Binder Designs.

[John Taylor]

Hi everyone, I just built a Binder Design Excel. One thing I liked that I never thought of before was the cutting of the airframe tube below the fin slots. This allows the removal of the mount with fins attached in order to put proper epoxy filets on the fin roots then slide it back in putting epoxy in the tube as you go like usual.this allows much greater strength to the fin attachment. Seems so obvious now. Anyone else do this on other builds?
Thanks,
John

 

[Steve Shannon]

Hi everyone, I just built a Binder Design Excel. One thing I liked that I never thought of before was the cutting of the airframe tube below the fin slots. This allows the removal of the mount with fins attached in order to put proper epoxy filets on the fin roots then slide it back in putting epoxy in the tube as you go like usual.this allows much greater strength to the fin attachment. Seems so obvious now. Anyone else do this on other builds?
Thanks,
John

That’s been a fairly common technique over the years.

 

[blackjack2564]

on paper rockets yes....fiberglass no way weakens the spiral winds.

 

[John Taylor]

Thanks, I was out since 2003 and just got back in so I was unaware. Learn something new every day

 

[BDB]

I did it on a Binder Design Tyrannosaur and Terrordactyl. I had never done it before either, but it works well.

 

[Arsenal78]

I built the Jackhammer from them. I'm not a fan at all of the slots all the way because they're just more filling and finishing work. If the tube is 3" inches or larger, I just use a popsicle stick.

 

[Binder Design]

I built the Jackhammer from them. I'm not a fan at all of the slots all the way because they're just more filling and finishing work. If the tube is 3" inches or larger, I just use a popsicle stick.

You save the tabs and just glue them back on, then fillet as usual. And you get a thrust ring that most kits don't come with.

 

[Binder Design]

That’s been a fairly common technique over the years.

Many builders use that method, but no other kit manufacturer utilizes that method in their instructions, nor do they include the extra thrust ring to make it easier. We've been doing it that way for the last 15 years. We call it a "modular fin can" construction, because it is built as a module and slid into the airframe.

 

[John Taylor]

Right on, love your kit Design,
(see what I did right there?)...
I am building an Excel and am very pleased with the material quality and the innovations you have brought into the hobby.
Thanks!

 

[mccordmw]

Binder rocks. I'd have to highly recommend them. Just check my signature.

I've used the modular fin can often in my scratch build designs. It's really nice.

 

[H_Rocket]

One thing you can do is cut the fin slot the way you would for "normal" construction, then slit the from either the center or the corner of the fin slot with a sharp knife. You can then just move the flap aside while inserting the fin can.

 

[neil_w]

on paper rockets yes....fiberglass no way weakens the spiral winds.

Wouldn't the body tube be pretty well supported back there by the aft centering ring and the rest of the motor mount?

 

[Winston]

Hi everyone, I just built a Binder Design Excel. One thing I liked that I never thought of before was the cutting of the airframe tube below the fin slots. This allows the removal of the mount with fins attached in order to put proper epoxy filets on the fin roots then slide it back in putting epoxy in the tube as you go like usual.this allows much greater strength to the fin attachment. Seems so obvious now. Anyone else do this on other builds?
Thanks,
John

See this thread:

https://www.rocketryforum.com/threads/re-rear-motor-mount-question.144220/

What I do is specifically described in this post in that thread:

https://www.rocketryforum.com/threads/re-rear-motor-mount-question.144220/#post-1757489

which I will reword slightly in brackets:

I tend to glue the forward CR to the MMT [according to measured placement described in the instructions]. I then prep the rear CR for easy removal (see above [important and found in the thread]). I will then glue the forward CR / MMT assembly into the [body] tube, with the rear CR in place [but not glued to anything] to ensure alignment [proper position is when the aft surface of the forward CR is aligned with the forward edge of the fin slot]. [The aft CR] is also far enough away [back] from the fin attachment area to ensure it doesn't get glued in place. (I've obviously ensure[d] the fins fit & and have done a 'dry fit'.) I then insert the fins & glue them in place [with adhesive applied only to the forward and bottom edge of the fin tab except for the last 1/4" or so of the aft portion of the bottom edge of the fin tab to make sure glue doesn't obstruct flush placement of the aft CR once the fin adhesive has cured].

A series of photos would be worth a thousand words. I think I've seen them somewhere, but don't recall where.

 

[blackjack2564]

Wouldn't the body tube be pretty well supported back there by the aft centering ring and the rest of the motor mount?

Spriral wound tubes have the tow bundles wrapped under tension.
Just cutting slots relieves some tension.
Ever slide a CR in tube from rear up to center of slot, tube grabs it , you can see how roundness is less between slots.Installing fins and cr's pushes tube back round.
Slots are usually cut 3/4 in. from rear of tube.
If you slice thought that 3/4in. ....the tube will spring out slightly.There is nothing left holding tube together, tension has been released.
[ not applicable to convolute wound tubes]

Then you must use clamps around airframe, to keep in place when glueing it back together. there is not much "bite" on a 1/8in or 3/16's Cr to glue to.
Much more effective to tack fins on MM tube and inject internal fillets. Does not disturb integrity of tube,or remove rear CR...do internal , glue rear CR on
Not needed on cardboard where this is non -issue.
..... many ways to build in rocketry, simply my opinion based on many, many years.There are others methods, I just think mine are easier to do and just as effective as anything else.

One thing you can do is cut the fin slot the way you would for "normal" construction, then slit the from either the center or the corner of the fin slot with a sharp knife. You can then just move the flap aside while inserting the fin can.

+1 I cut my teeth in rocketry with Binder kits and did this before it was recommended.
It's wonderful to see that now in instructions, and a GIANT plus you get a thrust plate included in kit from them.

It would be nice to see them at some of the larger launches vending their wares

 

[Steve Shannon]

Many builders use that method, but no other kit manufacturer utilizes that method in their instructions, nor do they include the extra thrust ring to make it easier. We've been doing it that way for the last 15 years. We call it a "modular fin can" construction, because it is built as a module and slid into the airframe.

That I didn’t know.
Thanks!

 

[Binder Design]

It would be nice to see them at some of the larger launches vending their wares

We used to. Not worth it. I was at XPRS one year and didn't sell a single kit. Same with the last two years I vended at NXRS here in Oregon. Drag all the stuff back home every time. It's a good thing I like the hobby.

 

[OverTheTop]

The Velociraptor is my favourite and most frequent flyer. Crowd pleaser on L motors .

 

[John Taylor]

We used to. Not worth it. I was at XPRS one year and didn't sell a single kit. Same with the last two years I vended at NXRS here in Oregon. Drag all the stuff back home every time. It's a good thing I like the hobby.

So glad you like the hobby! You're kits are great in my opinion!
Sorry about your negative experience. I endorse your product every chance I get. Truth be told I had not heard of Binder Design rockets until someone on here spoke very highly of you and several others chimed in. It was the next kit I bought and I couldn't be happier. The quality of materials and the included part list are outstanding and all inclusive.
Thank you for your help and support in making our hobby better.
John Taylor

 

[Binder Design]

So glad you like the hobby! You're kits are great in my opinion!
Sorry about your negative experience. I endorse your product every chance I get.

Much appreciated! Vending is a weird experience IMO. I'll give you one example, the year we came up with the Galaxy I took the protype out for some flights. I had a few people say they would buy one on the spot if I had brought kits with me. When I told them I had a bunch in the back of my SUV they just looked at their feet and slowly walked away. That has happened quite a few times with other products as well.

And then the issue of getting a vending spot. It doesn't matter how much notification I give the launch organizers, they never save me a spot. I end up at the end of the flightline down by the scout groups or similar. One time at NXRS our biggest launch in the PNW, they told me and another big local vendor to set up second row back in the camping area facing away from the flightline. Do that a few times and you just say screw it.

 

[neil_w]

I had a few people say they would buy one on the spot if I had brought kits with me. When I told them I had a bunch in the back of my SUV they just looked at their feet and slowly walked away.

LOL.

As a consumer (in general, not on that particular occasion) I can totally relate to this. It's incredibly easy to think you want to buy something, totally different when it comes time to pull out the wallet (and consider all the other issues involved with a decent-sized purchase). I can definitely imagine that large HPR kits are not easy on-the-spot sales.

Motors and supplies on the other hand... I would think those vendors do well at launches. I would probably do most of my buying at the launch if I had the opportunity (sadly our local launches are vendor-free).

 

[K'Tesh]

I am so glad to say that every time I told Mike that I would buy a kit from him, I have bought the kit from him. I would also like to say "Thanks!!!" for all the times that he delivered the kits to me.

 

[Ez2cDave]

And then the issue of getting a vending spot. It doesn't matter how much notification I give the launch organizers, they never save me a spot. I end up at the end of the flightline down by the scout groups or similar. One time at NXRS our biggest launch in the PNW, they told me and another big local vendor to set up second row back in the camping area facing away from the flightline. Do that a few times and you just say screw it.

You should put up signs that say "FREE BEER" with arrows pointing to the area you are in . . . Of course, there isn't any beer and they don't know who put up the signs, but it gets people to where you are . . . LOL !

Dave F.

 

[StanO]

Many builders use that method, but no other kit manufacturer utilizes that method in their instructions, nor do they include the extra thrust ring to make it easier. We've been doing it that way for the last 15 years. We call it a "modular fin can" construction, because it is built as a module and slid into the airframe.

When I first started in rocketry I asked club members about getting a kit and they recommended Binder Design. I ordered a Galaxy as I'm an old guy and liked the retro look. I was impressed with quality and precision of the materials and the thoroughness of the instructions. As my first rocket it wasn't a thing of perfection or a thing of beauty but it worked very well and got me my Level 1 and Level 2 certifications. As time has gone by and I buy kits for my nephews they are Binder Design and when people ask me for recommendations I recommend them. Mike makes great products.