Red River - USS Prometheus

[JAL3]

The USS Prometheus is a futuristic freighter designed to work on 18mm motors. I would call it a skill level 2 kit. There is some cutting of tubes and some alignment issues but the fins are die cut. It also uses a combination or white/yellow glue and epoxy with a few methods that are not seen in many simple kits.

 

[JAL3]

Construction begins with the motor mount. The first item is to make a mark for the engine hook but, instead to telling you to measure back some distance, the instructions take the practical route of saying to set the thrust ring alongside the motor tube to place the mark.

 

[JAL3]

Dimensions were then given to make marks for the centering rings.

 

[JAL3]

A slit was then made for the engine hook and the hook was inserted.

 

[JAL3]

Some electrical tape was used to hold the engine hook in place and the rear centering ring was slid into place and glued with yellow glue. It was allowed to sit a bit and then the forward ring was likewise placed.

 

[JAL3]

While the first round of glue on the rings was setting up, the thrust ring was glued into to forward end of the motor tube flush with the end of the engine hook.

 

[NjCo]

I love your build threads. On the one hand they contain so much useful information. But the best part is just seeing what's going on in your work area!! I'm always amazed when you get to the final 'I'm done' photo that there aren't extra rocket parts or other stuff from your workbench hanging off your rockets. Maybe a glue bottle stuck to a fin or a pencil glued to the body tube. Great job and keep up the interesting threads.

 

[JAL3]

I love your build threads. On the one hand they contain so much useful information. But the best part is just seeing what's going on in your work area!! I'm always amazed when you get to the final 'I'm done' photo that there aren't extra rocket parts or other stuff from your workbench hanging off your rockets. Maybe a glue bottle stuck to a fin or a pencil glued to the body tube. Great job and keep up the interesting threads.

I keep promising myself that I am going to clean the area up. I even make half hearted attempts to do so from time to time. Somehow, though, I wind up grabbing a kit of the wall and starting a new one. That partly why SHE WHO MUST BE OBEYED banished me from the house.:bangpan:

 

[e42]

Your build threads are enjoyable to follow. I have one of these in my build pile. Maybe if I sit and watch this thread op:, I may be inspired to build it. Good luck with the build.

--- Ron

 

[JAL3]

Your build threads are enjoyable to follow. I have one of these in my build pile. Maybe if I sit and watch this thread op:, I may be inspired to build it. Good luck with the build.

--- Ron

Thanks I don't want to spoil the ending but its done (except for flying) and looks pretty good. Its been done a few weeks but the last few weeks have been way too busy with hospital calls and funerals. Hopefully, things will slow down now and it will fly on Saturday.

 

[JAL3]

A light fillet of yellow glue was then placed on both sides of both centering rings.

 

[JAL3]

When these fillets had dried, I tied a Kevlar harness around the forward end of the motor mount and laid down a heavier fillet on top of it and on the other joints of the motor mount. This was allowed to dry thoroughly. I should point out here that the Kevlar harness is a modification on my part.

 

[JAL3]

When dry, glue was swabbed into the body tube and the motor mount was inserted. A swab was then used to build up a fillet around the aft centering ring.

 

[JAL3]

The fins for the Prometheus were all precut and were still held captive in their parent stock. I gently sanded both sides before removing the pieces.

 

[JAL3]

The main fins/wings are built up out of 2 pieces. I used a double glue joint to join the pieces and a steel ruler to make sure the root edges stayed aligned.

 

[Pantherjon]

I have one of those in my fleet! Nice flying rocket! Gets some good altitude on just a 'B' motor One day I will put a 'C' in her to see what she can really do!

 

[DRitchie]

I've got one of these, and yes, it flies extremely well....one of the better sci-fi designs to come out in recent years.

Oddly enough, I've ended up with a gash in the nose cone....twice....still not sure what caused it...

 

[tomar]

I just added one in my to build queue.

 

[JAL3]

I just added one in my to build queue.

I wonder if I'll get a "Diamond Ring" as a commission...

 

[JAL3]

As the main part of the fins were drying, I turned to the other balsa pieces which included the vertical tail and two more pieces to be fitted to the ends of the wings to support the nacelles. This balsa too was of good quality and I used the opportunity to round the leading and trailing edges, being careful not to mar the root or outer edges; those would need to remain flat for other joints.

 

[JAL3]

The drying time was also to mark the proper lines on the body tube. The kit came with a wrap around fin guide which was cut out and taped around the body. The lug line was aligned with the engine hook and then all of the lines were transferred. The guide was removed and an angle was used to extend the lines.

 

[JAL3]

I considered the main part of the fins to be dry enough to mess with again the next day. Looking them over, the joint seemed to be straight so I tried to round the leading and trailing edges of these as well. Again, I left the root and outer edges strictly alone in consideration of future joints.

 

[JAL3]

I had no doubt that filling and sanding the balsa would be a nightmare after the fins were installed so I painted a coat of Elmer's filler on the fins and let them dry for a day. They were then sanded down in preparation for installation on the body tube.

 

[JAL3]

The attachment of the main fins to the body is an easy but delicate operation. The body tube was laid on a flat surface with the lug line in the 6 o'clock position. This put the two main fin lines on the top on either side of the noon position. The BT was then taped into place so that it would not roll. A double glue joint of yellow glue was built up on the fins and the BT and, with the second coat, the fins were put into place along their lines. They are intended to NOT be mounted perpendicularly but are supposed to droop so that the out edge is even with the bottom of the tube. Their position was checked from several different angles and then the assembly was left alone to dry. The groove formed by the fins and the tube was not an issue for reasons which will later be apparent.

 

[JAL3]

The nacelle on the vertical tail is, like the other nacelles, made from a piece of BT20. Unlike the others, though, it has a beveled trailing edge. This bevel is cut with the assistance of a wrap around template which was cut out and wrapped around the tube.

 

[JAL3]

The tube was then placed on a mandrel and a razor knife was used to cut along the rear edge. Sandpaper was used to clean up the cut.

 

[JAL3]

The main fins dried in place for a day before I risked disturbing them. When I picked the rocket up, the seemed to be attached about as well as could be expected for a joint that involved just the corner of one edge for the connection. This left a V-shaped valley on the dorsal surface between the fin and the BT. At least they seemed to be straight and Red River had a plan to fix the gap!

 

[JAL3]

The kit came with a pair of wooden dowels the length of the fin root edges. These dowels were intended to fit into the gap between the BT and the fins.

 

[JAL3]

A batch of 5 minute epoxy was mixed and then some was brushed into the gaps. The dowels were pressed into the gaps and more epoxy was brushed over the top. I then used my finger whetted with some denatured alcohol to smooth out the epoxy and feather it to the BT and the fin.

 

[Fred22]

John the manufacterers ought to start paying you for this. Great build thread. I build one of those and its an awesome little flyer
Cheers
fred