Zooch Saturn 1B with Racer's Artwork

Was disappointed with how my tank assembly on the Zooch Saturn 1B turned out. In hind sight, I cut the spider beams too wide, and the tanks were lifted a small distance from the motor tube. This resulted in some compression of the tanks by the BT-60 tubes (on either end). Even worse, the pressure of the tank tubes distorted the walls of the thrust structure tube, so it was no longer round.

Instead of continuing the rocket to completion, I decided to rip apart the tank assembly (to retrieve the engine hook) and start again. I needed new artwork, so I printed out revision 5 of Rosco Racer's Saturn 1B artwork, provided in another thread.

However, I see a problem. The following picture shows one of the Zooch tanks (after I ripped it off of my ill-fated tank assembly) next to the freshly rolled tank composed from Racer's artwork. It looks like the new tank doesn't take into account the near 3/8” that will need to disappear behind the lower BT-60. It seems that the artwork on the bottom of the tank will become partially covered by the tank fairings.

Advice from anyone that built a Zooch Saturn 1B using these wraps is much appreciated.

Himitsu....I think you are correct...that is not going to work. The numbers are going to be hidden by the thrust structure. Last year I made a Zooch 1b but I did not use the Rosco tanks primarily because I didn't like the way I rolled them. Do you have any copies of the Zooch tanks? (I always make copies of the tanks and wraps just in case) If not maybe you can reach out to Dr. Zooch and see if he can help you out.

himitsu said:

Was disappointed with how my tank assembly on the Zooch Saturn 1B turned out. In hind sight, I cut the spider beams too wide, and the tanks were lifted a small distance from the motor tube. This resulted in some compression of the tanks by the BT-60 tubes (on either end). Even worse, the pressure of the tank tubes distorted the walls of the thrust structure tube, so it was no longer round.

Instead of continuing the rocket to completion, I decided to rip apart the tank assembly (to retrieve the engine hook) and start again. I needed new artwork, so I printed out revision 5 of Rosco Racer's Saturn 1B artwork, provided in another thread.

However, I see a problem. The following picture shows one of the Zooch tanks (after I ripped it off of my ill-fated tank assembly) next to the freshly rolled tank composed from Racer's artwork. It looks like the new tank doesn't take into account the near 3/8” that will need to disappear behind the lower BT-60. It seems that the artwork on the bottom of the tank will become partially covered by the tank fairings.

Advice from anyone that built a Zooch Saturn 1B using these wraps is much appreciated.

View attachment 155346

Click to expand...

NJRick said:

Himitsu....I think you are correct...that is not going to work. The numbers are going to be hidden by the thrust structure. Last year I made a Zooch 1b but I did not use the Rosco tanks primarily because I didn't like the way I rolled them. Do you have any copies of the Zooch tanks? (I always make copies of the tanks and wraps just in case) If not maybe you can reach out to Dr. Zooch and see if he can help you out.

Click to expand...

Thanks for the confirmation. Unfortunately, I didn't make copies of the Zooch tanks, so... I decided to create some replacement artwork in InkScape (just the tanks). The new tank is on the right.

looks like a fix to me!! nice job!

himitsu said:

Thanks for the confirmation. Unfortunately, I didn't make copies of the Zooch tanks, so... I decided to create some replacement artwork in InkScape (just the tanks). The new tank is on the right.

View attachment 155393

Click to expand...

Nice save!

himitsu said:

Thanks for the confirmation. Unfortunately, I didn't make copies of the Zooch tanks, so... I decided to create some replacement artwork in InkScape (just the tanks). The new tank is on the right.

View attachment 155393

Click to expand...

Owen Eldridge said:

Nice save!

Click to expand...

NJRick said:

looks like a fix to me!! nice job!

Click to expand...

Much appreciated!

Himitsu....can't wait to see pictures of your Zooch 1b. Looks like you saved the program with your new tanks! something about the Saturn 1b...just a cool looking rocket!



just for inspiration..thought I would attach a picture of Apollo 7 in flight....just spectacular!

himitsu said:

Much appreciated!

Click to expand...

NJRick said:

Himitsu....can't wait to see pictures of your Zooch 1b. Looks like you saved the program with your new tanks! something about the Saturn 1b...just a cool looking rocket!

View attachment 155670

just for inspiration..thought I would attach a picture of Apollo 7 in flight....just spectacular!

Click to expand...

Thanks for the inspiration! The Saturn 1B is one of my favorites, too. In fact, I own three Saturn 1B kits produced by: Zooch, Apogee, and Semroc. That is the order I intend to build them. I'll build the Apogee to specification with its 29mm motor mount, but the Semroc needs something better than four 18mm mounts or one 24mm mount. I'll do the Semroc last, but I'll modify its motor configuration somewhat.

This Zooch 1B will take some time. My primary goal is to finish my King Kraken for an L1 certification. Also, the holidays and the weather will slow things down, and of course, I've seen your work (and the work of others), so I can't exactly throw this one together, or the quality will not achieve the standards set by TRF. I'll provide progress pictures when they become available. For starters, here are my completed tanks (did them some days ago) printed on 80# bright white cover stock (card stock) and with the appropriate grain orientation.

Since I lost my original motor tube, I had to make new one from the scraps bin. However, I did not construct this motor tube as indicated in the instructions.



For one thing, the engine retention clip now exists on a spider beam line, and gone is the masking tape. I've replaced the tape with a couple of loops of 100# kevlar. Epoxy converts this kevlar loop into a strong composite. Nothing should prevent the tanks from contacting the central motor tube (I'll notch the tanks to accommodate the kevlar loop).



I split (and reconnected) the motor tube 1/2" above the engine retention clip. Underneath sits a 1" long BT-20 tube coupler. It doubles as both a thrust ring and as a measure against the hibachi effect.



How did I keep the springy engine clip against the motor tube long enough for the epoxy to set? I temporarily used a BT-20 to BT-50 centering ring as a clamp. I cut out a shallow (important) notch to accommodate the engine clip.

I couldn't salvage the four BT-20 to BT-60 centering rings from the original motor mount, and I only have replacement CR2060s composed of lite ply. I think that lite ply centering rings weigh a bit more than CRs made of fiberboard, so I opted to make them anew from (homemade) 3/32" 3-ply balsa plywood.

I decided to cut the new centering rings on this.



So I drew up some artwork in CorelDraw.



Then I created the tool paths using Cut2D.



Unfortunately, I haven't used my Zen Toolworks 7x7 CNC machine since 2010, and I lost the chuck key. I have a replacement on order. As soon as it comes in, I'll cut.

Edit: Found that my drawing was wrong: the slot for the engine hook needed to sit against the BT-20 (motor mount) opening and not the outside wall of the CR. Corrected the drawing and regenerated the CAM file for the final cut of the centering rings.

your tanks looks fantastic!
sounds like you are going to be busy with some builds!

himitsu said:

Thanks for the inspiration! The Saturn 1B is one of my favorites, too. In fact, I own three Saturn 1B kits produced by: Zooch, Apogee, and Semroc. That is the order I intend to build them. I'll build the Apogee to specification with its 29mm motor mount, but the Semroc needs something better than four 18mm mounts or one 24mm mount. I'll do the Semroc last, but I'll modify its motor configuration somewhat.

This Zooch 1B will take some time. My primary goal is to finish my King Kraken for an L1 certification. Also, the holidays and the weather will slow things down, and of coarse, I've seen your work (and the work of others), so I can't exactly throw this one together, or the quality will not achieve the standards set by TRF. I'll provide progress pictures when they become available. For starters, here are my completed tanks (did them some days ago) printed on 80# bright white cover stock (card stock) and with the appropriate grain orientation.

View attachment 155802

Click to expand...

Wow!! you are already several orders of magnitude over anything that I could do.
this is going to be fun to watch!

himitsu said:

I couldn't salvage the four BT-20 to BT-60 centering rings from the original motor mount, and I only have replacement CR2060s composed of lite ply. I think that lite ply centering rings weigh a bit more than CRs made of fiberboard, so I opted to make them anew from (homemade) 3/32” 3-ply balsa plywood.

I decided to cut the new centering rings on this.

View attachment 155823

So I drew up some artwork in CorelDraw.

View attachment 155824

Then I created the tool paths using Cut2D.

View attachment 155825

Unfortunately, I haven't used my Zen Toolworks 7x7 CNC machine since 2010, and I lost the chuck key. I have a replacement on order. As soon as it comes in, I'll cut.

Click to expand...

NJRick said:

your tanks looks fantastic!
sounds like you are going to be busy with some builds!

Click to expand...

Printing the tanks with respect to the grain orientation of the paper and using steam were the keys. Both of these tricks I learned on TRF. Honestly, it was your "old" Dr. Zooch Saturn 1B Build Thread that revealed the steam trick (which you credited to hcmbanjo aka Chris Michaelson). So, thank you for that!

NJRick said:

Wow!! you are already several orders of magnitude over anything that I could do.
this is going to be fun to watch!

Click to expand...

CNC is fun, and a hobby in its own right. However, I'll only really get to use it to recreate the lost centering rings. After this, I still have all the remaining ant-manufactured parts from the kit. I think the real challenge is going to be that escape tower, and the machine is no help, here. Well, maybe it could help. I suppose I could use the machine to carve an escape tower mold into a material like delrin plastic (I have some). Could embed some carbon fiber filaments, and cast the part out of resin. Or, I could cut the escape tower impression into wood (or plastic), and use it as a fixture to hold plastic rods or metal wire in place for gluing. We'll see. I really haven't decided how to tackle that challenge.

Himitsu...sounds like your LES will be better than the original! building the LES as Dr. Zooch has designed it isn't really all that hard...with mine, I just replaced the metal wire provided with some .20 plastic rods. I have another Zooch 1b ASTP on order. I am going to take another shot with the kit.

I look forward to your build as I am sure I will be learning new things as you go along! Also curious to see your other 1b builds with the Apogee and Semroc kits. I confess, I love the Saturn 1b....I just think it is a cool looking beast.

himitsu said:

Printing the tanks with respect to the grain orientation of the paper and using steam were the keys. Both of these tricks I learned on TRF. Honestly, it was your "old" Dr. Zooch Saturn 1B Build Thread that revealed the steam trick (which you credited to hcmbanjo aka Chris Michaelson). So, thank you for that!



CNC is fun, and a hobby in its own right. However, I'll only really get to use it to recreate the lost centering rings. After this, I still have all the remaining ant-manufactured parts from the kit. I think the real challenge is going to be that escape tower, and the machine is no help, here. Well, maybe it could help. I suppose I could use the machine to carve an escape tower mold into a material like delrin plastic (I have some). Could embed some carbon fiber filaments, and cast the part out of resin. Or, I could cut the escape tower impression into wood (or plastic), and use it as a fixture to hold plastic rods or metal wire in place for gluing. We'll see. I really haven't decided how to tackle that challenge.

Click to expand...

This is making me want to build another Dr Zooch Saturn!

I ordered a Zooch Saturn 1b ASTP and it is in the mail now!!

Are you going to do a build thread?

NJRick said:

I ordered a Zooch Saturn 1b ASTP and it is in the mail now!!

Click to expand...

NJRick said:

Also curious to see your other 1b builds with the Apogee and Semroc kits...

Click to expand...

Well, I might do a build thread on them (but it'll be some time).

Owen Eldridge said:

This is making me want to build another Dr Zooch Saturn!

Click to expand...

I think, Dr. Zooch would probably agree, and advise you to give in to that impulse!

himitsu said:

I think, Dr. Zooch would probably agree, and advise you to give in to that impulse!

Click to expand...

A word of caution here- it looks as if your engine mount is a bit of a heavy weight. All of my Saturns are very CG sensitive and heavier materials can cause an aft CG shift and instability- so use care.

Also, whenever someone froggs up a build, they can always contact me and I'll be happy to send replacement parts at little or no cost, the exception usually being the balsa parts (nosecones and adapter).

Hello Dr. Zooch (W. Oleszewski). I really enjoy your kits!

Dr.Zooch said:

A word of caution here- it looks as if your engine mount is a bit of a heavy weight. All of my Saturns are very CG sensitive and heavier materials can cause an aft CG shift and instability- so use care.

Click to expand...

I agree. The current motor mount (without the centering rings) is without a doubt heavier than the canonical form. However, the current assembly (without the centering rings) weighs 5g. I can't imagine that my changes added any more than 2g (1g really), and I'm going to make up for this extra heft with some ultra light centering rings.

The first picture shows a fiberboard CR5060 (I didn't have any fiberboard CR2060s) on a precision scale. A real CR2060 would actually weigh about 1g. The second picture shows the replacement CR2060, cut from balsa plywood, weighing just a paltry 0.35g. So, I'll make up over 2g (easily) just on the new centering rings (four of 'em).



Nonetheless, I'll be sure to check the CG/CP relationship before I fly it. I think I can download the relevant RockSim file from the Apogee website, yes?

Dr.Zooch said:

Also, whenever someone froggs up a build, they can always contact me and I'll be happy to send replacement parts at little or no cost, the exception usually being the balsa parts (nosecones and adapter).

Click to expand...

Thank you for that. I may take advantage of this should I run into additional trouble. I also have yet to build your Saturn V, Mercury Redstone, and Soyuz. They're still sitting in their boxes.

EDIT: I just realized that I do have a fiberboard CR2060, in my Zooch Saturn V kit (and this one weighed in at 1g exactly)!

The replacement chuck key finally arrived. I cut the rings and noticed a problem. My CR design had the retention clip notch placed incorrectly. The notch should "face" the BT-20, and not the BT-60. I reworked the CAD file, regenerated the CAM file, and cut a second time with acceptable results.

Attached the four centering rings to the motor tube, one at a time. To align a ring, I rested the assembly in an aluminum channel (a piece of angle "iron") and placed a BT-60 tube coupler against it (the ring) until the adhesive cured (I think this is easier than making adjustments by hand, and confirming alignment by rolling the assembly on a surface).



I blackened the surfaces adjacent to the tanks using a Sharpie. Although painting the whole motor tube assembly does look really good, it also adds some unnecessary weight (plus, right now, it's too cold to paint anything outside). However, the ink put down by a Sharpie will come up if virtually any liquid comes in contact with it, and that could turn into a mess. So after the ink fully dried, I sealed it with water thin CA.

looks good himitsu!

himitsu said:

Attached the four centering rings to the motor tube, one at a time. To align a ring, I rested the assembly in an aluminum channel (a piece of angle "iron") and placed a BT-60 tube coupler against it (the ring) until the adhesive cured (I think this is easier than making adjustments by hand, and confirming alignment by rolling the assembly on a surface).

View attachment 156078

I blackened the surfaces adjacent to the tanks using a Sharpie. Although painting the whole motor tube assembly does look really good, it also adds some unnecessary weight (plus, right now, it's too cold to paint anything outside). However, the ink put down by a Sharpie will come up if virtually any liquid comes in contact with it, and that could turn into a mess. So after the ink fully dried, I sealed it with water thin CA.

View attachment 156079

Click to expand...

NJRick said:

looks good himitsu!

Click to expand...

Thanks!

Cut the spider beams with a balsa stripper.



Then, glued them in place using Titebond, excepting for the spider beam located on top of the engine hook. That particular beam was glued down using epoxy on the portion over the engine hook, and Titebond for the rest of it.



This assembly departs from the instructions in a couple of ways. Firstly, the spider beams are a bit shorter: they stop just before the kevlar engine-hook retainer. Secondly, I moved the location of the engine hook, and placed it under a spider beam, instead of under a tank. I think this new location brings a few advantages:

1. The engine hook no longer "pressures" a tank (all tanks can now sit directly against the core motor tube).
2. The portion of the engine hook that needs to flex now occupies a gap between two of the tanks, instead of directly under a tank.
3. The placement of the engine hook looks better underneath. If we try to follow the engine placement of an actual Saturn 1B, an H-1 engine should exist exactly between two tanks. Now, the engine hook sits exactly between two tanks. This might seem to interfere, but we're only going to model four of the eight H-1 engines, so the engine hook can now appear equidistant between two of the H-1 engines, and give the bottom of the rocket a little more symmetry.

Cut notches into the back of the tanks to accommodate the kevlar strap used to hold down the engine hook.



Attached each tank in place using Elmer's Glue-All. Glued each tank directly to the motor tube at three places: top, middle, and bottom. Made 3/4" long glue lines (a lot of glue is not needed).



Here, the order of assembly differs somewhat from the instructions. Normally, one following the instructions would have installed the lower BT-60 of the thrust structure, before installing the tanks. However, if I did this first (installed the lower BT-60), I would have had to cut larger notches (each notch would need to extend to the end of the tank tube) in order to get each tank to slide over the kevlar strap (note: the kevlar strap is not a feature of a by-the-book Zooch Saturn 1B build).

Because the engine hook now takes the spot of an H-1 engine (between two tanks), it was important to make sure that the tank on the right was white (to match up with the real Apollo 7 Saturn 1B).

Edit: made a mistake, here. The white tank should be to the left of the engine hook. See post #33.

looks good Mimitsu....that is a good idea on gluing the tanks in...I have had some trouble with my 1bs where some of the tanks rotate a bit while handling the stage...it can be tough to keep the lettered tanks in the proper position...the lettering tends to rotate into the spider beams.

looks great so far!!

himitsu said:

Cut notches into the back of the tanks to accommodate the kevlar strap used to hold down the engine hook.

View attachment 156170View attachment 156171

Attached each tank in place using Elmer's Glue-All. Glued each tank directly to the motor tube at three places: top, middle, and bottom. Made 3/4" long glue lines (a lot of glue is not needed).

View attachment 156172

Here, the order of assembly differs somewhat from the instructions. Normally, one following the instructions would have installed the lower BT-60 of the thrust structure, before installing the tanks. However, if I did this first (installed the lower BT-60), I would have had to cut larger notches (each notch would need to extend to the end of the tank tube) in order to get each tank to slide over the kevlar strap (note: the kevlar strap is not a feature of a by-the-book Zooch Saturn 1B build).

Because the engine hook now takes the spot of an H-1 engine (between two tanks), it was important to make sure that the tank on the right was white (to match up with the real Apollo 7 Saturn 1B).

Click to expand...

NJRick said:

...that is a good idea on gluing the tanks in...I have had some trouble with my 1bs where some of the tanks rotate a bit while handling the stage...it can be tough to keep the lettered tanks in the proper position...the lettering tends to rotate into the spider beams.

looks great so far!!

Click to expand...

I didn't think of that, but I remember the same thing happened when I put together the tank assembly the first time. Apparently the seam in the back makes the tank "uncomfortable", and so it rolls to the side, like an egg rolling off of its narrow end. I actually glued the tanks for another reason, because I had to attach them before I installed the lower BT-60; otherwise, getting past the kevlar loop would turn into a problem.

BTW, slid on the lower BT-60 of the thrust structure without any struggle. I'm now to the point I was before I created this thread, but this time I'm happy with the tank assembly. The tanks either just make contact with the BT-60, or apply a negligible amount of pressure. Nothing looks distorted from any angle. Here it is (well, just one angle, but the others look good too).

I think everyone has a balsa stripper but me...

himitsu said:

Cut the spider beams with a balsa stripper.

View attachment 156119

Then, glued them in place using Titebond, excepting for the spider beam located on top of the engine hook. That particular beam was glued down using epoxy on the portion over the engine hook, and Titebond for the rest of it.

View attachment 156120

This assembly departs from the instructions in a couple of ways. Firstly, the spider beams are a bit shorter: they stop just before the kevlar engine-hook retainer. Secondly, I moved the location of the engine hook, and placed it under a spider beam, instead of under a tank. I think this new location brings a few advantages:

1. The engine hook no longer "pressures" a tank (all tanks can now sit directly against the core motor tube).
2. The portion of the engine hook that needs to flex now occupies a gap between two of the tanks, instead of directly under a tank.
3. The placement of the engine hook looks better underneath. If we try to follow the engine placement of an actual Saturn 1B, an H-1 engine should exist exactly between two tanks. Now, the engine hook sits exactly between two tanks. This might seem to interfere, but we're only going to model four of the eight H-1 engines, so the engine hook can now appear equidistant between two of the H-1 engines, and give the bottom of the rocket a little more symmetry.

Click to expand...