Wildman Jr + Two Stage

Wildman Jr has been on my build pile for a while. Got it back in 2010 during the Black Saturday sale. Got the motor mount and fins done, but then got involved in non-rocketry projects for a while.

Fast forward to the 2013 Black Saturday Sale - saw the year of the two stage - thought that would be pretty neat. Ordered the two stage for the Wildman Jr. Spent weekends over the winter building the sustainer and coupler (thanks for posting the instructions on here!).

Wanted to have it all done for LDRS, but did not make it. Hope to launch at an OAMC launch here in Springfield OH in the fall.

Will post here how it goes.

P.S. - In the two stage shot, the rocket was leaning against the door because it was a windy afternoon - that is why it is not straight!

Looks really good!

Looks great! Should be fun!

What do you have for staging electronics?

Sharp looking job.....outstanding!

Nice WM 2 Stage! Looks like the OAMC site will be perfect. Do you know what motors you will be flying?

Jim - I have a Perfect Flite Altimeter and a Missile Works PET2 for the staging timer. I need a rainy Saturday to build the avbay sled

Has anyone built this and have pictures to share of how they laid it out?

WoShuGui - As for motors, I am thinking for maiden flight an I booster to an H sustainer - have not looked to closely yet. Anyone fly this before and have any recommendations?

Horizon said:

Jim - I have a Perfect Flite Altimeter and a Missile Works PET2 for the staging timer. I need a rainy Saturday to build the avbay sled

Has anyone built this and have pictures to share of how they laid it out?

WoShuGui - As for motors, I am thinking for maiden flight an I booster to an H sustainer - have not looked to closely yet. Anyone fly this before and have any recommendations?

Click to expand...

I've used an AT I600R for the booster to get enough kick to keep things vertical. I had planned to use an H225 in the sustainer, but since it turned out to be a zero wind day; went up to an I303. The blue propellants light and come up to pressure faster. There was only about 0.2 seconds between the pyro channel on and full thrust in my flight. In any case, CTI motors with the BP pellet are more reliable to start the sustainer.

Put it on the scale today.

Complete Two Stage weighs in at 5 lbs, 7 oz.

The Sustainer weighs in at 3 lbs.

Plugged these numbers into thrustcurve.org.

Probably will go with an I161 to a H123 - that will keep it under 4,000 feet.

I'm working on one as well!
I already have a Wildman jr besides the 2 stage so, I made the booster a MD 54 mm booster.


JD

Horizon said:

Put it on the scale today.

Complete Two Stage weighs in at 5 lbs, 7 oz.

The Sustainer weighs in at 3 lbs.

Plugged these numbers into thrustcurve.org.

Probably will go with an I161 to a H123 - that will keep it under 4,000 feet.

Click to expand...

That's a very light build if it includes all recovery gear and electronics. Even so, I'd be curious to see if an I161 gives you a straight enough boost for staging. You might want to consider something with a little more kick like an I357T. Only 22 N-s more than the I161, so you shouldn't go much higher, but with the shorter burn time it will have less chance to wind cock.

How did you get such a light build? I have not built the sustainer yet but the single stage DS Jr I flew 2 days ago weighed in at about 4.6 pounds empty. That is close to what Tim said it should be although I think I went a little heavy with injected epoxy. Straight as an arrow on an H400 VMax by the way.

Are you using actual weights or just going off of RS file?
My Wildman jr alone weighs about 5 lbs loaded...

JD

Hope you don't mind if I post a quick picture of my inter stage setup based on CJs thread https://www.rocketryforum.com/showthread.php?55463-Convert-any-Wildman-Jr-kit-to-a-2-stage-build-Vindicator-JR&highlight=wildman+stage. BrAdam wanted to see it and there is no way to attach pictures to a PM without using a link.

View attachment 183934

It uses the RRC3 AUX channel to fire a 0.3 g FFFF separation charge in a latex glove finger tip ~0.5 s after burnout. The black and white wire pair on the coupler vent band show how the separation charge wires are routed. Wires run outside the AV bay and then back in above the forward bulkhead so pressurized gases can't get to the electronics. Just twist on the wires from the 0.3 g charge, cover exposed conductor with a little masking tape, tuck it all inside the coupler and slide on the sustainer.

Other wires coming out the AV bay side of vent band are twist and tape to power the RRC3. On the aft side through the wooden AV bay cap, RRC3 Drogue (red wire pair) pops the inter-stage off the booster at apogee with 1.2 g FFFF and RRC3 Main (white wire pair) fires an Archetype cable cutter at 700 feet. I want the booster coming down close so I can focus on sustainer recovery. The screw eye on the wooden AV bay cap is strain relief for the Drogue and Main wires. Two 2-56 screws at 180 degrees secure the AV bay cap. On the vent band there are two sets of vent holes. Three 3/32" aft of the bulkhead to vent the AV bay and three 5/64" above the bulk head to vent the sustainer motor in the event there is no stage separation.

Here is a picture of the RRC3 data for an I600R boost.

View attachment 183940

The separation was a little later than the 1.5 s after launch that I wanted because the RRC3 timer does not start until the arming altitude is reached (300' in this case). Also the booster main didn't get out of the burrito bundle in time so it was a hard landing.

This is a picture of the Raven 3 data for the sustainer on an I303BS to show the rest of the flight (up part).
View attachment 183941