Construction Tips?

[Rock_It]

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[zeke1312]

Thanks again folks for your suggestions. I've started my project by asssemlby of engines.

Also this is my 1st roadblock. For Sandman and any who have built the TLP Nike Ajax, according to the instructions and illustrations, the engine disks (2) are the issue.

One engine disk has the 3 holes in it for the 3 engine tubes. The other engine disk should have a notch in each of the 3 holes to allow the metal engine clip to flex, allowing the motors to removed. The 2 engine disks I received are the same, that is one does not have the notch in each hole.

Did your kit come like the instructions indicate or like mine, 2 disks without the notch in one?

 

[sandman]

It looks like they did an "OOPS" on your parts but you can fix it.

Do you have a paper hole punch?

If you do just make three "half punches" in the motor hook locations.

You can also cut them with an Exacto knife. It shouldn't be too hard.

OR!!! here's an alternate motor mount plan.

 

[zeke1312]

Sandman:

I goofed! After looking closely at each disk, one has the cutouts but are simply not removed! (Now they are)

I apologize for the error on my part!

Thanks again.

 

[sandman]

Not a problem. It's better to find it now than later.

ITMT I have been playing in paint.

This came out kinda cool.

My model is the one on the left with the shorter flame.

 

[zeke1312]

Sandman: Wow, looks great! How many launches have you made with the Nike Ajax?



Check this out for a Nike Hercules kill at White Sands, New Mexico:

https://www.archive.org/details/hercq4intercept

Also, a Nike Missile Battery story released to the public, early 1960s.

https://www.archive.org/details/nikeherc01

 

[Rock_It]

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[zeke1312]

Rock_it:

Thanks for the book tip!

 

[zeke1312]

I've got the motor assembly built and now working on the interconnect between booster and missile. Most of the balsa cuts have been made.

I have been using Elmer's white glue which seems to work out well.

Question: should I CA the fins before attaching them to the body? What else should be CA'd?

Now that I'm back into the hobby where can I find definitions for such things as BTxx and so on? Is there one manufacturer better than another regarding motors?

I'm thinking of using another type of parachute than what comes with the kit. Where can get parachutes and how do you size for the rocket?

As far as the launch controller (or whatever you call it) that ignites the motor(s), where can I look for schematics/drawings?

Thanks

 

[sandman]

Questions, questions questions!

OK, I used just the Elmer's white glue on my model except to seal the fins.

After the fins are installed and you have nice Elmer's glue fillets on them and all the glue has dried, THEN apply the thin CA to the fins.

I have been very happy with the cheap stuff (CA) to seal the fins. I get the four little tubes for $1 at my local Dollar Store. I've also seen it at the check-out aisle in Meijer.

Drissle on enough to cover and spread it out with a piece of card stock or an old business card. You may also want to do this outside. I also coated the upper stage paper tailcone with the CA.

For Body tube info (BTxx) save the attachement below which lists most of the low power tube sizes.

I replaced my parachute with a single 32" plastic chute from Apogee Components. That worked just fine. I got mine free at NARAM. I don't know if they sell them seperately.

For a launcher you'll need at least a 12v system. Do a search here on the forum a lot of guys have submitted schematics for them.

As for engines, 24mm BP (Black Powder), you pretty much have to stick with Estes. Hobby Lobby has the Estes D12-3's for $10.66 a pack and with a 40% off coupon that's only $6+ change for 3. The igniters that come with the motors work just fine in a cluster.

 

[zeke1312]

Does CA = Super Glue or similar?

 

[sandman]

Oh, yea it does.

CA is an acronym for cyanoacrylate or Super glue.

 

[zeke1312]

That poses another question. Which to use. Slow or fast CA?

I didn't know there was more than one type.

 

[sandman]

Slow or fast usually refers to the thicker CA glue.

For soaking the fins you want the "thin" CA.

I like the cheap stuff from the Dollar store for coating fins.

It only...a Dollar.

 

[terryg]

When coating the fins with CA, do it in a very well ventilated area, the fumes are a real killer!

 

[zeke1312]

Apply CA with business card? How much to apply? Otherwise, how did you apply?

 

[sandman]

How much to apply? Otherwise, how did you apply?

Like thin paint. Just coat the surface, it'll soak in.

I wit untill all the fillets are dry and all the finish sanding is done then just coat.

When the CA drys, finish sand with 220 or 320 grit.

 

[zeke1312]

I've got the booster and missile assembled, fins on the booster and am completing the install of conduits. I had to hand sand the conduits, I matched each as I sanded so they look and compare to each other and the instructions. I wll add the missile fins, already cut when the conduits are set. I have a set of decals. Anyone use the Excelsior decals? How difficult were they to install? I plan to paint the booster with flat black while using white gloss on the rocket.

 

[sandman]

I used the Excelcior decals and they are super! No problems but...be sure to give them a coat of liquid decal film first!

It's a very important step!

As for painting, I don't recall as any of the boosters were painted flat black but they may have been. There were thousands of them deployed so flat black may be correct.

The preferred color for the booster is either white of olive drab.

 

[maricopasem]

Like thin paint. Just coat the surface, it'll soak in.

Have you ever had the CA warp the fins?

 

[zeke1312]

OK, I'm adding the fins to the rocket body (booster fins done). I've had a hard time positioning and holding positionof fin after glueing with Elmer's. I thought about letting the glue setup more before attempting to attach a fin. This would make the glue more firm.....but what other choices or tricks are there? I ended up proping the fin with two pieces of balsa ( a problem for me as the fin kept losing position).

 

[sandman]

but what other choices or tricks are there?

This works for me.

Do only one fin at a time.

First mark the body tube for the fins with pencil lines.
Then using a push pin or straight pin, punch a row of holes the length of the fin root right on the pencil line.

Then sand the tube lightly along this line. Do this for all of the fins.

Now one fin at a time apply a nice bead of glue along the root edge of the fin.

Carefully place the glued edge onto it's line of pinhole and distribute the glue evenly. DO NOT STICK THE FIN ON YET! Just use it to apply the glue.

Make sure there is a nice line of glue on the root edge of the fin and along the pinholes.

Set the fin down carfully somplace safe.

With a toothpick push some of the glue into the pinholes making sure they are all filled nicely. This will allow the glue to form "glue rivets". A very strong joint!

Now go away and do something else for about 20 minutes. (go check posts on the Forum).

After 20 minutes the glue will be "mostly" set up and clear but you will still see some white uncured glue.

Apply a fresh bead of glue to the fin. Not much a nice thin film. This will "refresh" the existing glue.

Now carefully apply the fin in place and press firmly. It should stick fairly well at this point.

If you set it up right you can go directly to the next fin. By the time it's ready to be pressed into place the first fin should be pretty secure.

Get to work...for the Nike Ajax you only have 14 more fins to go!

 

[zeke1312]

Now that you mentioned stick pins, I remember when I built my previous Nike (mid 70s), I used a couple of stick pins to anchor each end of a fin about 1/2" in from each end at 45 degrees. Holds the fin in place perfect. Your pin hole appoach sounds great and I'll use to attach the other fins.

 

[zeke1312]

OK, I over did it with the CA. Have some area on a booster fin that's rough from CA running over dried CA. Tried sanding without much success. Any tricks to it or leave it go? Oh, by the way, any other areas on the rocket that can benefit from a coat of CA? Let's say you add one ounce to the rocket weight. How will this effect performance?

 

[sandman]

All I can say is try a heavier grit sandpaper to remove the oops.

Not much else needed to strengthen the model. It's a pretty strong design.

 

[zeke1312]

Yes, the heavy grit stuff works. I was afraid to try for fear of causing other problems. I'm close to painting. I plan to use a primer, then semi white on the missile, flat black on the booster. So far the Nike Ajax looks good to me. For some reason I'm having a problem(me) when attempting to upload pix. Anyhow I've used CA on the conduits, all fins, and interconnect (missile rear fin/engine) area. I'm thinking of building the Nike Herc from plans I've seen available. Anybody built one from scratch? How detailed are such plans? I'd be really new to the process but feel I could do it because of my experience with the Ajax and help from forum members such as Sandman. 15 fins is a bit much on the Ajax but the rocket is lookin' good. I'm afraid to launch it for fear of, well you know! I might just build a less daunting rocket to launch as the work to build would be less. Tell me folks, just curious, are there any other kits out there more complex to build than the Ajax? I'm sure there is. If I can figure out how to upload pix, I will have one with my Estes Ajax from the mid 70s next to the TLP Nike Ajax. Quite a difference as you would expect but the Estes Nike Ajax still looks sweet!

 

[zeke1312]

Is there material other than balsa wood that can be used for fin construction? Also, should the grain of balsa wood run parallel to the body or leading edge of a fin?

I ran mine parallel to the leading edge. The Nike Ajax model I'm doing fell on one of the missile body fins ad broke. I've reset with Elmer's White. Hope the bond will be stronger then the original grain bond.

 

[maricopasem]

One thing I use is cardboard from cereal boxes or equivalent thickness. They are generally too thin even for low-powered rockets. What I do is glue two pieces together using ordinary white glue. You need to sandwich it between plastic or wax paper and then place books or something flat and heavy on top to keep it from warping. You then need to be patient because it takes some time for it to dry completely. Once the glue has dried enough I will sometimes put paper or cardboard between the glued fin material and the books to help wick away the moisture and speed drying. This will create very strong fin material.

For low-powered fins I will usually just use a glue stick. It makes them plenty strong for that.

 

[zeke1312]

I completed applying CA slow. I have now added the 1st coat of primer. So far, looks OK. I plan to add another 2 coats of primer, then white semigloss on the rocket body and OD flat for the booster.

I don't want to fly this rocket...too much time put into it! But I must.....

 

[zeke1312]

How snug/tight should the nose cone fit into the body of the rocket? What makes the parachute deploy? I'm worried the nose cone fits too tight and the parachute will not open.