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  1. #1
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    Another Saturn IB

    Yes, this was inspired by this thread http://www.rocketryforum.com/showthr...B-1-23-Upscale It's great reading and highly recommended.

    Having just finished my Level 3 I was looking for inspiration, and this was it. It will be close to the same size, and I'm starting at a very similar point, but there will be some differences and that's why I'm starting this thread.

    The basic design will be the same. I'll have an inner structural airframe, and an outer "scale" airframe. I'll be using 3" mailer tubes for the fuel and oxygen tanks, and a sonatube as a mandrel for my exterior airframe.

    My mailer tubes aren't exactly 3" OD. This makes mine slightly larger at 1/22 scale instead of 1/23. It does make my sonatube diameter more appropriate. I will be using some CF, but the outer airframe of the S-IVB stage will be fiberglass. This will allow me to use my Altus Metrum TeleMetrum flight computer and tracker without worrying about the RF opaqueness of CF. I also have a 3D printer, so that will affect both my construction methods and detailing. I also have the advantage of seeing what someone else has tried!

    Don't expect frequent updates. This is a long term build. I travel a lot for work and I have to work around that. I'm also trying to spread the cost out over as long a period of time as is practical.

    So let's get at it!

    Last edited by grandcross; 3rd August 2016 at 08:59 PM.
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  2. #2
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    One of the first differences is in the tank supports. I don't have a laser cutter, but making a support out of 1/8" birch plywood isn't too hard.

    Start by marking the hole centers. I used a Dremel to make pilot holes to improve precision.
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    Using a 3.25" hole saw, I made the holes
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    One last hole and the support is done. A couple of passes of a sanding block and it's good to go.
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    Now this wasn't perfect. While a 3" hole is too small, the 3.25" is too large. It's not a good fit for the tube. But the concept is solid. So I'll try it again with a 3" hole saw and use the dremel to improve the fit. Rocketry is all about sanding right?

    I'll use a similar technique for the tank base and header, but with thicker plywood.

    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  3. #3
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    Well, - there goes the neighborhood!

    Seriously though, if you have any REALLY good ideas, I'll be happy to try them out.

    I'll give you all my bad ideas.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  4. #4
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    Quote Originally Posted by MaxQ View Post
    Well, - there goes the neighborhood!

    Seriously though, if you have any REALLY good ideas, I'll be happy to try them out.

    I'll give you all my bad ideas.
    Don't worry... I'll be a good boy and share I'll be quite a ways behind you though.
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  5. #5
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    Quote Originally Posted by grandcross View Post
    I'll be quite a ways behind you though.
    Maybe not for long.....I'm trying not to fall behind here myself.

    Asides from this rocketry thing, I've been an avid RC flyer for about thirty years...we're well into the 2016 flying season and I haven't been out once...and a check of my kit inventory showed about fifteen sailplane kits in the que, and at least as many power and electric, and I'm queuing up the Bomarc rocket glider build from Frank B., so the temptation is growing to cross over to the other hobby, before the season is over.
    And then the darn day job keeps getting in the way ...but I have to keep that - to pay for this stuff.
    Last edited by MaxQ; 4th August 2016 at 04:01 AM.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  6. #6
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    I've been doing some planning and simulations.

    This is going to be a heavy rocket at about 30 lbs based on the model, and extra weight added with experience. I'm looking at about 30 lbs. To reach a stable speed in less than 6 feet, I'm looking at an L1115 for the main motor (4G Cesaroni classic 75mm), and some I55 Mellow Yellows for the outboards. So this needs to have a strong core. Looking at the cost/effort tradeoff for the core, glassed phenolic isn't a significant cost savings over fiberglass so I'm going with that.

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    The fins are going to be a challenge. I'm thinking a fiberglass core, with the shape built up using birch plywood sanded to shape. This will be covered with CF. Instead of tip to tip, this will be reinforced with fiberglass inside of the lower part of the airframe. A quick check of flutter speed using FinSim gives me almost 300fps before I hit flutter speeds, so I'm good there. Because of the shape of the fins, assembly means putting the slotted lower airframe in place first, then the fins, then the tank skirt, and then the tanks. Should be fun!
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  7. #7
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    Well, slap my forehead. It appears I forgot to set the material type for my fins when I ran FinSim, and the settings were for balsa! Setting the material to 1/8" birch gave me an additional 1100 fps margin! So now I'm thinking a plywood core, with balsa sanded to shape. Still thinking the CF outer layer though.

    So now what about my core? Does the hive mind think fiberglass is necessary, or can I get away with phenolic or blue tube? Opinions please!
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  8. #8
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    I think you ought to make it lighter....but that's just me. LOL
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  9. #9
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    Quote Originally Posted by MaxQ View Post
    I think you ought to make it lighter....but that's just me. LOL
    Lighter is better as long as it doesn't shred or fold! But I'm starting to agree with you. Lighter is also cheaper
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  10. #10
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    Quote Originally Posted by grandcross View Post
    Lighter is better as long as it doesn't shred or fold! But I'm starting to agree with you. Lighter is also cheaper
    Yep....that's the fine line between success and failure......I'm cautiously walking the line on this one.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  11. #11
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    you can never have too many Saturn 1bs!! She will look awesome!

  12. #12
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    Time for a quick update. I'm currently traveling for work as I often do, so this thread will continue to have long pauses without any new developments. Of course this allows me plenty of time for planning and contemplation!

    I ordered a set of Saturn IB drawings from Real Space Models (http://www.realspacemodels.com/drawi...1b-drawing-set) back in July, hoping to see them before I left on this trip. I'd like to plan details before I get too far in, and the drawings help ideas percolate. They were shipped first class mail and were supposed to arrive August 4, before I left. After bouncing around New York for a while, and sitting in the back of a truck for a couple of extended periods, I contacted USPS to ask what was going on. They were finally delivered yesterday. I guess I'll see them next week when I get back.

    I decided to use Blue Tube for my inner cores, with dimensions similar to MaxQ's design. It will be a 3 in core in the S-IB stage that will double as a motor tube for the 75mm main motor, and a 5.5 inch tube in the upper S-IVB stage. Tubes are ordered and should be there when I get back.

    In terms of construction, I've decided to work on the S-IB stage first. That means fins x 8. I'll probably make a few extra for when (not if) I mess them up. They will have a birch plywood core, with balsa to build up the thickness, sanded to shape, and wrapped with a layer of CF. This is going to be a long and tedious job in and of itself. I have the birch and CF already, and just ordered the balsa. It will be waiting for me when I get back as well.

    The lower skirt has its own challenges. For starters, I'd hoped to use the CF cloth I have leftover from my Level 3. It's not long enough to do 3 layers in a single wrap. Ordering 3 1/2 yards (which probably means 5 yards) for a single 6.3 in strip seems excessive. So I can do 2 layers, 2 layers plus an additional layer separately, 2 CF + 1 FG or whatever. Separating layers means bumps and seams and tedious sanding that may compromise structure. I need to think on this.

    Assembly will be challenging as well. The fins will be TTW to the central mount, but that may mean I have to shave my tank tubes to fit around the fins. Some of them are motor mounts, but they're 38mm in a 3in tube so that shouldn't be too bad. The transition of the lower skirt up around the tanks will be a challenge as well. I could attempt to do this as a wrap, or do it as a conical transition to the central tube, with holes cut for the tanks. I'm thinking the latter but that could make alignment trickier. I also have to consider wiring for airstarts. Painting and detailing when finished is going to have to factor in the plan somewhere too. This is going to take some thought, and a whole lot of time.

    I also have some thoughts about adding details, but more on this later I guess.

    Let the tedium of the fins begin!
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  13. #13
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    I'm taking a break before tackling those fins myself.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  14. #14
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    One of the good things about travel is arriving home and seeing the rocketry fairies have dropped a load of supplies!

    I took a look at the Real Space Models drawings and they are wonderful. They're definitely filling in some of the missing blanks. I hope to include as many details as I can, but this is all new for me. Learning new stuff is what I love!

    I've been thinking on things with regards to the fins. I have a basic outline template that Ill be using to cut the birch core.

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    So my first thought is to cover this in balsa and sand to shape. This will be difficult to get right, so I've been designing some 3D templates for my printer that will serve as sanding guides. Which led me to thinking about a plastic rib and stringer approach which is easier to create accurately. The problem is that epoxy doesn't stick to PLA at all, and even ABS would be marginal, so the first level of cladding would have to be balsa and then the CF. I'm not sure how the weights (or the effort) will compare, so I'll be doing some experimentation over the next few days. This should be fun!

    First step is to clear the clogged printer nozzle so I can make some plastics
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  15. #15
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    Ah, the frustrations of working with scale.

    I've been looking at the RealSpace Models drawings by David Weeks. They're awesome. They certainly fill in many of the details the other materials I've sourced have been lacking, including the differences between various versions. Yes, I'm building SA-205 as much as anything because I like the paint scheme. I'm still not sure how detailed I'll make this. I'm certainly not the detailed scale model builder that you can follow in other threads, but I'd like to add what I can. But I have noticed that all drawings, whether original blueprints or composite drawings like these, are lacking in some key and fundamental details.

    On is the antenna panels between the tanks on the S-IB stage. They're offset. I still don't know why, but more importantly, the diagram doesn't show by how much. I could eyeball it. I could measure it from the drawing and hope the draftsman got the scale right. Can't say I really like either option. I did manage to find the measurement on another drawing (2.626" on the SA-207), but it should really be here.

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    My real frustration is with the fins though. This is a really important feature for a model that relies on them for stability. I've yet to get a handle on the dimensions. Compare these two:

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    The second one has all of the basic dimensions, but is missing the piece where the holddown assembly attaches to the fin root. The first one has few useful dimensions. One dimension along the root (92.08" from the start of the root) looks to be a bolt attachment point, and is just plain not useful from a modeling point of view. Frustrating.

    The struggle continues...
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  16. #16
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    Well, one thing I considered when weighing the need for detail and accuracy is this won't likely be an entry in a space modeling competition, and one surely won't see a lot of the details at a High Power standoff scale.
    That said, it's all about what makes you, the designer /builder happy.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  17. #17
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    I know that, and I wound up combining the multiple diagrams I had at my disposal, but it's still frustrating. Fins are so fundamental. I'd skip so many other details to make them correct. Le sigh.

    On a positive note, I started cutting some fins! Sure wish I had a laser cutter...
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  18. #18
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    Despite being quiet for a while, this has slowly been progressing.

    As I said my intent was to start with the fins. I have, but it got a little sidetracked.

    The fins themselves are going to be a birch ply core, built up with balsa, sanded to shape, and covered with a layer of CF. I started by creating templates for the birch and the balsa. I cut a single birch core (for practice) using a jig saw with the intent of sanding it down to it's final shape. Turns out this is a lot of work. Birch is not called a hard wood for nothing. Plus, allowing for the portion where the hold downs attach, the part that connects to the tank shroud, and through the wall fin tabs makes this a complex shape. Doing 8 of these (+4 extra for when I mess them up) would take most of my build time. So I broke down and ordered some laser cut versions. They were cut last week, but won't arrive until Tuesday, after my planned labor day build weekend. Le sigh.

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    You'll notice that the birch core has tabs on the fin tip. These will hold sanding guides that allow me to shape the fins more precisely. More on that in a later post. When complete, these will be cut off and sanded smooth.

    So on to other things. Since I've been receiving all the stuff I need to make my body tubes. I'll start with that. While I stole MaxQ's idea of using a concrete former as my mandrel, mine is a little different than his. It has a 11.5" ID and a 12" OD. Which puts it squarely in between where it needs to be for the upper stage (at 11.818") and the engine skirt (12.273"). As pointed out in his build thread, these are not super critical in terms of precision, I at least want to try.

    Step one is to build it up for the engine skirt using a corrugated cardboard box from one of my many online orders. It's about 0.125" so should be good for my required OD. Then I'll peel the paper in the former layer by layer until I get a good thickness for the upper airframe. If I mess that part up, it's no big deal... I'll just spend another $9 on a new former and accept that it's slightly out of scale.

    So, on to part 1. The former itself isn't particularly round. To help it keep its shape, I made some centering rings that will have the added bonus of holding it on a PVC axle. I ordered a Jasper circle cutting jig for my router and this thing rocks! It will definitely help when making complex centering rings with tank holes later. Highly recommended for larger holes, although regular circle cutters are probably preferred for the smaller holes.

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    I then wrapped the cardboard around the former holding it in place using duct tape. Red Green made it look easier than it is. The engine skirt is only 6.3" long, so the part I have covered is plenty.

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    So that's where things sit right now. It's warm enough my epoxy pot life would only be a few minutes, so I won't be wrapping today. I'll spend the rest of the day cutting the material and making it ready for application, but I'll do the actual lay up some morning this week before heading to work when the temperatures are more favorable.

    And I should get my fin pieces tomorrow.
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  19. #19
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    looking forward to this build! I thought your idea of allowing some tabs on the fins for sanding purposes was a really good idea....I have never attempted a build as big as yours or Max Q's...and truthfully you guys are light years ahead of me..but I always feel I struggle with the fins on the 1b....as well as the transition that covers the gaps between the fuel tanks and the thrust structure. Looking awesome so far!

  20. #20
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    Thanks for the confidence, but don't pre-judge. This is my first attempt at a project like this. I'm learning almost all of this as I go along, which is after all the point of it all
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  21. #21
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    Quote Originally Posted by grandcross View Post
    So, on to part 1. The former itself isn't particularly round. To help it keep its shape, I made some centering rings that will have the added bonus of holding it on a PVC axle.
    Good idea. I've yet to see a sonotube that wasn't out of round, even if by a fraction of an inch. Some are downright elliptical.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  22. #22
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    Quote Originally Posted by MaxQ View Post
    Good idea. I've yet to see a sonotube that wasn't out of round, even if by a fraction of an inch. Some are downright elliptical.
    That has to do with how they are shipped, the tubes are shipped nested together laying horizontally in semi-trailer, stacked floor to ceiling. You would not believe how many SonoTubes a semi trailer can hold. Anyhow the horizontal position alone over time will cause "egging" and its compounded a little by the weight of the upper layers pressing down on the bottom ones, and by the bouncing of the trailer as it travels down the highways. Most of the smaller Sonotubes (less than 12") really don't get much weight on them but they are allowed a bit more movement inside the larger tubes. As they say "It's good enough who its for!" well the average person looking at a concrete column poured in a Sonotube form isn't going to notice the very slight egging, however us rocketeers who use them for something they were never intended for do!
    Rich

    NAR# 99154

    L3-4x upscale Estes Cherokee-D- AT M1297W 5/28/2016 http://www.rocketryforum.com/showthr...r-rharshberger

    TriCities Rocketeers NAR section# 736 http://www.tricitiesrocketeers.org/

  23. #23
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    And in todays news, I'd like to announce the arrival of 12 precision cut birch ply cores! Now the tedium can really begin...

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    I'm going to create one first to practice my techniques and perfect my jigs. I'll post some pics when I've made progress, but this is a work week so some patience is required. And then I'll have to do 11 more...
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  24. #24
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    Quote Originally Posted by grandcross View Post
    And in todays news, I'd like to announce the arrival of 12 precision cut birch ply cores! Now the tedium can really begin...

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    I'm going to create one first to practice my techniques and perfect my jigs. I'll post some pics when I've made progress, but this is a work week so some patience is required. And then I'll have to do 11 more...
    Who did the laser cutting for you?
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  25. #25
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    I didn't do much shopping around, so it's possible there are better deals elsewhere, but I got them done at www.pololu.com. Cutting and materials quoted at $58, but I got a rush service so I paid a little more. I've used them before for other non-laser cutting stuff and have been happy with their service.
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  26. #26
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    Quote Originally Posted by grandcross View Post
    I didn't do much shopping around, so it's possible there are better deals elsewhere, but I got them done at www.pololu.com. Cutting and materials quoted at $58, but I got a rush service so I paid a little more. I've used them before for other non-laser cutting stuff and have been happy with their service.
    I was curious of you used one of the RC airplane kit cutters that are out there.
    We got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who DREAM about getting the hot planes.
    Now what are you two pud-knockers gonna have?... Huh?
    Pancho Barnes-
    The Right Stuff
    http://www.mwavs.com/0053148414/M4RS...udknockers.m4r

    Tripoli #2747

  27. #27
    Join Date
    29th August 2015
    Location
    Pittsburgh
    Posts
    189
    Quote Originally Posted by MaxQ View Post
    I was curious of you used one of the RC airplane kit cutters that are out there.
    They do a lot of stuff with R/C modelers. Their focus is robotics, but that includes servos and electronics also used by plane makers. Also some electronics stuff that was useful for some other projects I'd worked on.
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  28. #28
    Join Date
    27th August 2011
    Location
    NJ
    Posts
    2,725
    those fins look very cool! I am liking your avatar too!!

  29. #29
    Join Date
    29th August 2015
    Location
    Pittsburgh
    Posts
    189
    Busy weekend! I know I said I'd build the fins first, but my 3D printer needs some love and attention before I can make my sanding jigs. Besides the weather was nice, so I decided to go ahead with the CF for the engine skirt.

    Since my CF wasn't long enough for a continuous roll, I did three strips. My plan was to use some scrap fiberglass for an outer "sand through" layer, but it came up just a bit short. D'oh!

    Click image for larger version. 

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    The peel ply I got comes in 60" widths cut to length. It's nice and smooth coming off the roll, so imagine how happy I was that they folded and creased it for me! This of course led to a predictable imperfection in an otherwise nice layup. Someone needs to tell their shipping department how this stuff is intended to be used. They'll be getting a nasty email from me later today.

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    I was a little worried about the final result. The former I used for the mandrel wasn't exactly round to begin with. The cardboard I'd used to build up the required circumference made it a little worse. I was seriously thinking I'd have to try again.

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    The good news is that the finished CF is a little more pliable than other materials would be. Using a very slightly larger centering ring closed the gaps and made it nicely round. Hooray! The final result is about 1/8" wider than intended, but I can live with that
    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

  30. #30
    Join Date
    29th August 2015
    Location
    Pittsburgh
    Posts
    189
    Since I was cutting centering rings to make the CF round anyways, I decided to continue. I cut three centering rings for the engine skit section. There will be one at the top of the section, one internally just behind the TTW fin tab, and one at the rear of the section.

    The first two have holes for all 8 tanks and the main blue tube motor mount. 3 1/8" is a little too small, but the next size up is too loose. So I stand by my signature line, and will sand these to fit. Very thankful that I have a dremel!

    Click image for larger version. 

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    The rear one is the base plate. It only has holes for the main motor and the four outboard motors. It will eventually have access panels to allow me to access the wiring for the cluster airstart electronics. A lot more on that later.

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    That's a lot of holes! Seriously love my new router hole cutter! I can't imagine trying this without it (or access to a laser cutter.) By the end, I had it down pat, but that was still a lot of time cutting holes.

    While I was there, I cut one more hole for a jig. This will allow me to trim my concrete former mandrel to the correct diameter for my upper airframe. I'll peel and sand back layers of paper, using this to ensure it's both round and the correct diameter.

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    What's next? Will I'll probably start by cutting the skirt to size. I still need to make the section that tapers into the tanks, and of course fix my 3D printer to create some sanding jigs for my fins. I have some work travel coming up, so the upper airframe will have to wait until I return.

    David Carter
    NAR 98850, TRA 16834, Level 3
    http://www.psc473.org/ http://urrg.us/

    90% of rocketry is sanding! (And a little bit of cursing...)

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