Wildman 4" Patriot

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I just received my 4" FG Patriot (not DD) from the Holiday sales and it came with a 35" BT and a 54mm 6" long MMT. This looks a bit short for the size of this bird to me. I will primarily fly it with a 38mm adapter until I'm ready to go for my L2 cert. My thoughts are that I should go with a longer MMT (maybe 14") and a third CR. What say the experts?

Thanks - Jim
 
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The MMT tube only functions to keep the rocket engine aligned straight with the rocket. It doesn't need to be longer. It doesn't serve any real structural function since all the thrust is pushing on the centering rings and (if you have one) the thrust plate; all of which transfer to the frame.

I have a 4" Binder Design Excel with a 54 mm MMT of similar length, and it's just fine.
 
Thanks Mark. I figured the MMT would do but I was wondering if by adding a longer MMT and third CR, I could cut down on the interior volume of the tube since that is a lot of space for a single deploy setup with motor ejection. Also the shorter MMT doesn't give me a lot of wiggle room for placing the fin tabs and motor retainer.
 
I'm looking at the ork for the Proline 4" Patriot. The ProLine Patriot 4" model has a 12" MMT. You said yours is 6"? That would make for some short root chords on that Patriot. Seems like it would look odd. Who's the manufacturer?

proline_patriot.jpg

In the Proline model, looks like the distance from nosecone shoulder to top CR is about 28.5". Targeting 12 psi would need 2.2g 4F BP. If you put a 3rd CR at the top of the MMT tube, you can shave off another ~4" in your charge calculations. That drops the BP to about 1.9g. Either way, you'd need to supplement the charge that comes with the motor. I supplement all the time when I fly my 3" scratch built rocket in single deploy. Just sprinkle the extra BP on top of the existing charge and slap some duct tape on top to hold it tight. Most motors come with ~1.4g of BP. You'd need to have a MMT that is 6" longer with a CR at the top to cut the inner volume enough.

Then again, if yours is just 6" the airspace inside is about 34" long, so you need 2.6g BP. Still not bad. Dump 1g on top of the motor and tape it down.
 
Well, I decided to go with a 14" MMT and a nosecone Avbay for a future tracker.

Here's the kit:
Wildman Patriot.jpg

The original MMT is to the left of the replacement 14" MMT plus a third CR.

Nosecone Avbay.jpg

And here is the beginning of my Nosecone Avbay using the supplied bulkhead, 3/8" birch plywood cut out with my dremel, short piece of 54mm fiberglass tubing and a G10 sled from Wildman.
 
+1 on the longer MMT, and smaller internal volume..

Looking forward to seeing this Jim!! Looks like we both might be getting our L2 at the same time! :D
 
+1 on the longer MMT, and smaller internal volume..

Looking forward to seeing this Jim!! Looks like we both might be getting our L2 at the same time! :D

Hey Paul,

Yeah, hopefully sometime this spring if I can get this done. I can only work on it a little at a time with other commitments at home and work. Hope you are enjoying this relatively mild winter, up to this point anyway. This is my fourth build this fall and winter. Should have plenty of new stuff to fly come spring.
 
Jim,

I've got a 2nd L2 project coming in the mail, so I should have "something" to show off in the spring!

I've switched to a plane for this winter's build.. well, the main focus so far!

Are you going this week-end? Kevin & I are planning to..
 
I'll probably show up for a few minutes but don't think I'll be able to stay long due to other commitments. I will have to see how things work out in the next couple of days. I at least want to pick up the motors that Howie is holding for me and maybe some other stuff he is going to lend to me for a club demo in Essex next month.
 
Had some time to work on the Punisher's nosecone Avbay. Got the T-nuts in the plywood bulkhead and then epoxied into the coupler. G10 sled is mounted to the G10 bulkhead along with the U-bolt.

20170122_140255.jpg20170122_214118.jpg20170124_073133.jpg

Countersunk two screws through the coupler and into the plywood ring to ensure a good hold.

20170124_081113.jpg

And she's all set to go. Going to wait to epoxy the coupler into the nosecone until I'm done with the build just in case I need to add any nose weight.

20170124_073151.jpg20170124_081202.jpg

Next I'm going to start work on the MMT.
 

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Forward CR and shock cord bolt epoxied onto the MMT as well as the center CR. Aft CR is just slipped on while the epoxy sets up. Also ground down the corners of the fin tabs just enough to allow them to fit over the CR to MMT fillets.

20170125_123709.jpg
 
Made a little more progress on the Patriot. The MMT is epoxied in and rail buttons attached. All four fins are epoxied in place. Used one of the Payloadbay.com fin guides for the first time. I found it much more reliable getting the fins in position with the guide than my usual eye-balling method. Hopefully I'll get to doing the internal fillets and installing the aft CR sometime this weekend.

Fin Align 1.jpgFin Align 2.jpg
 
Internal fillets done and aft CR and retainer epoxied in place. External fillets next then add the recovery hardware, weigh her, check the CG, and see if any weight needs to be added to the nosecone.

Rear CR and Retainer On.jpg
 
My Patriot is done for the most part. External fillets done.

20170216_144632.jpg

7 oz of lead shot and epoxy in the nose cone using the john Coker method.

20170216_144551.jpg20170216_144949.jpg

Coupler and nosecone epoxied. Only thing left is paint and decals but that will have to wait till spring.

20170216_194406.jpg

She comes in at just over 6.5 lbs with a stability of 2.1 calibers ready to fly minus the motor.
 

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Looks good Jim..

An interesting note: I have the Madcow paper version 4" Patriot. The fins on mine look very much smaller than yours. I would assume the larger fins are for the (expected) larger 54mm motors..

Might have to do a drag race later this summer, or at least a 'double-salvo launch'!
 
Thanks Paul,

This one is my largest rocket so far. The fins are quite substantial. It was a fun one to build. Hopefully we'll get to see yours and mine in action sometime this spring. I'm hoping to use it for my level 2, assuming I can find the time to study for the test.

Here's my ork file if you are interested:

View attachment My Wildman 4 inch Patriot.ork
 
Looks good Jim..

An interesting note: I have the Madcow paper version 4" Patriot. The fins on mine look very much smaller than yours. I would assume the larger fins are for the (expected) larger 54mm motors..

Might have to do a drag race later this summer, or at least a 'double-salvo launch'!

I did my L1 with the Madcow 4" Patriot (vv). I believe the fins are smaller because its a better scale representation (and needs more noseweight)


Thanks Paul,

This one is my largest rocket so far. The fins are quite substantial. It was a fun one to build. Hopefully we'll get to see yours and mine in action sometime this spring. I'm hoping to use it for my level 2, assuming I can find the time to study for the test.

Here's my ork file if you are interested:

View attachment 312357

Ya know, I've been reading this thread for awhile now and barely realized: this is in the Mid-power forum! Something got lost lol.

I made up an L2 study sheet a couple months ago. Maybe you'll find it useful.
View attachment L2.xlsx
 
well the techniques discussed, for the most part also apply to mid power birds :).
Rex
 
My Wildman Patriot is complete and waiting for its Level 2 flight, hopefully next month. Another great set of Stickshock vinyl from Mark.

Patriot Complete.jpg
 
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