Estes Star Speeder MPR Upscale

[Exactimator]

Has anyone successfully upscaled an Estes Star Speeder? I’m considering doing an MPR version and was looking for any insights or tips.

I’m thinking of a 29mm main tube/mmt and either a 54 mm or 2.6” aft main body tube. I’d like to keep it as light as possible so I can get decent, stable flights on G and possibly F motors.

There’s a lot of fin on this rocket and I’m concerned if I use G10 FG or plywood it might be too tail heavy for stability.

I’m also looking for tips on how to assemble the T-tail so it’s square and sturdy enough not to snap off on landing. I remember struggling with that when I built the Estes kit when I was a kid. IIRC, when the Elmer's glue dried, it was a little crooked in both directions.

 

[TangoJuliet]

I've never built one, but I'll offer my thoughts/ideas on building the fins/wings/T-tail...

To keep it as light as possible, I'd probably use 3/16", maybe 1/4" Balsa, but I might add a hardwood leading edge, and for sure I would go through the wall to the MMT. I don't think using G10 or Ply is really necessary. As far as the T-tail, build it off the model upside down, so that the horizontal stab (top of the "T") is on the bench, then add the vertical piece. Use a square to keep it, well, square. Then I would probably add 1/8" triangular balsa as gussets in the corners where the vertical and horizontal parts meet for added strength.

 

[Exactimator]

I've never built one, but I'll offer my thoughts/ideas on building the fins/wings/T-tail...

To keep it as light as possible, I'd probably use 3/16", maybe 1/4" Balsa, but I might add a hardwood leading edge, and for sure I would go through the wall to the MMT. I don't think using G10 or Ply is really necessary. As far as the T-tail, build it off the model upside down, so that the horizontal stab (top of the "T") is on the bench, then add the vertical piece. Use a square to keep it, well, square. Then I would probably add 1/8" triangular balsa as gussets in the corners where the vertical and horizontal parts meet for added strength.

I like the triangle gussets idea.

I see what you're saying about the hardwood leading edge on the balsa fins. I'm more worried about snapping them on landing. I think I'd want to protect the trailing edges and roots. Maybe papered balsa?

 

[hornet driver]

Move the lower fin back just a tick and move the t -fin forward just a tick--that should take care of landing damage. Use a jig to make the t-tail--let it set for a few days after assembly. That should make it square and stay that way. Fill,sand and prime that assembly before you put it together.Mount it and paint and your good to go.

 

[Rex R]

I did a q & d strawman sim...if you wanted to keep the proportions roughly the same as the original, then you would need a piece of a) bt70 or b) bt70 coupler(which would be closer to the right size), to match up with 1.14" (29mm motor tube). think that those 'centering rings' could be a challenge, the aft section is off set*. personally I would go with papered balsa for the fins.
Rex
*according to the plans on the 'Jimz' site #1366

 

[EXPjawa]

I did an upscale of an Estes Orbital Interceptor last year. Not the same rocket as your project, but it does have a similar T-tail.

I'm not sure how well it shows here, but I used 3/8" triangle stock to gusset the tail plane. The rudder is 3/16" ply, the horizontal stabilizer is 1/8". I tabbed the two together as well, with a slot in the stab and tab on the rudder (similar to the Photon Disruptor or BSG Laser Torpedo). It has so far worked well.

 

[Exactimator]

I did a q & d strawman sim...if you wanted to keep the proportions roughly the same as the original, then you would need a piece of a) bt70 or b) bt70 coupler(which would be closer to the right size), to match up with 1.14" (29mm motor tube). think that those 'centering rings' could be a challenge, the aft section is off set*. personally I would go with papered balsa for the fins.
Rex
*according to the plans on the 'Jimz' site #1366

Thanks Rex. A BT70 tube is 56mm. I don't need it to be dead-on, just close enough, and I have a decent amount of 54mm tube I can use. Should be close enough. Did you do your quick sim on OR or Rocksim? (Sorry, I'm not sure if straw man means you used a program or not). If you did run a sim, could you attach the file?

I did an upscale of an Estes Orbital Interceptor last year. Not the same rocket as your project, but it does have a similar T-tail.

I'm not sure how well it shows here, but I used 3/8" triangle stock to gusset the tail plane. The rudder is 3/16" ply, the horizontal stabilizer is 1/8". I tabbed the two together as well, with a slot in the stab and tab on the rudder (similar to the Photon Disruptor or BSG Laser Torpedo). It has so far worked well.

That turned out awesome. How did you cut the slot in the stabilizer? Are those fins through the wall?

 

[Rex R]

lol. my 'straw man'* sim. was just the barest minimum needed to find the appropriate tube sizes. it had a bnc20 size nose, a bt20 tube, and a piece of bt55, no attempt was made to make it look right I only needed the tube sizes to get OR to scale them up. trying to get OR to offset the bt55 would have been more work. not to mention that OR doesn't do winglets.
*strawman defined; https://en.wikipedia.org/wiki/Straw_man_proposal
Rex

 

[EXPjawa]

That turned out awesome. How did you cut the slot in the stabilizer? Are those fins through the wall?

Thanks. Fins are through the wall; at this size I wouldn't do it otherwise. The stabilizer slot was a matter of marking it out as accurately as I could and drilling start & end holes. Then put the blade of the jigsaw thru one of the holes and cut the slot between them. Final fit was by filing to match the tab on the end of the rudder. Basically, it was a lot of hand fitting the parts together, but it came out well. I also attached the triangle stock to the rudder and final sanded the top plane (around the tab) once they were in place. Once it was all fit up, then I attached the stabilizer. The triangle gussets aren't "scale" but I'm willing to overlook that for structural purposes.

So, that's how I'd still go about if I did it again. It does more or less land on the tail, but I've also given it a large enough chute to minimize damage, and am fortunate enough to fly over a fairly soft field. I don't think I would try to land that on concrete. The cool thing is that for all that unconventional fin area, it flies dead straight, with a very slight "aileron" roll. Looks great on a G106 Skid.

 

[caveduck]

You should pop over this weekend...we can probably knock together a usable OR stability and CG sim in less than an hour. The t-tail can safely be ignored for CP margin as it's pretty close to the plane of the much larger wings. Likewise we can treat the tube diam change as a very short symmetrical transition.

 

[Exactimator]

I took a run at modelling it in OR last night. It's the first time I've tried to create something in it (I usually download an existing kit file and modify it as needed). I was unable to offset the tubes and the fins all have to be the same size and shape, which doesn't work for this design. So yes, I'm going to need some help, Caveduck.

I contacted Stickershock yesterday and confirmed he could get me a wrap for this. Some of the details are too small for cut vinyl, so it has to be a wrap. As soon as I confirm the dimensions I'm considering will work, I'll order the vinyl. It wouldn't be a Star Speeder without all the markings, and there's no way I can get there with paint and/or water slide decals.

 

[Bat-mite]

If I'm seeing the picture correctly, it looks like the "cockpit" is an uneven transition. If so, that will take some effort to model.

 

[Exactimator]

If I'm seeing the picture correctly, it looks like the "cockpit" is an uneven transition. If so, that will take some effort to model.

That sounds like a dare.

 

[Bat-mite]

That sounds like a dare.

Triple dog dare!

 

[neil_w]

You could easily get something similar to the cockpit with a single (very) thick fin. I don't know how well that would simulate, though.

I would think if you replaced the solid bulkhead behind the cockpit with a transition about half as long as the cockpit you'd have a reasonable representation for sim purposes. At least that's what my mindsim says.

 

[stantonjtroy]

Did one a few years back (also a straight clone). Mine was HPR (38mm mount) but I suspect a MPR version would be similar in construction. I have to admit I sold it to a friend before I flew it and lost touch with him so I don't know how it performed. I used Photoshop to upscale the bulkheads and patterns and then fabricated the cockpit from very thin G-10 (McMaster Carr). Construction was very straight forward. Building a straight 1:1 clone helped me identify any possible challenges I might face. The only difference between it and the clone was for the larger version I cut all panels individually, taped them together on the outside and glass taped them on the inside. Then I just removed the outer tape and cleaned up the seams. The wings were BIG. More so than I expected at the beginning of the project. All flight surfaces were light ply. If I do it over, and I might in MPR, I'm going to explore a lighter fin construction technique.

 

[Exactimator]

Did one a few years back (also a straight clone). Mine was HPR (38mm mount) but I suspect a MPR version would be similar in construction. I have to admit I sold it to a friend before I flew it and lost touch with him so I don't know how it performed. I used Photoshop to upscale the bulkheads and patterns and then fabricated the cockpit from very thin G-10 (McMaster Carr). Construction was very straight forward. Building a straight 1:1 clone helped me identify any possible challenges I might face. The only difference between it and the clone was for the larger version I cut all panels individually, taped them together on the outside and glass taped them on the inside. Then I just removed the outer tape and cleaned up the seams. The wings were BIG. More so than I expected at the beginning of the project. All flight surfaces were light ply. If I do it over, and I might in MPR, I'm going to explore a lighter fin construction technique.

Nice. I see you even got the strake shape on the bottom dorsal fin to match. Where did you get the stickers from?

 

[Exactimator]

Caveduck helped me a ton with an upscale in OR. Using a 29mm main tube ad 54mm rear tube, the sim is coming up at a half pound, which is a little too light for the motors I want to launch it on for a good show. We left the top stabilizer off and the canopy because there's no accurate way to model these.

I took his model and upsized it again to a 38mm main tube and 2.6" rear tube and the sim is showing about a pound. That works a little better with the motors and altitudes I was going for. Next step will be buying the materials and seeing if I can cobble one of these together.

View attachment Estes_Star_Speeder_29mm.ork
View attachment Estes_Star_Speeder_38mm.ork

 

[KenRico]

It is sounding like a rad upscale !

29mm you can speed along with H410 and somr electronics for deployment.

Kenny

 

[stantonjtroy]

Nice. I see you even got the strake shape on the bottom dorsal fin to match. Where did you get the stickers from?

Water slide decals I printed on Micro Mark Decal Paper. Up-scaled them in Photoshop from originals. Took 4 8.5 x 11 sheets.