Building Two Mega DRM At Same Time

sodmeister said:

Well Scott, I just cracked the bag on my Mega DRM and wow ,half the bag is almost sheets of Balsa ,nice and flat and very dense ,which seems to be the norm with Estes kits.I`m very pleased ,should be a fun build ,and your play by play will come in handy.

Take care

Paul T

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Thanks,

The Balsa was nice, I would be interested in your experience with the joining and glue up of the core and balsa sheets. After a couple of days, tending to life, I am going to do some sanding on some very dry poly and see what I get for a final finish.

My fins had almost returned to flat on Friday the last time I looked at them, I hope I find them flat as a flounder when I go work on them today.

The fins on the Mega Mosquito are assembled the same way. I had to literally screw them together and sand them together because when I laid them up and weighted them, they shifted. But they turned out just fine. On my MDRM, I intend to do the same, but I may glass them first, or I may just go tip to tip after they're on. (Some of you are saying "Why glass?" Because I will be putting in a 38 or 54 mm MMT).

kelltym88 said:

The fins on the Mega Mosquito are assembled the same way. I had to literally screw them together and sand them together because when I laid them up and weighted them, they shifted. But they turned out just fine. On my MDRM, I intend to do the same, but I may glass them first, or I may just go tip to tip after they're on. (Some of you are saying "Why glass?" Because I will be putting in a 38 or 54 mm MMT).

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After multiple coats of Poly it is time to do some sanding.:wink:


Three came out really nice and very close to square.:clap:



The next three did not exactly come out square,:cry: my wife took one look and said well "Just put two that are warped facing each other, so that they cancel each other out" God I Love Her!!



All six stacked up. :rant:

Wife Also: Gee with all my big cooking pots full of water on them you would have thought they would be flat!:confused2:

Any one got any bright ideas on where to get some unwarpium??:eyeroll:

SAC of MMMSClub said:

View attachment 111562

The next three did not exactly come out square,:cry: my wife took one look and said well "Just put two that are warped facing each other, so that they cancel each other out" God I Love Her!!

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Ouch!!

Any idea why three came out ok and three didn't?

Krusty

krusty said:

Ouch!!

Any idea why three came out ok and three didn't?

Krusty

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Oy, I would bet you a Vegemite sandwich it has to do with the uneven uptake of moisture from the Titebond by the balsa and plywood.

I was working on a good flat (dining room) table that I had protected with some plastic cling wrap.

I would glue the balsa together right on the plastic wrap, cover it with a second piece of plastic wrap.

Then apply a platen to spread out the load. I put a 4 L. pot of water or more to press it down. Same with the Balsa to Plywood glue up.

I was looking at one of the freshly curved pieces after it came out from under the press. I just dipped my finger in the pot of water and wetted the balsa

(the curve was toward the balsa vs. plywood and other balsa was not on yet)

It flattened right out but the curve came back when I glued the other balsa sheet on.

Both kits are from the same dealer and were new into his stock, I do not know how long the kit was bagged from "Long Bin Storm Door and Balsa Factory", but "sin loi":no: to me.

I have sanded into the poly today and I may try some rehydration of the short side, it is worth a shot.

P.S. what is "Vegemite"??? seriously? Found out, soo sorry I asked.

SAC of MMMSClub said:

Here are some fin shots, after they glued up the balsa sheets we just glued up the plywood cores and glued them to the balsa sheets. Cutting them out by following the plywood core at a template.

View attachment 109000

The reason I traced the fin shape was to load the corners with glue as there was some gaping at the corners. After the fins are done we will sand til the laser burn fades

View attachment 109001

Do not be afraid of loading the glue on.

View attachment 109002

Shock cord attachment with 15 feet of 3mm cord.

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That's nice looking shock cord. What is it made of? Nylon?? Where did you purchase it at??

So indeed ,it`s the waterbased glue no doubt.I think I`m going to use epoxy ,30 minute applied in a light film to laminate the skins.

When I made my Interceptor E, which has a pile of lumber to make those large fins ,most of which needed to be glued together to make one bigger fin ,I used 5 min, epoxy on the edge joint and sandwich between wax paper and weighed down.After 10 minutes they were cured and ready for samding, so I`m going this route also for all the glue ups.There really is little no reason why epoxy cannot be used ,as the glue layer is no thicker than a wood glue and less prone to warp.

I also plan on using 20 min finishing epoxy after they are sanded and given a fast few fills with SIG sealer.

I shall keep you updated.

Paul T

EMS Eastern Mountain Sports and It is just 3mm climbing accessory cord, and as I posted I think it is like over 200lb. but I am going to test it if I can find a strain gage. I should have taken some to MIT with me!!!

MarkH said:

Put the 3 straight ones on one model, and the warped ones on the other. Just live with it and enjoy the spin on the warped model.

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Ya and the wife was right two of the fins do counter each other.

sodmeister said:

So indeed ,it`s the waterbased glue no doubt.I think I`m going to use epoxy ,30 minute applied in a light film to laminate the skins.

When I made my Interceptor E, which has a pile of lumber to make those large fins ,most of which needed to be glued together to make one bigger fin ,I used 5 min, epoxy on the edge joint and sandwich between wax paper and weighed down.After 10 minutes they were cured and ready for samding, so I`m going this route also for all the glue ups.There really is little no reason why epoxy cannot be used ,as the glue layer is no thicker than a wood glue and less prone to warp.

I also plan on using 20 min finishing epoxy after they are sanded and given a fast few fills with SIG sealer.

I shall keep you updated.

Paul T

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Ya I would give that a shot, next time. But I do like the fins for scale.

SAC of MMMSClub said:

Oy, I would bet you a bitchamite(sic) sandwich it has to do with the uneven uptake of moisture from the Titebond by the balsa and plywood.

I was working on a good flat (dining room) table that I had protected with some plastic cling wrap.

I would glue the balsa together right on the plastic wrap, cover it with a second piece of plastic wrap.

Then apply a platen to spread out the load. I put a 4 L. pot of water or more to press it down. Same with the Balsa to Plywood glue up.

I was looking at one of the freshly curved pieces after it came out from under the press. I just dipped my finger in the pot of water and wetted the balsa

(the curve was toward the balsa vs. plywood and other balsa was not on yet)

It flattened right out but the curve came back when I glued the other balsa sheet on.

Both kits are from the same dealer and were new into his stock, I do not know how long the kit was bagged from "Long Bin Storm Door and Balsa Factory", but "sin loi":no: to me.

I have sanded into the poly today and I may try some rehydration of the short side, it is worth a shot.

P.S. what is "bitchamite"??? seriously?

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Looks like I may use expoy when my MDRM arrives....

I have two large flooring tiles - nearly 2' square and a tub with near on 20kg in it. Makes just about anything flat!

Have you thought about contacting Estes to see if they will send you replacement fins?

Krusty

I just finished the glue ups of the Balsa sheets with 5 min epoxy and all is good and flat ,but upon examination of the plywood center cores ,they all are a little warped and one more so than the others ,so this may be an issue in the end.But I`ll be doing some glue ups of the skins to the ply cores tonight ,so I`ll comment on how flat they turn out.

Cheers

Paul T

Hi All,

Back at it today, had the girls mesure and mix epoxy and I did the poor job on the pour:blush: But it turned out ok.

recoated the table with plastic wrap and set both body tubes aft end down. Slid MMT with forward Centering Ring glued in place into BT all the way so MMT and BT both were on table. Then slid Aft CR into BT to hold aft end of MMT centered in BT. Set it back down and checked and checked it again.

Then showed both girls how to mix epoxy via grams 50/50 ratio. They did not like the smell at all

epoxy is doing its thing and soon it will be fin can time!

I finished the fins today ,using epoxy (30 min) to laminate the Balsa to the ply core ,then painted both sides after sanding with 20 min. finishing epoxy and all the fins are flat and perfect ,with no warping ,even the warped ply cores came out nice and flat.

Cheers

Paul t

sodmeister said:

I finished the fins today ,using epoxy (30 min) to laminate the Balsa to the ply core ,then painted both sides after sanding with 20 min. finishing epoxy and all the fins are flat and perfect ,with no warping ,even the warped ply cores came out nice and flat.

Cheers

Paul t

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Cool! I will, if I make any more fin build ups, go with epoxy!

Hi All


I went with 5 min. epoxy cause its what I got and it is getting old so I wanted to use it up. 20 ml cups and sticks.



Fin tabs and middle CR with lightning holes and one opened up to allow for foam pour.



The tab as you can see in the next pix does not touch the top/forward CR and therefore the foam should move and fill around the part of the fin tab forward of the middle CR that you can not get any epoxy to.



The forward CR is about at the tip of the root of the fin so there is a lot of empty void to fill



The parts all test fit well and the slots for the fin tabs were nice and snug. Time to epoxy.

Hi Again,



Rocket doing the downward dog rocket yoga for epoxy.



Not that pretty, but it will stay together.



Starting on the second MDRM, small pours 5gr. total



The carnage.

Hi Again,



Parts for later steps.

I got my BT sanded ,seams filled with Bondo and sanded again as well as nosecone seams.Does your body tube have a lot of ridges and dimples in it...mine sure does.

Paul t

sodmeister said:

I got my BT sanded ,seams filled with Bondo and sanded again as well as nosecone seams.Does your body tube have a lot of ridges and dimples in it...mine sure does.

Paul t

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Well, its not fiberglass smooth by any means, but it is just a brown plastic coated BT. It has a mild ruddyness(sic) to it. But I plan to sand/prime/sand/prime/...... and then we will see I am sure that if I sanded and started smearing it with shmearo(pick your poison) it would hold some I am sure.

with just the fins and body tube, this is no light rocket!

Indeed ,I got mine at a reasonable state already(180 grit and 220) ,sandable primer and elbow grease will take care of the rest.

Bigger 29mm CTI loads should take this up pretty well.The finished kit is not as big as I thought ,height wise ,and very simple in design.This is my first DRM of any size ,never had one even as a kid ,it never piqued my curiosity as I was never into the 3FNC rocketry design "clique".

BUT then I got the bug and had to have this one ,go figure LOL

Cheers

Paul T

sodmeister said:

Indeed ,I got mine at a reasonable state already(180 grit and 220) ,sandable primer and elbow grease will take care of the rest.

Bigger 29mm CTI loads should take this up pretty well.The finished kit is not as big as I thought ,height wise ,and very simple in design.This is my first DRM of any size ,never had one even as a kid ,it never piqued my curiosity as I was never into the 3FNC rocketry design "clique".

BUT then I got the bug and had to have this one ,go figure LOL

Cheers

Paul T

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I purchased both kits from Robert, AMW and he was including a 2 grain CTI 29 mm case and closure.

I think the aim was to put it up on a "G", I might give it the 3 grain case and go with an H, depending on its last trip to the scales.

It is very much just an over grown Estes Skill lev. 2 rocket.

I do want to do the surface prep well, as I want to do a Candy Apple Red lower and Black metallic flake NC.

I like most kinds, some of the 3FNC are sleek and cool, not as cool as some of the Sci-Fi space craft rockets, but they are not as fragile.

I'm having fun and so are the girls except for the smells, eeew Dad, That smells so bad!

SAC of MMMSClub said:

I purchased both kits from Robert, AMW and he was including a 2 grain CTI 29 mm case and closure.

I think the aim was to put it up on a "G", I might give it the 3 grain case and go with an H, depending on its last trip to the scales.

It is very much just an over grown Estes Skill lev. 2 rocket.

I do want to do the surface prep well, as I want to do a Candy Apple Red lower and Black metallic flake NC.

I like most kinds, some of the 3FNC are sleek and cool, not as cool as some of the Sci-Fi space craft rockets, but they are not as fragile.

I'm having fun and so are the girls except for the smells, eeew Dad, That smells so bad!

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Oh I agree my friend ,prep work is most important at this stage ,and the results of a great finish will show this.

Candy apple and blk metal flake sounds beautiful.I look forward to seeing that.

As for me ,painting will have to wait until spring ,so April it is.Perhaps in Maine you may have a better chance ?

Paul T

sodmeister said:

Oh I agree my friend ,prep work is most important at this stage ,and the results of a great finish will show this.

Candy apple and blk metal flake sounds beautiful.I look forward to seeing that.

As for me ,painting will have to wait until spring ,so April it is.Perhaps in Maine you may have a better chance ?

Paul T

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I just put a electric heater in my one car garage and heat it up and spray away. I use rattle cans, so I do the best I can. I would love to have a paint set up. Need another building and winning lottery ticket.

I have watched online vids on how paint Metallic Candy Apple Red, I hope it works the same with rattle cans???

SAC of MMMSClub said:

I just put a electric heater in my one car garage and heat it up and spray away. I use rattle cans, so I do the best I can. I would love to have a paint set up. Need another building and winning lottery ticket.

I have watched online vids on how paint Metallic Candy Apple Red, I hope it works the same with rattle cans???

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I too use rattle cans with very good results.Do you know who makes the candy apple red ? Duplicolor makes some very nice acrylic lacquer colors in their "color match" line.I used a metal flake Garnet Ruby red on my Madcow Seahawk nosecone (it was very similar to the real missile color) and it really shines in the sun.I did of course apply a good number of gloss clear coats ,but the results were very nice.

The metalic black should be an easy find ,again Duplicolor may have this as well as many other companies.

Cheers

Paul T

sodmeister said:

I too use rattle cans with very good results.Do you know who makes the candy apple red ? Duplicolor makes some very nice acrylic lacquer colors in their "color match" line.I used a metal flake Garnet Ruby red on my Madcow Seahawk nosecone (it was very similar to the real missile color) and it really shines in the sun.I did of course apply a good number of gloss clear coats ,but the results were very nice.

The metalic black should be an easy find ,again Duplicolor may have this as well as many other companies.

Cheers

Paul T

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The Auto parts store looked it up and found some really high dollar paint like 5o+per can. They then found a Ford Candy Apple Red at 11 bucks a can, I do not know who makes it but Duplicolor is a very popular paint Co. in all the vids I watched on Youtube Duplicolor was what I saw on the cans. The color is acchived by spraying; Silver, CAred translusant, Clear coat, Now should you do decals before clear or after and another clear coat??

SAC of MMMSClub said:

The Auto parts store looked it up and found some really high dollar paint like 5o+per can. They then found a Ford Candy Apple Red at 11 bucks a can, I do not know who makes it but Duplicolor is a very popular paint Co. in all the vids I watched on Youtube Duplicolor was what I saw on the cans. The color is acchived by spraying; Silver, CAred translusant, Clear coat, Now should you do decals before clear or after and another clear coat??

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I would do a few clear ,then decals then several more clear to even things out.

I would definately test some of the clear on a decal that is not needed like the printing on the edges or the Estes logo ,anything.I`m not sure, but if the paint or clear is lacquer based (acrylic or celulose etc.) it may bugger them ,although laying the clear in light coats as it should be done may prove to be prudent.

I don`t see a problem myself with the Estes decals ,as they are of very nice quality as of late.

Paul T

Nice build thread Scott. Lookin good!op:

We are building two of these as well --though not at the same time. The first we used glue, and had some pretty warped fins, as you did. I think on the next, we'll use some epoxy and call it good. We added pressure by placing the fin between two panes of glass, then a shelf worth of books on top (Harrison's, a couple of traycased editions of various authors, etc). I just figured it was the glue. No big deal. We'll live with it on this one...


Later!

--Coop

I did just that ,even though the ply cores were warped ,after using 30 min. epoxy to laminate the skins I placed sheets of wax paper between the fin sets, placed between sheets of 1/4" thick glass plate and placed two bags of lead shot on top (50 pounds total) and the fins came out perfect.

I was very sure however ,that the Balsa skins did not shift off possition from the ply cores (as i cut the Balsa skins the same shape & size as the cores ,leaving a 1/16" all around) when I was stacking them together and placing the weight on top.

A little sanding on all edges(I also gave the leading edges a bit of a bevel) and a coat of 20 min finish epoxy and Bob`s your uncle.


Paul T