Alien Space Probe Build with modifications (#2038)

[Back_at_it]

Time to build another one of my favorite old school designs. I've built two of these previously and it's a love / hate relationship.. The first one flew until there was nothing left of it and the other I gave away when I got out of the hobby at one point. I've had this one new in the package since the early 90's and have even pulled it out and started working on it from time to time only to put it back on the rack for another day. My hesitation to build another is mostly due to all of the issues that the rocket has with breaking parts.

I learned a lot with the first two I built so I think I'm ready to try this one again. This one will incorporate those changes in hopes of keeping it together for more than only a few launches.

- Stock 3/16" Dowels cut to length.
- Stock BT80 body tube 9.5" long. Cut for TTW fins.
- NC-80B nose cone.
- Paper Centering rings with center opening enlarged to fit BT50.
- Plywood piece to Reinforcement Shock Cord mount.
- Lower Fins cut from Basswood with TTW tabs.
- Upper Fins cut from Basswood.
- 3/16" launch lug.
- Estes 24mm motor retainer.
- BT50 motor block.
- BT50 motor tube 2.75" long.
- Plywood landing pads. Made from BT20 and BT50 centering ring scraps.
- Stock water slide decals.



Got started with the motor mount. Inserted the motor block from into the motor tube from the rear and pushed into place with an old motor as a spacer.



Next the motor tube was sanded to remove the outer layer. The tube was then marked for the upper and lower centering rings. These will sit above and below the fin tabs.



Next the upper paper ring was attached on the upper mark.



Once dry, the motor mount was flipped over and the reinforcement plate was installed. This piece will fit between the motor tube and the outside wall of the body tube. Glue was placed on both surfaces then clamped in place on the underside of the upper ring.



Once dry, 500# Kevlar was added as a leader for the shock cord. A small hole was drilled in the plywood and the Kevlar was pushed through. A knot was tied in the Kevlar and it was glued in place.



That is as far as I've gotten this weekend. Hoping to wrap this one up enough to fly it at the club launch this Saturday.

 

[Huxter]

Great start! I recently finished a ASP. The stock decals were extremely brittle and did not lay down very well on the rocket - even w Micro Sol. I need to look at getting decals else where or try to print my own??

Please keep posting - love to see your pics!

 

[DigBaddy]

May I suggest carbon fiber rods for legs. Have worked well on my clone and 4" upscale.

You'll love it on 24mm motors.

 

[MALBAR 70]

Mark at Stickershock has a very nice set. I ran into the same problem, the stock decals disintegrated as soon as they came out of the water.

 

[DigBaddy]

Great start! I recently finished a ASP. The stock decals were extremely brittle and did not lay down very well on the rocket - even w Micro Sol. I need to look at getting decals else where or try to print my own??

Please keep posting - love to see your pics!

Stickershock for nice vinyl decals.

 

[Back_at_it]

Great start! I recently finished a ASP. The stock decals were extremely brittle and did not lay down very well on the rocket - even w Micro Sol. I need to look at getting decals else where or try to print my own??

Please keep posting - love to see your pics!

I'm a little concerned with the old decals as I'm familiar with them be brittle. Add in the fact that I absolutely HATE water slide to begin with and it's just makes matters worse. I've been looking at the decals and they are a simply enough design that I can reproduce them in Vinyl is needed.

Worse case, Mark from Sticker Shock will bail me out

 

[Back_at_it]

May I suggest carbon fiber rods for legs. Have worked well on my clone and 4" upscale.

You'll love it on 24mm motors.

I'm strongly considering it. I remember your build.

Back with my second one of these I found a way to keep the legs on it during most flights. Problem was that I transferred that load up to the fins so it then started breaking fins off instead of snapping the legs. Hoping to bring everything I've learned together in one build.

If I have issues his time around, the next one will be carbon tubes and plywood fins.

 

[icyclops]

I love this model rocket and have built 3 of them many years ago. The way I handled the landing legs was to use carbon fiber dowels for the legs and small springs the wrap around the bottom 1” of the leg and the other end attached to the leg pad. Like a shock absorber. Was enough to keep the fin leg area from breaking On harder or off center landings. I also made sure that the top motor tube centering ring was at the same level where the dowels attached to the outside body tube. This was easier due to using a bigger motor tube (24mm motor size) and longer. I also increased the size of the chute to a custom 24” instead of an 18”. When they landed they held up nicely, but eventually lost them all to wind drift Over the years.

 

[Initiator001]

Great start! I recently finished a ASP. The stock decals were extremely brittle and did not lay down very well on the rocket - even w Micro Sol. I need to look at getting decals else where or try to print my own??

Please keep posting - love to see your pics!

I coat old rocket decal sheets with Microscale Industries, Inc. Liquid Decal Film.
I just finished an early 1980s Estes Bandit kit (K-48) and used the Liquid Decal Film on the kit decal sheet. I had no issues with the decals.

 

[Back_at_it]

I coat old rocket decal sheets with Microscale Industries, Inc. Liquid Decal Film.
I just finished an early 1980s Estes Bandit kit (K-48) and used the Liquid Decal Film on the kit decal sheet. I had no issues with the decals.

I really hate water slide so anything that will make them stay together and make them easier to apply is appreciated. I'll order a bottle today.

I assume you just brush it on the decals and let it dry a day or so before you wan to apply them.

 

[Back_at_it]

I love this model rocket and have built 3 of them many years ago. The way I handled the landing legs was to use carbon fiber dowels for the legs and small springs the wrap around the bottom 1” of the leg and the other end attached to the leg pad. Like a shock absorber. Was enough to keep the fin leg area from breaking On harder or off center landings. I also made sure that the top motor tube centering ring was at the same level where the dowels attached to the outside body tube. This was easier due to using a bigger motor tube (24mm motor size) and longer. I also increased the size of the chute to a custom 24” instead of an 18”. When they landed they held up nicely, but eventually lost them all to wind drift Over the years.

24" chute will be a must. Maybe even 30".

Even with the D12 on board I'm looking at relatively low flights as this thing is going to be heavy so I'm not really concerned with chasing it. I found that doubling up the dowels on the legs prevented them from breaking on my las tone but that just transferred the shock to the fins and caused the fins to pop off but this time I'm doing TTW so hopefully that is resolved.

 

[Back_at_it]

Back with an update as I managed to get a little more done last night.

Started with assembling the two part fins. For this I used an old piece of glass (not shown) to ensure the surface was perfectly flat then glued the upped fin to the lower using TBII and let that dry completely. Repeated this for all three fins.



Next it was time to insert the motor mount. Before inserting the mount I coated the top of the paper centering ring with TBIII for a little fire protection. I then added glue to the inside to the tube and slid the mount in until the top centering ring was flush with the top of the fin slots. When doing this I was sure to position the mount where the reinforcement plate for the shock cord was between the fins.

In this pic you will notice that there is a length of coupler in the body tube. This runs from the rear of the tube and stops to leave enough room for the nose cone shoulder. As I mentioned once before, I've started and stopped building this kit a couple of times in the past and one of my thoughts many years ago to fix the fin breaking issue was to reduce the flex in the body tube. This was obviously before I understood TTW fins.



After letting the mount dry it was time for the first fin. A bead of glue was added to the motor tube where the fin will attach and let soak into the tube.



A bead of glue was then added to the root edge of the fin and it was inserted into the slot.



After about 30 mins I went back and gave the inside of the fin a small fillet where the fin meets the outer tube.



First fin attached. More to come tomorrow.

 

[Initiator001]

I really hate water slide so anything that will make them stay together and make them easier to apply is appreciated. I'll order a bottle today.

I assume you just brush it on the decals and let it dry a day or so before you wan to apply them.

I tape the corners of the old decal sheet to a larger piece of wax paper.
Then I pour some of the Liquid Decal Film at one end of the decal sheet.
Using a foam brush I spread the Decal Film across the decal sheet evenly. If needed pour on more Decal Film.
Let dry 24 hours.
Cut and apply decals as normal. It is best to cut as close to the decal as possible.

 

[teepot]

I did an upscale and used colored vinyl tape and pin stripping instead of pre-made decals or vinyl. My legs are 3/8th" dowels. I'm afraid to fly it. Because we fly off a rock hard dry lake bed. After I built it I saw @DigBaddy use carbon fiber tubes. I looked at some. Way to much money for this size rocket.

 

[Back_at_it]

I tape the corners of the old decal sheet to a larger piece of wax paper.
Then I pour some of the Liquid Decal Film at one end of the decal sheet.
Using a foam brush I spread the Decal Film across the decal sheet evenly. If needed pour on more Decal Film.
Let dry 24 hours.
Cut and apply decals as normal. It is best to cut as close to the decal as possible.

View attachment 539576

Thanks. It is out for delivery today so I’ll do the decals and let them sit for a few days.

 

[Back_at_it]

Fins attached. Did the internal fillets next. Did two rounds of fillets. The first was with TBII to allow it to soak into the materials. I then went back with thick and quick to give it a little more surface area. Note the fillet around the reinforcement plate for the shock cord.



Once the internals were dry it was time for the external fillets. Did one pass with TBII then a second pass with Thick and Quick this morning. These are currently drying.




I'm working on the legs during the day. Hoping to have them attached tonight. I have some interesting testing I did with various adhesives on the dowels looking for the best bond.

 

[Back_at_it]

Made some additional progress but I wanted to share a little testing that I did using dowels. Just skip down if you aren't interested in the testing. When I built this rocket the first couple of times the main issues I had were with the legs breaking on landing. The issue was the rod snapping somewhere in the middle between the pad and the fin. To resolve this on my second build I doubled up the legs from the pad to the fin but all that did was transfer the load to the fin itself so I was then either popping the entire dowel off the fin or ripping the fin off the tube. I attributed this to the rather weak Elmer's Glue-All I was using back then.

This time around I wanted to do a couple of tests to make sure the glue I was using bonded to the dowels. I used a couple of scraps pieces, sanded them with 100 grit then added TBII to both dowels, rubbed it into the wood then clamped them and let it sit. Honestly I kind of forgot about it for a couple of days so it was definitely cured. To my surprise, adding just a small about of pressure to the two pieces popped them apart. The remaining glue could be picked off the dowels. It didn't stick at all. I repeated the test with Elmer's Wood Glue with the same results. It just wouldn't stick to the dowels.

Decided on one more test. Before I got crazy and went and bought some 3M epoxies I decided to test BSI's 30min. Same process. Sanded with 100 grit. Warmed the epoxy in hot water. Warmed the parts just slightly with a heat gun then mixed and applied to both piece of the dowel. Clamped and let them cure over night. I was unable to get the dowels to come apart with any amount of force I could apply by hand. I grabbed both sides with pliers and was able to break the bond but it took a fair bit of the wood with it when it finally failed.

Lesson learned. If working with dowels, Use Epoxy.

Now to the update.

I built the legs using BSI 30 min. Holes were drilled in the pads so the dowels pass through the pads. Next I measured and cut pieces to fill the entire space between the bottom of the fin and the pads effectively doubling up the lower legs. These were sanded with 100 grit, warmed then the epoxy was applied and they were clamped and let cure.

Once cured I marked the area where the dowel would attach to the fin. I repeated the sanding, heating, epoxy process and used blue tape to hold them in place while they cured.




Before heading to the office this morning I applied a light coat of DAP brand wood filler to the fins and any rough areas of the dowels. Hoping to sand and primer tonight for a test flight at the club launch tomorrow.

 

[DigBaddy]

Made some additional progress but I wanted to share a little testing that I did using dowels. Just skip down if you aren't interested in the testing. When I built this rocket the first couple of times the main issues I had were with the legs breaking on landing. The issue was the rod snapping some in the middle between the pad and the fin. To resolve this on my second build I doubled up the legs from the pad to the fin but all that did was transfer the load to the fin itself so I was then either popping the entire dowel off the fin or ripping the fin off the tube. I attributed this to the rather weak Elmer's Glue-All I was using back then.

This time around I wanted to do a couple of tests to make sure the glue I was using bonded to the dowels. I used a couple of scraps pieces, sanded them with 100 grit then added TBII to both dowels, rubbed it into the wood then clamped them and let it sit. Honestly I kind of forgot about it for a couple of days so it was definitely cured. To my surprise, adding just a small about of pressure to the two pieces popped them apart. The remaining glue could be picked off the dowels. It didn't stick at all. I repeated the test with Elmer's Wood Glue with the same results. It just wouldn't stick to the dowels.

Decided on one more test. Before I got crazy and went and bought some 3M epoxies I decided to test BSI's 30min. Same process. Sanded with 100 grit. Warmed the epoxy in hot water. Warmed the parts just slightly with a heat gun then mixed and applied to both piece of the dowel. Clamped and let them cure over night. I was unable to get the dowels to come apart with any amount of force I could apply by hand. I grabbed both sides with pliers and was able to break the bond but it took a fair bit of the wood with it when it finally failed.

Lesson learned. If working with dowels, Use Epoxy.

Now to the update.

I built the legs using BSI 30 min. Holes were drilled in the pads so the dowels pass through the pads. Next I measured and cut pieces to fill the entire space between the bottom of the fin and the pads effectively doubling up the lower legs. These were sanded with 100 grit, warmed then the epoxy was applied and they were clamped and let cure.

Once cured I marked the area where the dowel would attach to the fin. I repeated the sanding, heating, epoxy process and used blue tape to hold them in place while they cured.


View attachment 539777

Before heading to the office this morning I applied a light coat of DAP brand wood filler to the fins and any rough areas of the dowels. Hoping to sand and primer tonight for a test flight at the club launch tomorrow.

View attachment 539778View attachment 539779

Thanks for sharing what you found in your testing! Really good to know!

 

[Back_at_it]

Pushed hard to get this one close enough to fly this weekend. Was outside late on Friday getting primer shot on. Two quick coats of SEM high build then brought it inside and let it sit over night.



Had a little time to do some sanding on the nose cone before the launch. Maiden flight was on a D12-3. Perfect straight flight. No weather cocking, just a nice stable flight to about 400ft. Recovered safely on a 20" Nylon chute. Went a little large on the chute as we had plenty of room and I wanted to ensure the legs stayed on it.




Need to do some additional sanding but I might have this one in color in a day or so.

 

[Back_at_it]

Finally had warm enough weather to get the first color sprayed on. I went with two coats of SEM white primer followed by three coats of Ace brand Safety Red.

The cure time on the stuff is slow but the finish is great once cured. Just need to resist touching it for a couple of days.

Sometime mid week I’ll paint the legs and apply the decals.

 

[Dad of Sapling]

Looks great. What paint did you use ?

 

[Back_at_it]

Looks great. What paint did you use ?

Three coats of Ace brand Safety Red over a white primer.

 

[BABAR]

Three coats of Ace brand Safety Red over a white primer.

Safety Red. Good name and color choice!

 

[Back_at_it]

Little more progress. Decided to do something I haven’t done in a while and went with hand painting the lower legs. Used Tamiya acrylic silver.

Painted on two coats and letting that cure for a day. Doing vinyl this weekend.

 

[Back_at_it]

Had some time this afternoon to wrap this one up. I attempted to use the original Estes decals but as is typical with me and water slide decals, this once again was a complete disaster but this time it wasn't my fault. The decals were just old to use. About a week ago I received a bottle of Liquid Decal Film. I picked this up as a recommendation from a member here. I watched a couple of videos on using the product then taped down my decals and gave them two coats and let that sit for a few days. Once I dipped the decals in water they crumbled but I was left with a weird clear film that I'm going to assume was the decal film.

Not to worry. I planned ahead and had ordered some vinyl from Stickershock when I started this build.

Here is the finished product. Sprayed the vinyl with a little water so I could move them around if needed then used a little heat to warm them and get the water out. End result came out pretty nice. I wiped the rocket down with 50/50 water/alcohol then shot on two good coats of Duplicolor clear coat.

 

[DigBaddy]

Very nice!

 

[MarsFire]

Such a cool rocket. Excellent build, well done!


Andrew

 

[BABAR]

Wish you a straight trail, a short walk, and five unbroken legs!

 

[SCooke123]

Turned out really nice - I like the colors!

 

[Fishhead]

Mark at Stickershock has a very nice set. I ran into the same problem, the stock decals disintegrated as soon as they came out of the water.

Same here. Most brittle decals I've ever worked with.