Much faster to CNC parts out of 2mm plywood than to 3D print parts. This is my first time making a multi-part-component with CNC'd parts. I think that they two wedge fins came out pretty good.
X-15 (3D printed parts + BT-80 body tubes + plywood fins)
- Thread starter BigMacDaddy
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Nice!
Saluki
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I have to agree Nice. Glad to see things are coming along.
Are you going to fill them with foam or anything?
I was not planning on it -- I left some little tabs on the side pods so hope that lets me attach them more strongly to the body.
Some progress was made -- first assembly of all the parts... I think it is coming together pretty good but I really need to figure out how to make the side pods straighten out. In future version I will add a little corner lip to the print so that the part that goes against the body tube is more rigid (also some small tabs to make them lock inside each other). The tabs are great to hold these side pods onto the body. 213g so far w/o glue, chute, buffer tube, nose weight, or engines (I can swap the single engine mount out for the 2x engine cluster)...
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What are you going to do about the aft end of the cockpit? Will it be attached to the NC or the BT?
One of the things I was working on this morning... In V1.0 I had setup the rear portion of cockpit to attach to the body tube. In V2.0 it will attach to the nose cone and extend out over the body tube.
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I did an upscale version of the Estes Wolverine (BT-60) and placed the aft end of the canopy on the body tube. It worked well and is a nice "key" to get the canopy lined up with the fins. The down-side is I can't rotate the NC once it's seated. Not a big deal.
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Very nice job love the X-15 looks outstanding.
Finally had a chance to get back to this model for a bit last night and this morning. I wound up reprinting the 3D parts and starting from scratch. Big Bertha included for scale comparison.
One of the interesting challenges in designing from scratch / scratch-building is in figuring out the assembly order that makes the most sense. Marking body tubes fully and taking my time meant no major mistakes in assembly this time (still test fit everything before gluing things together).
Bit more work on fillets and need to prime it, sand, fill, prime to see what needs to be filled / sanded for a clean finish.
One of the interesting challenges in designing from scratch / scratch-building is in figuring out the assembly order that makes the most sense. Marking body tubes fully and taking my time meant no major mistakes in assembly this time (still test fit everything before gluing things together).
Bit more work on fillets and need to prime it, sand, fill, prime to see what needs to be filled / sanded for a clean finish.
Looks great! Definitely interested in these 3D files if you sell them.
Thank you so much!
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That looks nice, properly proportioned and you avoided all the issues I normally have with rocket only X-15's, very nice.
Thanks Frank - big compliment given your expertise with this model! This 3D printed version needs quite a bit of nose weight to fly with the full sized wings, etc... - around 3-4oz. Here is fully updated OR sim.
Ditto
That dual motor cluster looks seriously serious. Very cool indeed.
Weight with chute but no motors or nose weight is 310g (CG is 38.8cm from nose). Looks like I will need 3-4oz of nose weight so it will come in at around 508g w/ 2x D12 motors added. 133m is a good flight for me and my fields.
bunkermonkey9
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Looking good
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Outstanding build great job.
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The twin motors hurt, they weigh about an ounce and a quarter to an ounce and a half, if you went with a single composite e motor it would weigh the same as a single motor with double the impulse and you would dump an ounce and a half in the nose and an ounce and a half in the tail so a 3 oz saving.
Thanks. What type of composite engine do you recommend that is in the D-E range for this weight rocket?
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I would think an e20 single-use would be good with the right delay for your final weight or e18 reloads there are some two pack econo jet or energet motors now that should probably work as well.
I like the cluster and am not averse to nose weight, but it would be cool to leverage your modularity skills and have both mounts be available.
Thanks. In the current design I can use a single 24x90mm motor or a pair of 24x70mm motors. I could also use longer 24mm single engines but would need to consider the engine block / retainer setup. I might try less nose weight and a E12-4 although the speed off the rod is only around 12.5-13 m/s which is a bit slow.
E12 doesn't have much more initial thrust than the D12. It also weighs more, so in my experience you get worse rod speed than with a D12.
