Quinstar #7241 Build

[Back_at_it]

I'll be the first to tell you that I had ZERO clue about this kit. I picked it up on a whim a couple if years back when HL had them discounted to $1.99. It's been hanging on the wall and I never even gave it a second look until this past weekend. The build desk was clear and I just wanted to build something simple and quick so I grabbed the Quinstar and figured I'd throw it together in an hour. That was a mistake.

I can honestly say that this was one of the most interesting and fun builds I have done in this hobby in a very long time. I literally could not stop working on it once started. I started around 8pm and didn't realize wht time it was until I got up to got to bed at 2am. I just couldn't walk away.

Below are pictures from the build. Now that I have built one, I can honestly say I loved the build but I'd like to try a few things differently next time.

Here are all the piece laid out. At this point I had just popped the balsa out of the sheets and removed all of the smaller inner pieces. Overall there are a lot of parts to this kit. Before you begin, be sure you have an emery board or a small file to sand around the insides of all of those openings. Note that the main pieces are numbered 1 to 5. This is important later.



First step of the instructions is to assemble the motor mount. Initially I thought I was going to build this with the stock 18mm mount but around 1am decided to go 24mm. Maybe I was exhausted but after reading some reviews on here it seems like a good idea. The instructions tell you to mark the motor tube at the 1" and the 2.5" mark then mark a slit for the motor hook a the 2.5" mark.



Next step is installing the motor spring. I used a little CA under the top inch of the motor spring to keep it from coming loose. The clear retainer ring was then pushed into place at the 1" mark and more thin CA was used to keep it in place.



Next step is the motor block. This was glued in place on top of the motor clip.



Next comes the the outer centering rings. The ring with the slit goes on the bottom while the solid rings goes on the top. Both sit flush with the end of the motor tube.



Finally the motor mount is slid into the larger BT50 outer tube and allowed to dry.






That's it for the motor mount.

 

[Antares JS]

I have one, it's a great small field flyer and great for just doing something a little different.

 

[Back_at_it]

Building the main structure.

The main cage structure on this thing is amazing. Someone has some CAD skills when this was dreamed up. The balsa this entire kit is made from is very thin and very fragile. It reminds me of the stuff Estes used back in the day with their BT20 cheapo kits. It's extremely easy to break so be very careful with it. DO NOT try to simply push these out of the sheets. You need to use a blade to cut the little nubs that are still holding the pieces together. Also, DO NOT sand the sheets prior to removing the pieces. These things are way too thin as it is. Don't make them any thinner.

If I were to do this again I'd like to do two things differently. First I'd like to build one with removing all of the little cutouts in the main structure. The only slots that are required during the build are the four vertical slots and the two tiny horizontal slots. I'd leave everything else there and paper the entire thing with card stock. Yes it really is that thin.

For the first step you need to take note of the numbers on each piece as these go together in a specific order and you must ensure that the numbers are all facing inward when assembled.



The instructions have you dry fit the pieces together. Just go slow here. Everything does fit together. If it's not lining up you either have the wrong piece or you have the piece backwards. Once I had it dry fit I used s single drop of instant CA to on a few of the joints to keep it together. At this point the center of the structure has some strength but the arms are still very weak.



After letting the CA cure for about 10 mins. I went back with TBII. Using an old small paint brush I brushed each join with glue. When you really start looking at it, there are a lot of joins to to here. I did two coats on each joint. By the time you're done with the doing all the joints the first coat is dry and you can go right into doing the second coat.

This is another place where I would make another change. With the balsa being so thin you really should coat the entire thing is either CA, Epoxy or wood glue. I chose to coat mine in Epoxy after wards but given the chance to do it again, I coat the entire thing in epoxy while all of the pieces are exposed.



The next step has you glue the pentagon shapes together. Note that one of the three is larger that the other two. The largest piece is the top.



You then begin installing the piece by inserting the pentagon into the top of the main structure.



Next on the list are the smaller triangle pieces that cover the upper part of the structure and form the main star. There isn't a top or bottom to these so just glue them in place. It's worth noting at this point that due to how floppy this structure is, Not everything fits together all that well. You will need to be prepared to hold things in place while the glue sets up.



Next comes the outer triangles. These pieces only fit one way. When fitting them you will notice that they angle down and left. Ensure that all piecs angle down the same way as this is intended to spin when launched. Again, be prepared to hold pieces in place while the glue sets up.



The last part of the main structure is the pieces that span the area between the legs. These are not directional and fit into place very snugly so they kind of snap into place. Note that one of them has a cutout for the launch lug.



It was also at this moment that I realized that I had forgotten the top pentagon piece. I was wondering why the gaps were so large then found the piece hiding under the instruction sheet




That is it for the main structure.

 

[neil_w]

I love mine, almost certainly have more flights on it than any other rocket. If anything ever happened to mine I’d definitely get another.

I left out the 18mm mount and usually fly it on a D12-0 (highly recommended).

 

[neil_w]

With the balsa being so thin you really should coat the entire thing is either CA, Epoxy or wood glue.

Not needed. By the time everything is assembled it’s quite solid.

I did apply TBII fillets anywhere that two pieces of wood touched, to make sure it would stand up to D motors.

 

[Back_at_it]

I let that all sit for about 15 mins. Once it was dry enough I went back and brushed on TBII into every connection I could reach and finally decided to call it a night.



The next morning I did some reading here on the forums and decided that I wanted to use a 24mm mount. I cut a piece of BT50 at 2.75" long and inserted a motor block. The motor mount was then glued into the main structure.




Later that morning I was looking the at the build and decided to open up the hole in the top to allow for the flame from the larger 24mm motor to escape without burning the wood.

At this point I was moving the arms around and still didn't care for how flimsy the balsa was on the bottom of the arms. I decided to coat the entire kit in thinned T-88 epoxy. Once brushed on I warmed the kit to allow the epoxy to soak into the wood.

Here is where the kit sits today. The epoxy is cured and it's ready for paint.

 

[Back_at_it]

Not needed. By the time everything is assembled it’s quite solid.

I did apply TBII fillets anywhere that two pieces of wood touched, to make sure it would stand up to D motors.

I didn't care for how flimsy the areas shown with arrows were even after everything was cured. I actually broke one by handling the kit while painting on the epoxy.

 

[neil_w]

I didn't care for how flimsy the areas shown with arrows were even after everything was cured. I actually broke one by handling the kit while painting on the epoxy.

I agree that is a relatively weak spot. I think the ideal solution in that spot is cross-bracing between two frame pieces.

 

[goose_in_co]

For the first step you need to take note of the numbers on each piece as these go together in a specific order and you must ensure that the numbers are all facing inward when assembled.

Well that's why my Quinstar has those outside pieces angling all different directions. I looked at my assembly pictures and sure enough there is at least one number on the outside of the pentagon. It still flies nice.
That just means that I need to make the second kit that I have correctly, and with a 24mm motor mount.

Thanks for the ideas and great build thread!

By the way, if you liked the way the Quinstar went together, try the Asteroid Hunter.



Now back to your regularly scheduled Quinstar Build

 

[Back_at_it]

Well that's why my Quinstar has those outside pieces angling all different directions. I looked at my assembly pictures and sure enough there is at least one number on the outside of the pentagon. It still flies nice.
That just means that I need to make the second kit that I have correctly, and with a 24mm motor mount.

Thanks for the ideas and great build thread!

By the way, if you liked the way the Quinstar went together, try the Asteroid Hunter.

View attachment 605018

Now back to your regularly scheduled Quinstar Build

I have one of those and really looking forward to building it.

 

[Back_at_it]

Since this thing isn't in anyway shape or form aerodynamic I decided I wasn't spending a ton of time making it smooth I just knocked off the large bumps where the epoxy made the fibers stand up and called it good. This was shot with two coat of SEM trim black then the top was painted with two coats of Tamiya gloss Red. Probably could have used a third coat of Red but it's going to get beat up so I'm not worried about it.

Base coat of Trim Black.



Tamiya Red applied to top surfaces.




Decals applied.



In summary, this was an absolutely awesome kit to build. Yes I would do some things differently if I built another one but this was a ton of fun to put together. I'm looking forward to flying this one at this weekends club launch.

 

[neil_w]

Nice two-tone! Wish I had thought of that for my upscale. On that one, I just papered/smoothed the surfaces that received decals. Was pretty easy since they're all simple-shaped parts.

Have fun flying it!

 

[Back_at_it]

Flew the Quinstar this weekend on a C11-0. I positioned the rocket about halfway up the rod. The C11 took off with a ton of thrust and the Quinstar began spinning right off the rod as expected.

Total altitude was about 125-150ft. After the motor burned out the rocket stopped spinning then slowly began to spin in the opposite direction and landed safely about 30 ft from the pad.



I'm calling this one a success.

 

[neil_w]

Even better on a D12-0. Always fun.

 

[Back_at_it]

Even better on a D12-0. Always fun.

Looking forward to the D12. I just couldn't put my hands on them before the launch. I have a pack on order from AC.