Dr. Zooch Saturn I Blk II SA-6 to SA-10

[illini]

Received my Dr. Zooch Saturns (also purchased a Saturn IB) from Rebar today. Haven't started building much yet, just been going over the instructions and staring at the parts. So this post is just to give you my "first look" impression. I'll try to post more on building details later.

First, the kit is packaged in a heavy rectangular 12 x 4 x 4 box. The shipping demons would really have to stomp on this sucker for you to experience any shipping damage. All parts arrived neatly packaged in the box and in good shape. The first things you notice when you open the box are the two large rolls of paper. One of these is the instructions, the other is the set of wraps and pre-printed card-stock fuel tank tubes.

The instructions are 11 full size and well illustrated pages (last page provides some historical background). None of the steps appears to be particularly complicated, although this is clearly a builder's kit. Each step requires a certain minimum level of skill, but nothing a reasonably experienced modeler can't handle. The instructions are laced with loads of Dr. Zooch oddball humor with lines such as, "Use a semi-soft surface, such as a rubber mat or the skull of one of those folks who believes Apollo was faked..." (see "The Moon" thread in The Coffee House for further details).

I've noticed a couple of oversights that I hope will be corrected in the instructions in the future:

1) Step 2 calls for painting a number of parts white. A missed comma in the list of parts to be painted confuses the issue a bit. It reads "...spacecraft tube S-IV tube...", which sounds like one part, when it should read "...spacecraft tube, S-IV tube..." - two separate parts.

2) Step 2 also tells you to paint the spacecraft tube and balsa transition section white. Only later, in step 10, are you told that the transition section and part of the spacecraft tube should be black for the model SA-6 & 7 Saturns, and all white for the SA-8, 9 & 10 Saturns. I'll be painting mine black since I think it looks much cooler that way.

All in all, looks like a fun kit to build. Parts are excellent. Requires skill. Instructions are fun (in spite of oversights). Hope to get some time to do that painting for Step 2 soon...

 

[loojack]

Sounds like Christmas in October! Please post some pics soon! Sound like a great kit, keep us informed!... loojack

 

[Stymye]

great !post lots of pics ,,,! I was hoping someone would post a build article soon ! .. keep the posts coming on it illini. I have 2 kits on the waiting list

 

[illini]

Originally posted by stymye
great !post lots of pics ,,,

I just *knew* the pic request was coming, so I grabbed the digital camera and...both sets of batteries dead! D'oh!!

Will get some pics ASAP once the batteries are charged.

 

[illini]

Okay. Here's what a Dr. Zooch box looks like when you open it (this is actually my Saturn IB which I haven't started yet).

 

[illini]

Here are some of the parts after painting white from step 2. Capsule, spacecraft tube & transition, and S-IV tube. The transition and half the spacecraft tube will be painted black soon.

 

[illini]

Here is the MMT after completing step 4. The spider vains are cut from 1/32" balsa and are intended to act as seats for the fuel and lox tanks. The kit actually includes a template for the spider vains, but they are so small (only about 1/16" wide) that I just cut mine using Mark I eyeball and a straight edge. One comment on this step. The instructions suggest that you seat the centering rings without gluing, glue the spider vains, then glue the rings. I used thin CA to tack the rings in place - squaring them with the end of my Estes tube marking guide, then glued the spider vains, then applied white glue fillets to the rings.

Next step is to assemble lox and fuel tank tubes. Might be a day or two before I get to those.

 

[flying_silverad]

In the Satrun V kit that I bought, the instructions show the motor hook to be inserted only two inches from the aft end of the motor tube. This would allow for a 3/4" overhang when the motor is inserted...does that sound right?

 

[illini]

It is 1/4" overhang for the Blk 2. 3/4" sounds like a bit much, but looking at the picture on the Rebar site, it *does* look like the hook is extending pretty far. Possibly this is so that the MMT isn't hanging down, spoiling the look for display. An engine hook isn't quite so obvious.

 

[illini]

Here are the Fuel and Lox tubes from Step 5. Note the size...the tubes are 5.25" long. The dowel is included with the kit for the purpose of rolling the card stock into tubes. I spent at least an hour today rolling and rolling those tubes before gluing them. I suggest rolling them TIGHT...TIGHTER...TIGHTEST. The instructions would have you paint the lox tube card stock white (in step 2) before cutting and rolling. Frankly, this made no sense to me, so I cut, rolled, and glued today. Will paint them white before gluing onto the MMT. The fuel tank tubes are, of course, pre-printed.

 

[JStarStar]

Great updates on the construction. I have a couple of the Zooch Saturns boxed in my shop awaiting constructions. It helps to see step-by-step progress on the build.

Looks like it's reasonably challenging although not super-tough. Should be fun.

 

[illini]

Glad you're finding it useful. I've found others' build reports to be very helpful in the past, so glad to return the favor. I think you'll enjoy the kits. So far, I'd rate the Blk II a 4-1/2 out of 5 on the EMRR construction scale. Only demerits are for some of the oversights and questionable techniques (like painting the cardstock before rolling the tubes) in the instructions. I like 'em so much that I ordered two more Zooch Saturns to complete my set. More building pics soon. Been off it the last two days with softball playoffs...a little Flex-all and ibuprofen and I'll be good for building again tonight.

 

[illini]

Here's a shot of step 5 nearly completed. The tank tubes are tacked in place. I used an elastic slip knot to hold them in place while they dry (shown in the pic). Although this was my idea (not mentioned in the instructions), it really helped to keep the tanks from popping out while the tack glue dries.

I should also back up to mention that there is no thrust ring include in the kit, just an engine hook. I prefer to have a thrust ring ahead of that hook, so I glued one in the standard way ahead of the hook. Also, the kit uses an Estes style shock cord mount. I'm using Kevlar with elastic and looped the Kevlar around the thrust ring.

 

[flying_silverad]

I should also back up to mention that there is no thrust ring include in the kit, just an engine hook. I prefer to have a thrust ring ahead of that hook, so I glued one in the standard way ahead of the hook. Also, the kit uses an Estes style shock cord mount. I'm using Kevlar with elastic and looped the Kevlar around the thrust ring.

I am working the saturn V right now and there isn't any thrust ring in that kit either. I'm taking the hook out. and using a engine block to friction fit the motor. In the Sat V I think it will look better.

 

[illini]

Originally posted by flying_silverad

I am working the saturn V right now and there isn't any thrust ring in that kit either. I'm taking the hook out. and using a engine block to friction fit the motor. In the Sat V I think it will look better.

That's a pretty good idea. I like to have the motor hook for better retention, but I can see where on the Sat V that could spoil the look since the hook protrudes 3/4". I'll have to see how it looks on my Blk. II before I decide how I want to do it on my IB. The motor hook *does* interfere slightly with one of the fuel and lox tanks on the Blk II, causing it to bulge out slightly. This was the reason for using the elastic "lasoo" to hold the tanks in place while the tack glue dried above.

 

[illini]

Starting step 6, which is to glue on the S-IV tube, fairing, and wrap. Here's a shot of the S-IV tube in place waiting for the tack glue to dry before doing the fairing and wrap. I put the transition, spacecraft tube, and capsule in place just for show.

 

[illini]

Question for anyone reading this: I started this thread as a rolling review due to what appears to be high interest in the Dr. Zooch kits. I'm planning to start my Dr. Zooch Saturn IB this weekend. Would a parallel review detailing that build be of interest? I think the kits are pretty similar and you'll get the general flavor from this thread, but if anyone is interested in a similar rolling review of the Saturn IB then I'll start a thread for that one too. Otherwise, I'll assume y'all are getting what you need from this one.

 

[rstaff3]

illini, please consider turning this material into reviews for EMRR.

 

[illini]

Here's a shot of step 6 completed. The S-IV tube now has its fairing at the base and the wrap. One word about the fairing. The instruction would have you paint the card stock with the fairing in step 2 before assembling the fairing. I assembled it first, then painted it, then installed it.

Building the escape tower in step 7 next.

 

[illini]

Step 7 is to build the launch escape tower. The good Dr. Zooch gives you two options for this. The first is to build up the tower with sticks, small metal bars, tweezers, and glue. The second option is to simply cut the pre-printed lattice out of supplied card stock. "Method B," as the doc says, "is for those who have little or no skill and don't desire to take the time to develop any skill. In other words, a lazy slob." Obviously, I chose Method A.

First, a note on the capsule. Waaaaay back in Step 2 the doc told us to paint the capsule white. Should have been obvious at the time, but for some reason this one slipped past me and I actually followed the instructions. Would have been better to wait until the tower was built before doing the painting. In fact, now that I'm nearing completion of this kit I think I can make the following statement: Step 2 should be abolished from the instructions. Period. In its place should be the small figure currently in Step 10 which shows the paint scheme and a comment along the lines of, "here are the colors, we'll tell you when to paint later just in case you're such a doofus you can't figure it out for yourself" (in Zooch-speak). It just seems that the instructions are nearly useless and, even worse, give bad advice wherever painting is concerned.

Back to Step 7. The capsule is hand made and pre-weighted. Pretty decent, but does contain some imperfections that are easily touched up with some wood filler. Building the lattice by method A requires you to first cut a supplied stick into 4 equal length pieces, glue it evenly spaced around the LES skirt, then glue the other ends onto the capsule. The stick is 2" long and the lattice is supposed to be 1/2" on each side. The problem is that without bevels (which the instructions don't mention) you won't get good contact with either the LES skirt or the capsule. By the time you bevel the supplied sticks the tower will be too short. So...I used round toothpicks cut to 5/8" inch with a 1/16" bevel on each end so that the exposed side would be 1/2". The round toothpicks are a bit thicker than the supplied stick, but I think it turned out okay (certainly better than the pre-printed cardstock lattice used by the lazy slobs). Once the four sides are glued in place on the LES skirt and capsule, you cut small pieces from supplied metal strips and glue them between the sides...piece by tiny piece. Tweezers, thin CA, and a heapin' he'pin' of patience are required here. Once dry, spray the capsule and tower glossy white and you're done.

Step 8 begins by gluing a wrap onto the thrust structure tube. Next comes gluing fairings to fill the gaps between the tank tubes and thrust structure tube. Step 8 concludes with gluing fins in place. I have the wrap in place, but when I cut the fin template I noticed that the fin root is 1-3/16" long and the thrust structure tube is 1". The fins are supposed to be nearly flush with the bottom of the tube. What gives? The root should be 1" long so that the ramp at the leading edge rests on the fairings. Not sure what gives here, so I sent an e-mail to the good Dr. Zooch to get his call on this. I'm pretty sure I'll get an answer in a day or so, and that it will call me a moon hoaxing idiot.

Until I figure out what to do about the fins, here's a shot of my status. Note the fancy new tower on the capsule and the wrap on the thrust structure tube. Looking pretty darn cool, no?

 

[illini]

Got an answer back from Wes (the man behind Dr. Zooch) regarding the fin issue in my previous post. Turns out I'm not a moon-hoaxing idiot! The answer is that the fins in the photo on the Rebar site are precisely scale, and this is stable, but he sized them up 15% to provide a little extra margin for selling to the public. He was good enough to provide me with copies of the original engineering drawings for the fins (as in the *real* ones, not just his lame imitation <-- see...I can do Zooch-speak too!) so that I could do 'em to scale if I want. Wes sent me the Rocksim file a few days ago and I plugged in the scale fins to check the static margin. I'm satisfied that stability will be no issue with the scale fins, so I'm going with those.

Note that this constitutes a mod to the orginal kit as sold by Dr. Zooch. Therefore, I - not Wes - am assuming the responsibility for this change to *my* kit. What you do with yours is up to you.

Also note that these fins are the same as those for the Saturn I Blk II SA-5, so the same issues regarding scale and stability will arise there. HOWEVER, I have not checked the static margin of the SA-5 with the scale fins the way I have for the SA-6 to SA-10. The impact there *may* be different.

More Info: I have now checked the scale fins on the SA-5 and the static margin is considerably less, although still stable. Also, I weighed my SA-6/10 in its current state (without engine bells, fins, trim, or recovery device) and it is currently running about 1/2 oz. heavier than the total weight computed by Rocksim. I also checked the current CG and it appears to be stable vs. the computed CP. I'll continue to check the CG as I finish the build to make sure static stability remains in good shape. I expect this will be a bit dicier for the SA-5 since the modeled margin is already narrow.

 

[JStarStar]

Hey, do you think additional nose weight will be needed for the SA-5 to remain adequately stable to fly? Keep us posted on that.

 

[illini]

I spent a good chunk of my morning improving Wes's RockSim models of the SA-5 and SA-6/10 to make them more closely match the actual kit (his models were clearly pre-production...omitted a few parts and had others with different dimensions). I then modeled 3 options for the fins for each model: 1) Wes's scale+15% fins, 2) Scale fins, and 3) Wes's fins, keeping the span the same but shaving 3/16" off the trailing edge to eliminate the "overhang". I wanted to check both the static margin and the "look" of the 3 options. Here's my conclusion:

Overall: The shaved fins (option 3) have nearly the same static margin as Wes's scale+15% fins. The scale fins look the best (duh!), but the shaved fins (option 3) don't look bad...you'd have to stare at a picture to notice that they aren't scale. Wes's fins with the overhang (i.e., the stock version) look the worst (sorry Wes).

SA-6 to SA-10: Should be no stability issues with any of the fins.

SA-5: Stability will be marginal with the scale fins. However, I added 1/4 oz to the nose and this nearly doubled the static margin. Should be stable with 1/4 oz in the nose and scale fins.

One caution: The Rocksim calculated weight of the SA-6/10 is about 1/2 oz. shy of reality, although the CG appears to be dead on. Given the error in the weight measurement, its very difficult to put much faith in the 1/4 oz added noseweight estimate above without also being able to measure the CG of an actual model. I have an SA-5 on order and may be able to comment further when it arrives.

 

[illini]

Here's a shot with fins attached. These are the scale fins that I built by shrinking the kit template to 86%. I've already built and painted the engine bells (using card stock, kevlar, and a dowel). These will be attached next once the fins are dry.

 

[flying_silverad]

Originally posted by illini
Here's a shot with fins attached. These are the scale fins that I built by shrinking the kit template to 86%. I've already built and painted the engine bells (using card stock, kevlar, and a dowel). These will be attached next once the fins are dry.

Looks great, nice work!

 

[illini]

Originally posted by flying_silverad
Looks great, nice work!

Thanks! I'm really happy with how its turning out. Clearly a lot of work...not for the faint of heart, limited of skill, or lazy slob (as Dr. Zooch would say). But really enjoying this kit.

Have also started my Saturn IB. Very similar as you might expect, although the kit was missing the 1/32" balsa needed for the spider vains and the spacecraft tube was only 7/8" long when it was supposed to be 1.3" long. Fortunately, I had the spare parts on hand to replace the missing and "wrong" parts. A bit of an annoyance, but still enjoying it.

 

[illini]

Attached the H-1 engines today. Okay...maybe not *exactly* H-1's, but itty bitty little look-alikes. The engine bells are made from card stock, then wound with some kevlar to make the "hatbands", then a small piece of dowel for the turbine exhaust manifold. Paint 'em all up with steel paint and yer good to go. Here's an end view shot.

 

[illini]

...and here's a closeup of the H-1's.

 

[illini]

To finish this kit requires cutting and gluing some dowels to form the detailing of LH2 ducts, etc. Unfortunately, the kit came with 3 1/16" x 6" dowels, but requires about 2" more than is provided. By the time you add up all the lengths in the instructions this is pretty obvious. My Saturn IB kit also had omitted and wrong sized parts, but I had replacements on hand. I've been all over looking for 1/16" dowels and haven't found them yet - Michael's, Walmart, two different hobby shops. 1/8" is the smallest they sell. Verrry annoying. Would really like to finish this kit, but can't find the stinkin' dowels. Anyone know where I can get 1/16" dowels online without having to pay $6 shipping (e.g., Tower Hobbies has them, but I'm not about to pay their shipping charge for what I need)???

 

[Stymye]

can you use evergreen or plastistruct rod ? the hobby shop should have it