Semroc Saturn IB Build Thread

Well ladies and gentlemen, this begins my Saturn IB build. I dug out the kit
last night and started reviewing the instructions. I might actually get a
start on it tonight pending on work...

First question:
Anyone who has built this kit please provide any and all insight you may
have.

Second question/idea:
I am thinking of making this a five engine cluster. What are your thoughts
on this? I was going to use four of the 8 tank tubes as the outboard engine
mounts and then central motor, the outboard motors would be plugged engines
to eliminate and ejection issues. I can go either 18 or 24mm on any of the
motor mounts.

Rather than plug your outboard engines, I would consider ducting them into the body.

If you choose not to and you run 5 engines, and if the central one fails to ignite, it will still lift off and the recovery system will NOT deploy.

Someplace there is a picture of Micromeister's 3-engine SR-71 doing just that. The outer engines were not ducted to the body and the center failed to ignite.

Other than that, good luck and keep us posted!!!

RangerStl said:

Rather than plug your outboard engines, I would consider ducting them into the body.

If you choose not to and you run 5 engines, and if the central one fails to ignite, it will still lift off and the recovery system will NOT deploy.

Click to expand...

Good point.

Well now you have me thinking ("out loud").

The real S-IB's had eight H-1 engines.

The 4 engine cluster option on the kit does not line up exactly
as the real central four but the design allow for 4 of the tank
tubes to be used as engine mounts.

So at least the rear veiw of an 8 engine cluster would be correct
as far as engine position would count.

Only the relative fin position would be off by 22.5 degrees. Hell
what's 22.5 degrees between friends.

With the four central engines ducted that would eliminate the
issue if one did not fire and the others did. And I could still run
plugged outboard engines...

Of course nose weight will be needed to shift the CG forward
but with eight engines that is kinda a so what...

Now I have to sim out what eight Aerotech D10's would do with
it, hehehehe (evil laugh)

Here is my experience with the kit:
[YOUTUBE]ZOq3hQrqwH0[/YOUTUBE]
[YOUTUBE]cXhRHekurj8[/YOUTUBE]
[YOUTUBE]8L_XoNPHoro[/YOUTUBE]
[YOUTUBE]WBdhigVYUCY[/YOUTUBE]

Modded to use a 4x24mm cluster. I added 5.6 ounces of lead shot and epoxy to nose cone assembly. Total weight without motors is 23.7 ounces. All motors are ducted together for ejection purposes. I used 2xE9-6 and 2xE9-8 in my launches to ensure all 4 ejection charges were not pushing through the stuffer tube at the same time.

Flying on 4 Estes E motors does mean the total propellant mass is over 125 grams. Any rocket with over 125 grams total propellant mass is considered high power, and FAA waiver should be obtained prior to launch.

8 Aerotech D10's would be well below 125 grams. I suspect the D10s are not black powder motors, and will be more of a challenge to get a cluster of the D10s to light than any of the Estes black powder motors. Reliably lighting 8xD10s may require special igniters and launch controller. Maybe someone with more clustering experience can pipe in?

I believe a number of other builders made exchangeable mounts for their Saturn 1Bs (1x24mm, and 4x18mm).

Good luck with whatever approach you take,

Bob

Looks great bguffer. I too have just started my Semroc S-1B Build, thanks for the info on the Apogee Capsule..I am not liking how my dowel rod tower is looking.

I never attempted the stock tower, as i was lazy and time conscious. I think if i did attempt the stock Semroc tower, i would temporarily piece it together with silly putty and then apply glue.

Bob

bguffer said:

8 Aerotech D10's would be well below 125 grams. I suspect the D10s are not black powder motors, and will be more of a challenge to get a cluster of the D10s to light than any of the Estes black powder motors. Reliably lighting 8xD10s may require special igniters and launch controller. Maybe someone with more clustering experience can pipe in?

Click to expand...

Bob,

Thanks, and yes if anyone has input on clustering AP motors I would appreciate
it. I do plan first flights on just the four central engines and they will be BP
to start with.

One small note, I live in "dial up hell", yes I am on gravel road also. As a
result the imbedded pictures and youtube links kill me for uploading the
thread. I know I am in the small minority these days but my only option
other than dial up is Satellite, and trust they know where I live, and I am not
paying $160 a month for internet... $160 a month can buy alot of
rockets and engine you know...

Delta-IV said:

Looks great bguffer. I too have just started my Semroc S-1B Build, thanks for the info on the Apogee Capsule..I am not liking how my dowel rod tower is looking.

Click to expand...

Hey Carl we get to do it together, I am thinking this might be a good work up
for your Delta-IV kit I have sitting on the shelf...

The tower I will build like a tissue and balsa planes I have built I will take
pictures.

I started on the build tonight I will up load pictures later (left the camera out
in the shop, LOL)

I was cutting the slots out of the "fuel tubes" to allow for the cluster mount,
and there is always that part of me that says "What the **** are you doing
cutting into a perfectly good body tube.

I have the cluster MMT, the cluster bulkhead and stuffer tube sub-assemblies
glued up and will be headed out to assy. them next. The "fuel tubes" are
slotted. Next is getting the stars prepped and on the tube as well as
starting on the built up fins.

I had a thought of making the a gap staged 2 stage model but choose not
to; maybe I will do a version like that in the future.

Here are some pictures.

Hello,

I just completed one with the 4C cluster and 4 outboard A10-PT's. Carl was nice enough to send the the centering rings so I did not have to do a custom job. Yet to fire but it LOOKS way cool!

matt38 said:

Hello,

I just completed one with the 4C cluster and 4 outboard A10-PT's. Carl was nice enough to send the the centering rings so I did not have to do a custom job. Yet to fire but it LOOKS way cool!

Click to expand...

Can you post a picture of the aft view?

glueing up the fuel tubes, taking my time on those.

Started one of the fins. To crease the lines in the paper wrap I use a
straight edge and a ball point pen, then on top of my cutting mat I
draw an line on top of the printed line to make an easier and more
accurate fold.

Okay I did the Mark 1 Mod. 0 18mm engine mount for the fuel tubes. The
fuel tubes are a special size, I check that before so the standard centering
rings for the BT-50 tubes are loose in the Fuel tubes. Like I said checked not
an issue. The solution used, I cut strips of the same material the fins skins,
tansition and fuel tube fairing came printed on. it is a heavy paper with one
glossy side. The strips I cut were 1/4" x 2-15/16" I wrapped these strips
around the CR's used blue painters tape to hold them and glued them in place
with a little CA. Now they make an nice fit. I glued the one in so 3/16" of
the MMT was sticking out of the Fuel tube this puts it flush with the cluster
mount.

The first fin came out good so I cut out the remaining skins and will work
on those later. SWMBO decided we are going out for dinner... (sweet!)

Also a quick picture of the aft end so far.

I also took a picture while I was walking in from the shop, did not turn out
that well but you can see the thunderhead in the distance, just thought it
looked good with the critters in the forground but the buttheads started to
walk off as soon as I lifted up the camera.

Ron, looking real nice!

I decided to keep mine a bit simple with a single 24mm motor. I plan to use reloads as I just love the sight of APCP on a scale bird.

So far, I tossed the capsule aside awaiting on my Apogee to arrive. I have the stuffer tube and motor tube with the two star rings glued up and drying.

-Carl-

Delta-IV said:

Ron, looking real nice!

I decided to keep mine a bit simple with a single 24mm motor. I plan to use reloads as I just love the sight of APCP on a scale bird.

So far, I tossed the capsule aside awaiting on my Apogee to arrive. I have the stuffer tube and motor tube with the two star rings glued up and drying.

-Carl-

Click to expand...

Thanks, with the 18mm mount I can run the Aerotech D10's or 21 in ACPC
but as mention earlier clustering that many ACPC will take some planning.

The Semroc capsule is a challenge, I think I am going to use some Tig wire
instead of sanding the wooden dowels down to size.

Here are a few more photo's

Here is the CAD drawing I did to prep for the modification to the
Lower cap ring.

Shade said:

Thanks, with the 18mm mount I can run the Aerotech D10's or 21 in ACPC
but as mention earlier clustering that many ACPC will take some planning.

Click to expand...

Using 8 motors does a lot for scale looks, but going from zero to light speed with a cluster of D motors will be nothing like the slow scale liftoff of the real Saturns. The model looks so good it needs to be in full detailed view for the complete flight. I don't see any reason to fly higher than a 4 C6 cluster, which I'd estimate around 500-600 ft. according to how heavy it's built. We usually fly on 3 C6's or 4 B6's (removable mount) and probably average around 250-300 ft.

IMHO, of course.

The Semroc capsule is a challenge, I think I am going to use some Tig wire
instead of sanding the wooden dowels down to size.

Click to expand...

Build the SEMROC capsule for flight, using whichever materials you choose for the tower. Bite the bullet and get an Apogee capsule for display.

tbzep said:

Using 8 motors does a lot for scale looks, but going from zero to light speed with a cluster of D motors will be nothing like the slow scale liftoff of the real Saturns. The model looks so good it needs to be in full detailed view for the complete flight. I don't see any reason to fly higher than a 4 C6 cluster, which I'd estimate around 500-600 ft. according to how heavy it's built. We usually fly on 3 C6's or 4 B6's (removable mount) and probably average around 250-300 ft.

Click to expand...

I could not agree with you more, but the "Tim Taylor" gene kicks in every so
often so I have to appease it.

tbzep said:

Build the SEMROC capsule for flight, using whichever materials you choose for the tower. Bite the bullet and get an Apogee capsule for display.

Click to expand...

Thanks for the info, will do, gives me more of an excuse to upgrade my
Rocsim 8.0

Hello all,

Here is a pic of the aft end of my Semroc 1B. I also have a pic of my Estes SatV cluster designed to fly with the engine fairings which I am currently working on as well as my completed Apogee Saturn V. After buying a RTF Estes rocket last fall for my boy, the bug bit and these are my first 3 builds. I am looking at buying a Sirius Sat V to cluster next...

Ron,

Any progress lately?

Man what an awesome thread The videos were great. Shade how is your project going?
Cheers
fred

Not to steal Ron's thread but wanted to post the almost complete photo of my build. I installed the 24mm motor mount to launch it on my RMS reloads probably an E18-XW. I have the Apogee Apollo Capsule and still working on the wood dowell Semroc capsule. If I do use the Apogee capsule for flight I am thinking possibly to add clear acrylic to the sides of the tower for strength.

Edit: Added info: I didn't like the painted silver/aluminum on the Service Module and while I was at Lowes the other day I picked up a roll of aluminum tape. It's a tad heavy, but I needed some forward CG ballast anyway and looks almost like the real thing.

Delta-IV said:

Not to steal Ron's thread but wanted to post the almost complete photo of my build. I installed the 24mm motor mount to launch it on my RMS reloads probably an E18-XW. I have the Apogee Apollo Capsule and still working on the wood dowell Semroc capsule. If I do use the Apogee capsule for flight I am thinking possibly to add clear acrylic to the sides of the tower for strength.

Edit: Added info: I didn't like the painted silver/aluminum on the Service Module and while I was at Lowes the other day I picked up a roll of aluminum tape. It's a tad heavy, but I needed some forward CG ballast anyway and looks almost like the real thing.

Click to expand...

Awesome loooking rockets. That capsule is incredible
Cheers
fred

Delta-IV said:

Not to steal Ron's thread but wanted to post the almost complete photo of my build. I installed the 24mm motor mount to launch it on my RMS reloads probably an E18-XW. I have the Apogee Apollo Capsule and still working on the wood dowell Semroc capsule. If I do use the Apogee capsule for flight I am thinking possibly to add clear acrylic to the sides of the tower for strength.

Edit: Added info: I didn't like the painted silver/aluminum on the Service Module and while I was at Lowes the other day I picked up a roll of aluminum tape. It's a tad heavy, but I needed some forward CG ballast anyway and looks almost like the real thing.

Click to expand...

Nice looking CSM. What did you use for the radiator panels on SM?

astropilot said:

Nice looking CSM. What did you use for the radiator panels on SM?

Click to expand...

MS Powerpoint and sticker paper from Staples. To do it better the radiator panels should have raised ridges, I still might add that before she flies.

I also used Powerpoint for my Delta IV wrap artwork. There are many uses for Powerpoint beyond slides I discovered.

I flew my Semroc Saturn 1B twice today.

My S-1B uses a single 24mm motor, I used the Apogee Apollo Capsule and CSM Thrusters. I did augment the tower by adding 1/10" clear acrylic panels for strength.

Flight 1 and 2 both flew straight as an arrow even in a mild 5 to 10 mph wind. Temp was near 92 and humidity was about 40-50%. Estimated altitudes was close to 700 feet.

Only damage to the rocket was on both landings, the built up cardstock balsa frame fins did not stand up well. Perhaps I should have soaked the paper in CA before painting??

Other than that I thought the flights were awesome, the motor I used were 24mm E18-4W RMS, ejection was slightly past apogee.

Carl,
Those were amazing Saturn 1B launches today! That E18-4 has got to be the optimum engine and delay for it.

Delta-IV said:

I flew my Semroc Saturn 1B twice today.

My S-1B uses a single 24mm motor, I used the Apogee Apollo Capsule and CSM Thrusters. I did augment the tower by adding 1/10" clear acrylic panels for strength.

Flight 1 and 2 both flew straight as an arrow even in a mild 5 to 10 mph wind. Temp was near 92 and humidity was about 40-50%. Estimated altitudes was close to 700 feet.

Only damage to the rocket was on both landings, the built up cardstock balsa frame fins did not stand up well. Perhaps I should have soaked the paper in CA before painting??

Other than that I thought the flights were awesome, the motor I used were 24mm E18-4W RMS, ejection was slightly past apogee.

Click to expand...

That's some pretty substantial damage considering you are in deep grass and had no wind. The worst we've ever had with a good chute was a slight bend at the last 1/4" or so of the BT-101. Did it land on something or come down at an angle to cause the fins to hit first?

tbzep said:

That's some pretty substantial damage considering you are in deep grass and had no wind. The worst we've ever had with a good chute was a slight bend at the last 1/4" or so of the BT-101. Did it land on something or come down at an angle to cause the fins to hit first?

Click to expand...

Breeze picked up a bit on that last flight and yes it landed at an angle on a dirt path. On a sod farm and it landed on the path..but a water filled ditch was only 5 feet away..I guess I am lucky really.

-Carl-

Really nice shot up the length of the rocket Glad your flights went well .
Cheers
fred

Delta-IV said:

Only damage to the rocket was on both landings, the built up cardstock balsa frame fins did not stand up well. Perhaps I should have soaked the paper in CA before painting??

Click to expand...

I think building up the fin frame is the answer. At 8:23 of top video, you can see i did just that. On the second video you see my 1.5 lb Saturn 1B descend quicker than meant (chute did not fully open). The hard landing caused 3 fins to be cleanly knocked off from the airframe, but the fins were not bent.

Nice pics,

Bob