiber wet lay up. does this sound like a good plan or is there an easier/better way considering I have a cnc? Another variation would be attaching the 2 plug halves together to make a complete plug before applying duratec, then split into 2 molds using the method shown in the air box video, but i feel that it will be less work to just attach the 2 halves to flat sheets for making the molds, just need to make sure both sheets are perfectly flat planes.
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Hanaldo	Hanaldo posted 7 Years Ago HOT Post Details
Group: Forum Members Posts: 2.5K, Visits: 28K	Dont worry about the gauge, they are all going to be inaccurate in one way or another. Some may be better calibrated than others, but at the end of the day the number they point to really doesn't matter. Keep in mind that elevation above sea level and atmospheric conditions will change the reading the gauge gives you as well. So one day it might read 26", the next day it could be 30mm past the 30" mark - and I promise you wont be pulling 32" of vacuum! Stick with what you've got. Your pump should be perfectly capable of pulling full vacuum, so if it goes quiet and stops emitting oil vapour when the gauge says you are at full vacuum then you are likely at full vacuum. If you're really worried about it, do some playing around and infuse some flat sheet. You'll learn a lot, and you'll also be able to look at the flat sheet and diagnose any problems - pump related problems are going to be obvious.
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Lester Populaire	L Lester Populaire posted 7 Years Ago HOT Post Details
L Group: Forum Members Posts: 311, Visits: 13K	+x Hanaldo - 8/12/2018 2:40:40 AM Dont worry about the gauge, they are all going to be inaccurate in one way or another. Some may be better calibrated than others, but at the end of the day the number they point to really doesn't matter. Keep in mind that elevation above sea level and atmospheric conditions will change the reading the gauge gives you as well. So one day it might read 26", the next day it could be 30mm past the 30" mark - and I promise you wont be pulling 32" of vacuum! Stick with what you've got. Your pump should be perfectly capable of pulling full vacuum, so if it goes quiet and stops emitting oil vapour when the gauge says you are at full vacuum then you are likely at full vacuum. If you're really worried about it, do some playing around and infuse some flat sheet. You'll learn a lot, and you'll also be able to look at the flat sheet and diagnose any problems - pump related problems are going to be obvious. I would highly recommend infusing some flat sheets of glass fiber and carbon fiber and whatever to figure out all small details of the process!
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quinn	q quinn posted 7 Years Ago HOT Post Details
q Group: Forum Members Posts: 155, Visits: 992	+x Hanaldo - 8/12/2018 2:40:40 AM Dont worry about the gauge, they are all going to be inaccurate in one way or another. Some may be better calibrated than others, but at the end of the day the number they point to really doesn't matter. Keep in mind that elevation above sea level and atmospheric conditions will change the reading the gauge gives you as well. So one day it might read 26", the next day it could be 30mm past the 30" mark - and I promise you wont be pulling 32" of vacuum! Stick with what you've got. Your pump should be perfectly capable of pulling full vacuum, so if it goes quiet and stops emitting oil vapour when the gauge says you are at full vacuum then you are likely at full vacuum. If you're really worried about it, do some playing around and infuse some flat sheet. You'll learn a lot, and you'll also be able to look at the flat sheet and diagnose any problems - pump related problems are going to be obvious. you were right about the gauge. figured out an easy way to test the pump. room temperature water boils at 29.1 inches. put a few drops of water in the end of a tube hooked to the pump, capped it off and turned it on. boiled immediately. so now i know at least its hitting over 29, probably pretty close to full vac.
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