Wildman Jumbo 8" Interceptor Sim File?

[AllDigital]

Does anyone have a Wildman Jumbo 8" Interceptor sim file? (OR or RS)

I am going to build one of these to use as a test platform for a new deployment system, but it would be good to sim a few things before the kit arrives. I can upscale and modify the 6" version, but if anyone has a more accurate version that would be helpful.

Thanks,

Mike

 

[AllDigital]

For other travelers looking at this beast of a rocket (or my future self), I got the kit and created a sim file for it. I was surprised that the fin can was broken into two body tubes with a coupler between the span of the fins. That is a lot of extra weight to carry, but this thing is not setting any records. enjoy.

 

[jd2cylman]

As far as the fin can, his tubes are 66” long. To scale up correctly, your fin can needs to be ~75” long. His slotter can only reach ~35” (might be a hair more). So even if he could come up with a 8”x75” tube, he still couldn’t reach the upper slot location. I thought about one, but decided on the 6” instead. My 6” is 42lbs w/o motors. That’s plenty to lift by myself…

 

[StreuB1]

.......that thing is enormous.

 

[AllDigital]

This thing is a beast. It flew beautifully last weekend on a six grain 98mm sorbitol motor. Low and slow.
Also, as a fun fact... We really don't like painting big rockets, especially a test rocket that might not survive its first flight, so I took it to Maaco. They claim they will paint any vehicle and they aren't lying.

 

[jd2cylman]

Cool. That thing is definitely big. Sorbitol motors look weird. No flame... Is the sound similar to AP motors?

 

[AllDigital]

Sorbitol motors look weird. No flame... Is the sound similar to AP motors?

About the same sound. Sugar has 40% less power by weight/volume, but that M1800 equiv (8300 N-s) sugar motor only cost me $20 in propellant reloads vs. $700+ for a commercial APCP of the same power.

 

[krislhull]

If you don’t mind me asking, what did Maaco charge for the paint on that?

 

[FlyBy01]

If you don’t mind me asking, what did Maaco charge for the paint on that?

+1

 

[AllDigital]

If you don’t mind me asking, what did Maaco charge for the paint on that?

It wasn’t cheap… they wanted $375 for one color, including primer and clear coat. They wanted $650 for two colors (fins, nose, AvBay).

I asked them about, “we’ll paint any car for $99” and they were quick to point out that was Earl Scheib and like 30 years ago. Regardless, they did a great job and the paint is strong. After getting chute dragged across the desert tundra on landing it doesn’t even have a scratch. A friend asked me, “did they give you the little touch-up bottle?” — sadly no. I’d still highly recommend this for those that don’t like setting up a paint shop.

 

[mtnmanak]

It is expensive to get your big rockets painted at an auto body shop, but when you compare it to your alternatives, it isn't outrageous.

The cost to set up your own system means buying a compressor, spray guns, automotive paint, thinners, nozzles, etc, etc. In addition to the initial outlay of funds, you need to have a good space to setup this paint booth and store all the equipment (this is my biggest problem). And, you have to plan to paint enough projects to make purchasing all this setup worthwhile. And don't forget about cleanup, maintenance and the learning curve of getting viscosities right, spray techniques, etc. If you have the funds, space, time and need, this is a great option, but most people can't do this.

If you go the rattle can route, be ready for a LOT of cans. The last 8" rocket I painted with rattle cans took me a month to paint and consumed about 6 cans of primers and 15 cans of color and clear coats. Each coat on the booster alone consumed and entire rattle can. And I used Duplicolor, so my paints costs were somewhere around $200, plus the month of painting and sanding. Not sure how other people value their time, but a month of my time and the back breaking work of sanding alone is worth the cost of an auto body shop to do the job.

The national branded stores like Maaco are good, but finding a local shop with a kid just starting out and looking to get business can be more fruitful. Last time I needed to get an 8" rocket painted, I found a local kid that would prime, sand and give me a one color coat for $200 cash. That was worth it for me. I added the smaller colors and decals myself and then clear coated it myself. Saved me weeks of work. And I was happy to support a young entrepreneur!

 

[jd2cylman]

I painted my 6” WM Interceptor with rattle cans. Rusto 2X. Bought 4 cans of red and 2 cans of white. 4 cans of primer. 2 coats of each. Had one can of red left over. It’s not perfect, but it sits at the away cell anyhow. Did in my garage red one weekend and white the next. It can be done.

 

[mtnmanak]

The 6" Wildman rockets are significantly easier to paint than the 8" models. My 6" Wildman Darkstar wasn't too difficult to paint with rattle cans. I ended up with about the same number Adrian used. But the 8" Darkstar Jumbo was the bear that needed a month and over 20 cans of paint. The sanding alone took me days. The jump to the 8" rockets is a big one in terms of finishing.

 

[jd2cylman]

What is this sanding you make reference to…

 

[Neutronium95]

Video of the launch. Unfortunately it missed the parachute deployment.

 

[AllDigital]

We launched this beast again last Saturday out at FAR and we had issues. It launched to 4K feet on a six grain 98mm sugar motor. It was a very windy day with 25mph surface winds. The winds did not impact the up or the down, but the surface drag on landing created a 15" airframe zipper and knocked loose all three fins.
The up part of this flight was perfect, as was the experimental spring-hinge nose and drogue release. This configuration is a two out the top HEDD configuration with a backup main chute in the aft compartment (under "FTS" radio pyro).
After the drogue released, the 5/8" kevlar line severed where it folds around the airframe. A padded protector had been sewn into the line, likely weakening the line. A few seconds later, the line failed again at the knot loop connecting the drogue to the nose, so the nose dropped without a chute. A good lesson that knots weaken any line by >50%. This drogue line had flown on the past flight successfully, so it is also possible that it was worn or weakened from that flight.
Without a drogue, the vehicle came in ballistic, reaching a speed of 282fps. The main chute latch released below 2k feet, but there was no drogue to pull it out and the vehicle was facing "nose down" so the air drag held the main in the upper airframe. We fired the FTS pyro backup, which separated the lower section and released the backup chute. The backup chute tangled (again!), but the pyro separation force was enough to push out the stuck main chute on top and it opened, while traveling 280 fps. The 14 foot main tore and lost a panel, but otherwise Ky's chute held up to the forces.
The rocket landed at a nice 24.5 fps, but ground winds thrashed it across the desert, creating a bad fin can zipper and tearing loose all three fins. The nose came down a few seconds later and surprisingly had only minor fiberglass damage.
We had four cameras on board (three survived) and three altimeter/telemetry systems, so we got a lot of good data. The two big lessons from this flight are... 1) we needed an even stronger kevlar drogue line (was a 5/8" 1500 lb test) configured without knots and 2) we should not have launched with high surface winds -- we had calculated and considered the up and down, but not the beating it would take on landing.

Here is the video... enjoy!

https://vimeo.com/manage/videos/685342633
Mike