View Full Version : Tower Launchers
1st May 2009, 03:08 AM
Trying to get motivated to finish my Mongoose and fly.
Looking for ideas to build a tower launcher for this bird.
There were some great examples shared when I asked this once prior before the board lost all it's data. Anyone able to share some of their craftwork for a tower launcher?
1st May 2009, 03:21 AM
What size and is the mongoose 3 or 4 finned? How much money are you willing to spend on it?
I built this for a minimum diameter 75mm rocket, I friend borrowed it for his rocket a 98mm minimum diameter N (weighed nearly 30kg IIRC), and it held up fine, only a little bit of burning at the bottom.
Edit: the rocket was sitting on a block of wood which was half buried in the ground.... but that got blasted about 5 meters from the pad at lift off
1st May 2009, 10:49 AM
The Mongoose is 54mm minimum diameter with 3 fins.
Cost is not so much of an issue other than I prefer to make something up myself, so don't want to buy a premade item.
17th October 2010, 09:30 AM
I make mine with a 6" or so PVC coupling. First, mark it like a 3 fin rocket. I always number the places the bolts go through before the coupler is sawn in half making 2 rings. Using my drill press I drill a 1/4" holes spaced 120 degrees apart. You can make a large fin marking guide in VCP or other rocket program. Now you will need to give the tower some back bone. I always used a 1"x2"x3" piece of oak lumber, This is the piece that keeps the two rings apart. I've made both 3 and four foot long towers, but the length is up to you. next we need 3 lengths of aluminum tubing abut 3/4" in diameter.these need to be the same length as your strong back. I used a grinder to make 45 degree cuts on the end of every tube so we can thread the head end of the bolt there. You need 6 1/4" -20 bolts 6 inches long. each bolt needs 3 nuts on it. insert the bolt into the aluminum guide rod and tighten the nut, you do the same of each end of the 3 guide rods. You should have a nut on the inside of the PVC ring and another on the outside of the ring. I put a steel plate on the strong back using counter sunk hardware. The plate is at the balance point of the tower and drilled and tapped it with a 1/4"-20 hole so I can use the tower on my Leitz Tilt-All tripod. This makes it very easy to steer to the ideal direction. I keep a chart on the tower that tells me how far the bolts stick out for 13mm, 18mm. or 24mm body tubes, Then you whip out your 7/16th wrench and have at it. This tower design works well , but it is a bit of a PITA to adjust in the field. I made 3 of them so I would be all tuned up for most any contest.
I know that my verbal avalanche is hard to de-cypher, so I will try to post some pictures. As far as the design goes it is nothing new and I make no claim on it, the rocketry public is free to use it and improve it.
I re-read this post, I swear I wasn't drunk when I wrote it! Jeez, I really sounded like the semi-literate knucklehead I truly am!
10th November 2010, 02:54 AM
I am starting on a 12" diameter tower. I found some guys on Ebay that sell 12" sections of 12" diameter Schedule 40 PVC. I'm going to use 1 inch square aluminum 6 feet long as the guides. I think the square cross section offers more control over the model than cylindrical tubes. I'm hoping that this tower will work well with rockets up to 4" in diameter. They just have to have fin tips smaller than 12" I had a lot of fun building my small towers, this one should be great. I cant 'wait to take the launch lug off my Lil' Nuke. It would be nice if I could find some teflon strips to face the guide rods. I figure I can finish them up to 2000 grit and that ought to be good enough. I am going to try to document the build, I just got to figure out how to post pictures here.
10th November 2010, 03:08 AM
I debuted my rebar/PVC/5-gallon bucket lid launch tower at MWP8 two weekends ago. Worked great on my 2.6" dia., 79" long Drag Race kit on a K350. Would be no problem for anything smaller like a Mongoose 38 or 54. Total cost of the tower: $6. I'll try to get pics up sometime.
10th November 2010, 03:17 AM
How did you finish the rebar so it was not too rough? You could probably have several sets of receiver tubes at 120 degree angles so you can use it for more than one size. The first towers I made were for 13mm and 18mm contest rockets. I just used three wooden dowels set into a wooden base. I sanded the dowels smooth and waxed them really well. It still works great.
10th November 2010, 03:48 AM
How did you finish the rebar so it was not too rough? You could probably have several sets of receiver tubes at 120 degree angles so you can use it for more than one size.
1" PVC sections slid down/over 1/2" rebar. 1/4" scrap steel plate with multi-hole pattern for base to allow differing diameters.
14th November 2010, 03:56 AM
This is a cool and timely thread. I've been thinking about the same situation. My idea so far would have been complicated and expensive. Thank you all for the excellent ideas. I look forward to seeing some pictures.
I will be starting on my Kestrel build very soon. I like to 'see' the entire project before I start on it. The project includes a tower.
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