Binder Design 54mm Excel Dual Deploy Kit

I've had a Binder Design Excel Dual Deploy sitting in a box for over a month now. Since my LOC Bruiser L2 Cert flight attempt that I had planned for tomorrow has been cancelled because of a "Burn Ban" down here in drought stricken Florida, I have a little time on my hands this weekend. So, I got permission from my wife and its building time!!!

First off, I want to say "Thank You" to Mike Fisher of Binder Design. Before ordering this kit, I had done lots of research and read several other build threads. The only flaw/complaint that anyone consistently stated regarding the Excel kit was that the motor tube was too short. That causes the eye bolt to be out of reach of most human arms, so reaching down into the body tube to replace the shock cord, even with a quick link, would be difficult to impossible. So I took a chance and emailed Mike and asked if I could get a longer motor tube and a third centering ring. He responded back quickly with a "Jeff, no problem". Now THAT was customer service!! True to his word, the kit arrived a few days later and it had three centering rings (in addition to a thrust ring) with a longer motor tube. The kit lists the stock motor tube as 8", Mike shipped mine with a 16" motor tube. Maybe this would make a good permanent change to this kit.... hint hint.

The first step was to epoxy the thrust ring to the business end of the motor tube. Although the kit shipped with adequate motor retention, I'm hooked on AeroPack motor retainers. So, I test fit the parts, backing the tube out past the thrust ring enough to fit the retainer, marked the tube with a sharpie, and pulled them back apart and sanded the glassine off where the Aeropack and thrust ring would attach. It was very hot in the garage this evening, thankfully my wife let me do the JB Weld bonding in the kitchen if I promised to be very careful. I put an adequate layer of JB Weld on the marked off end of the motor tube, slipped on the Aeropack, and then pressed on the thrust ring from the other side. A Popsicle stick made a great tool to shape the fillet around the base of the Aeropack and a few Q-Tips dipped in alcohol helped me clean off any that got where it shouldn't.

The parts are now drying overnight in the garage, I'll attach the rear centering ring to the thrust ring with 30 minute epoxy tomorrow and start sanding and shaping the fins. I love the way the motor assembly is built. You slide the motor tube/thrust ring/and unbonded centering rings into the body - once the fins are properly positioned and tacked to the motor tube with a few spots of epoxy, you cut the small body tabs between the thrust ring and the back of the fins and slide the whole assembly out. Then you can put some decent fillets on all the internal bonds before reinserting the finished assembly and epoxying into the body. It looks like a great assembly process, and I look forward to a fun build. The directions are very well written as well.

I recently completed my build of an Excel Pluss DD kit, I also used a longer motor mount tube, I built the fincan differently to the instructions, I glued the 2 front centering rings to the MM then glued the assy into the bodytube ,left the rear centering ring off till after internal fillets were done and foam filled the rear section.
Build thread Here :- https://www.ausrocketry.com/forum/viewtopic.php?f=6&t=3547 , hopeing to give it its first flight next sunday weather permiting.
Stewart

Stewart - nice build thread. This is my first dual deploy so I'll be learning as I go with the electronics. We have the same SL100 altimeter.

Earlier today I used my palm sander and dremmel to shape the fins and sand the wood to a nice smooth finish. I'll add some sanding sealer when I'm farther along in the build.

I just finished tacking the fins to the motor tube through the body tube with 5 minute epoxy. Next I'll cut out the tabs behind the fins and slide the motor tube/fin/thrust ring out of the body and complete the internal structural fillets. I've got some small dowel rods I'll put in along the joint between the fin and motor tube and fillet with West epoxy mixed with colloidal silica.

One way to have a more easily replaceable shock cord when it's not possible to tie a knot by hand is to put the cord through the eyebolt and back, tie a bowline in it, and then quick-link the loop to the shock cord itself. Just pull on the shock cord, and the quicklink will slide down to the eyebolt and sit there solidly.

To remove it, you just fish out the quicklink using something like a coat hanger bent into a hook, undo it, cut the knot (if you can't untie it), and pull the cord back out of the eyebolt.

Of course, the better solution is a longer motor mount, hehehehe...

Also, what's the difference between a centering ring and a thrust ring? Does the thrust ring match the OD of the body tube instead of the ID? EDIT: that seems obvious now that I just looked at the photos in your most recent post...

I think I reached a good stopping point for the night, so I'll upload these pics of what I've done so far:

I cut the tabs behind the fins and pulled the motor tube/fin assembly out of the body tube. That went smoother than I thought it would, I was very worried I would have gotten sloppy and permanently glued the whole thing together. Not to brag, but I seem to have done a very nice tack job with the 5 minute epoxy. *pats self on back*

After making an impromptu work stand out of some Gatorade bottles to prop the assembly on, I then cut a small dowel rod to size and fit it along the fin root where it meets the motor tube. Not sure if this is even remotely needed on this rocket - but I've seen it done on a few other build threads, I had the rods handy, so I figured "why not". It won't hurt anything! Might as well practice what I've learned from all you more experienced builders.

Next, I mixed up a batch of West epoxy/colloidal silica and applied generous fillets. I only did one set of fins (the top of the "V"). Even though it usually won't run when its thickened with the silica, I'm not in a huge hurry so I'll do the other two sets tomorrow.

The only "gotcha" I've seen so far on this three centering ring configuration is I won't be able to put an epoxy fillet on the middle ring. Of course, since this rocket uses a thrust ring (and the Aeropack motor retainer is JB Welded directly to the thrust ring), all the real energy is transferred directly to the body tube. Between that and the fact I will have fillets on the front and back centering rings, I'm pretty sure its a non-issue. Certain of it.

Once again, I will state how impressed I am with the quality of this Binder Design kit - its my first Binder, but not my last. I'm seriously thinking of ordering the 38mm Stealth rocket next week. This is going together quickly, so my rocket factory will need another kit to work on soon.

Carvac - While I had the motor tube in the body, I reached in the body tube to see if I could reach the top of the motor tube. Its a tight fit with my arm, but I should be able to attach a quick link to the eye bolt without too much problem. I've considered something similar to your tip, fishing a line though the eye bolt and tying something to the other end and running it back down to the bolt where it would stop. So, shouldn't have any problem on this one.

Thanks for the compliment Jeff, My Excel is fitted with my 3rd SL100 altimeter, I have one in a Wildman Jr and another in a modified/rebuilt Binder Aspire , both of which have flown several times without a hitch Aspire rebuild here https://www.ausrocketry.com/forum/viewtopic.php?f=6&t=3528 and Wildman Jr here :- https://www.ausrocketry.com/forum/viewtopic.php?f=6&t=3404
For internal fillets I use 30 min hobbypoxy with microballoons mixed in then mixed in some chopped carbon, the micro reduces the weight of the fillets , the carbon reinforces it . The micro also stops the chopped carbon from clumping it mixes evenly and gives a grey colour to the epoxy mix.
for external fillets i use 15min/midcure epoxy with microballoons , the midcure is more flexible when set than either the 5min or 30min , so is less prone to cracking.
Useing micro or micro+ chopped carbon gives strong enough fillets without a big weight penalty of full epoxy.
If you look at my Excel build thread at the motor mount/CR fillets you can see the grey colour of the carbon/micro mix, with no carbon clumping.
Stewart

Stewart said:

Thanks for the compliment Jeff, My Excel is fitted with my 3rd SL100 altimeter, I have one in a Wildman Jr and another in a modified/rebuilt Binder Aspire , both of which have flown several times without a hitch Aspire rebuild here https://www.ausrocketry.com/forum/viewtopic.php?f=6&t=3528 and Wildman Jr here :- https://www.ausrocketry.com/forum/viewtopic.php?f=6&t=3404

Stewart

Click to expand...

Had a quick question on your Excel. This is my first DD, and I don't have anyone local to show me things in person....... plus all the club launches North and South of me have been scrubbed here in Florida due to burn bans because of the drought index.
How do you attach your AV Bay to the lower half of the rocket? Shear pins? How do you connect the top tube to the AV Bay? With screws? I'm assuming you are deploying the main out with the nose cone. Once again, are you using shear pins for that?
Also, how much BP are you using in your ejection charges? I've got a plugged end closure for my motors, so I was going to use the altimeter to fire both the drouge and the main.
I've seen a few DD's on youtube where the AV bay released both attached tubes, seems like it would be rougher on the AV bay with it "free floating" out there and not wedged in a tube.....
Thanks!

Jeff,
The Av Bay/upper bodytube assy is friction fitted into the booster, it needs to fit tight enough that you can lift the rocket from above the booster without it falling off , but loose enough that a few gentle shakes will start it slideing off. I hardened the insides of all the tubes with superglue and also on the outside of the Avbay couplers , then sanded them for smooth fits.
The AvBay/upper tube is held together with reuseable plastic rivets ( https://www.ausrocketry.com/shop/index.php?main_page=index&cPath=199_169) , I highly recommend these!
in addition to hardening the inside of the upper tube/nosecone joint , I also epoxied brass shim .010" thick inside the bodytube and on the outside of the plastic nosecone at the positions of the 2/56 nylon bolts as shear pins, the use of metal shim stock gives cleaner cutting/breaking of the shear pins and saves damage to both the body tube or nosecone.
Re the plastic nosecone, I and others recomend not useing the plastic loop cast into the nosecone for its attatchment to the shockcord, they are notorious for breaking off, , I cut a "U" shaped flap opening in the lower NC coupler to allow me to fit an eyebolt and a large dia flat washer inside the NC, I used a 6mm stainless steel eyebolt from a boating supplier , these are commonly used for sail rigging so are quite strong enough.
Re Qty of Black Powder , theres a good online tutorial and calculator here :- https://www.info-central.org/?article=303 , well worth bookmarking, according to the calculator I need 1.1g , I plan on useing 1.5g as my shock cords are plenty long enough and I loop and rubberband them to both avoide tangles and to help soak up shock loads. Hope this helps
Cheers
Stew

Re fitting an eyebolt in the NC, I used epoxy under the flat washer , inserted the eyebolt tightened up the nut then added more epoxy around the nut to prevent it comeing loose. the flap can be neatly closed back buy holding the NC over a hot soldering iron to gently heat the plastic, allowing it to be folded back into place. Then "V" the cut edges and epoxy the cut to hold it all together, a little sanding to smooth it all out.
The brass shim for the shear pin plates ( aluminium drink can also works) needs the area on the NC sanded and the shim stock for good epoxy adhesion.
Stew

I finally started on the AV Bay..... very nervous as this is my first one. As Steward suggested, I used thin superglue on the outside of the tubes (now sanded smooth) and a coating of epoxy on the inside. Earlier in the day I was in Home Depot and picked up some u-bolts as an easy upgrade over the eye bolts.

Is the blast cap too close to the outside edge of the bulkhead, or won't it matter? Still need to get a junction block (guess that is what they are called) to connect the electronic match to. Anyone recommend who to order one of these from?

The fillets on the rocket were finished this morning, so I'll start sanding them and smoothing them with a touch of bondo so they are smooth as silk.

Stewart, do you have picture of how you mounted brass shims in the body tube?

I'm starting on the electronics sled soon..... found some rigid plastic tubing that fits nicely over the all-thread. I'll epoxy the tubing to fit along the sides of the sled and then start mounting the electronics.

I'm hoping to try for my Level 2 cert next month on the 9th, hopefully I'll have this one ready so I'll have two rockets with me in case one doesn't behave. :y:

Making more progress on the build this weekend. Here are my comments on the attached pictures:

I measured out and cut the wood for the sled.

You can see the "gooey" mini-wax wood hardener I used on the fins. It was thick and nasty and didn't dry, it stayed like thick honey. What a drag to sand it all off. I'll stick with aerogloss from now on.

Applied plenty of lock-tight to the nuts on the av-bay.

Used epoxy to attach guides the av-bay sled and bolted on the Perfectflight altimeter.

First coat of Krylon primer on the bottom section. I'll sand it all down later today and recoat it.

Later today I'll go to Radio shack and get wires, shrink wrap, and try and find some Molex type quick disconnects so I can finish wiring up the av-bay.

Almost finished!

Managed to get everything painted yesterday, it all turned out great (no runs) but I have an issue with the colors. I used Krylon white primer on the body but used DupliColor gray high build primer on the nose. Now the upper body and the nose are a slightly different color after being painted with the topcoat. I used the same can of Pumpkin orange, but the nose cone is now darker.... like the primer is showing through a bit. Darn. Will another coat of the orange paint "lighten" up the nose cone and make it match the body piece?

I'll be putting on the decals tonight. Now I just have to finish wiring up the Av bay, drill holes for the altimeter to breath, and of course install the switch. And add a few push button nylon buttons to mate the upper body tube to the av bay. I ordered a few two wire quick disconnects so I can easily disconnect the bulkheads and on/off switch from the altimeter. When they come in, I'll get all the wiring finished.

I'll wait a few more days for the paint to finish curing and then I'll spray the whole thing with some Rustoleum Crystal Clear. So far, looking good for this to be my backup level 2 rocket on the 9th next month.

Looking nice.. That kit is a beaut

Salvage-1 said:

Looking nice.. That kit is a beaut

Click to expand...

Thank you. I sprayed another coat of orange when I got home today, now the nose cone matches the upper body. I used different color primers on those two parts and it really showed with only the first coat of paint. Can't wait to see it fly....... Countdown to June 9th!!!

Almost finished! I've been distracted with my JackHammer build, but I'm knocking off the final items left to complete.

Description of the attached pictures:

1. I shot a Krylon Crystal Clear Acrylic and followed up 15 minutes later with a Rustoleum Crystal Clear Enamel. Seems to keep the Rustoleum from bubbling the paint. The Krylon clear by itself is too "matte" for my taste, the Rustoleum leaves a better final finish. I let it cure for almost a week. Time for decals. I"ll probably hit it with some Future to seal in the decals.

2. The decals are on! Came out great. Had a sticky wicket getting all the little vinyl letters to line up, they really stuck to the release backing.

3. Rocket assembled, and 4 altimeter holes drilled in the avbay.

4. Nylon rivets (4) installed to hold the upper tube to the avbay. I'm going to use tape on the nose cone, might upgrade to shear pins depending how the tape works.

Now I just need to finish a bit of wiring on the altimeter and get a battery mounted. The Quest igniters I'm going to use for ematches are taking forever to get here...... looking forward to testing it. So for now, I don't have any black powder, ematches, etc.... so I'm not sure I'll be ready to fly next Saturday. Still planning on using my LOC Bruiser for the Level 2 cert attempt.

Well been awhile, my Excel was launched for my L2 a couple of weeks ago, perfect flyte on a CTI J381 darkmatter . Thread on our launch day here :- https://www.ausrocketry.com/forum/viewtopic.php?f=13&t=3763&start=15 and high res pic here :- https://www.ausrocketry.com/forum/download/file.php?id=2817&mode=view
Stewart

Stewart said:

Well been awhile, my Excel was launched for my L2 a couple of weeks ago, perfect flyte on a CTI J381 darkmatter . Thread on our launch day here :- https://www.ausrocketry.com/forum/viewtopic.php?f=13&t=3763&start=15 and high res pic here :- https://www.ausrocketry.com/forum/download/file.php?id=2817&mode=view
Stewart

Click to expand...

Stewart,
Thanks for posting the links. Great looking rocket and flight.

I'm embarrassed to say my Excel hasn't flown yet. I went the simple route with my L2 Cert using a LOC Bruiser and have been on a building frenzy adding more rockets to the "fleet" and never got the avionics bay finished. The brass shims are installed in the nose cone, I just need to drill the holes for the shear pins and then install a battery holder and it should be ready for ground test. Its such a beautiful rocket, I'm almost afraid to launch it!! I don't think it will be ready for the TTRA launch this month - I'm currently planning on launching it in December if the weather is good, so expect some video links and pictures when I do. :dark:

Sorry to drag up my old thread, but I finally flew this awesome rocket yesterday up in Bunnell. A J350W powered the flawless flight and a PerfectFlite SL100 handled the dual deploy recovery - it almost landed on my tent. I'm considering using a CTI 6XL for its next flight.

Here is some video and pictures of the flight:

[video=youtube_share;fDCRL3fMOLI]https://youtu.be/fDCRL3fMOLI[/video]

Nice flight!

Nice flight.

TA

Very nice! I'm looking to build one of these for my level 1 & 2 certification. Do you by any chance happen to have rocksim or openrocket files you would be willing to share? I have found several, but only for single deploy.

Here is one.


TA

View attachment binder_design_excel_plus_38mm.rkt