Semroc MX Jayhawk now available

[kuririn]

https://www.erockets.biz/semroc-flying-model-rocket-kit-mx-jayhawk-kmx-04/

 

[Ronz Rocketz]

Does micro mean mini engines? Couldn’t see it in the description.

 

[kuririn]

Micro Maxx engines.
6 mm, 1/8A power.
Did you get your "I survived Hurricane Douglas" T shirt yet?

 

[kuririn]

Bigger than the ASP model, comes with a wing alignment jig you put together.
Also more detailed with a boat tail and scale accurate belly tube instead of just a launch lug.


Nice 3D printed nose cone with canards.

 

[kuririn]

Primer on.

 

[kuririn]

Basecoated.

 

[user 13]

Looks great!

I just picked one (and a fat boy) up! Looking at yours makes me want to move it up in the build rotation!

Any build tips?

 

[kuririn]

Both kits have fin/wing alignment jigs making them relatively easy builds.
The Jayhawk's decals have a mask because of the white areas on the star and bars. They are printed on clear decal paper.
You are supposed to paint the area under them white, I'll be trying a different approach.
Stay tuned.

 

[user 13]

It looks like the boat tail is a paper wrap?

 

[kuririn]

Yep, glossy cardstock wrap.
And the bottom conduit as well.
For me, the real challenge is the miniscule parts.

 

[hcmbanjo]

The Jayhawk's decals have a mask because of the white areas on the star and bars. They are printed on clear decal paper.
You are supposed to paint the area under them white, I'll be trying a different approach.
Stay tuned.

I've cut white decal paper to make to give the stars and bars a white background before -
but not as small as your MMX Jayhawk!

https://modelrocketbuilding.blogspot.com/2011/04/starlight-jayhawk-build-part-26-white.html

 

[kuririn]

I've cut white decal paper to make to give the stars and bars a white background before -
but not as small as your MMX Jayhawk!

Chris, I knew someone must have done it before. Should have known it was you.
I did the same thing with the decals on the Fliskits MMX V-2:
https://www.rocketryforum.com/threads/fliskits-v2-v2-bumper-wac.158214/

 

[kuririn]

Masked and brush painted the black on the nose cone.


A stencil/mask is provided with the jigs but I opted to use Tamiya tape instead.
Still had some minor bleeding. Will touch up with the brush later.
Speaking of brushes, picked up this micro brush set a few months ago:


Ultra fine tip, ergonomic handle.
Great for really fine detail work.

Next: decals.

TBC.

 

[kuririn]

The cardboard stencil was used to trace the star and bars outline on the back of the white decal paper.
You want it to cover the clear area of the decal but not go beyond the blue border.


It worked!
Knowing my masking/painting skills, this probably worked better than trying to paint the white area.


And done.
Great kit, kudos to kitbasher for an excellent design.


Will update whenever I get to fly this beauty.
Laters.

 

[user 13]

Beautiful!

Well done, I hope you get to fly it soon.

 

[kitbasher99]

Thank You, I do my best.

 

[kuririn]

Update.
She flew today.

And the video. (I said ASP in the video but it's Semroc).

 

[user 35280]

Update.
She flew today.
View attachment 477599
And the video. (I said ASP in the video but it's Semroc).

Gary, is that the micromaxx holder/rod from rocketship games?

 

[kuririn]

Gary, is that the micromaxx holder/rod from rocketship games?

Glad you asked!
I had a problem a couple of weeks ago because the MX rod from Rocketship Games was too wide for the Semroc launch lug. When I tried loading it there was scraping and binding. So this time I loaded the erockets MX rod holder on top of the Rocketship Games holder and used the Semroc MX rod. It's narrower.
Apparently there's two standards for MX lug diameters. I didn't know that.

 

[Ronz Rocketz]

Apparently you have to squint to tell the difference.

Usually my son is enthusiastic about catching rockets but not this morning.

 

[kitbasher99]

Looks like that should have been called a "Heads Up Flight".

 

[Ronz Rocketz]

Looks like that should have been called a "Heads Up Flight".

It was more like a "Glance Up Flight".

 

[user 35280]

Glad you asked!
I had a problem a couple of weeks ago because the MX rod from Rocketship Games was too wide for the Semroc launch lug. When I tried loading it there was scraping and binding. So this time I loaded the erockets MX rod holder on top of the Rocketship Games holder and used the Semroc MX rod. It's narrower.
Apparently there's two standards for MX lug diameters. I didn't know that.

Didn’t know that either, but I’ve just used the eRockets holder.
Thanks for the information.

 

[tjkopena]

I had a problem a couple of weeks ago because the MX rod from Rocketship Games was too wide for the Semroc launch lug. When I tried loading it there was scraping and binding. So this time I loaded the erockets MX rod holder on top of the Rocketship Games holder and used the Semroc MX rod. It's narrower.
Apparently there's two standards for MX lug diameters. I didn't know that.

That's news to me too. I thought they were all based around 1/16in launch rods.

If anything I'd expect the Rocketship Games rod to be ever so slightly narrower, because it's a metric 1.5mm instead of a true 1/16in, which is 1.5875mm. Unfortunately I must confess I don't have a Semroc MMX kit or their launch adapter on hand (none of the shops I usually order rocketry stuff from carry their micro kits so I haven't gotten around to it). But Semroc's launch rod adapter is listed as including a 1/16in rod. I'll have to pick some up and investigate unless @kitbasher99 or somebody else can shed some light on the topic. The 1.5mm rods I use though work as expected with the Quest and ASP micro-rockets I have, so I don't think I'm totally crazy.

 

[kuririn]

That's news to me too. I thought they were all based around 1/16in launch rods.

If anything I'd expect the Rocketship Games rod to be ever so slightly narrower, because it's a metric 1.5mm instead of a true 1/16in, which is 1.5875mm. Unfortunately I must confess I don't have a Semroc MMX kit or their launch adapter on hand (none of the shops I usually order rocketry stuff from carry their micro kits so I haven't gotten around to it). But Semroc's launch rod adapter is listed as including a 1/16in rod. I'll have to pick some up and investigate unless @kitbasher99 or somebody else can shed some light on the topic. The 1.5mm rods I use though work as expected with the Quest and ASP micro-rockets I have, so I don't think I'm totally crazy.

The erockets MX rod also fits the lugs on the original plastic Quest MicroMaxx rockets.
The Rocketship rod is too wide.
I think the original Quest Micromaxx rod may have been music wire.
I don't have a micrometer, but here's some side by side pics of the rods and the launch lugs.
l: Semroc r: Rocketship


l: erockets r: Rocketship


erockets rod fits Quest MX rocket


Rocketship rod does not


Joe, if your rod was a hair narrower it would fit all brands of MicroMaxx.

 

[tjkopena]

Thanks for those notes, @kuririn.

I've found out more. I was making up an order of MMX kits and the Semroc launch rod adapter on eRockets to investigate and just happened to go trawling through all the random parts categories and so on while I was there. Turns out there are separate parts listings for each of the wire, MDF pieces, and instructions. While the complete launcher adapter entry simply lists the rod as being 1/16", the wire's entry lists it as '1/16" Diameter Rod (0.055")'. That matches your recollection: 0.055" is a common size of music wire.

So, where things appear to stand:

True 1/16	0.0625"	1.5875mm
Rocketship Games' rod	0.059"	1.500mm
Semroc's rod	0.055"	1.397mm

And then Semroc's kits are presumably using sufficiently tight launch lugs that this tiny difference shows up. E.g., if their lugs are a true 1/16" inner diameter, 0.0625in, then the 0.055" music wire might slide within easily as it's ~0.2mm smaller, but my rods are only ~0.1mm smaller and can bind. Seems like a bit of a stretch that this miniscule mismatch would make such a big difference, but it's plausible if their lugs are very tight.


I'll have to think a bit about the best course of action to be compatible w/ Semroc's sizing.

Going forward isn't much of an issue. My kits aren't a problem, all of them out already or in production have either a 2.5mm or 2mm ID launch lug. That should be tight enough, especially given how quickly they accelerate and bring the aerodynamics into play. For my adapter I'm already planning to add an additional set screw for the small rod like we've talked about, which would make it able to handle a range of sizes and obviate this whole question. I also don't have so much 1.5mm wire stock on hand that it would be crushing to switch over.

For people with my existing adapters, a wrap or two of tape around the thinner Semroc rod should make it fit snugly. I'll probably offer to include a 0.055" rod in their next order for anybody that already bought an adapter and rod.

My only real question is how much more, if at all, does that 0.055" music wire flex? I guess I'm a bit nervous about that because it's often sold in coils.

 

[kuririn]

Sorry Joe, didn't mean to open up a whole can of worms for you.
Just that I ran into this and was wondering what's going on.

 

[tjkopena]

No worries at all, not a big deal and certainly not your fault. Actually glad you pointed this out, I'd rather be compatible with all the existing micro-rocket stuff out there. I've ordered a bundle of 0.055" wire, should be here just in time to switch w/ my next kit release at the end of the month.

 

[kitbasher99]

eRockets launch rod wire is bought in 36" straight lengths. It is piano wire and is plenty stiff, my hands can attest to that!!!!!

 

[kitbasher99]

We have also corrected the description on the website and eliminated the 1/16" designation.

Randy's not an engineer!!!!!