Wildman Cherokee Mini Build

[tsmith1315]

There doesn't appear to be a thread for this kit yet, so I'll document my build here.

https://wildmanrocketry.com/collections/wildman-mini/products/cherokee-mini-1

For those who may not be familiar with Wildman's mini kits, they are 1.5" diameter all-fiberglass rockets with 29mm motor mounts. The kit comes complete with recovery system and rail guides, everything you need to fly except a motor.

Their size straddles the MPR-HPR line and this thread would have been equally applicable in the HPR forum. I wouldn't hesitate to put the largest 29mm motor in here that would fit, though it would leave visual range. Preliminary OR sims suggest that full G-motors will take it to 2500' or so, that's bound to be the limit of visual tracking for a rocket of this size. Hence the MPR forum posting.

I expect to fly it mostly on F-G power, and will add an Eggtimer Mini Tx sled mount in the nosecone for HPR flights. There was temptation to trim the fin roots to the airframe's thickness and build it as a minimum diameter rocket for 38mm motors. I decided that there are plenty of 29mm HPR motors to lose this thing on, so no need to go there.

Note that the build was already started before taking this group photo. I notched the centering ring, and the stock shock cord is a length of tubular kevlar without the heat shrink shown.

The kit:


OpenRocket screenshot (previously posted in another thread):




And the preliminary .ork file is attached.

Parts details coming later.

03/25/2024 Edit. OpenRocket file problems listed in post #5 corrected, edited file attached.

 

[kjhambrick]

Nice, @tsmith1315 !

The Cherokee E is one of my favorites.

Will be watching your build !

-- kjh

 

[MarsLander]

Following!!! I have one in the build pile.

 

[n3tjm]

Nice, I will be following . I was thinking if I was going buy myself something for my birthday, what would I get myself? And a kit like this would fit that bill nicely (sometimes I get money for my b-day, sometimes I don't, and I don't ask [I told my wife at our age we don't expect getting anything from our family for b-days, but its nice when we do])

Do you know if the 15" p-chute is big enough or should a upgrade be concidered?

 

[tsmith1315]

Do you know if the 15" p-chute is big enough or should a upgrade be concidered?

Good question, and it’s probably dependent on your recovery area.

Tonight, I’ll look more closely at estimated mass** when finished and compare that to other flyers I’m familiar with.

@kjhambrick found 2 errors in my .ork file posted up top:
1- motor tube not designated as such
2- nose cone assembly mass was duplicated in the coupler.

Thanks for checking behind me, Konrad! I’ll replace that with the corrected file tonight, and post parts photos and details.

 

[kjhambrick]

Shucks, you're welcome Tim

I was trying to remain anonymous

But thank YOU for the 3D Finished model ... it sure is purty ... it is a keeper !

-- kjh

p.s. All I really wanted to do was to 'fly' the biggest obtainable motor that fit

 

[tsmith1315]

Alrighty, parts.

The nosecone is filament wound with a metal tip. The shoulder is integrated, not attached so there's no coupler to mount, or internal lip. A fiberglass washer holds the tip in place.

Exposed length: 175.3mm
Shoulder length: 38.87mm
Max OD: 40.92mm
Internal OD: 34.70mm
Shoulder OD: 38.40mm
Mass without tip: 90g
Mass of tip: 8g
Tip length: 43.79mm
Tip external dia: 15.63mm
Tip shoulder length: 2.56mm
Tip shoulder dia: 13.55mm
Mass of machine screw: 6g
Overall length: 257.96mm
Overall mass of assembly: 102g









Slotted 1.5" Airframe:
Length: 555.6mm
OD: 40.64mm
ID: 38.52mm
Mass: 145g
Slot length: 93.0mm
Slot distance from aft edge: 12.5mm
Slot width: 1.9mm





29mm motor tube:
Length: 126mm
OD: 31.86mm
ID: 29.18mm
Mass: 34.0g



Centering rings:
Length: 8.6mm avg
OD: 38.63mm
ID: 32.13mm
Mass: 6g each
Note 1 - I've already notched one of mine for the recovery harness.
Note 2 - These were a little too big to fit in the airframe, some sanding was required.



Fins next, then recovery bits.

 

[tsmith1315]

3 Fins:
Thickness: 1.52mm
Mass: 16.5g each
Root: 97mm
Tip: 55mm parallel to the airframe
Leading Edge Sweep: 20.5mm
Span: 68mm
Tab height: 5.2mm

Fin tip radii make some measurements a little subjective, the image will make those details more evident. I may scan one before beveling to see how well OpenRocket uploads it.

 

[tsmith1315]

Shock cord
Tubular kevlar
Width: 4mm
Length: 84 inches
Mass: 6.8g

Sorry, I have no pic of the shock cord as it came in the package. I had already cut it, knotted it and had heat shrink in place on the shock cord for ejection charge and anti-zipper protection.

I chose to cut this piece to 54" length and loop the forward end for use as an anchor. Another length will be attached to the loop as a shock cord.
The remaining 30" from this piece will reserved for other use. Image and details when the build documentation starts.



Parachute:
Diameter: 17" corner to corner, 14.5" across parallel sides
Mass: 11.5g

Typical nylon MPR 'chute:






Rail buttons:
Length: 25mm
Width: 15mm
Height: 4mm at the center, about 5mm overall
Mass: less than a gram for the pair.
Mounting hole: 2mm x 3mm
My scale showed 0g for a single (less than 0.5g), and 1g (0.5g or more) for the pair. Make what you care to out of that.

These are 3D printed, conforming to the airframe diameter and have a single countersunk hole for mounting.
The mounting hole is about 3mm diameter, and truncated at about 2mm.
I assume this is designed for a 2-56 screw. That threads in gently but doesn't slide through, and a pan head fits about right in the indention.

 

[tsmith1315]

At this point, I'll mention that there are no instructions specific for this kit included or linked from the web page for this kit.

I did find general instructions for Wildman mini kits on the page for one of the others, that should be applicable. You may or may not consider that appropriate for a beginner.

Also- I have built fiberglass rockets before, but this is my first fiberglass kit. As such, I won't be able to draw comparisons to other fiberglass kits.

 

[Emsley]

I bought 3 of these so the kids and I can drag race them. Appreciate the build thread and the openrocket file.

 

[tsmith1315]

My apologies, y’all, for the delay.

I should be able to make some progress in a few days.

 

[kjhambrick]

My apologies, y’all, for the delay.

I should be able to make some progress in a few days.

No worries, Tim.

Do it at your pace to keep it fun and then share when and if you can

Your weights and measures have already made this thread a keeper !

-- kjh