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Renegade blunder, oops

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Missileman

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Well now I gone and did it.
I am near completion of my Renegade kit.
Fins and boosters in place almost ready for paint.
I am looking in the bag at whats left of the parts and to my horror I see a thrust ring.
On further inspection I find that I forgot to install the thrust ring in the sustainer motor mount. Ouch.
Now the question is, Do I risk getting glue all over the inside of the motor tube and push it up from the bottom or do I just leave it out and rely on a good friction fit? (this model uses no clips so the motor is friction fitted anyway)
I have to keep in mind the pressure of the booster when staging as well as thrust of the sustainer motor.
Any ideas?
 

Fore Check

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This is easy - if there's no motor hook on the sustainer.



Get a 5" + length of dowel. put a pencil mark on it about 2.5" from one end. That way, you know how far to stick the dowel in before you start smearing glue.

Now, pour a small puddle of glue on a piece of scrap paper. Dip the tip of your dowel (the one that's 2.5" or so from the pencil mark) in the glue. Now, *carefully* thread the dowel into the motor tube from the aft end without touching the sides. When you get it in up to the pencil mark, press to the side of the tube and start swirling to cover the entire interior circumference. Pull out, re-dab the glue, and repeat as necessary until covered.

Then, insert your thrust ring into the aft end of the motor tube. Use a spent motor casing or one of those "dummy motor tubes" that Estes puts in their kits and push in (twisting whilst you do so) until you get it in to the right depth. Marking your dummy motor casing at that same 2.5" length helps.

It's essentially the same method as installing a thrust ring in a minimum diameter or stuffer tube rocket.

I suggest you use white or wood glue. You should be fine!



Now, if there's a motor hook on the sustainer, *that* creates a problem..........
 

jflis

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Ditto what Fore Check said, but I would add this...

Using your wood dowel a second time, sharpen a small point on the end of it, dip it in the glue, and apply a small filet of glue on the *bottom* side of the thrust ring as well, for added strength. If you are careful, you can do this without getting any glue on the inside wall of the engine tube and you will have an engine block installed at *least* as strongly as a proper installation would have made.

good luck!
jim
 

Missileman

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Thanks for the tips.
I am off to install my engine block.:)
 

Bill

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Originally posted by Fore Check
Then, insert your thrust ring into the aft end of the motor tube. Use a spent motor casing or one of those "dummy motor tubes" that Estes puts in their kits and push in (twisting whilst you do so) until you get it in to the right depth. Marking your dummy motor casing at that same 2.5" length helps.
...and for the most important step, immediately remove the motor casing so that it does not become a permanent part of the rocket.


Bill
 

Karl

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Originally posted by Bill
...and for the most important step, immediately remove the motor casing so that it does not become a permanent part of the rocket.


Bill
Ive just had a similar incident , I dipped the boat-tail of my POF ALARM in a mix of PVA & warm water. I thought , it might make the mmt shrink if I dont do something to keep it's shape. So I added a spent motor casing ..... Now I've lost the rear centering ring , motor tube & boat tail ::mad: :mad: :mad: :mad:

If anyone in the UK has any 24mm mmt's & can make a centering ring to suit this rocket , please please let me know!
Thanks
Karl
 

DJ Delorie

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Roll up some paper and insert it into the BT first, just short of where you're gluing, and tape it in place. That will keep glue off the inside of the engine mount where it doesn't belong.

I use turned wooden "engines" (i.e. my paint stands) to insert thrust mounts. The wood doesn't soak up glue like the cardboard does, and there's a big handle attached to remove it with.
 

hokkyokusei

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Originally posted by Karl
If anyone in the UK has any 24mm mmt's & can make a centering ring to suit this rocket , please please let me know!
Contact Tony at PoF, I'm sure he'll sort you out. He's a nice guy.
 

Missileman

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I got the thrust ring in place with no problems.
I then noticed that the ring in the booster is in the wrong end:(
I must have forgotten how to read.
That or my natural instinct to put a thrust ring at the forward end of a motor mount bypassed the instructions.
After closer examination I discovered that the engine block (not thrust ring at all) goes in the aft end of the booster on the Renegade.
I have removed it via a sanding drum on my Dremel. (not a pretty sight but should be OK)
I have commented to my friends how easy the Renegade was to build and was wondering why it is rated skill level 3.
I now know why. It's the thrust rings/engine blocks:D
 

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