An Agglomeration of Andromedas (HPR)

[les]

COMMON INFO
Well, off to another 3 way build.... I've done a trio of Tridents and the Mars Snooper Mayhem.
But a slight issue, one is LPR, another is MPR, and the last is HPR.
Where to put the build thread? Average to MPR?? But then LPR or HPR folks may miss it......
I decided on creating 3 threads, one in each sub-forum. There will probably be some cross-referencing between the threads.

So what am I building? The thread title tells some of the story. I have:
Semroc USS Andromeda (LPR) - Clone of the Estes model, 18mm motor
Q Model USS Andromeda (MPR) - 1.65X upscale, 24mm motor
Wildman USS Andromeda (HPR) - 3X upscale, 54mm motor

I've had the Q model kit sitting around for a while. I had planned to clone the Estes size version, and bought some parts for it, but never started it. Then Semroc came out with their clone. I was thinking of starting the two, when Wildman announced he was coming out with a 3X version. So.... off we go
END COMMON INFO

 

[les]

I was impressed when the box arrived from Wildman. And slightly dismayed by the shipment of peanuts....



And all of the parts



At least there are no spirals to fill and I don't have to paper the fins like the LPR and MPR versions.........

 

[les]

Of the 3 kits, the Wildman version is least like the Estes original.
Instead of a basic conical transition, the transition is more elliptical.
And the nose cone is way off.
And since the nose/transition are longer, it appears Tim compensated by shortening the tubes. The Semroc/Estes central tube if 36". To be 3X these tubes should be 108". Instead they total to 102" (6 inches short). If you sub the nose cone to a more appropriate version, the model will be short.

 

[Off Grid Gecko]

Bah! those horrible peanuts! Kraft paper, people. Why is that so hard?
It does look like quite a kit.

 

[les]

Batteries Not Included - and neither are instructions.
I re-layed out the pieces as to how I thought it would go together.



The wood centering ring appears to be used with the transition.

This is how it would go together





Dry fit

 

[Tim51]

Very unusual to see something so unconventional kitted as HPR. Kudos to Wildman for producing it. Will be following with interest.

 

[neil_w]

Bah! those horrible peanuts! Kraft paper, people. Why is that so hard?

Even the biodegradable, non-staticky ones that look like cheese doodles are way better. But styrofoam peanuts? Evil.

It does look like quite a kit.

I've been looking forward to a build thread of one of these monsters!

 

[les]

COMMON

Wanted to show the differences in the sizes of the sail fins

END COMMON

 

[les]

Before the actual build - bath time


I did find the tube ends and fins all needed some cleanup and deburring
Before and After

 

[les]

Used JB weld to bond an aeropack retainer to the bottom tube, plus a centering ring

 

[les]

I wanted to mark where the fins would mate and almost made a MAJOR MISTAKE!
Fortunately - "ALMOST"

You can see in my pixs where I first marked the tube, and then realized you need to ensure the sail fin will be in line with the slots for the fairings.

 

[WILDMANRS]

Bah! those horrible peanuts! Kraft paper, people. Why is that so hard?
It does look like quite a kit.

We also use paper but it won't protect on that type of space with that type of weight like peanuts .
we also reuse almost all of the packing that comes to us.
The starch ones are 3 times the price plus they attract mice .

 

[WILDMANRS]

Batteries Not Included - and neither are instructions.
I re-layed out the pieces as to how I thought it would go together.

View attachment 427581

The wood centering ring appears to be used with the transition.

This is how it would go together

View attachment 427585

View attachment 427584

Dry fit
View attachment 427586

Nice job Les
Thank you for doing a build thread with this if you have any questions i will be happy to help .
Tim

 

[les]

I epoxied a centering ring onto the top of the larger lower tube. I do think I made a mistake. When doing some other work, I discovered with the 3 CR, one was thicker than the other 2. I suspect that thicker one was for the transition to upper large tube.


I did assemble the transition section per my diagram in my previous post.
I positioned the wooden CR low on the tube. I dry fit a CR on top of the rocket body and slid the transition up then carefully lowered it again. This showed me where the wooden ring would end up which I marked. I then scuffed up the tube, inside the transition, and coupler. Then I put a bead of Rocketpoxy around the lower edge of the coupler and installed it into the transition. Three more beads of Rocketpoxy on the tube where the transition ends, the ring itself, and the location where the ring should end and slid things back into position. I used one of the smaller pod tubes with the dry fit CR to ensure the transition was centered. A ring of blue was used to hold the transition while the epoxy cured. I did use a small dowel to ram against the wooden ring to make certain it was seated as far down as possible.

 

[les]

My plan was to "fill" the transition with 2 part expanding foam to help beef this up, but I discovered my leftover foam had dried up and unusable. As I backup, I grabbed a dowel and sanded it down thinking to provide three points around. Just dry fit right now.

Comments/Thoughts???

 

[mrtriton]

My plan was to "fill" the transition with 2 part expanding foam to help beef this up, but I discovered my leftover foam had dried up and unusable. As I backup, I grabbed a dowel and sanded it down thinking to provide three points around. Just dry fit right now.

Comments/Thoughts???

View attachment 428066

I like that idea. Thanks for this thread. I haven't started mine yet, so this is giving me lots of ideas!!

 

[Wally Ferrer]

My question here is how did you decide on the location for the transition- is that measured for a scale tube length between the two three inch sections? I haven't check the fit, but I'm now wondering if the wooden ring would fit in the end of the short coupler, where you are placing your dowels, and just use epoxy at the 2 inch transition joint. I'm trying to understand how effective the wooden ring is at the base of that transition. That being said, I believe the dowels should more than adequately reinforce the transition/coupler joint.

 

[les]

My question here is how did you decide on the location for the transition- is that measured for a scale tube length between the two three inch sections? I haven't check the fit, but I'm now wondering if the wooden ring would fit in the end of the short coupler, where you are placing your dowels, and just use epoxy at the 2 inch transition joint. I'm trying to understand how effective the wooden ring is at the base of that transition. That being said, I believe the dowels should more than adequately reinforce the transition/coupler joint.

On my kit, the inner diameter of the wooden ring just fits over the smaller body tube. The outer diameter fits...nothing, except some inner point of the transition.
Besides, I passed this (see post #5) by Tim in an email who responded "spot on".

In terms of length, there is a 3 point connection between the small and large body tubes: Small end of transition, wooden ring, and FG center ring at the end of the small tube. The further down the transition is on the small tube the distance between the small transition end and the FG ring, the more stable/secure is the joint. BUT - As I stated previously, the tubes are a bit short so I wanted to minimize the amount of overlap. I ended up a bit over 2.5". But with the shorter overlap the weaker the joint, which is why I wanted to enhance the joint.

For scale, the smaller tubes are already 6" short, and the transition itself is much longer than scale. The LPR version is 1" long. Being 3X the transition should be 3". It is about 7".
On the LPR version, there is a 2" overlap for the large upper tube to the small upper tube. For 3X this would become 6". So my shrinking this back down to around 2.5" is compensating for the small diameter tubes shorter length vs the transition long length.

My figure from post #5. The 3 points are again the small end of the transition (far left), the wooden CR (tan) and the FG CR (green). The transition/coupler/large tube effectively become a single rigid structure once epoxied together.

 

[Wally Ferrer]

Cool, I wasn't sure what the fit was for the wood ring, great that Tim confirmed it. I think your dowel solution will be plenty strong. My concern is with the connection of the two 2" tubes, the coupler just seems short- I know it should be long enough to connect a 2" tube, but the overall length with the extra weight at both ends just makes me think it should be longer.

 

[les]

While waiting for feedback on whether I should proceed with the dowels, I started work on the fin mounting. Per post 11, I "correctly" marked the location of the fins. I scuffed up the appropriate areas, and then had to remark the locations. I then made some fin pockets from some scrap plywood that I attached via CA.

One point to discuss. The upper and lower slots for the fairing are slightly misaligned on mine, so the fairings will mount with a light slant. I aligned the sail fins with the bottom of the fairing so my tube will have a very slight bend to it....

 

[les]

My concern is with the connection of the two 2" tubes, the coupler just seems short- I know it should be long enough to connect a 2" tube, but the overall length with the extra weight at both ends just makes me think it should be longer.

There are 2 couplers with different lengths. I used the short one for the transition, and planned to use the longer one for the nose cone. That provides about a 3" shoulder for the cone. Right or wrong, I will typically allow a shorter overlap for a more rigid joint (like one that is epoxied) vs. one that has to slide and separate. But if you feel more comfortable, you can reverse the use of the two couplers. But again, that will move the transition down and those tubes are already short..........

 

[Wally Ferrer]

There are 2 couplers with different lengths. I used the short one for the transition, and planned to use the longer one for the nose cone. That provides about a 3" shoulder for the cone. Right or wrong, I will typically allow a shorter overlap for a more rigid joint (like one that is epoxied) vs. one that has to slide and separate. But if you feel more comfortable, you can reverse the use of the two couplers. But again, that will move the transition down and those tubes are already short..........

Sorry for any confusion, I agree 100% with your use of the 3" couplers in the transition/nose cone- I was referring to the 2" coupler connecting the two smaller tubes. It just 'feels' like the coupler/av bay should be longer due to the overall length of the rocket, skinny in the middle and bigger/heavier at both ends. I know it doesn't need to be. Then I look at it again... but I know it's fine...

 

[les]

As I stated in post 20, the fairing will get mounted on a slant. I decided to work the slots a bit. Sanded the right side of the top slot and the left side of the bottom slot (as indicated by the arrows)


I masked the fairings and tube, scuffed and scored them.



Now for a confession.... Part of doing a build thread includes showing your goofs.

Ever have a thought that I have to make sure I do A before I do B? And then the next day you jump directly to B? Or is that only a 65 year old issue.....

I thought about "I need to put the large tube on before the fairings". Next day, I installed these fairings and realized I forgot the large tube. Fortunately, I only tacked them with CA. Thank goodness for Acetone!!!!

I made some templates for the fairings, dry assembled, held things together with rubber bands, and then tacked them with CA. I made certain the top of the fairings were pushed to the right and the bottoms were pushed to the left. They are now fairly straight.






Now my next issue.... first, the carbon rods are slightly different lengths.
Second, how I was going to mount the large tube has the tubes come up short.

If I keep the large tube where I planned, they are about 0.5" short. If I slide the large tube as far forward as my fin pockets support, I end up being about 0.25" short



Options:
1) - Leave the fin pockets and placement as is. Use a piece of wooden dowel to make up the difference on the fairing (after paint most likely will not be noticable, especially from any reasonable distance)
2) - Slide the large tube forward the 0.25". I would need to update the pod fin pockets.
3) - Update all 4 fin pockets to move the large tube forward by the 0.5"

I thought about trimming the fin tabs to allow them to move forward without adjusting the fin pockets, but that only helps with the large sail fin pockets. I would still need to mod the pod fin pockets.

And for options 2 & 3, I need to trim the longer rod down to the same length. Option 1 avoids that issue. I was thinking of using a dremel cutoff wheel for this. I've never had to cut a carbon fiber tube before.....

So again - thoughts?

 

[Wally Ferrer]

Options:
1) - Leave the fin pockets and placement as is. Use a piece of wooden dowel to make up the difference on the fairing (after paint most likely will not be noticable, especially from any reasonable distance)
2) - Slide the large tube forward the 0.25". I would need to update the pod fin pockets.
3) - Update all 4 fin pockets to move the large tube forward by the 0.5"

I thought about trimming the fin tabs to allow them to move forward without adjusting the fin pockets, but that only helps with the large sail fin pockets. I would still need to mod the pod fin pockets.

And for options 2 & 3, I need to trim the longer rod down to the same length. Option 1 avoids that issue. I was thinking of using a dremel cutoff wheel for this. I've never had to cut a carbon fiber tube before.....

So again - thoughts?

At this stage, I would likely go option 1. I also know it would bother me, until it flies- then it goes from display to functioning rocket and any imperfections become moot.

 

[les]

I decided to leave the fins/tube placement as is and use dowels to extend the rods.

Tried making some foam jigs for alignment - those large sail fins are a challenge!



Did learn (and experience from the LPR and MPR builds) it will be best to tack the rings on first.
Using the jigs (and a few swear words) got things dry fitted and marked. I then used a file to scuff where the rings will be, and scuffed the fin ends. Note on the pod fin I scuffed both ends in prep for the pods. Also scuffed the tube for the fins.

 

[les]

Using the pod fins (since they are smaller and easier to work with), I positioned the rings and tacked them with CA. Need to be careful not to accidentally get CA on these fins at this time.


Next step, I tried to do too much...
I needed to epoxy the large outer tube on, ensure it was properly aligned with the fin pockets, and since the top of the pockets for the fin pods in the centering ring on the large tube, I wanted to get the pod fins installed as well.
Here is where I went too far - I also tried to do the sail fins - I should have just placed them for alignment and then removed them. Needing multiple hands I got my son to help. I triple buttered the fin ends (plus injected a bit of epoxy into the pocket) and and got everything together. I used a strap to pull the sail fins in - their weight kept trying to pull them out.



For the most part, it worked out OK - however I did find the pod fin pulled out a bit. I don't think this will affect its performance and I am not going to try to fix it (if I could figure out a way to even try!)

 

[WILDMANRS]

The most challenging hp build

 

[les]

Sorry for the delay - various life events.....

Scuffed up the transition area, installed my dowel spacers, and epoxied the CR on. Sitting on some wax paper while curing.

 

[les]

A bit of fillet on top. Some masking tape to help keep things clean. A bit of epoxy and final result

 

[les]

Cut the rods for a 45degree angle then cut some dowels. The angle helps blend the pieces.
Presently dry fitted using clamps to hold things in place. I purposely made the dowels a bit long figuring I could sand them to length once installed.

A little bondo and paint and no one will know the difference..... (except you folks following this....)

I also test fitted the antenna - the slot will need a bit of sanding.