Madcow Adventurer 2.2"

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mrwalsh85

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Did anyone score the Adventurer?

Looking forward to this build. It may become minimum diameter since it has TTW... I will probably try the TTW minimum diameter method.

We'll see how well the thin wall tube holds up!

-Mike
 
I will probably try the TTW minimum diameter method.

Bumping my question.

Is this the method where you trim down the fin tabs, wrap a motor case with wax paper, insert into body tube, tack on the fins, then remove said wrapped motor case? Do the fins seem as solid as a surface mount MD build?
 
My kit arrived. Looks good, mostly, but I gotta say I am a little disappointed in some of the workmanship:

  • The kit was not packaged in a bag. All the parts or group of parts were just loose in the shipping box. This kit seemed small enough to bag up, but I can understand the packaging shortcut given the sale price.
  • One part was missing. MC notified and they will send a replacement.
  • The fins tabs are about 3/16" too long and protrude above the BT. I wonder if these fins were cut for thickwall body tubes by mistake. This can be sanded and/or covered in the epoxy fillet, but still.
  • Each bulkhead and centering ring have noticeably different thicknesses. I thought maybe this was by design, but the instructions gave no indication.
These are not show stoppers, of course, and the build will continue. The sloppiness is unusual for MC, and the miscues seem avoidable. This is my 2nd FG purchase. Maybe this is typical of the tolerances?

OK, flame on. "Stop whining and suck it up, Buckeye. You got a screaming deal on a cool FG kit." "Every kit requires some sanding to fit, so don't get all butt hurt." And so on........

mc3.pngmc2.pngmc1.jpg
 
My kit arrived. Looks good, mostly, but I gotta say I am a little disappointed in some of the workmanship:
[*]One part was missing. MC notified and they will send a replacement.

Av Bay Body Tube Spacer?
 
These are not show stoppers, of course, and the build will continue. The sloppiness is unusual for MC, and the miscues seem avoidable. This is my 2nd FG purchase. Maybe this is typical of the tolerances?

OK, flame on. "Stop whining and suck it up, Buckeye. You got a screaming deal on a cool FG kit." "Every kit requires some sanding to fit, so don't get all butt hurt." And so on........

i believe the phrase is “classic Curtis”
 
I got one a couple weeks back... Minimum diameter you say. Yep, the CTI case slips right in there. Hummmmmm. Maybe I could setup for minimum diameter and then use adapters to launch 38mm when I felt like it. I have wanted to learn about the Aero Pac minimum diameter parts. I guess here's my chance. Early Rocksim models shows it is still overstable with a CTI 4gr 54 loaded... Trouble is I'll have to find sites with a 14K'+ waiver for THAT config. This will be a good trainer for my Mac Performance Rain Maker CF minimum diameter build later. OK, convinced.
 
Minimum diameter you say.

I say no. The fins are too thin and the structure has been compromised with the fin slots. Maybe if you fiberglass you can get away with it, but I don't plan on doing that. This will just be a sturdy, through the wall, sport flyer replacement to my cardboard 2.2" rocket. I am sure somebody will chime in and say they successfully converted this kit to minimum diameter, but I am cautious.

This is why true minimum diameter kits (Wildman Blackhawk) come with beefy fins for solid surface mounting and no extra reinforcement needed.
 
I say no. The fins are too thin and the structure has been compromised with the fin slots. Maybe if you fiberglass you can get away with it, but I don't plan on doing that. This will just be a sturdy, through the wall, sport flyer replacement to my cardboard 2.2" rocket. I am sure somebody will chime in and say they successfully converted this kit to minimum diameter, but I am cautious.

This is why true minimum diameter kits (Wildman Blackhawk) come with beefy fins for solid surface mounting and no extra reinforcement needed.

I think you might be right. Certainly won't be running any VMAX loads. Maybe a Pro54 1211J140-P, longburn might not rip the fins right off? It will be interesting for sure!
 
The Kestrel kit of a few years ago was a “true minimum diameter kit” that had a slotted body tube and flew just fine on motors up to and including long 54mm L motors. Tip to tip reinforcement was advised. Tony (TFish38) on YouTube put together a terrific video showing the tip to tip video for that rocket.
As far as long burn vs VMax, I don’t know for sure, but I suspect that passing through the subsonic to supersonic transition more slowly would be damaging than getting through it quickly. Worst would be to stay at that speed where fin vibration is maintained.


Steve Shannon
 
My kit arrived
No bag, no instructions. The fins don't fit into the slots. MC recommended I sand the slots. With the amount of material that needs to be removed to make the fins fit, I would need a router and a jig to keep things straight. I'm not set up for that.
I also ordered three other kits from MC: small FG V2, cardboard Jayhawk, and the Nike Apache. The fins for the V2 are tight but the fit will be easily adjusted with minor sanding. I'm waiting to receive the Apache to see if those fins fit. I may send back the tubes to get the slots cut to the right width. It is way less effort when the fins fit into the pre-slotted tubes.
 
My kit arrived
No bag, no instructions. The fins don't fit into the slots. MC recommended I sand the slots. With the amount of material that needs to be removed to make the fins fit, I would need a router and a jig to keep things straight. I'm not set up for that.
I also ordered three other kits from MC: small FG V2, cardboard Jayhawk, and the Nike Apache. The fins for the V2 are tight but the fit will be easily adjusted with minor sanding. I'm waiting to receive the Apache to see if those fins fit. I may send back the tubes to get the slots cut to the right width. It is way less effort when the fins fit into the pre-slotted tubes.

I had this issue with many FG kits (different manufacturers). I use a needle file to fit into the slot and slowly widen it. If off by a 1/16" it takes a while, but otherwise easier than I expected. Overall the tolerances have gotten better since the first years.

All BF/BS FG kits I received with the exception of minis from MadCow were not bagged. Pretty much OEM kits. Not ideal, but worth the discount (at least to me) when you buy a bunch of stuff.
 
My kit arrived
No bag, no instructions. The fins don't fit into the slots. MC recommended I sand the slots. With the amount of material that needs to be removed to make the fins fit, I would need a router and a jig to keep things straight. I'm not set up for that.
I also ordered three other kits from MC: small FG V2, cardboard Jayhawk, and the Nike Apache. The fins for the V2 are tight but the fit will be easily adjusted with minor sanding. I'm waiting to receive the Apache to see if those fins fit. I may send back the tubes to get the slots cut to the right width. It is way less effort when the fins fit into the pre-slotted tubes.

When this happens, and it’s really not unusual, I just draw file one side of the slot. By draw filing I mean you slip the file into the slot, hold it perpendicular to the body tube, and slide it lengthwise along the edge you’re opening up. Only work on one side, and the same side on all slots in order to maintain the same angles between fins.


Steve Shannon
 
My kit arrived
No bag, no instructions. The fins don't fit into the slots. MC recommended I sand the slots. With the amount of material that needs to be removed to make the fins fit, I would need a router and a jig to keep things straight. I'm not set up for that..

Ouch. My fin slots were not that bad. I just needed some minor sanding/filing.
 
I usually sand the fin tabs fairly aggressively before test fitting them. I number each slot and fit, and work until they just fit with a light tap of a mallet ;)
 
The Kestrel kit of a few years ago was a “true minimum diameter kit” that had a slotted body tube and flew just fine on motors up to and including long 54mm L motors. Tip to tip reinforcement was advised. Tony (TFish38) on YouTube put together a terrific video showing the tip to tip video for that rocket.
As far as long burn vs VMax, I don’t know for sure, but I suspect that passing through the subsonic to supersonic transition more slowly would be damaging than getting through it quickly. Worst would be to stay at that speed where fin vibration is maintained.


Steve Shannon

Interesting. I wonder at what point a fin slot is preferred over no fin slot for MD?
 
Interesting. I wonder at what point a fin slot is preferred over no fin slot for MD?

Based on my experience, 75mm & up, you do NOT want a slot.
Airframe structural integrity more important.
54mm & below [with the exception of extreme motors like the Loki M or 38mm L] not that significant.
I don't want any slots in any size.
I am also guilty of modifying slotted kits to minimum, but either replace fins with carbon plate [same thickness as stock or thicker stock G-10]

More importantly I don't want thin wall tubing in 75mm & larger!
So far smaller rockets have held up with thin wall.
Column bending becomes the airframe issue.

When designing a minimum diameter, usually built around largest motor being flown.
I would suspect those doing this would be knowledgeable enough to know proper parameters.
Issues abound when less experienced jump on the band wagon, and try modifying kits slotted for MM and going Minimum with thin fins, not up to stresses involved.

''Can you say...deconstruct before motor burnout"
Simply replacing fins, with proper fin stock usually alleviates problem or tip-tip to strengthen.

As usual when it comes to Xtreme projects, there is no simple one answer fits all.
Simulations are your best friend! [before building LOL]
 
I am using this kit to experiment with some new techniques (for me). First up is fin beveling via mechanical means. These fins are thin enough that beveling hardly seems necessary, but I did it anyway. I made a John Coker-style jig to fit my cheap disc sander. The bevel is a modest 10 degrees. One must be careful, as your fingers are very near the moving parts (I sanded my finger tip - ouch!).

The bevels are just OK, not great. Feeding the fins through the jig was a little herky-jerky while I re-positioned my fingers as I went. I had to touch up the bevels with a Dremel.

20171230_175154.jpg20171230_175058.jpg
 
Hmm, I see. This kit does show up on the legacy RW page, not a Madcow original.

The original Adventurer3 from Rocketry Warehouse was 3" with a 54mm. I have one in my build pile. Picked it up on one of the Hump Day Happy Hour specials for $149.99 if memory serves.

Original "Hump Day Happy Hour" thread: https://www.rocketryforum.com/showt...ay-Happy-Hour-is-Back-!!&highlight=adventurer

The Rocket was originally designed by the wife of the Rocketry Warehouse owner, just before her passing...

I am looking forward to following along with your build, as it may give me inspiration to get mine going.
 

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