Tacos for 10 K motor minimum diameter flight to 27k with Mac Performance X rated airframe

[Conway Stevens]

On the 4/16/23 we had a launch at Northern Colorado Rocketry Pawnee grasslands north site. Waiver to 40k. I flew my new scratch built rocket called Tacos for 10. It's made from new airframe from Mac Performance Rocketry X rated phenolic airframe, canvas phenolic fins. Pretty much everything was the new X rated phenolic except fins and nose cone. Sled is a 3d printed holder for the new Blue Raven altimeter as well as the featherweight tracker. Motor was K375 AT. Was a beautiful day. Recovered 2 miles from the launch site about 10 feet off the main county rd. Altitude was 27,762 ft.

This was a practice flight with this rocket for my attempt at NSL in Anamosa Co for the TRA K altitude record.

Rocket weight without motor just under 32oz with everything. HED deployment.

Here are some pictures of the rocket and flight

Will be posting more pics and video. Feel free to ask any questions on the new airframe.

 

[Neutronium95]

This was a practice flight with this rocket for my attempt at NSL in Anamosa Co for the TRA K altitude record.

Good luck on the record. What motor are you planning on using? From my sims the K300 seems to be the best option available these days. Unfortunately it's also been very unreliable in recent years.

 

[teepot]

Your field looks like a good place to fly. Like our dry lake only bigger and with nice soft grass.

 

[Conway Stevens]

Good luck on the record. What motor are you planning on using? From my sims the K300 seems to be the best option available these days. Unfortunately it's also been very unreliable in recent years.

The K300 would be a good choice but I've seen a total of 10 fly and only 2 work personally. So that motor is out. I'm going to try it with an Aerotech K250. I've also shortened the rocket more and it's still loosing weight. And flying out of a tower

 

[Conway Stevens]

Your field looks like a good place to fly. Like our dry lake only bigger and with nice soft grass.

One of my most favorite places to fly

 

[Neutronium95]

The K300 would be a good choice but I've seen a total of 10 fly and only 2 work personally. So that motor is out. I'm going to try it with an Aerotech K250. I've also shortened the rocket more and it's still loosing weight. And flying out of a tower

That reliability rate matches what I've heard anecdotally. A friend of mine tried to break the record twice, both times the motor failed.

I had initially discarded the K250 in the past on the basis of it not having enough impulse, but the listing on Aerotech's site says it has 2500Ns, while Thrustcurve only claims it has 2,353. Not sure what's up with that.

Edit: I just checked Openrocket, and the file there has 2553Ns. Weird.

It is kind of frustrating that there are so few motors for the K record. As far as I know the K250 isn't made anymore, so it's hard to find and expensive. The Loki K350 might work, but with how optimized the K record is, going with anything less than the perfect motor means you're playing on hard mode. Maybe @AeroTech will cook up a endburning close to full impulse K motor to liven things up.

 

[mrwalsh85]

SU or LMS K250?

I have one of both... I'm looking forward to playing with them someday at Argonia.

 

[tfish]

@Neutronium95
As you've pointed out before...The K record will probably fall to a 'new' K long burn motor..The old K250/k300 record rockets are old school!
Back in 2011 I flew a K300 in an AeroPac altitude contest I came in 2nd place with 29,456..it's a tough crowd when 29k+ gets you to the first looser.
The new up and coming altitude junkies will be using cardboard and 3D printers..like this guy.



I' m flying my last ...K300 in September...hopefully it's a good one : ( ..old school emoji.

Tony

 

[Conway Stevens]

That reliability rate matches what I've heard anecdotally. A friend of mine tried to break the record twice, both times the motor failed.

I had initially discarded the K250 in the past on the basis of it not having enough impulse, but the listing on Aerotech's site says it has 2500Ns, while Thrustcurve only claims it has 2,353. Not sure what's up with that.

Edit: I just checked Openrocket, and the file there has 2553Ns. Weird.

It is kind of frustrating that there are so few motors for the K record. As far as I know the K250 isn't made anymore, so it's hard to find and expensive. The Loki K350 might work, but with how optimized the K record is, going with anything less than the perfect motor means you're playing on hard mode. Maybe @AeroTech will cook up a endburning close to full impulse K motor to liven things up.

I'm not sure what's up with the Thrust Curve numbers on that motor. Everything I've ever been told about it is its over 2500ns by everyone else.

Back in October of 2001 I bought 2 of them that they had in stock. So I have 2 on hand currently. Now they are part of the "seasonal" production list. With the K250 I will be sitting at thrust to weight ratio of close to 16:1 on the pad. With the duration of a good burn. Plus flying from a altitude just shy of 8k ft to start with. Hoping for warm temps. No winds. Strait boost. It may or may not come up short. But Worth the effort and fun. Definitely better than taking a chance with the K300. I've flown the Loki K350. It's no where close to enough motor with its hardware weight being so heavy.

Guess regardless I'm fixin to find out here come the end of May. Fun no matter what.

 

[Conway Stevens]

SU or LMS K250?

I have one of both... I'm looking forward to playing with them someday at Argonia.

Lms single use

 

[Egoldee]

Is the X-rated phenolic airframe different from the canvas phenolic airframe?
I can't seem to find it on their website.

 

[Conway Stevens]

Is the X-rated phenolic airframe different from the canvas phenolic airframe?
I can't seem to find it on their website.

Yes it is different. The Canvas is great stuff. Mike is going to offer both airframes. He hasn't listed them yet as he is waiting on 3 inch to get in stock this week. Then he will do the release. He had asked me if I would test the stuff out. I have abused it. Beat on it and love it. Cheaper then glass. Lighter then glass. Water proof. Bonds very well. Sands easy. Very durable . Still breaks easier then fiberglass but a very close 2nd. It's basically X rated phenolic tube like you would see in a motor Liner for higher performance motor Liners. Except in body tube sizes. Mike should be posting it real soon. I think the 3 inch arrives this Thursday. That's all he is waiting on. 54mm 3 inch and 3.9 inch offerings.

It was perfect for this project.

 

[bobbyg23]

I love the new x-rated airframe! So nice to work with. I have a 54mm and a 4" made with it.

 

[Conway Stevens]

I love the new x-rated airframe! So nice to work with. I have a 54mm and a 4" made with it.

It's pretty nice stuff. The outside finish is awesome. Very smooth and clean. Easy to set to paint. I've been testing with 54 since about first if the year and have 4 inch stuff as well.

 

[jmasterj]

Is the x-rated tube less brittle than the canvas tube, in your experiences?

 

[Conway Stevens]

Is the x-rated tube less brittle than the canvas tube, in your experiences?

Absolutely. One of my tests I did on the 54 mm airframe was use it like a club and pounded a table with it abut 6 to 8 times really hard. Got video. Just need to host it and post it if testing it. It's pretty stout compared.

 

[jmasterj]

Absolutely. One of my tests I did on the 54 mm airframe was use it like a club and pounded a table with it abut 6 to 8 times really hard. Got video. Just need to host it and post it if testing it. It's pretty stout compared.

That's exciting. I keep cracking my canvas tubes. Do you know if the OD/ID match the canvas exactly?

 

[Conway Stevens]

That's exciting. I keep cracking my canvas tubes. Do you know if the OD/ID match the canvas exactly?

That I don't know. I suspect they are or close. But not for sure.

 

[Egoldee]

Yes it is different. The Canvas is great stuff. Mike is going to offer both airframes. He hasn't listed them yet as he is waiting on 3 inch to get in stock this week. Then he will do the release. He had asked me if I would test the stuff out. I have abused it. Beat on it and love it. Cheaper then glass. Lighter then glass. Water proof. Bonds very well. Sands easy. Very durable . Still breaks easier then fiberglass but a very close 2nd. It's basically X rated phenolic tube like you would see in a motor Liner for higher performance motor Liners. Except in body tube sizes. Mike should be posting it real soon. I think the 3 inch arrives this Thursday. That's all he is waiting on. 54mm 3 inch and 3.9 inch offerings.

It was perfect for this project.

Thanks for clearing up the confusion.
Sounds like really great stuff.