Binder Design Excel Dual Deploy Build

I just received my Binder Design Excel kit with the dual deploy option and I'm looking forward to building it. This will be the second mid/high power rocket I've built, so, I'm open to suggestions on things I can do to make it better. I've gone with the 38mm motor mount since 38mm motors seem like they are a bit more cost effective than 54mm and I'll probably build something that handles larger motors once I've gained some experience with this kit. Depending on how this goes, I may eventually just build another booster section for this with a 54mm motor mount.

So far, I like the design of this kit and I'm sure it would work well if I just built it as described by the directions. The instructions are very detailed and at first glance all of the components look solid. I'm planning to use AeroPoxy structural epoxy for most of the construction and I'm considering a few other minor changes. First, I'm considering putting in a longer MMT so that I can reach the eye bolt. I realize there are ways to attach the harness to the MMT without touching the eye bolt, but, it might be nice to be able to reach it directly. If I do this I'll probably add another centering ring at the upper end of the MMT. The other change I'm considering is replacing the stock motor retention with an Aero Pack screw on retainer because I've had good luck with that on my other rocket.

Once complete, I may launch it a few times without the dual deploy kit, but, eventually I'm planning to configure it for dual deploy using an RRC2+ altimeter system.

When I have time I'll post pictures as I go along.

Here's how it looks right out of the box....

https://www.rocketryforum.com/showthread.php?56182-L2-Build-Binder-Excel-Plus-Success

I built and flew the exact same thing for my level 2 cert.
Check out the thread for my build, may be a few tips and tricks you can use.

Great rocket, you won't be disappointed.
JW

By the way, mine was built with longer motor tube, third centering ring, and Aeropac retainer like you mention.
I can easily reach the eye bolt for tether attachment.

I'd use structural wood glue on the build. Light, strong and easy to use.

I'll be watching this one... op:

Here is the obligatory dry-fit picture. I've been looking at other build threads for this kit and I've decided that I am going to use a longer MMT and a third centering ring so that I can reach the eye bolt. I'm also leaning toward sticking with the motor retention that comes with the kit as it seems to be simple yet effective.

Thank you for the advice on the wood glue....I will keep it in mind while I'm building. I probably won't comment any further on glue choices as that seems to be a sticky subject on this forum (pun intended).

I'll be waiting a bit for the new MMT and extra centering ring to arrive, so, rather than starting with the motor mount as the instructions suggest I'm going to start by sanding the fins and filling the spirals on the tubes. So far I'm thinking of using a palm sander for the fins and CWF for the spirals. Hopefully I'll get to work on it this weekend. Also, I'm thinking I'll finish this kit in blue and white using the same layout as found on the Binder Designs web site.

The MMT and extra centering ring arrived today, so, I cut the MMT to about 14" (which should make reaching the eye bolt easy) and glued it to the thrust plate. I've been busy lately so I haven't gotten to sanding the fins yet. Hopefully tomorrow I'll get time to glue on the rear centering ring and start rounding the fins.

On a side note, I helped my 3rd grade daughter launch a Mini Mosquito with her science club this week and although it went so high that it initially appeared to be gone forever, we found it later in the day in good condition but farther away than we expected.

kswing said:

I've gone with the 38mm motor mount since 38mm motors seem like they are a bit more cost effective than 54mm and I'll probably build something that handles larger motors once I've gained some experience with this kit. Depending on how this goes, I may eventually just build another booster section for this with a 54mm motor mount.

Click to expand...

I'm sure this rocket will work very well and last a long time. You will have a lot of fun with it. But.. I really would have suggested you start with the 54mm just because then you wouldn't have to build another booster or a new rocket when you want to fly that K motor. I built my L2 rocket with 54mm and never regretted it. I've probably flown more 38mm motors in it for the reason you mentioned, but on those perfect calm days being able to put a big 54mm in there has been great.

BTW, there is no "probably" about it. If you stick with the hobby, you will definitely build a 54mm L2 rocket and probably a 75mm one at some point. That is just the way things evolve.

Good Luck...

I am definitely going to be watching this build, as I have cast my eye on this as a possible L1 airframe and beyond. Like you, I was thinking the same , start flying with out the E-bay and upper at first to get some experience with it then go from there. A very versatile design in my mind. I am just a BAR but I came to the same conclusion about going with the 54mm mount that Handeman mentioned for the same reasons. You just never know! Just more options. I will just use an adapter for the 38mm. It will be a while before I am ready for it, until then I will watch your build with interest! Best of luck!

I seriously considered getting the 54mm version, but, this is only my second larger rocket so I'm looking to learn while building and flying this and then as Handeman suggested keep moving up in size. (You can never have too many rockets?) The Excel will also likely be my L1 airframe unless I get brave and try an H motor in my 2.56" LOC Graduator one day when the winds are light.

kswing said:

I seriously considered getting the 54mm version, but, this is only my second larger rocket so I'm looking to learn while building and flying this and then as Handeman suggested keep moving up in size. (You can never have too many rockets?) The Excel will also likely be my L1 airframe unless I get brave and try an H motor in my 2.56" LOC Graduator one day when the winds are light.

Click to expand...

I just purchased an Excel Dual deploy for my level 2 attempt. I also went 38mm. It will be vastly cheaper to obtain level 2 with it and finances are a little tight. I am looking at picking up a Stratologger for my main deploy and an Alts2 I have had for nearly 20 years, that works fine(I tested both outputs yesterday), as a backup. I can actually build a level 3 at some point with a larger than 54MM motor mount stepped down (for less daring flights)when finances permit it. I have everything (disk and closures)but the motor tube for an Aerotech 38mm J350 so should be cost effective. The rocket itself looks great to me so I will probably be flying it a lot, if I can get the E-deploy done right. I look forward to seeing how you do with it. I also had already considered using their paint scheme with a few personal touches. This should probably be in another thread but are you planning on putting up more than one altimeter? IF so, are you going to run the igniters to the same charge or rig separate charges for the deployments? I only ask because I have thought about it both ways and I am leaning to just one charge cup with two separate circuits to deploy them.

Take pictures! I want to see how it progresses. I too am using the stock retainer for this rocket.

Ray51 said:

... are you going to run the igniters to the same charge or rig separate charges for the deployments? I only ask because I have thought about it both ways and I am leaning to just one charge cup with two separate circuits to deploy them.

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My suggestion is, if you are going to use redundant altimeters, use redundant charges too. Use about 20% more powder in the backup charge. Although ground tests improve reliability a lot, one failure mode is the charge going off but the rocket not opening or nose cone not coming off. With a second larger backup charge, you still have a chance of the backup charge working. If you use a single charge, you don't have any redundancy for this failure mode.

kswing said:

I seriously considered getting the 54mm version, but, this is only my second larger rocket so I'm looking to learn while building and flying this and then as Handeman suggested keep moving up in size. (You can never have too many rockets?) The Excel will also likely be my L1 airframe unless I get brave and try an H motor in my 2.56" LOC Graduator one day when the winds are light.

Click to expand...

I too was seriously thinking about the Excel, but when I came up with my Excelerator paint scheme I now know that I've got to do that first.

Tonight I finally got to work on this kit some more, so, I glued the rear centering ring to the MMT and the thrust ring. Here's a picture of how I've got it clamped while the glue dries.

I'm using AeroPoxy ES6209 so although it is strong it takes about a day to cure. I've also found that it is much thicker than the epoxy I've used in the past (think of honey or thick syrup), so, I warm up the cans in warm water to make it easier to pour prior to mixing. Also, a few times after I put the pieces together I used a squared-off tongue depressor to clean off the excess glue that squeezed out so I won't have to sand it off later.

As far as the dual-deploy setup goes, I'm still new to that so I'm also looking for advice. So far I've been planning to use my RRC2+ dual deploy altimeter from Missle Works and so far I wasn't planning for a redundant altimeter but I was planning to use the motor charge (with a long delay) as a bit of a backup. I went with the RRC2+ because it was fairly cheap and it seemed to be easier to configure than some of the other models. From what I've seen of Handeman's rockets and posts I'd take his advice on dual deploy and backup charges. For my setup, I'm thinking I'll mount the altimeter and battery on a plywood sled that mounts onto the threaded rods that came with the kit and I'll secure the battery with two zip ties and I'll use the screw switch that came with the kit. I'll post some pictures once I've figured out the layout. I'm planning to leave room for a backup altimeter and battery in case I decide it's needed. I've tested (in the back yard) ejection charges for a smaller rocket that are simply made of paper straws filled with black powder folded and taped around an e-match and the tests worked well, but, I haven't flown with them yet. For the Excel I'm thinking I may use PVC caps packed with black powder and some recovery wadding as suggested in the kit.

I like the Excelerator paint scheme, I'm curious to see how it progresses. So far I'm thinking I'll use a blue color that is very similar to the Excelerator and then a white body tube and white fins with the kit provided decals.

kswing said:

I like the Excelerator paint scheme, I'm curious to see how it progresses. So far I'm thinking I'll use a blue color that is very similar to the Excelerator and then a white body tube and white fins with the kit provided decals.

Click to expand...

I don't know how long you've been lurking here. So, I don't know if you've read about what I'm currently up to. Nearly all my projects are on an indefinite standby as I'm currently in the People's Republic of China teaching English, and my rockets are currently in the US.

The Excelerator's .ork file (and the Excel's) can be found in my .ork files thread.

Tonight I filled the tube spirals and started sanding the fins. Here's a picture of the filled tube spirals...

I filled them with thinned Elmer's Carpenter's Wood Filler (like this) using a small paint brush and then after a brief drying period (10-15 minutes) I used a putty knife to remove most of the excess so that I won't have to sand it off later.

I've also started sanding the fins and I'm wondering how "rounded" I have to make them. The instructions point out that since this is a sport kit the fins don't need to be airfoil shaped and I don't want to spend a huge amount of time sanding, but, I'd also like them to be somewhat aerodynamic.

Today I finished rounding off my fins and I cut out a simple fin alignment jig from some foam poster board using the guide provided with the kit.

Hopefully some time in the next few days I'll get to use the jig and some rubber bands to hold the fins in place while I tack them (one at a time) to the MMT.

Over the past few days I've tacked the fins to the MMT using the jig for alignment. The jig worked well so they look to be well aligned. In order to save time, I used Bob Smith 15 minute epoxy for tacking the fins. After they all cured I cut out the body tube slots behind them and slid the entire fin can from the body tube. As I've seen others do on this forum, I numbered the slots before removing them so that I can match them when I put them back. Here's the MMT and fins prior to having the forward two centering rings glued in place.

Last night I glue the middle centering ring in place against the fins and gave it a nice fillet using Aeropoxy ES 6209 and then installed the eye hook onto the forward centering ring. I also coated the exposed ends of the body tube with thin CA to make them a little more durable.

Tonight I glued the forward centering ring onto the MMT and gave it a fillet for strength. Also, in case anyone is wondering, one of the reasons I'm using the Aeropoxy on this build is to get familiar with it for when I start building fiberglass kits. Hopefully tomorrow I'll get to start the internal fin fillets and I'll get to post some more pictures.

kswing said:

As I've seen others do on this forum, I numbered the slots before removing them so that I can match them when I put them back.

Click to expand...

Shouldn't matter because the slots are currently CNC machined on a zero backlash harmonic drive 4th axis with a resolution of .0002 degrees. It should slide in easily in any position. Try it and see.

Binder Design said:

Shouldn't matter because the slots are currently CNC machined on a zero backlash harmonic drive 4th axis with a resolution of .0002 degrees. It should slide in easily in any position. Try it and see.

Click to expand...

Sorry if anyone misunderstood....I didn't mean to imply that the fin slots weren't well machined. The fins slots are very well machined (as is the rest of the kit) and the fins will fit into any of the slots. The only thing I need to match up is the small piece of body tube that I cut out from behind the fins and they don't match exactly because of my own less-than-perfect skills with an X-Acto knife.

kswing said:

Sorry if anyone misunderstood....I didn't mean to imply that the fin slots weren't well machined.

Click to expand...

No misunderstanding at all. What you mentioned is pretty much common practice, we even used to recommend it before our slotting was at high resolution. Still not a bad idea.

Tonight I started on the internal fin fillets. The epoxy is very thick at room temperature, so, after applying it I warmed it up a bit for a short time to help it even out and smooth out. Here's a picture of the first set...

kswing said:

I just received my Binder Design Excel kit with the dual deploy option and I'm looking forward to building it. This will be the second mid/high power rocket I've built, so, I'm open to suggestions on things I can do to make it better. I've gone with the 38mm motor mount since 38mm motors seem like they are a bit more cost effective than 54mm and I'll probably build something that handles larger motors once I've gained some experience with this kit. Depending on how this goes, I may eventually just build another booster section for this with a 54mm motor mount.

So far, I like the design of this kit and I'm sure it would work well if I just built it as described by the directions. The instructions are very detailed and at first glance all of the components look solid. I'm planning to use AeroPoxy structural epoxy for most of the construction and I'm considering a few other minor changes. First, I'm considering putting in a longer MMT so that I can reach the eye bolt. I realize there are ways to attach the harness to the MMT without touching the eye bolt, but, it might be nice to be able to reach it directly. If I do this I'll probably add another centering ring at the upper end of the MMT. The other change I'm considering is replacing the stock motor retention with an Aero Pack screw on retainer because I've had good luck with that on my other rocket.

Once complete, I may launch it a few times without the dual deploy kit, but, eventually I'm planning to configure it for dual deploy using an RRC2+ altimeter system.

When I have time I'll post pictures as I go along.

Click to expand...

I usually just buy the kit with a 54mm and use an adapter to fly 38's. This way you get the best of both worlds and have a wider selection of motors to choose from. I think adapters from Aerotech are $25, but don't quote me.

Just my :2:

Great designer BTW

AfterBurners said:

I usually just buy the kit with a 54mm and use an adapter to fly 38's. This way you get the best of both worlds and have a wider selection of motors to choose from. I think adapters from Aerotech are $25, but don't quote me.

Just my :2:

Great designer BTW

Click to expand...

IIRC, they're $10 from Binder Design.

Great fillets! Since I found this forum and started crawling through build logs, I have enjoyed seeing different techniques that others use on the same kits.

kswing said:

Tonight I filled the tube spirals and started sanding the fins. Here's a picture of the filled tube spirals...
View attachment 287453
I filled them with thinned Elmer's Carpenter's Wood Filler (like this) View attachment 287454 using a small paint brush and then after a brief drying period (10-15 minutes) I used a putty knife to remove most of the excess so that I won't have to sand it off later.

Click to expand...

Thanks for posting this up as I was interested in the Binder rockets, but I'll never buy another rocket that I have to fill spirals on.

hobie1dog said:

Thanks for posting this up as I was interested in the Binder rockets, but I'll never buy another rocket that I have to fill spirals on.

Click to expand...

No need to fill them, I never do. What material do you prefer?

Binder Design said:

No need to fill them, I never do. What material do you prefer?

Click to expand...

If there are grooves in the cardboard tubing, then they need filled unless the modeler would have no concern about cosmetics. I guess that would be like putting drywall in a room and leaving all the joints and screw indentions exposed. Weak cardboard is great for a low power Estes, but the much stronger and smooth exterior of fiberglas is my preference(well actually I'm hoping to progress to all aluminum construction). BTW, you have a great looking Logo.

hobie1dog said:

If there are grooves in the cardboard tubing, then they need filled unless the modeler would have no concern about cosmetics. I guess that would be like putting drywall in a room and leaving all the joints and screw indentions exposed. Weak cardboard is great for a low power Estes, but the much stronger and smooth exterior of fiberglas is my preference(well actually I'm hoping to progress to all aluminum construction). BTW, you have a great looking Logo.

Click to expand...

Thank you for sharing your opinion, we take all feedback seriously. Stock Binder Design tubing has flown on L motors stock or M motors double walled with couplers. For a L1 rocketeer like yourself, they are great kits that deliver about twice the performance on L1 and L2 motors compared to heavy fiberglass kits. Quite a few rocketeers leave the spirals exposed, in fact, we even have instructions on how to deepen the spirals on our Galaxy kit for a great retro look.