Another Saturn IB

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Where do you get your PCB prints? I have a simple staging controller made in Autodesk's Circuits.io but I haven't been able to find a ton of information about printing.

I used https://www.4pcb.com/. It looked a little expensive but it gets high marks on quality. So I started processing the order and got a grand surprise on checkout. 90 FREAKING BUCKS for shipping! I will not repeat. There are a number of sources for PCBs out there that batch hobby quantities. You just have to plan ahead.
 
Well it's not ready to fly. Not even close despite a week of solid effort. My 3D printing issues had me put just too far behind. Le sigh.

Sorry I haven't been posting updates but I've been kind of focused. I'll post more when I get back from URRF. In the mean time it's time to pack up and go fly some rockets!
 
Well it's not ready to fly. Not even close despite a week of solid effort. My 3D printing issues had me put just too far behind. Le sigh.

Sorry I haven't been posting updates but I've been kind of focused. I'll post more when I get back from URRF. In the mean time it's time to pack up and go fly some rockets!

Hey...have fun!
 
With the big push I gave to try getting this ready for URRF, I've taken a short break to recover and relax. On the positive side, now I have the luxury of being able to do things as I want. So tonight I'm taking stock of where I am.

First up is the SIB stage. This is the part that wasn't structurally complete in time. Shown here is the fin can with LOX tanks installed, and the fuel tanks ready to be added. I needed to paint these before installing and with rainy weather this was my demise. The coupler is shown in place, but this is obviously not attached yet.

IMG_2065.jpg

There are a few details on the tanks worth mentioning. I 3D printed some of the vents and fill pipes. The red stripe is the shaped charge used to destroy the rocket in the event of failure, but mine is just a red stranded wire passed through holes drilled in the tanks and CA glued into place.

IMG_2066.jpgIMG_2067.jpg

As you can see, the fin can is still in need of some more sanding. So the delay is a plus in that regard. Plus I'll be able to add some more details.

Also, the clustered motor mounts won't be installed until after the tanks are in place, and now that may take a little longer. Wiring also has to happen.

Next up... upper stage.
 
Here's the upper section. Yes, it's that tall.

IMG_2073_crop.jpg

The CM and LES bring the total height to about 6 feet (using the always precise it's almost as tall as I am technique).

IMG_2071.jpg

There are still details to add, including all the plastic stringers. Unfortunately due to cleaning up the epoxy that ran down when I added the nose weight, some of the existing stringers were damaged and will need replacing. It's not too difficult but it is a pain. Other than the stringers because there's just so many of them, this should go pretty quickly.

So other stuff. Wiring still has to happen, but that is all ready to go and won't take long. The mating portion for the two stages will be a little trickier in terms of getting the internal tubes cut to the correct lengths and glued into place. Priming, sanding, painting, and repeating. Oh, and decals.

I've been talking to stickershock, but I was supposed to send him detailed requirements a few months ago. I should get on that!

So not sure when it will launch yet. Depends on my motivation level as much as anything. Hopefully this year.
IMG_2063.jpg
 
Dave...you are going to need to build a smaller version of the VAB in your back yard to store her. Just looks spectacular! she is a tad bit bigger than my last 1b build.
 
Dave...you are going to need to build a smaller version of the VAB in your back yard to store her. Just looks spectacular! she is a tad bit bigger than my last 1b build.

Just a wee bit :)

I already have plans for a display stand. It uses a 75mm x 3' oak dowel, and it will be displayed on an angle to that it can fit in a standard height room.
 
After the failed push to get it flight ready for URRF, I've been taking a break. Well, I'm back.

To get it flight ready, I was taking some short cuts in terms of finish and details. Today, I'm back to sanding, filling, and repeating, for the fin can anyways. I'm not sure how this is all going to play out with the whit oxidizer tanks in place, but I'll muddle through somehow. I'm away for work this week, but the week following I'm off so it's all rockets all the time. If it's flight ready, I'll fly it at the URRG September launch but I'm not going to push it. Let's see how it goes.

IMG_2146.jpg

Everybody likes sanding, right? That's what I thought. On a positive note I got a new detail sander. It's perfect for the small spaces and tight corners on this fin can.

IMG_2147.jpg

I still hate sanding.
 
Sanding.
And more sanding. LOL.

Well, as you said....90 % of rocketry is sanding!

I've spent much of my summer flying RC with my local club and finished several new planes...I had my share of sanding to do on those.
Can't seem to get away from it - unless you fly RTF/ARF planes or those darned foamies.
 
Well, it's been a busy few days. Mostly sanding. The fin can looks good from a few feet away, but not so good close up. I have no patience for another week of fill, prime, sand, repeat, so I hereby declare it good enough.

So on to details.

IMG_0024.jpg

8 groups of 14 stringers = 112 stringers. It's not sanding but it is tedious. I also added personnel hatches cut out of Avery labels for effect. Unfortunately the addition of paint caused them to warp.

IMG_0035.jpg

Guess what I'm doing in the morning? Sanding. Le sigh. And then I dropped the paint container as I was removing it from the sprayer. Splash!

Time to watch some TV. But hey... progress!
 
Big day today!

It started with the previously mentioned sanding. I redid the white paint, but I haven't done the roll patterns yet. My original thought was to get that done before putting the tanks in place, but I have enough touch ups to do I don't think it will matter. So...

The tanks are in place! Yay!

IMG_0037.jpg

The coupler and spider beam cover are just dry fitted, but they'll be put on later tonight. I still have to add the 38mm motor mounts, the 75mm retainer, some other mechanical odds and sods, and of course electronics. But it's looking promising for the URRF launch this weekend. It just won't look that pretty. Yet.
 
SO much stuff! Looks like I'll launch this weekend but it's been a busy few days, so let me catch you up.

First up... motor mounts. Getting the outboard clusters at the right angle required a jig, so to the 3D printer.

IMG_0039.jpg

Next, it was a matter of filling the holes. The business end of this is looking impressive :)

IMG_0040.jpgIMG_0041.jpg

And of course wiring the custom cluster controller with the two PerfectFlite Mini-Timer 4's.

IMG_0043.jpgIMG_0042.jpg
 
The hardest part of this build is connecting the inner airframe. I have a 75mm tube going into a 98mm tube. That involves centering rings, and of course my pyrotechnics bay. It's like an ebay, except the electronics are external, but it is my separation point.

IMG_0045.jpgIMG_0046.jpg

This is a critical piece. Too short, and the outer airframe takes the load, which it is not supposed to do. Too long, and there is a visible gap between sections, the electronics don't fit in the right place, etc... Too long would be better though as I can at least remove material more easily. After careful measurement, I glued the transition into the upper airframe.

IMG_0044.jpg
 
First fitting!

I had to use the whole length of my kitchen for this. I certainly couldn't do it standing up. With the typical I could use 3 more hands, it was a bit of a task getting it lined up correctly, but with a final push it went home. Yay!

IMG_0048.jpg

This thing is impressive! Still a lot of details to add but it's looking pretty sharp.

And I was off by about 1 cm in my measurements. Time to do some trimming...

IMG_0047.jpg

Well, back at it. I have a few more details to wrap up so I can fly!
 
First fitting!

I had to use the whole length of my kitchen for this. I certainly couldn't do it standing up. With the typical I could use 3 more hands, it was a bit of a task getting it lined up correctly, but with a final push it went home. Yay!

View attachment 328591

This thing is impressive! Still a lot of details to add but it's looking pretty sharp.

And I was off by about 1 cm in my measurements. Time to do some trimming...

View attachment 328590

Well, back at it. I have a few more details to wrap up so I can fly!

Beautiful!

I may have to make it "across the pond" someday to see what you guys are doing at URRG... Yes, I finished first, but I didn't have 300 stringers to add :facepalm:
 
Well, it didn't fly this weekend. Le sigh.

When I did my mating test, I used the coupler without the end caps, and without the plastic rivets that hold it in place. When I was finally ready to do the ejection charge tests, we couldn't get it aligned. This should be an easy fix, but not on the field. Then we ran out of time.

So I have 2 months before the November launch. Third time's a charm?
 
Well, she flew!

It was a nice stable, impressive flight and good recovery, but there was some damage. Give me a day or so to figure out what planet I'm on and I'll start posting details
 
Just saw the discussion on PCBs earlier. I am not sure what prices you are paying in the USA but these guys are cheap for us down here:
www.pcbwell.com
PCBwell.png

I just had a fancy 4-layer impedance controlled PCB done for a 1000Base-T Ethernet PHY. Bare PCBs were $132 for 10, including $20 worth of DHL. Great quality. Delivery in under 10 days

Regular boards were about $5 each for quantities of 10.

Had quite a few boards done by them now.

They have an online quoting system for simple stuff for instant quotes.
 
Last edited:
Today's the day... post mortem day. I'll be posting several times throughout the day as I gather my photos and my thoughts.

The rocket has a major design flaw. If you've been following the thread, you'll know that the core structure is the inner blue tube, and the large parts on the outside are effectively a facade. Here we see the pyrotechnics module in the forward section of the rocket. If you look at it from the context of this inner structure, this is the ebay of a dual deployment rocket. The only real difference is that the electronics are external to this, with just the pyrotechnics where the ebay would be. This is held in place in the forward section with plastic rivets. At apogee, the drogue deploys from the rear section, and the main ejects through the nose.

IMG_0095.jpg

The problem is that the two sections have to mate and that proved extremely difficult. We spent about an hour trying to make it work. I'd had it together before, but that was without the rivets. We just weren't able to get it fit. So we went with Plan B. We removed the rivets, and reconfigure the wiring so the main would deploy at apogee... effectively a single deployment configuration. I risked loosing the pyro bay (my electronics were pretty secure but I may have ripped the wires off), but this is literally the last chance I had to fly before moving off the continent. So that's what we did. It still took an effort but we were able to get the parts to mate.

IMG_0099.jpg

You'll notice that a lot of the LES structure is missing. More on that later.

While trying to get the pieces to mate, we did some minor damage. A few of the 3D printed details came off. More importantly, the switches on my clustering electronics got knocked off of the mount. I knew this mount was poorly designed. I'd forgotten to include spots for the battery switches so they had been CA glued to the plastic. I've yet to have what I consider to be a reliable CA glue joint, including this and several of the details on the exterior that keep getting knocked off. In the end, I had to secure the switches using good old duct tape.

IMG_0096.jpg

Also, the switch on the PCB used to check cluster igniter continuity got knocked off so I wasn't able to use that feature at all. More about that when I talk clustering.

So that's it for post 1. I'll post more later today.
 
Back
Top