Pigasus build thread

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Mushtang

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The new kit from ODD'L ROCKETS, Pigasus, arrived on my doorstep earlier this week and I've finally gotten some time to start working on it. I'm doing this build thread because I'm a huge fan of ODD'L ROCKETS and I really hope I do a good job. HCMBanjo, aka Chris Michielssen, aka Hans Olo, might be watching and I don't want him to do a face palm and say, "Oh crap. I wish someone else was doing this."

Chris, feel free to comment with anything. Tips, corrections, alternate ways of doing things, etc. will be welcome.

Everyone else, feel free to do the same.

Pigasus 001.jpg

It's time to start makin some bacon.
 
Here is the required picture of all the parts. There's a few bags of misc rocket parts, instructions, a couple of sheets of balsa, decals, and one of the new parachutes from ODD'L ROCKETS that look like the ones used by NASA in the early days of the space program. Very cool stuff.

Pigasus 002.jpg

The first step is to put on the motor clip. So this will be the first place where I'll deviate slightly from the instructions, although I don't think HCMBanjo will mind too much. Over a year ago I bought a few packs of Extra Long Engine Hooks from ODD'L ROCKETS and have been using them on all kits since then.

To use these you need to have a 3" long engine tube, which this kit has, and a 1/4" engine block ring, which this kit did not have. The engine block was longer and I didn't have a 1/4" block ring to substitute. But I did have a tube that was used in a previous kit in place of an engine, so I could cut off a 1/4" piece and use that.

Pigasus 003.jpg

Using a coping saw it took about 5 minutes of slow cutting to get a good usable engine block ring.

Pigasus 004.jpg

In the picture below you can see the mark on the left where the engine hook would have gone into the engine tube, and on the right the mark where the Extra Long Engine Hook will go. The engine block will be glued BELOW the upper end of the engine hook and when the ejection charge goes off there will be more than just the wall of the engine tube for the hook to pull on.

Pigasus 005.jpg

Glue was spread inside the engine tube and the engine block pressed into place. An engine was used to push the engine block ring up against the engine clip and then removed. Glue was then added above the ring. You can see where the engine block tube is glued in, and the upper end of the engine hook is above the ring. A few layers of blue electrical tape was used to hold the engine hook in place against the engine tube.

Pigasus 006.jpg

This was set aside to dry.
 
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The upper centering ring has two cut outs, one for the engine clip, and another one opposite for a length of Kevlar. The Kevlar is tied around the engine tube below the upper centering ring and through the cut out, and will be used to tie onto the shock cord.

A ring of glue was put onto the tube and the centering ring was slid over the Kevlar and onto the tube, with the engine hook and Kevlar in their proper places.

Pigasus 007.jpg

Glue was spread around above and below the centering ring to hold the Kevlar in place and to hold the centering ring onto the tube.

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After the upper centering ring dried for a while the lower centering ring was glued into place.

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While the engine mount was drying I moved ahead. The pig snout is made by gluing a circle of thick card stock onto a short tube. The circle isn't laser cut, so it needs to be cleaned up some when the glue dries.

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After the glue dried you can see in the picture below where some of the circle extends beyond the tube a little.

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Using a hobby knife I trimmed the excess off, and then used some sandpaper to smooth the ring all the way around. When I was finished with this I added a fillet of glue along the inside of the tube to add strength to hold the ring on.

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The balsa nose cone has a large hollow hole in it for clay weight. A plywood disk is supplied along with a eye hook to plug the hole when the weight is added.

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The eyelet is screwed into the ring and glued in place.

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Here is the big hole in the bottom of the nose cone and the clay that is supplied for weight.

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I molded the clay in my hand for a few minutes to make it pliable and then flattened it on the table. I curled up the clay and slid it into the hole.

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Using the eraser end of a pencil I pressed the clay into the bottom of the hole.

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After the glue on the eyelet had dried I pushed it into the hole, recessing it about 1/16". A ring of glue was added to hold the plug into place.

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Before punching out the fins from the sheets of balsa, a watered down mixture of Carpenter's Wood Filler was painted on each side and set aside to dry. After drying I'll sand them smooth.

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A thick coat of watered down CWF was also painted onto the nose cone which was set inside the body tube for drying.

Pigasus 020.jpg
 
In a recent thread in the off topic section, LucasSpringsteen asked about filling tube spirals. Many methods were discussed but I mentioned how I use primer to do it. This is a method that HCMBanjo mentioned in his blog (I think) at one point, which was a method that George Gassaway came up with. I may or may not be doing this the way George does it, but it's worked VERY well for me and I no longer fill spirals with CWF.

First I make sure I can see the spirals. The spiral that is easiest to see doesn't need to be filled. The other spiral which does need filling is nearly invisible, so I used a pencil to make it show up by drawing on it lightly. Here's the spiral with the pencil mark halfway around.

Pigasus 021.jpg

I used some blue painters tape to mask off about 1/16" on each side of the spiral. This doesn't need to be a super accurate job, and certainly doesn't need to be done with expensive Tamiya tape. The point here is to avoid sanding off as much primer as you can. It's possible to do this without the tape (I've done it a couple of times) but much easier with. Putting tape onto the tube took about 3 minutes.

Pigasus 022.jpg

The primer I like to use best for this is Rust-Oleum 2-in-1 Filler & Sandable. This goes on fairly thick so it fills the gap well, and sands easily when dry.

Pigasus 023.jpg

I sprayed the primer into the spiral VERY close to the tube. Maybe an inch or so away from the surface. This is a lot closer than you'd normally spray primer or paint onto something because you don't want it to drip. But to do this it doesn't really matter. The thicker the better. Because I'm spraying so close I can only get short lengths painted on each pass, so it takes a few minutes to go round and round. It dries fast enough that once I get all the way down the tube I start over and can get two coats on. You can see how far to each side of the spiral the primer has gotten. Not very far at all. This shows you how close I was to the tube when spraying.


Pigasus 024.jpg

About 5 minutes later I took off the tape and the result is a very thick spiral of primer filling the tube spiral. When this fully dries I'll sand it smooth. You can see that there's really not a lot of primer to take off because of the masking. You can also see that I had some runs under the tape, but that's okay. It took about 3 minutes to put the tape on, but that will save about 10 or 15 minutes of sanding.

Pigasus 025.jpg

After I sand the spiral I can spray another coat of primer on the entire tube. After sanding most of that coat off the tube should be really smooth with no spiral, and ready for gluing on fins.
 
Boy, you've been busy!
Great work so far.

With Semroc going away and not doing any custom work, I had to cut the nose cap pieces by hand.
BMS had cut some for me but they were black! Not Bill's fault, I didn't specify what color and thought they'd be white.
I couldn't see anybody getting a good pink color spraying over on that black nose cap piece.

I'll be following this one! Thanks Mushtang.
 
Before gluing the engine mount in place I did a test fit with an engine. I had quite a bit of trouble getting the engine out because the hook wouldn't move far enough out of the way. Knowing that it would be even more difficult with the mount inside the tube I decided to cut the hook slot a little longer. This made a huge difference. I don't think it'll be difficult at all now.

Pigasus 026.jpg
 
Time to sand. You can see in this picture that I'm about halfway done sanding off the primer I sprayed into the seam.

Pigasus 027.jpg

When finished, the seam is filled and rubbing a thumbnail down the tube the seam is as smooth as the rest of the tube, and it's VERY hard to tell where the seam is without looking.

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I sanded the nosecone first with 180 grit, and then with 400 grit. When I was finished it was as smooth as an android's bottom.

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The sheets of balsa were taken to my workbench and a palm sander was used on them. When finished, they too were super smooth!

Pigasus 030.jpg
 
To get the grain filled on the fins I showed how I painted the balsa sheets with a watered down mix of CWF and sanded them smooth when dried. A drawback to this is that the CWF gets into the laser cut groove and fills it in, making fin separation more than a little tricky.

Usually the fins can still pop right out, but this time I had some trouble with the very first fin I tried to remove. One of the feathers on a fin broke off at the wrong place and remained behind in the balsa scrap. I pulled it out so that I could glue it back on. Using the double glue method the feather was soon back to where it should be.

Pigasus 031.jpgPigasus 032.jpg

For the rest of the fins I was much more careful. I used a hobby knife to cut the balsa out slowly and I didn't have any more broken fins.

After they were all out I used some sandpaper to get in between the feathers and remove any additional CWF that needed to go. I'll finish sanding the edges of all the fins as I put them on. One side of each of these wing fins will get papered with the feather design, so that should add a lot of additional strength to them.
 
Four sets of fins come in two pieces that need to be glued together. This can be tricky since the edges of fin sections don't always line up well. The way I made it work was to place the pieces that go together flat on the table in the correct positions, and then rotate them up as though I'm folding them at the seam. This leaves the edges that glue together next to each other facing down.


Pigasus 033.jpg

Then I lay some sandpaper flat on the table and sand the fins together at the same time. You still need to be careful when doing this to sand them as evenly and as flat as possible.

Pigasus 034.jpg

When all the fins pieces were sanded on their joining edges I used the double glue method to glue them together. Here's all the pieces with the first coat of glue drying.

Pigasus 035.jpg

Once they were all glued together I put them in between two cookbooks and stacked a lot of other books on top of them. This should hold the fins in place while they dry and keep them flat. In the picture below the fins are in between the bottom two books.

Pigasus 036.jpg

The reason I like to use cookbooks is that they're normally covered with a waxy coating to keep food from sticking to them. This makes it easy to avoid gluing stuff to the book covers. They're also fairly heavy.
 
After covering the body tube with a solid coat of primer I failed to get a picture, but here's one of the tube after I'd sanded almost all the primer off again. I started with 180 grit and after it looked like the picture below I moved to 400 grit to make it super smooth.

Pigasus 037.jpg

The pig ears need to be sanded at an angle. The instructions show how to wrap sandpaper around the body tube and sand the base sort of like this. I think I sanded it with the end a bit lower, but I was trying to take a picture for this thread and show sort of how I did it.

Pigasus 038.jpg

Here's one of the ears before sanding and the other after.

Pigasus 039.jpg

They look like they'll fit correctly now.

Pigasus 040.jpg
 
The glue on the inside of the snout was dry so it was time to glue it to the end of the nosecone. I put some glue on the edge of the tube, and then a thick band along the inside so it would run down and put an inside fillet for strength.

Pigasus 041.jpg

With the nosecone in the tube for support I set the snout on top and got it as level as I could, and left it to dry.

Pigasus 042.jpg
 
The next thing I did was to glue the ears onto the head. After sanding them they fit snug but the instructions aren't crystal clear on where to mount them. It's probably because it doesn't matter if each rocket looks slightly different. It shows how far from the back of the nosecone to put the front tip of the ear, and suggests to turn them slightly as show. In the pic below I'm dry fitting the left ear, and the right ear is laying on the table. I made a small pencil mark up from the nose cone shoulder at the correct distance. The distance between the ears isn't specified at all. I had to look at the picture on the front of the instructions to get an idea of where to put them. The goggles sitting in front of the ears gave me a bit of a reference, so I measured the goggle print out and decided that the tips of the ears should be 1" apart. Your ears may vary.

Pigasus 043.jpg

Another pencil mark was made approximately 1" off to the side of the first one. The front edge of each ear will be glued on the pencil marks.

Pigasus 044.jpg

The ears were glued on, and after the glue dried I put some small fillets all around for strength.

Pigasus 045.jpg
 
Now that the fins had set up I needed to mark fin locations on the tube. A fin marking guide in the instructions was used. Normally I hate using these kinds of marking guides as they give me fits, but since the fin locations on this kit aren't the normal 90 or 120 degrees apart, I had no choice. It worked out okay.

Pigasus 046.jpg

An aluminum angle was used to extend the lines up the tube.

Pigasus 047.jpg

The wing fins had to be sanded at an angle so they'd be able to be glued to the body at the right angle, which according to the instructions is about 40 degrees. The picture below shows me sanding that root edge at what I estimated to be the correct angle. After that I sanded the rest of the fin all the way around to remove the laser cutting burn marks.

Pigasus 048.jpg

A couple of stacks of pennies were used to let the wing fin sit level while the glue dried. The double glue method was utilized to get the fins in place.

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I let the fin set up before trying the second one.

Pigasus 050.jpg

When I got both fins on they didn't look like the instructions, apparently I'd sanded the wrong angle on the root edge of the wing fins. They're supposed to be parallel and mine diverge a bit. Hopefully this won't keep it from flying well.

Pigasus 051.jpg

Chris, any clues on how bad this might be?
 
After the wing fins were mostly dried I realized I still haven't glued the motor mount into the body tube. Oops. I meant to do this before I started gluing the fins in place.

First I dry fitted the mount into the tube. I used the centering ring to draw a circle at the correct depth in the tube. This would show me where to put glue.

Pigasus 052.jpg

The mount was pulled partway out and glue was poured in the tube around the pencil line. If I did this with the mount completely out most of the glue would be pushed away by the upper centering ring, and ther wouldn't be enough to completely glue the lower ring in place.

Pigasus 053.jpg

The mount was slid into place. When the tube was set upright the glue would run slightly to give a good fillet on the lower centering ring. More will be added under the ring when the glue above the ring has had time to dry.

Pigasus 054.jpg

Glue was also added to the upper centering ring around the outside edge.

Pigasus 055.jpg

The tube was set upright while the glue dries.
 
When I got both fins on they didn't look like the instructions, apparently I'd sanded the wrong angle on the root edge of the wing fins. They're supposed to be parallel and mine diverge a bit. Hopefully this won't keep it from flying well.

View attachment 167573

Chris, any clues on how bad this might be?

It'll be great! I've built and flown a few prototypes, one had wings glued on without a sanded angle.
It flew fine. I just preferred the look of the fins being straight up.
 
After looking at the ears and nose, I decided that I'd like to fill in where they meet the head with some CWF to try and make a smoother looking transition. The plan is to cake on some CWF with the hobby knife blade and then tomorrow when it's dry sand it down to a fillet. White glue might have worked but this seems to work better for me.

The ears after putting the fill on.

Pigasus 056.jpg

You can see the harsh corner where the snout is glued to the nose cone on the bottom. Hopefully this will make it look more like one piece.

Pigasus 057.jpg
 
After looking at the ears and nose, I decided that I'd like to fill in where they meet the head with some CWF to try and make a smoother looking transition. The plan is to cake on some CWF with the hobby knife blade and then tomorrow when it's dry sand it down to a fillet. White glue might have worked but this seems to work better for me.
The ears after putting the fill on.

View attachment 167682

You can see the harsh corner where the snout is glued to the nose cone on the bottom. Hopefully this will make it look more like one piece.

View attachment 167683

I just used some Titebond M&TG on the ear joints. Both filler and Titebond will be fine.
On the nose cone, I found that pressing and twisting the open tube edge against the balsa nose cone makes a slight indent line.
You just have to make sure the nose is set straight before twisting in the round ridge.

It looks great so far Joe! Thanks.
I'll be curious to see what you think of the new parachutes.
 
While the CWF dried I looked ahead and decided to glue up the goggles. The instructions say there are two copies of these so you can use one for practice, but I only had one copy in my kit.

First I had to cut out the square around the goggle print.

Pigasus 058.jpg

I folded the square back to glue it so that it will be double thickness.

Pigasus 059.jpg

After putting on a little bit of glue, I spread it around with my finger and let it sit to dry for a couple of minutes to get super tacky. The glue was on the non-printed side just in case it was too much or caused the paper to warp.

Pigasus 060.jpg

After a few minutes I folded it all the way in half and out came the cookbooks. I'll leave them there until tomorrow. I'm sure it won't take that long to set up, but I won't be doing anything else until then and it won't hurt anything either.

Pigasus 036.jpg
 
I found that pressing and twisting the open tube edge against the balsa nose cone makes a slight indent line.

Ahh, I can see how that would definitely work well too. Balsa is soft enough to be able to deform it a bit. I wish I'd thought of that. If I'd done that I'm sure a regular glue fillet would have been enough.
 
The next step is to glue on the leg fins and the razor back. But before I did that I had to sand all around them to remove the laser cut burns. You can see on this picture what they look like before and after the sanding. If I didn't sand them off it would look really bad when painted.

Pigasus 061.jpg

I did this for both legs and for the razor back (above). Where the two pieces of the legs are glued together there was a little bump where the pieces weren't put together exactly flush. Sanding all the edges also makes this go away and both ends of the seam are now perfectly flush. I also rounded over what will be the leading edge of the fins.

Pigasus 062.jpg

The double glue method was used to attach the razor back and the fins.

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Here they are drying. After about a half hour I put a round of glue fillets on all the fins.

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The launch lug was glued next to one of the legs. I hate when I forget to glue on a launch lug and then notice it after the paint is finished. Luckily I didn't miss it this time.

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The goggles were brought out from the cookbooks and cut out using a straight edge and hobby knife on the straight lines, and scissors on the curves.

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This is the best I could do. These will be put aside until after all the paint is finished.

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Whenever I would test fit the nose cone into the body tube it was a very tight fit. So tight that I wouldn't be 100% confident that the ejection would work. So I took a strip of 120 grit sandpaper to the section that slides into the tube and sanded away.

The most important thing to remember here is, you can take away a lot easier than you can put back. I sanded slowly, and test fitted a lot. Sand a little, test, sand a little, test, sand a little, test, etc. At one point it felt snug but was a lot better than when it started, so I stopped sanding. It was good enough.

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Here's the Pigasus all put together and ready for some finishing.

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The wings get paper glued onto one side after it's painted, so this isn't really the same thing as papering the fins. I'm sure it'll add a little strength, but the main purpose seems to be the graphics and not the strength. If these fins were papered there would be a layer of paper glued to the fins before the primer was sprayed on.

Looking back, it might have been a good idea to paper the legs because of the joint between the two leg pieces.

These wing graphics have a lot of curves and interior cuts, so it's very tricky to stay on the lines when cutting them out.

Pigasus 070.jpg

I don't have as much experience cutting this type of graphic as some of the paper modelers on here, but I think I did okay. Using mostly scissors, but a hobby knife some too, I cut them out.

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I'll let other folks chime in here on the best way to cut curves, right vs left, with scissors.

After I was finished I did a test fit onto the wings and it's not a perfect fit. Some alterations will need to be made when I'm ready to glue them on.

Chris, the instructions say to use spray adhesive. Is there a reason not to use a very thin coat of white glue instead? I have a few days before I get to the point where I need to buy some adhesive if it's necessary.
 
Now the pig is ready for primer. I have a spent engine casing that I use slid over the end of a dowel for painting. The rocket slides onto the engine and is held firmly in place and makes a great tool for this. This is a tip I learned from Luke Strawwalker over a year ago and have used it on numerous rockets. Thanks Jeff!

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My primer can ran empty right as I was finished coating this. How often does that happen? I'll still need more for the next coat after I sand this one down.

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The legs and wings are made up of two pieces of balsa butted up and glued. At the seam there was a groove that I'd thought was smooth but when I painted it with primer I could see that it wasn't. If I could go back I would have primered and sanded these fins before gluing them on to make the seam removal easier. There's going to be a LOT of sanding on these and I'll be very surprised if I don't break at least one off before I'm done.

After the main coat was sprayed on the entire rocket I came back and did a very close shot of primer right along the seams to try and fill them in better. I'll sand them off and see how well it worked. This might require a few layers of closely sprayed primer to make it go away. Maybe even some more CWF. I'll have to see how it looks after I sand this off.

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