thobin
Well-Known Member
- Joined
- Nov 9, 2009
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I just couldn't pass up the Loki Research sale so I picked up a 76mm 3600 deal, quick run of the numbers and its about a hundred dollars off. Im getting the L-930 white. Only I have one small problem I dont own a 76mm rocket so its time to fix that.
As the title suggests I'm building a 8 dia short rocket and so far I'm only into it about $19 in materials. The most expensive part so far has been the ply for the fins and the centering rings, the tube is just a 8 sonotube I got from Lows, it was about $7.50 for a 48 piece. Its pretty stiff and should make a nice air-frame. The motor mount is a 76mm, just a 3 packing tube that I pulled out of the garbage at work, all the 3 tubes that I have found so far will work for a 76mm motor mount, some are a little loose but I have yet to run into one that was too small.
The 5 x 5 x ¼ Baltic birch ply I bought from a local lumber yard for $27 a sheet, by the time Im done with the rocket I will have used roughly 1/3 of it. So its around $9 in wood, and I have a few dollars in some hardware, U-bolts and T-nuts.
Im sure the nose cone will eventually be the most expensive part, I havent quite decided what to make it out of or how. I have access to a lathe; its just getting there and doing it. Right now the plan is turning a form out of Poplar, Basswood or Alder which ever I can get thats cheapest and then do a fiberglass layup, Im figuring $12 in glass and epoxy and around $25 in wood, I will be able to use the form more than once.
This isn't going to be a very in-depth build mostly because I can never remember to take pictures. As you can see I have already cut out the fins and two of the centering rings and coated the tube inside and out with epoxy. One of the things about a Sonotube is you have to peel the inside layer out, as it is impregnated with a wax and will repel glue, that was a major pain. What I couldn't peel out I had to sand out, and it was fun getting epoxy all the way up to my arm pit and thats with starting with the middle and working my way out. More than likely put one more coat of epoxy on the outside once I get it all assembled.
This is just the rough draft Open Rocket file I will fine tune the weights and sizes as I get closer to the finish line.
TA
View attachment bigfat.ork
As the title suggests I'm building a 8 dia short rocket and so far I'm only into it about $19 in materials. The most expensive part so far has been the ply for the fins and the centering rings, the tube is just a 8 sonotube I got from Lows, it was about $7.50 for a 48 piece. Its pretty stiff and should make a nice air-frame. The motor mount is a 76mm, just a 3 packing tube that I pulled out of the garbage at work, all the 3 tubes that I have found so far will work for a 76mm motor mount, some are a little loose but I have yet to run into one that was too small.
The 5 x 5 x ¼ Baltic birch ply I bought from a local lumber yard for $27 a sheet, by the time Im done with the rocket I will have used roughly 1/3 of it. So its around $9 in wood, and I have a few dollars in some hardware, U-bolts and T-nuts.
Im sure the nose cone will eventually be the most expensive part, I havent quite decided what to make it out of or how. I have access to a lathe; its just getting there and doing it. Right now the plan is turning a form out of Poplar, Basswood or Alder which ever I can get thats cheapest and then do a fiberglass layup, Im figuring $12 in glass and epoxy and around $25 in wood, I will be able to use the form more than once.
This isn't going to be a very in-depth build mostly because I can never remember to take pictures. As you can see I have already cut out the fins and two of the centering rings and coated the tube inside and out with epoxy. One of the things about a Sonotube is you have to peel the inside layer out, as it is impregnated with a wax and will repel glue, that was a major pain. What I couldn't peel out I had to sand out, and it was fun getting epoxy all the way up to my arm pit and thats with starting with the middle and working my way out. More than likely put one more coat of epoxy on the outside once I get it all assembled.
This is just the rough draft Open Rocket file I will fine tune the weights and sizes as I get closer to the finish line.
TA
View attachment bigfat.ork