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  #11  
Old 04-06-2016, 08:59 AM
scott_mills scott_mills is offline
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Join Date: Dec 2013
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Does anyone know what the purpose is for the jt-60p plastic tube, is in the 1239 k39 KIT ? I can't figure out by the instructions whether I'm supposed to cut through the plastic tube as well, or just the body tube. Does the model need the extra strength in that particular area? I purchased a lot on eBay that had most of the KIT, and now I'm thinking of building it.
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  #12  
Old 04-06-2016, 11:23 AM
jdbectec jdbectec is offline
the middle-aged rocketeer
 
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You cut through the paper tube and glue the plastic fins to the clear tube
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  #13  
Old 04-06-2016, 11:08 PM
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luke strawwalker luke strawwalker is offline
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IF you're gonna do a cluster flight, *DON'T EVEN TRY IT* with a "standard" Estes controller, REGARDLESS of what type ignitors you use.

Ditch the Estes wimpy "AA" battery powered junk with dinky bell wire and get you (or build one, or rebuild your Estes controller) a controller capable of using a GOOD 12 VOLT power supply, either a car battery, car battery jumper, motorcycle or lawnmower battery, or an RC car battery pack-- NOT high-resistance short-surge current capable (low "C" rating) stupid DRY CELLS or ALKALINE BATTERIES. Use good heavy "lamp cord" or extension cord lead outs from the controller to the pad, to deliver maximum current with minimum resistance. You want to deliver AS MUCH CURRENT AS THOSE IGNITORS CAN POSSIBLY USE so they heat up VERY QUICKLY and VERY UNIFORMLY to get those motors lit IN A HURRY (not like the standard "AA" battery powered launch where you count down and press the button at "0" and can count to 1, 2, or even 3 before the motor actually lights!)

For the most reliability with clusters, I'd get some Quest Q2G2 low-current ignitors and use those-- but be warned, even a continuity check (inserting the safety key) on an Estes controller is capable of setting those off... To launch those with an Estes controller, hold the button down and insert the key at "zero". Just to be on the safe side I'd STILL want a 12 volt system-- those wimpy "AA" batteries just can't cut it with clusters, and even with the low current ignitors IMHO using a crappy current source like "AA's" is reducing your probability of success.

With a large, heavy rocket like the Saturn V, you want all those motors firing TOGETHER and the liftoff to occur with all motors burning. If you have one motor that doesn't light, you'll probably have a "shovel recovery".

If you stray into the territory of choosing your own "repower" or staging options, different clusters than the kit recommendation, etc., carefully double-check your CG and CP to ensure stability is maintained so you don't have a skywriter or landshark on your hands.

Later and good luck! OL J R
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  #14  
Old 04-07-2016, 01:09 AM
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ghrocketman ghrocketman is offline
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As I stated in an above post, there IS a difference between the K-36/1236 and the 2001 Estes Saturn V.
It is the recovery separation point.
On the 2001 version it separates at the same point as the Centuri kit; at the BT-101.
On the K-36/1236 it separates at the capsule which sucks for decent deployment on a single D12-3.

The 2001 uses a fixed 24mm engine mount, where the K-36/1236 includes the interchangeable 24mm mount and the 3x18mm cluster mount.

I wish they would include a 29mm mount in the one that reportedly is coming out.
The E30 they are going to reccommend (like the little Joe II) is adequate, but I'd like a factory-included mount for use with 29mm F and G engines on a rocket this large. On a decent sized field, a H128 would NOT be unreasonable either.
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