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My old shop was 720 sqft, after the first few rains my milling machine had surface rust, I installed a dehumidifier with a hose to a drain for continuous operation and never had a problem again.

Oh okay that sounds pretty nice. Do you know how water tight the building was? My shop is pretty much a segment of a leaky metal building with the exterior wall insulated but nothing else. my main worry about getting a dehumidifier is that the moister will be coming in faster than the dehumidifier can pull it out.
 
Okay it's been a couple days and the board has still not flattened out. Do you guys have any suggestions on how to flatten it out?
 
Okay it's been a couple days and the board has still not flattened out. Do you guys have any suggestions on how to flatten it out?

You need a nice flat surface in a dry area with enough weight on it to flatten it out and then lots of time. Might be better off getting another sheet, and then keep it under your bed or somewhere dry until ready to use.
 
Okay so since school was let out I've been able to get some stuff done. Fins are centering rings are finished.

I'm also getting ready to glass the airframe. I should be able to get the upper section finished today.

My setup for glassing the tubes is shown in one of the pictures below. Found the two metal brackets sitting out the shop and rivets from another rocket fit perfectly into the holes. The tube is sitting on the rivets. Kind of makeshift but it should work.

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One thing I love about Texas is that epoxy cures VERY fast in the heat. I was able to layup the tube today around noon and I was able to pull the peel-ply off just a couple minutes ago! It still needs a little more time to completely cure but it should be done tomorrow.

Now for a question, I made the fins for this rocket out of 1/4" plywood and they seem fairly strong to me. Problem is that this is my first rocket with a 54mm motor mount so I'm not so sure how strong they need to be. Would you guys recommend putting a layer of fiberglass on the fins? I also thought it'd be cool to use carbon fiber on the fins. I have some laying around and it would definitely make these fins strong enough... And it'd look cooler. :p
 
One thing I love about Texas is that epoxy cures VERY fast in the heat. I was able to layup the tube today around noon and I was able to pull the peel-ply off just a couple minutes ago! It still needs a little more time to completely cure but it should be done tomorrow.

Now for a question, I made the fins for this rocket out of 1/4" plywood and they seem fairly strong to me. Problem is that this is my first rocket with a 54mm motor mount so I'm not so sure how strong they need to be. Would you guys recommend putting a layer of fiberglass on the fins? I also thought it'd be cool to use carbon fiber on the fins. I have some laying around and it would definitely make these fins strong enough... And it'd look cooler. :p

First of all how fast are you going to go? Anywhere between Mach 1 to 1.4 I assume will be fine without reinforcement. After that the heat can start to roast it and destroy them. I'd recommend adding two layers on each side to beef them up good enough. Use your 20 ton press to squeeze out excess epoxy and will give you good sandwiched fins.
 
I say a layer of 6oz or whatever you have one each side more for protecting the fins from damage upon landing rather then for the actual flight. This is of course if you plan on staying under about M1.4 or so like Alex said.
 
First of all how fast are you going to go? Anywhere between Mach 1 to 1.4 I assume will be fine without reinforcement. After that the heat can start to roast it and destroy them. I'd recommend adding two layers on each side to beef them up good enough. Use your 20 ton press to squeeze out excess epoxy and will give you good sandwiched fins.

Okay thanks. With the largest motor it can take the rocket I believe gets up to around mach 1.6 so it probably wouldn't be a bad idea to either glass or carbon them.
 
Upper and main air frame tubes are both glassed. I think the peel ply was applied too loosely though because it wrinkled up and now I have a lot of sanding to do on the lower air frame. :/ I've also decided to laminate the fins with a sheet of carbon fiber on each side. I'm also going to laminate the leading and trailing edges to protect the wood. I'm considering investing in a cheap vacuum bagging system so that would definitely help with the fins especially around the leading and trailing edges.
 
Today I'll be working on getting the wrinkles out of the lower airframe tube. Does anyone have any ideas on why the peel ply wrinkled during the cure? I'm at a loss of why it did.
I guess the good news is that the glass stayed flat so I can just sand the ridges off.
 
that happened to me when i started making composite tubes. I found it was actually sagging from being pulled down. Now I rotate the tube every 10 or so minutes to avoid the epoxy from moving to the bottom which keeps the peel ply in place.
 
that happened to me when i started making composite tubes. I found it was actually sagging from being pulled down. Now I rotate the tube every 10 or so minutes to avoid the epoxy from moving to the bottom which keeps the peel ply in place.

Yeah that's a good point. I thought that might have been the case at first but I noticed that the ridges are all around the tube...

It really is odd, I've never had this happen before. The only difference was that I had a friend help me out because the heat down here cures the epoxy so fast I needed a helper. I watched him while we worked and he was doing everything great.

Is it possible using too much epoxy would do this?
 
Yeah that's a good point. I thought that might have been the case at first but I noticed that the ridges are all around the tube...

It really is odd, I've never had this happen before. The only difference was that I had a friend help me out because the heat down here cures the epoxy so fast I needed a helper. I watched him while we worked and he was doing everything great.

Is it possible using too much epoxy would do this?

Yes using too much is the cause. What happens is that gravity pulls the excess epoxy downward and creates those ridges.

This happened to me also when I applied too much epoxy, its not pretty to sand all that down.

ImageUploadedByRocketry Forum1434828329.508940.jpg
 
Thanks for sharing. :)

'tis a fine line between too much and not enough epoxy :p
 
okay so sadly because of different reasons, mainly the driving time to and from, I decided a couple weeks ago that LDRS wasn't going to happen this year. :( Good news is there is a site in Hearne about three hours from here with a 16000 ft waiver and a launch on July 11th that I should be able to attend. So the new target date for completion is in time for the Hearne launch.

So far I haven't been able to get much more done on the rocket in the past couple days. I've been trying to find some way to attach the tube to our wood lathe so it would make it a bit easier to sand down the epoxy ridges.
 
Yesterday I spent all day sanding the body tube and I think I've finally got it to where I'm okay with it. I'll still have to use a ton of filler primer but I'm not expecting this rocket to look flawless.

Got the motor mount cut to size and epoxied the retainer and rear centering ring on. Also drilled a hole in the forward CR and attached an anchor point for the shock cord.

Finally, I cut the coupler tube to size and painted it with a coat of epoxy to try and add a bit of strength to it as well as make the connection more flush.

I'm still trying to decide how to layup the fins. I've been thinking I'd lay them up, airfoil and them and then laminate a strip of composites over the leading edge but I'm not sure. I'm sure a vacuum bagger would do the same thing with less work but I'm not sure if I want to drop money on one quite yet. I might end up buying one anyway though.

Any suggestions are welcomed. :)
 
As mentioned before, use the plate press. It works just the same as vacumm bagging. You'll be making your wallet cry with all those consumables.
 
As mentioned before, use the plate press. It works just the same as vacumm bagging. You'll be making your wallet cry with all those consumables.

Yeah the problem with using the press for these are that it'd be nice to get the composites wrapped around the airfoil of the fins. I can't think of any way to do that with a plate press.
 
Yeah the problem with using the press for these are that it'd be nice to get the composites wrapped around the airfoil of the fins. I can't think of any way to do that with a plate press.

Ah I thought the fins had no bevel yet. Hm, well like conman said, cheap is the best way and well maybe this can help. I couldnt find a source where it is cheap, but maybe you can find one somewhere.

It is a hand vacumm pump. This would be a good way to do this without the expense of an electrical pump.

ImageUploadedByRocketry Forum1435444764.004183.jpg

Hope this helps.
 
Ah I thought the fins had no bevel yet. Hm, well like conman said, cheap is the best way and well maybe this can help. I couldnt find a source where it is cheap, but maybe you can find one somewhere.

It is a hand vacumm pump. This would be a good way to do this without the expense of an electrical pump.

View attachment 266342

Hope this helps.

Thanks! that looks like it might be a lot cheaper than getting a full out pump system. I actually haven't beveled the fins yet but once I do I'll have the problem that the leading and trailing edges will be exposed wood. If wood is at risk of getting too hot at, or around mach 1.6-1.8 then I'm going to want some sort of composite protection on the beveled edges... Right? :confused:
 
Thanks! that looks like it might be a lot cheaper than getting a full out pump system. I actually haven't beveled the fins yet but once I do I'll have the problem that the leading and trailing edges will be exposed wood. If wood is at risk of getting too hot at, or around mach 1.6-1.8 then I'm going to want some sort of composite protection on the beveled edges... Right? :confused:

Nothing like adding some JB weld to the beveled area will fix.
 
Today was a fairly productive day. I was able to trim, sand, and airfoil two of the fins and finish layering the other two with carbon fiber. I also marked and cut the fun slots on the main body which took MUCH longer than expected...

Did a dry fit with the two fins I had done. This rocket is going to look pretty bad a$$. :cool:

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Got all four fins trimmed sanded and airfoiled and did a dry fit with all the parts.

Real rocket have curves. :p

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Got a lot of stuff done over the last two days! I had a much better, more detailed post written out but then I accidentally deleted it... :facepalm:

Fins have been finish sanded, motor mount has been glued into the air frame, Av-bay has been assembled, and fins have been tacked onto the rocket.

Photos to come. :)
 
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