Smokin Rockets X-15 build

I have some ideas in my head for how we're going to build the electronics bay for this little project. It's a bit challenging due to space, but I've Got A Plan!

John likes the MARSA54s, so that's what we'll be designing around. One option is to disable the accelerometers and lay them flat, but I don't like that option.

Once I get some parts ordered, I'll post a few pics of how we're going to do this.

-Kevin

troj said:

One option is to disable the accelerometers and lay them flat, but I don't like that option.

-Kevin

Click to expand...

BAD Option

You cannot disable the accelerometer. You can only have the software ignore it for apogee detection. The accelerometer is used for many other functions in the altimeter including orientation detection, safety, and baro override for really cool flights. It has to be mounted correctly.

jderimig said:

BAD Option

You cannot disable the accelerometer. You can only have the software ignore it for apogee detection. The accelerometer is used for many other functions in the altimeter including orientation detection, safety, and baro override for really cool flights. It has to be mounted correctly.

Click to expand...

Ah, good to know! We were planning on orienting them properly, regardless. I misunderstood what ignoring that did, obviously.

-Kevin

The next photos show the fairing fit step . All went pretty smooth and I was happy with the end results. Next, on to the fillets,prime/fill, prime


John

I put the rest of the photos together up to the point the project is currently at. They show the fillets,prime/fill and the final check prime coat.
The next steps from here will be the av bay and motor retainer attachment, before the final preps and paint/decal thing

Troj is currently working on the av bay thing and the motor retainer is going to be a 75mm AeroPack flange mount. The dang cold weather has slowed me down and I will be waiting for the next window to do the paint and decals.

Thanks for viewing

A few more photos, "The Shadow"
John

Looks great!!!

Just curious, how much weight are you having to add? With the Hangar-11 phenolic it is close to 8 or 9lbs; so much so, I was thinking about using the fore of the shroud cavity to add a pound or two.

Curious to see what the nosecone weight will be..

Jmac,

Gorgeous job especially on the fillets,prime/fill.

Dave

DavieRockets said:

Jmac,

Gorgeous job especially on the fillets,prime/fill.

Dave

Click to expand...

Thanks for the compliment
I appreciate it
Maybe I take too much time doing things but it makes me happy with the end results, really like building scale looking projects

John

dixontj93060 said:

Just curious, how much weight are you having to add? With the Hangar-11 phenolic it is close to 8 or 9lbs; so much so, I was thinking about using the fore of the shroud cavity to add a pound or two.

Click to expand...

Hi Tim
I have not finished my RockSim file yet to mess with the weights yet. The file is being made withe the parts being weighed which I did during construction.
I like your idea of adding weight into the fairing fronts which I could still do easily. On the inside of my main tube I marked the inside outline of the fairings before it was primed. I had thoughts of possibly constructing an av bay inside either side but the weight idea if needed would work well I would think.
My nose cone is still wide open. Several thoughts have popped in my head as how to construct an av bay in the nose while allowing weight to be added.
Troj is working on a av bay idea in the main body tube which still has plenty of room in front of the last bulkhead to do. If that happens, the nose would be fair game for anything.

You know, in the past I constructed the 38 scale Saturn V kit from Polecat. The nose weight I ended up adding was 25 lbs in the nose just too get it to work out in balance when you used a single motor in the main 98 mm motor mount. Then if you added any additional motors in the 4 54 mm mounts cluster , you had to add the same amount of weight of the additional motors to the nose to get it to work in RockSim. Once I was all the way up to 60 lbs. pretty crazy.

Where is the CG on yours? I will try t I finish my RockSim file shortly and let you know what happens with mine.

I like the way yours is looking. From what I see it is going to be fantastic.
Thanks for the kind comments.

John

She's looking impressive. Nice work.

John,

It appears this kit is pre-slotted for straight fins rather than angled fins. That seems to apply to the shroud as well.

It also appears to be far easier to keep the fins straight from a build perspective.

I realize you are going for an authentic appearance, but do you think the angle of the fins matters from a performance aspect?

Also, why did you add a slot for the aft fins and centering ring?

grizzly said:

John,

It appears this kit is pre-slotted for straight fins rather than angled fins. That seems to apply to the shroud as well.

It also appears to be far easier to keep the fins straight from a build perspective.

I realize you are going for an authentic appearance, but do you think the angle of the fins matters from a performance aspect?

Also, why did you add a slot for the aft fins and centering ring?

Click to expand...

Hi grizzly,

You asked
It appears this kit is pre-slotted for straight fins rather than angled fins. That seems to apply to the shroud as well.
It also appears to be far easier to keep the fins straight from a build perspective.
I realize you are going for an authentic appearance, but do you think the angle of the fins matters from a performance aspect?

My reply

Yes, The kit parts were pre-slotted with straight slots for the fins, wings and the shrouds/fairings.

As for building the kit, it would or can be built with all surfaces straight as supplied which would make it easy to complete the project.

As far as performance being affected, by the horizontal tail surfaces being angled, it may or may not. I see the probability of creating more drag on the rocket by doing this, from another set of airfoil edges being exposed to the airflow in flight.

Also, why did you add a slot for the aft fins and centering ring?

I cut the slots in the aft fins and ring so they would lock together when assembled at the desired angle I was looking for which turned out to be about 25 degrees, give or take.




My own reasoning for building the rocket in the manner I did was to:
be reasonably authentic in looks, To me, it just would not be an X-15 without the angles.
I always view kits of this nature and subject are being supplied as a builder's kit with basics being done for you. This manner allows the builder to be creative and detailed as they desire to be.
I have always liked to recreate Scale looking rockets/models which is a challenge in some manner.


John

Thanks for the confirmations, John. I see now it would be a lot easier to build without the angles.

One thing you might then consider would be to create the original x15 wedge shape for the top and bottom/vertical fins. I think you could get two more fins for each, cut off the fin tabs, bevel them with a sander, and glue them to each side of the current top/bottom fins.
You would probably have to redo the fin fillets though. PIA.

I got mine today. I'm excited... Nice fit and finish...

I built one of these about 10 years ago from a Smokin Rockets phenolic kit. It was always an attention getter and had a few nice flights. I took a job overseas shortly after building it and Mark Canepa bought it. There were a few things that I remember about it, mostly that it was heavy. I glassed the phenolic tubes and used the altitube system I got from Bill. I see Ken still offers that. The tail cone was very fragile because of the weight, if I were to build another I would look for ways to lighten it up. I was thinking about laying up some thin strakes and making a set of honeycomb fins but never got around to it. I made a basic Rocksim file that was pretty close for engine and delay selection.

Awesome. What motor?

According to the few notes I have, that was the maiden flight on a J-460 in Orangeburg SC. That flight got right around 1000 feet confirmed by the altimeter. A few weeks later we flew it in Lilly GA on a J-415 and almost doubled the altitude. That's the last flight I have anything on, I don't know what kind of luck Mark had with it.
George T

gltruett said:

I built one of these about 10 years ago from a Smokin Rockets phenolic kit.View attachment 160365 It was always an attention getter and had a few nice flights. I took a job overseas shortly after building it and Mark Canepa bought it. There were a few things that I remember about it, mostly that it was heavy. I glassed the phenolic tubes and used the altitube system I got from Bill. I see Ken still offers that. The tail cone was very fragile because of the weight, if I were to build another I would look for ways to lighten it up. I was thinking about laying up some thin strakes and making a set of honeycomb fins but never got around to it. I made a basic Rocksim file that was pretty close for engine and delay selection.

Click to expand...

You did a great job with the build, looks very impressive coming off the pad, Nice!. You are right about these babies being heavy. I chose the all glass kit and it's built like a tank. If I build another, I'm with you in finding ways to save weight.
Thanks for the information and the RockSim file. Can't wait till spring weather gets here to finish up and paint it.


John

A small note to everyone to say Thank You again for the comments and input . My build progress has come to a standstill this point, darn work gets in the way 90 percent of the time and waiting for the weather to show its Spring face, to get it finished up and painted

John

gltruett said:

The tail cone was very fragile because of the weight, if I were to build another I would look for ways to lighten it up.

Click to expand...

Kinda like this: https://www.rocketryforum.com/showt...-with-my-new-router-table&p=449958#post449958.

dixontj93060 said:

Kinda like this: https://www.rocketryforum.com/showt...-with-my-new-router-table&p=449958#post449958.

Click to expand...

your build sure does rock !. The effort you are putting into it is fantastic. Going to be a real honey of a rocket

John

jmac said:

your build sure does rock !. The effort you are putting into it is fantastic. Going to be a real honey of a rocket

John

Click to expand...

Thanks. I have the nosecone along with the nosecone av-bay and weight compartment components all sitting in the corner of my workshop. I have suspended work on it while I build some fiberglass kits (5) for LDRS33. Looking forward to getting back to it though.


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