Favorite Modification to Low Power Rockets

Fliskits Tres: it looks like a two-stager, so I modified it to be a two-stager.

Edmonds Elcie: I needed BT-5 in a hurry at a flying event, the on-site vendor didn't have any, but he did have the Elcie. So I bought the Elcie and used its booster tube for my own model. Not wanting to waste a perfectly good glider, I then modified the Elcie to fit onto the booster of my old Deltie.

adrian said:

Fliskits Tres: it looks like a two-stager, so I modified it to be a two-stager.

Edmonds Elcie: I needed BT-5 in a hurry at a flying event, the on-site vendor didn't have any, but he did have the Elcie. So I bought the Elcie and used its booster tube for my own model. Not wanting to waste a perfectly good glider, I then modified the Elcie to fit onto the booster of my old Deltie.

Click to expand...

WOuld love to see a build thread on that Tres. I know of several that have been so modified but have yet to see the details of how they did it and how it worked out for them.

jim

Sorry, I never wrote a full build thread. But basically, the lower body tube is cut in half. One of the motor mounts connects to a duct running through the base of the top half. The coupler at the base of the top half is a piston which fits over this duct. The balsa coupler originally intended to join the two parts of the Tres is replaced by a hollow paper and cardboard coupler. The upper part of the Tres becomes the upper stage with a normal single motor mount. And, since we're allowed to use quickmatch fuse without needing a licence in the UK, a piece of quickmatch dangles from the upper stage motor through the duct to near the top of the lower stage motor mount which holds a B6-0 or C6-0; this mount has a gold ring painted round it so I know where to put the booster motor. The other two hold B6-2's or C6-3's and are responsible for blowing the lower stage apart after separation.

Here are photos of the motor mount plus duct, the piston and the stage coupler. There's a launch report with photos here.

oh, that is just too cool! Thank you!
jim

adrian said:

Sorry, I never wrote a full build thread. But basically, the lower body tube is cut in half. One of the motor mounts connects to a duct running through the base of the top half. The coupler at the base of the top half is a piston which fits over this duct. The balsa coupler originally intended to join the two parts of the Tres is replaced by a hollow paper and cardboard coupler. The upper part of the Tres becomes the upper stage with a normal single motor mount. And, since we're allowed to use quickmatch fuse without needing a licence in the UK, a piece of quickmatch dangles from the upper stage motor through the duct to near the top of the lower stage motor mount which holds a B6-0 or C6-0; this mount has a gold ring painted round it so I know where to put the booster motor. The other two hold B6-2's or C6-3's and are responsible for blowing the lower stage apart after separation.

Here are photos of the motor mount plus duct, the piston and the stage coupler. There's a launch report with photos here.

Click to expand...

I'm working on a two-stage Tres right now. But on mine, the lower stage is only the last few inches of the body, and the gap staging is only an inch or two. I've had to reshape the fins a bit for stability. I'll start a build thread when I'm a little further along.

Digging around for my previous posts about Three To One turned up a reply by Will Carney that he'd done something similar to what you're considering. Mind you, his Tres doesn't look much like a standard one; the lower fins are completely reshaped and the upper fins are completely missing.

There are some photos here:
https://cia-rocketry.smugmug.com/gallery/1743114/1/86223500#86223467

Tres wasn't the first Fliskits rocket which I modified. A similar modification to Freedom Forge resulted in Fred'n'George.

Swivels on 'chutes.
Kevlar or Kevlar/elastic shock cords.
Shock cords 2x - 3x BT length (within reason)
Paper laminated fins.
LL standoffs

1. (not really a mod) Use 18mm or 24mm RMS motors!
2. Kevlar to mmt or baffle
3. Baffle
4. 2-stage
5. bigger/more motors
6. Nylon parachute

7. Did I mention APCP?

adrian said:

Sorry, I never wrote a full build thread. But basically, the lower body tube is cut in half. One of the motor mounts connects to a duct running through the base of the top half. The coupler at the base of the top half is a piston which fits over this duct. The balsa coupler originally intended to join the two parts of the Tres is replaced by a hollow paper and cardboard coupler. The upper part of the Tres becomes the upper stage with a normal single motor mount. And, since we're allowed to use quickmatch fuse without needing a licence in the UK, a piece of quickmatch dangles from the upper stage motor through the duct to near the top of the lower stage motor mount which holds a B6-0 or C6-0; this mount has a gold ring painted round it so I know where to put the booster motor. The other two hold B6-2's or C6-3's and are responsible for blowing the lower stage apart after separation.

Here are photos of the motor mount plus duct, the piston and the stage coupler. There's a launch report with photos here.

Click to expand...

I was just thinking of how to do a two stage Tres last night without modding the external looks! What a coincidence that I read this today. You guys are pretty lucky to have quickmatch...


My favorite mods are to:

1. switch the motor mount to a accomodate a bigger motor.
2. mod the motor mount to accomodate AP motors (similar to 1. but not quite the same).
3. add kevlar or a baffle.
4. add a better parachute (the new chute could be bigger/smaller or nylon).
5. occasionally making new fins out of basswood or plywood, or changing the thickness of the wood.

My favorites are as follows:

1. Modify motor mount for AP reloadable motors
2. Increase size of motor mount
3. Change shock cord to triple length of cotton covered elastic
4. Use Kevlar to attach shock cord to MMT
5. Install permanent Nomex parachute protector
6. Install rail buttons on all models over 16 oz. weight

I always replace the shock cord with longer / stronger elastic. recently discovered the LOC shock cord mounting method. i love it. use it or something similar (kevlar) for everything now.

have a couple rockets on the back burner that will get the motor upgrade to the next size up (18mm to 24mm). use my own method for fin fillets.

these are not big changes. i really like the LOC shock cord mounting method.

gw

1. An audio transponder so you can hear it and find it,
2. swivel snap,
3. baffle,
4. reinforced top of tube so shock cord doesn't cut through upon ejection.

I was curious which modifications were used the most, so I compiled the top twelve suggestions from all of the previous posts. They are shown below in order from most suggested to least. The number of times each item was suggested is shown in parenthesis.

1. Upgrade the motor mount (18)
2. Kevlar shock cord mount/leader (15)
3. Nylon or mylar chute (14)
4. Improve the shock cord (10)
5. Ejection baffle or nomex (7)
6. Quicklink/Swivel (6)
7. Mount launch lugs on standoff (5)
8. Replace balsa fins with Basswood (5)
9. Rail buttons (4)
10. Laminate the fins with paper/cardstock (4)
11. Clusters (3)
12. Two stage (3)