BELDAR, A Build Thread

[Gary Byrum]

I planned on doing a build thread on this, but since I knew the nose cone was going to be a learning process, I postponed. Never made a foam cone before and I also had great concerns about how to put a hard surface on it. Found a killer deal on a damaged sheet of 2” extruded polystyrene foam board and so the search was on for adhesives and coverings. This being a 6” nose cone made it senseless for me to consider turning it with balsa. That would be a pricey special order.

I chose to try using Great Stuff as an adhesive and was quite satisfied with its ability to hold the pieces together. Too bad that I had to learn later that stacking disks of foam would have been way easier than stacking flat cuts that I chopped down to size with a hot knife. The knife was a big mistake as it charred the outer surface making it a bear to work down on the lathe.

(this is a cut off from the block I am using. Quite charred and crystallized.)


I also found out about using another adhesive just a bit late and I now have it for the next one. Glidden makes a primer called GRIPPER, that the “foam board community” in Hollywood and the artist that make large Halloween props have used for years. My tests with it went so well that I’m sold on it. Takes a few days to completely dry though.

I got the nose cone down to size but I overdid it a bit and had to build up the surface with the Great stuff. After sanding that back down, there were a plethora of gaps and valleys left behind by the great stuff.



Jim Hendrickson and I discussed a number of products to try as a filler/hardener and I saw a boat load of videos on YouTube that showed some promise, but the one I finally ordered online was a bust. I took his suggestion to use Durham’s Rock Hard Water Putty because I have used it before and I know how it is. What I didn’t know, was how seriously difficult this stuff is to sand. 60 grit will make for a smooth surface if you can believe that. I thought about using a turning tool on it, but feared I might chip away the surface.

I got it down to a better surface, but it still needed some attention. I made a more diluted batch of putty and painted that on. Hopefully, I can work that down to a slicker surface. Chances are, I may not need to finish coat this with the DIY foam surface hardener I planned on using. I’ll save that for the next cone that doesn’t require Rock Hard Putty for a filler.

 

[Gary Byrum]

So, you want a look at this mysterious Beldar rocket? Keep in mind, I am repurposing a 6” hard cardboard coffee can as an airframe and this will be rear ejection. I have no choice in that matter since there is NO room under the cone for the laundry. The nose cone is a trace & scale of Beldar’s cone from a promo pic I found online.

Jim also talked me into a 29mm motor mount instead of 24mm, and knowing what I do now, it makes perfect sense. I thought this bird was going to be much lighter than it’s turning out, so 29mm it is. Furthermore, I have to say, this is one of the most involved oddrock builds I’ve ever done. And a first, having used only plywood. “Thar be no balsa in this here contraption laddy”

The motor mount will protrude about 3.5” from the aft CR and run through a BT 101. The 6 fins are surface mounted to the motor tube and the aft CR of the motor mount. The motor mount with fins, IS the rear eject portion of Beldar. It’s a cheesy rendering, but you get the picture.



Found this wonderful video on a DIY cutter that I used to cut the rims off the can. This worked really well and beats the crap out of hand cutting or Dremel sawing them off. I cut these off in (MY) record time and you can see how clean the cuts are.



NOW….. These cans have aluminum sheeting on the inside and the outside. These have to come off. The inside came off in one sheet using a ½” dowel with a corner of the sheeting tucked in, but the outside was a ******! Got pieces and strips off but some of it was too stubborn. I had to rough up the surface and sand off the remaining aluminum. Gotta have somewhere for the laminations to stick to. Inside and outside surfaces were sheeted with some light weight poster board and I (pats self on back) did a heck of a job on those. Laminating this tube seemed necessary because after you get all the crap off of it, it’s less durable.

Now you’re asking yourself, “Why didn’t he just use a HP tube?” Couple of reasons here. I don’t keep those in stock. Most of what’s available comes in 4’ lengths. I only needed about 6” and my closet of loaded with these coffee cans that were FREE!

Here are all the internal pieces and parts including the laminated coffee can and fins cut and sanded. The solid disk is the ejection plate that shields the nose cone. That will be dealt with in some sort of fire proofing method. The fins btw, still have to be fitted and corners sanded smooth. That'll come soon enough.

 

[neil_w]

That is pretty darned funny. Look forward to seeing how this turns out.

 

[Gary Byrum]

That is pretty darned funny. Look forward to seeing how this turns out.

I've had visions of it launching and that goofy face on Beldar zipping through the air lmfao.

 

[rstaff3]

I trust Beldar will consume mass quantities (of propellant).

 

[qquake2k]

Too funny, Gary!

 

[dhbarr]

Ahh, this one comes from France.

 

[Gary Byrum]

Geez!!! I reckon I better make way for the launch lug. That'll run all the way through on the outside of the BT 101 through the nose cone. Gonna have to get juuuuust a little bit creative on that.

 

[Gary Byrum]

The aft end of the nose cone now has a 3” deep recess wide enough for the BT 101 to fit. I did this with a deep hole saw and a large barrel sander that fits on my drill. That worked out much better than I thought it would.



I can honestly say, this nose cone has been a learning experience. I think, for my first go at it, I did reasonably well. It could have gone much better gluing with that gripper primer and stacking my layers as disks though. Shown here, is the white outer shell of the DYI coating blend. This was applied over 3 applications of Rock Hard Putty which was a BEAR to sand. 60 grit sand paper gave it a glossy finish. There were an abundance of gaps and such that additional layers and continued sanding eventually took care of and the final sanding was a tolerable (not perfect) surface that maintained a well rounded and formed shape. The DYI formula will get sanded and coated 2-3 more times. This is acting like a primer filler does so it’s also helping with the few remaining imperfections on the surface. Stuff’s pretty hard by itself, but that Rock Hard is really the muscle on this guy.

 

[Gary Byrum]

I was going to coat the blast plate with JB Weld Extreme Heat, but found it difficult to find, so I opted for something a little different. This muffler patch kit fit the bill with a 2400* rating. I covered the blast plate with 5 minute epoxy and let it almost dry to a light tacky stage. The muffler patch suggested a wet surface, so I’d say it was…uh….kinda wet? 4 - cut to length strips of the patch ribbon, were applied and weighted down to dry for 24 hours.



All 6 fins were sanded and tapered to make for a sharp point. I had a pit on the top fin that got puttied and will sand that tomorrow.



Now for the “play by ear” portion of this build. I’ll have to get creative getting that copper launch lug fitted through the nose cone. Copper wasn’t my first preference, but there was no aluminum to be found and I didn’t want to use a BT 2.5 for a lug. I marked & cut where it was going.



After that portion was fitted, I moved on to go further in the cone. I experimented with that paddle bit to find it would serve well drilling that polystyrene, so I went in as far as I could. I still needed to go about 3 more inches to get to the surface so I took a smaller bit and a matching size dowel, both that would fit in a sacrificial BT 2.5 I used as a sleeve, and continued my journey through the polystyrene tunnel. My rig was working quite well actually.

 

[Gary Byrum]

Finally, I felt a slight push on the surface, (my hand was there) so I took the bit extension off the drill and went the rest of the way through by hand to minimize the surface damage.



With an array of sanding sticks and a round file, I was able to get the hole through with very little surface cracking. All that’s left to do is finish sanding the hole out to fit the lug in. Right now, it’s too small.

 

[Amsterdam]

Gary,
looking nice. I like the experimenting with coating the insulation.

How happy are you with that lathe? Pretty sure I saw the same one at harbor freight.
Been hemming and hawing ever since.

 

[Daddyisabar]

Very cool cone head oddroc. Could you cut one of those Hobby Lobby/Craft Fabric Store foam heads for hats and wigs to give a 3-D facial appearance on the coffee can body tube? Some Beldar eyes from the dolly isle? Danger in being seen in the dolly isle as well as screwing up the CP for a more 3-D facial image, but that is the peril of the oddroc world.

 

[Gary Byrum]

Gary,
looking nice. I like the experimenting with coating the insulation.

How happy are you with that lathe? Pretty sure I saw the same one at harbor freight.
Been hemming and hawing ever since.

1) That experimenting with coatings took over 2 weeks. I waited on a shipment of some stuff that didn't work well, and there was a ton of research...videos--forums and what not, that led me where I am. I still may not have the best I could get, but it's the best I found.
2) The lathe has performed quite well in the 4-5 years I've had it. And it is the one at HF.

Very cool cone head oddroc. Could you cut one of those Hobby Lobby/Craft Fabric Store foam heads for hats and wigs to give a 3-D facial appearance on the coffee can body tube? Some Beldar eyes from the dolly isle? Danger in being seen in the dolly isle as well as screwing up the CP for a more 3-D facial image, but that is the peril of the oddroc world.

I ain't EVEN gonna go that distance. Ackroyd's nose alone, would cause a serious weathercock. I'll do well to get the right balance just as I have it planned. Nah....Beldar's face will be a laminated print Daddy. It's already odd enough as is. I should have some update postings later this evening.

 

[K'Tesh]

Very cool cone head oddroc. Could you cut one of those Hobby Lobby/Craft Fabric Store foam heads for hats and wigs to give a 3-D facial appearance on the coffee can body tube? Some Beldar eyes from the dolly isle? Danger in being seen in the dolly isle as well as screwing up the CP for a more 3-D facial image, but that is the peril of the oddroc world.

Being seen in the dolly isle will result in you having to narfle the Garthok.

 

[Daddyisabar]

Next time maybe a 3 or 6 canted tractor motor version with three faces. A motor(s) out Ackroyd's nose, outta Curtin's nose and outta Newman's nose.

Plenty of nose room from those actors to house the motors up front! Good fer CG.

A nice long cone shaped skirt bottom with plenty of base drag so no fins! Good fer CP.

Not so good fer yer RSO!

 

[Daddyisabar]

Being seen in the dolly isle will result in you having to narfle the Garthok.

Pressing the button on such an oddroc will also result in having to Narfle the Garthok.

 

[Gary Byrum]

Well, this muffler patch didn’t completely pass the burn test. It ought to help some regardless. Tough as nails.



I’d really like to know why this disk looks brown instead of chrome. Anyhoo, after I got that patch layer trimmed down, I covered it with some heavy chrome duct tape. I know how this stuff resists fire because I have it on my giant heli job. (soon to be renamed The Decapitator) The disk should be fairly fire proof at this point.



Seems I lucked out on that copper lug. It’s exactly the right length. I knew my hole would have some gaps to fill, but the lug is nicely paralleled to the airframe. Once I epoxy this in, I’ll fill those gaps and grind that lug flush with the surface of the nose cone.



Here’s an aft view with the CR. Everything is dry fitted at this point.



Been a slo-go on it this week. I sorta lost my appetite for building when a case of "slug syndrome" overwhelmed me.

 

[Gary Byrum]

I’m having a real hard time bouncing around on other parts of this rocket. I can’t do anything to one area without taking care of something else first. My inconsistencies with the plans I drew aren’t helping either. I have all the 101 rings measured at 1/8” when none of them are. Especially the ejection plate. It got way thicker after I got the burn shield on. It’s like ¼” anymore. It’s only going to matter when I’m ready to install the 2nd motor mount ring anyway. I’ll still have to dry fit everything until I’m nearly finished building. I still have to find out how much nose weight I’ll need.

Here’s a look at the motor mount blocks. I have since got these epoxied in. I used the blast plate as my 2” “flat edge”, if you will. The blocks are 1” long making for a 2” deep gas chamber. All of that will get some CA and quite possibly some JB Weld for burn purposes.



I sanded the launch lug with some coarse paper and parked it. The forward CR for the MM is gluing as we speak and another shot of the motor blocks with epoxy. Hope I got some of these measurements right. I have a sneaky feeling that the MM is going to come up short and I’ll have to shim it. That’d be me jerry-rigging again.

 

[neil_w]

This seems to be quite a bit more involved and challenging than I had originally imagined from seeing the design....

 

[qquake2k]

I have faith in you, Gary!

 

[Gary Byrum]

This seems to be quite a bit more involved and challenging than I had originally imagined from seeing the design....

I knew it would be a bear. Just because of the rear ejection. But I didn't expect it to be as involved as its been.

I have faith in you, Gary!

You a good ole boy Jim. You watch, all of a sudden it'll get easier and be done in no time. Providing I don't botch it.

 

[Gary Byrum]

This phase of the assembly went much better than I thought it would. I made a simple marking on the MM where the aft CR was going and that got epoxied in place. I did want to secure the aft CR for the dry fit and that blue tape is holding another piece of tape that’s stuck to the underside of the aft CR. Kinda like an anchor. There were three of those and they helped a lot when I slid the entire MM and 101 in place. There was some resistance in some places and I found that the large aft CR had small areas that had to be sanded some. After getting my fit, I was quite pleased to find that all the CR’s are where I wanted them…YAY!!! Those fins will be glued to the MM CR and the MM itself. None on the large aft CR.



I figured it was time to get a preliminary CG on the rocket and I weighed it also. Right now it’s at 23.5 oz without the laundry. Two chutes, Kevlar and some elastic. Laundry mounting gear, more glue and paint with the lamination. All the major pieces and parts are pretty much where they’re going to be. The aft end of the MM is the absolute bottom of the rocket. I figure by the time I get it finished, I’ll have accumulated another couple of ounces, but that weight will get evenly distributed…..sort of. I’ll do a final CG after I get it mostly finished and determine if I need to add any weight to the nose cone. I have to be pretty dead on correct with this because once I get that 101 installed, there’s no going back to add weight to the nose cone from inside.

 

[Gary Byrum]

Next step was to get the lug glued in. I made a small paper funnel and poked it in the top between the lug and the hole in the cone, mixed me a small batch of 30 minute epoxy and heated it for 4 sec in Mr Micro. PERFECT! Just barely warm enough to pour nicely. Too runny is no good in this case, so I went at it. ½ hour later, I figured on topping it off since there was still some space. Hence, round 2. To make sure my lug was straight, I had the big CR dry fitted to keep things aligned.
After the next ½ hour I looked to see, that there was STILL some space left. (scratching head now) I went to turn the rocket sideways and…..well…… it wouldn’t move. That epoxy had ran down the lug and made a really nice looking seal on that aft CR and glued it to the counter top. (panic mode kicks in with a dozen choice words) I grabbed a 5” wide putty/wall mud blade and went at it. Fortunately it was on an old Formica type counter top I use as a buffet/coffee slab I bought cheap, so it came up fairly well. (it’s also where the microwave is) NOW, I’m really shaking in my boots that I might not be able to get that CR off of that lug. Good thing it didn’t get any on the body tube or I’d have been in a mess. The epoxy hadn’t totally hardened yet so a knife and some wriggling of that CR finally broke it loose. Without damage I might add. Still had that glue on the CR so I heated it up in a skillet to soften the epoxy and it came off fairly easy. Did the same to any glue on the lug that was in the path of fitting the 101 in place. I made another batch and filled the gaps on either side of the lug and letting it dry on its side. I made sure that spot where the glue came through was sealed and I’ll top it off tomorrow.

Sorry no pic in panic mode.

The blast shield on the other hand was drilled for a Kevlar feed as was the forward CR on the MM. They’re a little hard to see in the pic. There’s a ¼” igniter tube that was CA’d inside and out. This will mount to the blast plate and the side of the 101. It too will be a feed for the Kevlar. I made it so I could attach one of those Quick Links and feed more Kevlar out and beyond somewhere around 10’ or so. The other end will get unbraided and fanned out so it’ll be flat when I epoxy it on the back side (pink side) of the blast shield. Don’t want no bumps back there. I’m doing all this to seal everything off in the ejection area. It’ll make for easier epoxy insulation also.

 

[neil_w]

This build is quite an adventure. :eyepop:

BTW, looking at the pic in the previous post... that nose cone really is a perfect conehead. You nailed the shape.

 

[Gary Byrum]

This build is quite an adventure. :eyepop:

BTW, looking at the pic in the previous post... that nose cone really is a perfect conehead. You nailed the shape.

It should be. I traced a picture Beldar's head/cone in Autocad and scaled it for the 6" tube. Thanks btw. And ppl wonder why I use Autocad as a design tool. A great many things you can trace and scale in that program.

 

[Gary Byrum]

I’m sure glad I caught this. That hole that was in the forward CR had to change. If I had fed the Kevlar like I planned, the whole rocket would be tethered. That wasn’t part of the plan. I need for this to come down in 2 sections, So, starting from left to right, you can see where I modified that hole to a “U” shape, allowing the pieces to descend separately. That CR also got a nice coat of Epoxy too.

In front of that is the adapter for 24mm motors. Simple little quick job. Still have to install a motor block inside the 29mm tube for it though.

Then right of that is the back side of the blast plate. I fed the Kevlar through the hole and frayed the ends about 2+” or so and laid the epoxy on. Eventually that’ll all pass through the ¼” lug you see inside the 101 behind it and connect the Quick Link. From that point a long stretch of Kevlar to a chute.
Inside the 101, the metal tape was a real bear getting it laid down evenly. All the while, keeping a ¼” bare section at the end where the blast plate will be glued. Looks kind of bad in there, but everything’s protected.

What are all these "bare/bears doing in here?

 

[Gary Byrum]

After installing the 29mm motor block, the fins needed tweaking. I knew I’d have to do this in order to allow just enough space between the ”fin horns” and the uncalculated build up of lamination and paint, So all of those were addressed. Since I had already marked the motor tube for fins, I thought I’d play it safe and print off a template so I could mark the CR as well. Sounds reasonable enough, right? Lookin’ purdy good here.



NOT!!! Especially if you glue to the right of the mark, (or left whichever you choose) Took about 5 minutes of di*king around with it to realize, no matter what I did, that fin wasn’t going to center up. When I lined it up by eyesight, I saw where my CR marks were offset at about the thickness of the fin. It started to make sense and I just blew that off. Went with line of sight and all looks like it should.



With a little help from a previous homemade jig, a custom cut cardboard box and a rubber band, I’m on my way to fin installation.



And FWIW, a box hoarder like myself, has a really serious problem cutting up a box. I save those for shipping and the hopes of using them for that grand move to a different city……someday…….

 

[K'Tesh]

Looks Good!

And FWIW, a box hoarder like myself, has a really serious problem cutting up a box. I save those for shipping and the hopes of using them for that grand move to a different city……someday…….

There's always the dollar store foamcore.

 

[Rktman]

op: