Another ACME Spitfire build thread?
- Thread starter Blast it Tom!
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So now, with @JoeFilgas's help, I cut 1/4" off the BT-50 body tube and glued BT Section 4 in place. The side photo shows how the #7 ring sits on the top of the BT-50 tube and the apex of BT Section 4.
From the top, you can, looking carefully, see the place where a toothpick glued to the inside of BTS 4 will protrude through a slot in ring 7:
I'll have to be careful that the toothpick doesn't poke Calvin - err, Spaceman Spiff, in his backside!
From the top, you can, looking carefully, see the place where a toothpick glued to the inside of BTS 4 will protrude through a slot in ring 7:
I'll have to be careful that the toothpick doesn't poke Calvin - err, Spaceman Spiff, in his backside!
Ok, tonight I fileted around the joint between BTS 3 and 4, the one with the door opening in it.
Then I CA'd the top edge of the BT-50 tube - guess I could have done the top of BTS 4 as well -and test-fitted Ring 5. As best as I can do, it leaves quite a smile.
That maxes out at about 5/64". And the ring is tilted when it should be flat. Still, the relationship between the BT-50 tube and the upper edge of BTS 4 is at least within tolerance, as the toothpick will fit into the inside end of the slot on Ring 7, as shown in the last post. To me, that indicates that BTS 4 could have more tilt on it. But I hope this is ok.
I think I'll fill that gap with a piece of cardstock as I glue the ring up. The door assembly must be in place for that, so I will have to be VERY careful with the glue. If I glue that door in place, @NPT2 will never let me live it down!
Then I CA'd the top edge of the BT-50 tube - guess I could have done the top of BTS 4 as well -and test-fitted Ring 5. As best as I can do, it leaves quite a smile.
That maxes out at about 5/64". And the ring is tilted when it should be flat. Still, the relationship between the BT-50 tube and the upper edge of BTS 4 is at least within tolerance, as the toothpick will fit into the inside end of the slot on Ring 7, as shown in the last post. To me, that indicates that BTS 4 could have more tilt on it. But I hope this is ok.
I think I'll fill that gap with a piece of cardstock as I glue the ring up. The door assembly must be in place for that, so I will have to be VERY careful with the glue. If I glue that door in place, @NPT2 will never let me live it down!
Here's a layout of the card stock patch that will close the gap between Ring 5 and BTS 4.
As I move forward, I'm finding that the stock nose cone pattern seems to be forming up too big. I've carefully preserved the original cardstock pattern from the kit, and carefully duplicated it using both typing paper (showing my age there!) and also a try with .010" styrene sheet. I met the glue lines, I was quite exacting, and yet both are too big to fit the #7 ring the way the instructions say to - and it's so much too big that it will interfere with my Spaceman Spiff cockpit design.
I ask the veterans again - did any of you encounter this?
I ask the veterans again - did any of you encounter this?
I don’t recall any issues with my nosecone fitting like it was supposed to. Can you scan the original and re-size it on your computer to fit like you need it to?
Joe, thanks. I already have it scanned. As a matter of fact, I have the cone modeled in SW to the measurements of the pattern, and I could possibly do a "flatten" operation on the inside surface and see if the resulting pattern matches mine.I don’t recall any issues with my nosecone fitting like it was supposed to. Can you scan the original and re-size it on your computer to fit like you need it to?
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Ok, so get this: I jumped onto Solidworks and made a new cone pattern from my model. Printed the thing and figured out that I had serendipitously put the parting line 180° from the kit pattern. But I compared the two and the relevant dimensions were the same. But when I rolled my new pattern, it came out perfect.Sure thing! Here’s some under construction pics of mine if that helps any?
So craftsmanship is important, I guess?! Who knew! Still don't know why my first two were off.
But now that I have my parting line along the short side, I can precisely position the canopy cutouts, which had been along the parting line in the kit before...
Well, maybe I spoke too soon. I am moving forward, but in looking again, I realized that the angles on the two patterns were not the same:Cool glad you got it worked out and can move forward!
My included angle is just a little smaller, and that reduces the circumference at the location of the #7 "off-centering" ring to "just right". So I'm seeing now if I can make a Solidworks assembly that includes this and the precisely-positioned canopy patterns. This may indeed be the way to go.
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This, then, is what I did. To save too many pictures, here is the final result:
The outward side has been sprayed bright red, kinda obvious from the overspray, then I cut a piece of .010" clear styrene for the canopy and glued it in place with liquid styrene cement (the solvent type). Hopefully that can stand up to the stresses of forming this. The nosecone is also .010" styrene from Evergreen.
If it seems wimpy, don't forget the original is card stock. And I can reinforce it!
The outward side has been sprayed bright red, kinda obvious from the overspray, then I cut a piece of .010" clear styrene for the canopy and glued it in place with liquid styrene cement (the solvent type). Hopefully that can stand up to the stresses of forming this. The nosecone is also .010" styrene from Evergreen.
If it seems wimpy, don't forget the original is card stock. And I can reinforce it!
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Thanks, Joe! So with Spaceman Spiff set to arrive at the Vehicle Assembly Building on Wednesday, things have to start happening. I was having problems with the access door for my Flightsketch Mini, so I fashioned a door handle from .040" wire and epoxied it in place. I had cut a window in the door as a vent so the altimeter gets a good barometric reading, and so with the same batch of epoxy, I put .020" styrene bars across the window opening, as this will be designated as quarters for 1st Tiger Hobbes. I also wicked thin CA into the top of the motor tube, BTS #4, the edges of my door, and the edges of the door opening. Behold!
Next will be a little trim on those door handle wires and then place that assembly and be sure it works with the Flightsketch Mini. Then I'll glue in #5 off-centering ring and the cardstock patch and toothpick segment for indexing the nose cone assembly. Might get some fin work done today as well.
Next will be a little trim on those door handle wires and then place that assembly and be sure it works with the Flightsketch Mini. Then I'll glue in #5 off-centering ring and the cardstock patch and toothpick segment for indexing the nose cone assembly. Might get some fin work done today as well.
And now the #5 off-centering ring has been placed. I did not attempt to place glue on the inside of the body tube 1st. I placed it dry, then filleted the arc that was tight against BTS #4. Then I placed the cardstock filler into some glue on the top of #5 ring and filleted the rest of the way, and around the BT-50 motor tube as well. Two more card stock patches covered the alignment hole and the alignment mark; this is me being OCD about keeping Hobbes's quarters airtight except for that window opening.
Then I placed the toothpick and made sure it was aligned with the black alignment line on the outside of BTS #4. Here's the pic, I'll probably re-fillet some spots later.
Then I placed the toothpick and made sure it was aligned with the black alignment line on the outside of BTS #4. Here's the pic, I'll probably re-fillet some spots later.
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Now the fins.... I know this is the ACME Spitfire, and further, that it's purportedly built by a 6 year old... but... but... but... I WANNA SHAPE THE LEADING EDGES AT LEAST!!!! It's almost against my religion not to! Oh, I know, it makes very little difference, but...
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While I considered that whole issue, I checked the directions... my Tiger Quarters are on the launch lug side so I'll probably switch the lug to the other side. So I cut out the standoff and beveled a section of lug to suit and then I... I... then I... uh... I SHAPED THE LAUNCH LUG STANDOFF! I COULDN'T HELP IT!!
#3 Fin is on, as the first fin! And.. err... uh...
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I SHAPED THE FINS!!!!
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I SHAPED THE FINS!!!!
There was a reason for doing fin #3 first. Fin #1 is glued to the meeting line of the base cone, and so doesn't sit well on the lapped paper joint. So I supported the rocket horizontally between two 2 x 4's so the I could sight both fins and be sure that Fin #1 held its position while drying. I used the glue, place, lift technique, letting the Titebond 3 tack up, and then refreshing with just a little more glue and doing final placement. Thus endeth the day. It migh be a little bit off again...
This AM, I went to my mother-in-law's to make one last move before the carpet layers came, and then off to my men's group at the church. But she wasn't up yet, so I thought I'd check on the fins and maybe glue another one on.
And that's what I did. After assuring that I had perfect alignment on Fins 1 and 3, I realized that I had Fin 2 in Fin 1's position. So after carefully removing Fin #2, I glued Fin #1 where it belongs.
A wise man once told me. "Tom there's no sense being stupid if you never show anyone!"
And that's what I did. After assuring that I had perfect alignment on Fins 1 and 3, I realized that I had Fin 2 in Fin 1's position. So after carefully removing Fin #2, I glued Fin #1 where it belongs.
A wise man once told me. "Tom there's no sense being stupid if you never show anyone!"
Ok, all four fins are on now, in their proper positions. Another advantage of doing opposite pairs of fins on 4 finned birds is that you can fillet the first pair as you place the second pair!
Today is fin fillet day. But I have a new acquaintance whose 11 year old son is just entering our magnificent obsession, so I stood it up and stacked the test nose cone on it and took a picture for him.
Oh, and the final verdict is in... I DID NOT GLUE MY DOOR SHUT!!! It works like a champ. So my Flightsketch Mini.... err... First Tiger Hobbes, I mean... will have safe place to ride. Now off to the Post Office to retrieve Spaceman Spiff!
Oh, and the final verdict is in... I DID NOT GLUE MY DOOR SHUT!!! It works like a champ. So my Flightsketch Mini.... err... First Tiger Hobbes, I mean... will have safe place to ride. Now off to the Post Office to retrieve Spaceman Spiff!
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Hence my signature block.
Well, things are moving now. But a challenge of this design is the launch lugs. Any time that they are in two pieces, alignment becomes critical; at my first club launch ever last year I the LCO asked me to help a mid-teen fellow trying to get his rocket on the rod, and unfortunately the two segments had a parallel offset and would never have worked. I hate to see a kid disappointed like that, but you don't forget it when you learn something that way.
So in that spirit, we have this issue with the Spitfire. How do you align a 2 piece launch lug to a body tube like that? A segment of 3/16" launch lug is mounted to a parallelogram-shaped piece of balsa and is to be glued to the tube in line with the joint between Body Tube Segments (BTS) #2 and 3. It's on the vertical side of the rocket (All the "kinks" in the outer "BTS" segments are in one plane). But how to line it up as straight as possible with the motor tube inside? And with the other segment of launch lug on the #2 fin? I wasn't about to try to "eyeball" this and try to sit there holding a piece in alignment until the glue set up. I like setup jigs whenever possible. So I came up with an alignment method using a couple of parallel rails:
The astute observer will see that I am actually putting the launch lug on the #4 fin side, as the door for the Flightsketch Mini - err - 1st Tiger Hobbes - is on the #2 fin side. The piece of balsa is from the fin stock, and the spray can visible under the top end at the right of the frame is adjusted until the motor tube is sitting level, as measured from either end. This was a bit challenging, but successful. I was very happy to see that the #2 and 4 fins were laying flat on the parallel rails, indicating as perfect of an alignment as one could hope for. The piece of balsa insures that both pieces of launch lug are at the same elevation.
But the launch lug assembly needed further shimming under the balsa standoff if the standoff were to be glued to the body tubes perpendicularly (that's probably a new conjugation of "perpendicular"...). So after fiddling with a some card stock and .010" styrene strips, I finally got a stack that I liked. A little hint, always press a stack of "shims" like this with your fingers as well as possible, maybe even glue them if it's critical, so that they act the same in service as they do in setup.
I then put both pieces of launch lug on some extra 3/16" rod and dry placed them.
I then checked that the launch rod was parallel with the motor tube laterally. Once satisfied, and now that the rod is as parallel to the the motor tube as is possible, I put enough glue on both (without moving them) to hold them in position.
This morning, after everything was set overnight, I pulled the rod out and finished the glue joints; I'm filleting now. I plan to trim the lower lug parallel with the shroud so as to not have a "dead corner" there.
We're into the final steps here, folks, I hope to be painting soon - and just wait until you see Spaceman Spiff! A fellow forum member, @Bravo52, is to be greatly praised for his work!
So in that spirit, we have this issue with the Spitfire. How do you align a 2 piece launch lug to a body tube like that? A segment of 3/16" launch lug is mounted to a parallelogram-shaped piece of balsa and is to be glued to the tube in line with the joint between Body Tube Segments (BTS) #2 and 3. It's on the vertical side of the rocket (All the "kinks" in the outer "BTS" segments are in one plane). But how to line it up as straight as possible with the motor tube inside? And with the other segment of launch lug on the #2 fin? I wasn't about to try to "eyeball" this and try to sit there holding a piece in alignment until the glue set up. I like setup jigs whenever possible. So I came up with an alignment method using a couple of parallel rails:
The astute observer will see that I am actually putting the launch lug on the #4 fin side, as the door for the Flightsketch Mini - err - 1st Tiger Hobbes - is on the #2 fin side. The piece of balsa is from the fin stock, and the spray can visible under the top end at the right of the frame is adjusted until the motor tube is sitting level, as measured from either end. This was a bit challenging, but successful. I was very happy to see that the #2 and 4 fins were laying flat on the parallel rails, indicating as perfect of an alignment as one could hope for. The piece of balsa insures that both pieces of launch lug are at the same elevation.
But the launch lug assembly needed further shimming under the balsa standoff if the standoff were to be glued to the body tubes perpendicularly (that's probably a new conjugation of "perpendicular"...). So after fiddling with a some card stock and .010" styrene strips, I finally got a stack that I liked. A little hint, always press a stack of "shims" like this with your fingers as well as possible, maybe even glue them if it's critical, so that they act the same in service as they do in setup.
I then put both pieces of launch lug on some extra 3/16" rod and dry placed them.
I then checked that the launch rod was parallel with the motor tube laterally. Once satisfied, and now that the rod is as parallel to the the motor tube as is possible, I put enough glue on both (without moving them) to hold them in position.
This morning, after everything was set overnight, I pulled the rod out and finished the glue joints; I'm filleting now. I plan to trim the lower lug parallel with the shroud so as to not have a "dead corner" there.
We're into the final steps here, folks, I hope to be painting soon - and just wait until you see Spaceman Spiff! A fellow forum member, @Bravo52, is to be greatly praised for his work!
So... I'm a very slow builder, and even slower when I'm both scratch-building AND learning how to use 3D printed parts. But just to show you where I'm at, here's some pictures of Spaceman Spiff and his cockpit.
I have to paint the outside of the capsule before I can finally build out the inside of it. Once again, thanks goes to @Bravo52 for some "Above and beyond" 3D workmanship!
I have to paint the outside of the capsule before I can finally build out the inside of it. Once again, thanks goes to @Bravo52 for some "Above and beyond" 3D workmanship!
And tonight, finally, Spiff gets his "office".
I had to do some plastic surgery and get the floor properly aligned with the nose cone. Once the CA set I pulled the nose cone away.
Then I aligned Spiff and glued him.in place, again assembling the nose cone to be sure he was centered up properly. Then came his side instrument consoles.
I had to do some plastic surgery and get the floor properly aligned with the nose cone. Once the CA set I pulled the nose cone away.
Then I aligned Spiff and glued him.in place, again assembling the nose cone to be sure he was centered up properly. Then came his side instrument consoles.
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The nosecone has been sprayed as well, and the rocket is in primer. Spiff tries out his quarters....
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Never has the term, “That looks really spiffy!” Been more apt.
Seriously though, really nice craftsmanship and imagination here.
Gonna have a Tiger stripe chute?
Sheesh, I hadn't thought of that!!!
