Building the Estes Little Joe II: Tips, Tricks, and Modifications

Discussion in 'Low Power Rocketry (LPR)' started by James Duffy, Jan 28, 2016.

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  1. Apr 30, 2016 #241

    MaxQ

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    I've been wading through this thread. Thanks for the info.
    Haven't built mine yet, will this summer.

    Is there a top 5 five building tip list for getting this one right.?

    Apparently the right adhesive for the type of material of each component is at the top of the list.
     
  2. May 5, 2016 #242

    KB1DC

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    Hello,

    I wanted to note that I just purchased the LJII this month (April 2016) and I'm studying your design notes - thank you for doing this BTW. I observed that the body tube wrap fixes like a glove leaving no air gap between the body tube and the body tube wrap nor is there hardly any gap where the seams come together. So now I'm confused why I even need the small body tube and also the procedure you outlined for this section of building. What am I missing in your explanation? I taped the wrap so if warrantied I can take a picture.

    Thank you very much!
    Jon
     
  3. May 24, 2016 #243

    Brent

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    Has anyone checked these out yet? I will be building my second Little Joe II and was wondering how they looked. They are not terribly priced if they looked good.
     
  4. May 24, 2016 #244

    kjohnson

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    James was given a set while at TARC a couple of weeks ago, but I don't know that he's had a chance to put them side by side.

    kj
     
  5. May 27, 2016 #245

    James Duffy

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    Kevin has shamed me into digging the parts out for a quick evaluation. First impression: the parts are perfect, and look a heck of a lot better than the nozzles supplied with the Estes kit. (That's not a slam on the Estes parts, as I fully recognize that this mold tool is almost half a century old, and I am thrilled that it has been resurrected.)

    IMG_1876.jpg

    A nozzle snapped off of my LJII model a couple of weeks ago and traveled into the aether of eternity, so I elected to glue one of the turned aluminum Eagle RCS nozzles into the vacated position to see how it looks. A small drop of medium CA was used for attachment. Here's a photo that compares the Eagle part to the three surviving kit-supplied parts.

    IMG_1878.jpg

    Would I fly with these expensive little boogers in place? Only if I were in contention for a top-four place at NARAM, frankly, as it seems inevitable that a few would pop off on landing. On the other hand, this would be just the accessory to dress up a nice static model, especially if one was entering it in a local IPMS show.

    Mad props to Jim Filler for sourcing this part set, BTW!

    James
     
    Last edited: May 27, 2016
  6. May 27, 2016 #246

    Brent

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  7. May 27, 2016 #247

    James Duffy

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    That's really cool, thanks for the tip! I appreciate the fact that the designer provides four extra nozzles in anticipation of the inevitable losses. The only challenge would be dealing with the unfortunate grainy texture inherent in every 3d printed part.

    James
     
  8. May 29, 2016 #248

    P-40Warhawk

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    I don't know about a "top 5," but here's what I learned in building mine:

    First, you are correct in that using the right adhesive is paramount. I used 3M Super 77 spray for my wrap. I was a little apprehensive since I have never used this type of adhesive before, but it worked very well with an excellent bond. Just make sure you line up the wrap correctly when you place it on the body tube for I found little play once I started. I used the forum-recommended Plastruct Plastic weld to attach the fins and launch lugs to the wrap. I had one fin knocked off during a very hard landing, but since there was no damage to the underlying wrap it was an easy fix. I'm still not a huge fan of how this was designed since there is so little surface area contact between the base of the fin and the corrugated wrap, and I see the potential for more fin failures in the future.

    I did not use tube-type plastic cement for any of the construction as the directions indicate, but instead Tamiya extra-thin cement. This is my glue of choice for plastic models and worked fine for gluing the fins and nozzles together and for the construction of the tower (which requires a little patience to build). I did not have Plastruct on hand at this point, but I believe it would work just as well.

    The decals really cling, and after having some issues with the capsule decals either folding in on themselves or sticking like glue so that fine adjustments in their positions were very difficult (even with setting solutions), I decided to cut out the squares for the body tube in groups to apply them. I felt that if I tried to apply that huge one-piece decal as is, that if I didn't ruin it then the very least is that I would end up with a lot of wrinkles.

    Other than that, I pretty much followed the directions and had no problems. But I didn't super-detail mine like many others have.

    HTH,

    Mark
     
  9. May 30, 2016 #249

    johnpursley

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    Hey Warhawk,

    The Tamiya cement is not going to bond the plastic of the corrugations like all the other parts in the kit which are polystyrene or similar. (I've tried...it bonds to the corrugations but nothing like the following recommendations). You need something that can bond the ABS (or whatever the corrugation material is...it behaves like every other ABS I have handled over many years). Tenax 7R, "Same Stuff" from Micro Mark (it's the "same" as Tenax, just cheaper), Plast-I-Weld from Flex-I-File, Plastruct Plastic Weld (not Plastruct Bondene...description makes it seem like it will work but doesn't really adequately dissolve the corrugated skin) or other liquid cements which contain either methylene chloride (preferred...it goes after ABS and tough plastics better) or MEK (methyl ethyl keytone). Just experience talking here. I'm wrapping up my 11th LJII build and other than on my first one, zero problems with bonding with Tenax, "Same Stuff" (my preferred) or Plast-I-Weld (second choice).

    I also equipped all of the builds (except first one) with a fin spar that runs through the corrugated wrap, body tube, and to the engine tube. The spar method is covered earlier in this thread. Even with proper cements, the method of mounting the LJII fins is inadequate. The weak point is the bond between the corrugation and the body tube on the inside of the skin. A spray adhesive with the limited contact area caused by the corrugations is the "weak" joint in the whole "stock" Estes mounting method.

    Going to toot my own horn now... I offer a "skin" kit for the LJII that includes the SM (which includes panel lines, radiators, and the roll pattern), the BPC (includes markings to simulate the cover used on A-004), the Escape Motor (markings for the roll pattern, electrical conduits, various joints, and jettison motors) and the motor nose (mainly the pitch motor and the canards). It's a very thin vinyl material with very high rez printing (not silkscreened like decals) and are self adhesive. Super easy and fast to apply...plus the wraps completely cover the body tube spirals of the LES motor and the SM...seams are camouflaged by falling on detail lines. Go to eBay and search for "Estes Little Joe II" and you will see my "Accur8 Skin Kit". When using the skin kit the only decals you need from the Estes Kit are the "UNITED STATES" which are just the right weight and quality to snuggle down easily in the corrugations with the use of a good setting solution like SolvaSet.

    Within a month (I hope) I will offer a set of true 1/45 scale RCS quads...depending mainly on if there is demand (let me know). I had the good fortune of having in my possession a quad off a production SM a few years ago for a conservation project...and measured every square inch of the bugger while I was working on it. The RCS motors are the same as on the LJII but the RCS housing is a bit different. The motors will have the neat external stiffening rings and, of course, be of the proper shape and dimensions. Right now, the plan is to have a metal pin run through the throat of the motor to secure it to the RCS housing for added strength.

    You can contact me at johnpursley@accur8.com

    ---John Pursley

     
  10. May 30, 2016 #250

    P-40Warhawk

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    Hi John,

    Perhaps I wasn't clear in my post. Definitely not the first time and certainly not the last. I used Tamiya Extra-thin cement to glue the fin and nozzles halves together, along with much of the capsule assembly, but Plastruct Plastic Weld to attach the fins and launch lugs to the body tube wrap, which is what was recommended in this thread. It worked fine for the most part, but if I wasn't so far along in my build I would have used the spar method that you mentioned earlier. If I build another Little Joe II I definitely will, along with your "skin" kit.

    This first kit was sort of a trial, crash 'n burn one....and it definitely did crash upon landing (if you read my previous post regarding its launch)!

    Regards,

    Mark
     
  11. May 31, 2016 #251

    johnpursley

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    I mainly figured it was worth reiterating the cements since you talked about it in your post. I lose track of who did/said what on long threads...which I, of course, contribute to making even longer by repeating myself (Sorry All!).

    I don't test "every" adhesive I see...but I am an addicted "experimentalist" and will pretty much try anything...even if (sometimes especially if!) someone says its impossible or otherwise "won't work" (typically, the well-meaning advisers haven't tried or thought very much about what they say is impossible <G>). One other thing I haven't mentioned in past posts is that the cements containing methylene chloride (Texax, "Same Stuff", Plast-I-Weld, etc.) seem to evaporate more quickly than those that are predominantly (or exclusively) MEK. They form a pretty solid bond very quickly (you can generally "let go" after 5 or 10 seconds) and if you happen to get an excess of the stuff on your parts...even to the point of "pooling"...it evaporates so quickly that it doesn't turn the affected area into "plastic putty." One really nice thing about the Estes corrugated wrap IS that it is quite thick for a vacuformed part (compared to past model rocket wraps) and will survive adhesive abuse or overapplication very well. That's a check in the "Plus" column in my opinion.

    ---John Pursley---



     
  12. May 31, 2016 #252

    dhbarr

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    For ABS, acetone smoothing. PVA is typically a much better print than ABS, which is lucky since I know of no way to smooth it other than fill-n-sand.
     
  13. Jul 13, 2016 #253

    kcobbva

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    I am SO GLAD that DMO has pointed this thread out to me. I am soon to embark on my own Little Joe II and this just has Invaluable information in it!! Love this thread!
     
  14. Nov 16, 2016 #254

    zog139

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    John , I may have missed this.... did the replacement set get added for sale ? Would like to do a big Saturn 1B :)
     
  15. Nov 27, 2016 #255

    MaxQ

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    3M 90 is impressive stuff, but be careful where and what you use it on.I had a rather unfortunate experience with some thin plastic sheeting.
    I was doing a styrene sheet layup on a scale project - sprayed the 3M 90 on thin sheet and laminated the styrene sheet on the component...a CF body tube - bound it with painters tape.
    Came back an hour later and the styrene sheet was buckling in many places. The sheeting eventually started dissolving and actually segments tore off in pieces when I removed the tape.
    The aerosol solvent was the culprit - I suspect.

    When in doubt - test.
    I believe the ABS sheet with this kit may be more resistant.
     
    Last edited: Nov 27, 2016
  16. Feb 23, 2017 #256

    Hoss

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    Hey George

    I am finally working on finish the Little Joe with your input on how to up-rate it for a Nice sport scale model.

    Do you have a sketch for the Recruit motor that you built from an old nose cone..??

    Thanks

    Dan
     
  17. Feb 23, 2017 #257

    georgegassaway

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    Loads of LJ-II drawings here: http://georgesrockets.com/GRP/Scale/DATA/LJoeData.htm

    Including this one, at the upper right the two versions of the Recruits, angled (outer ones) and straight (center set on A-004).

    [​IMG]


    Also, some pics from QTV's preparation.

    [​IMG]

    [​IMG]


    BTW - the above two photos came from this site. There are a few others showing Recruits, and a whole lot more LJ-II photos, including the launch pad construction. A lot are about the pad and QTV, not as much for the other flights. The images are not as big, I enlarged them 2X as seen above, and they didn't suffer too badly.

    http://www.apollomissionphotos.com/index_apollo_littlejoe.html


    Wow, a year ago I finally had the model built (As mission A-004). Hadn't flown yet. Here's a pic I posted before, showing the Recruits.


    [​IMG]
     
    Last edited: Feb 24, 2017
  18. Feb 23, 2017 #258

    Hoss

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    George

    Thanks again... I am amazed at how much you know about this subject...

    Yep..time does fly..hopefully my LJII will soon:)

    Dan
     
  19. Mar 29, 2017 #259

    Hoss

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    George

    Are you rebuilding your website..??

    Went to go look at the Little Joe pages and the images are missing..

    Let me know

    Thanks

    Dan
     
  20. Mar 29, 2017 #260

    georgegassaway

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    No, not updating the site. I just looked and everything seems to be there.

    May have been a server / backup issue.

    Try it again.
     
  21. Mar 29, 2017 #261

    Hoss

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    Nope....no luck...

    it is not everything , just the little joe directory.

    I go to your site, click on "scale Directory" then on "Little Joe II Main Directory"...

    all the text is there, just no images.

    tried from PC and Android phone...
     
  22. Mar 29, 2017 #262

    samb

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    FWIW I'm see the same thing as Hoss, no pictures. :(

    Georges LJII page.jpg
     
  23. Mar 31, 2017 #263

    georgegassaway

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    It would have helped if anyone had posted the actual link they tried.

    Weird. The pages are there, but somewhere along the way the link in the "Scale Main" page is showing links to an earlier version of the Little Joe pages. So this is the Scale Main page with the bad Little Joe-II links:

    http://georgesrockets.com/GRP/Scale/SCALE.htm

    HERE is the correct link that it should have directed to:

    http://georgesrockets.com/GRP/Scale/DATA/LJoeMain.htm

    It is a bit of a hassle for me to update my home page. I have to get an old 2004 model desktop I rarely use, to run some 1996-era webpage software (Orphaned) , make the changes, save to a USB thumb drive, then put them into my laptop and do a dance to login to update the site files.

    So, I do need to fix that, but it'll have to wait awhile. It's not something I can go in and fix in 5 minutes (HA, if only), even though the actual change to the link will only take a few seconds to fix.

    Now that i've gone in and looked around for an old nugget to post here....

    One early idea for testing the Apollo abort system, was to adapt the Apollo CM and LES to the top of the original sized Little Joe-I booster. Performance would have been underwhelming. Wind Tunnel model drawing, as yes, it got at least far enough for wind tunnel testing. See this link for the report it was from: http://georgesrockets.com/GRP/Scale/DATA/JoeReports.htm#aero

    [​IMG]
     
    Last edited: Mar 31, 2017
  24. Mar 31, 2017 #264

    samb

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    George, to say you've paid forward would be a gross understatement. Thank you !
     
  25. Mar 31, 2017 #265

    Hoss

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    George

    Thanks for the redirect...just never had to do it that way before...

    If you ever do a "Gofundme" page to help update your archive..let me know...I will pitch in.

    This is information definitely worth preserving..

    Dan

    P.S..hope to have my Little Joe completed soon with the upgrades you mentioned earlier...will definitely post a few pics..the regional is in two weeks..:)
     
  26. Mar 31, 2017 #266

    TangoJuliet

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    Me too! I spent quite a bit of time this morning on your website gleaning information. (I especially appreciate the "Contest" and "Plans" pages, even though I no longer compete)
     
  27. Apr 6, 2017 #267

    Hoss

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    George

    Do you have any insight on what makes for a good documentation package for a sport scale of the 004 mission..??

    Thanks

    Dan
     
  28. Apr 22, 2017 #268

    zog139

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    Did anyone end up going with mini rail buttons on this model ?
     
  29. Apr 23, 2017 #269

    Hoss

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    THANKS to everyone on this build thread....Especially George Gassaway, John Boren & John Pursley for all the excellent info and help.

    Finally got it done and did some of George's recommendations..
    1. Reworked capsule to Mission 004
    2. Added small recruits to bottom..
    3. Used John Pursley printed wraps....
    4. Made fins Thru the wall with plywood adapters..

    Dan
    LJII_BOTTOM.jpg LJII_CAPSULE.jpg
     
  30. Apr 27, 2017 #270

    georgegassaway

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    Didn't see your post till now.

    You can go to my website and find photos specifically of the A-004 mission. Also this page of drawings, mostly generic but which identify which aspects are unique to a specific mission like A-004.

    http://georgesrockets.com/GRP/Scale/DATA/LJoeData.htm

    And then this one huge GIF overview specifically of A-004. I used that for my FAI Scale (S7) documentation which requires a 1:1 scale "workshop drawing". This drawing was printed onto 36 x 48" paper.

    [​IMG]

    So, it has dimensions of full scale and also the 1/39.5 scale that I built my model to (that is the scale factor that works when using Evergreen Scale Model's "Metal Siding" plastic sheet, 12" wide, .010" spacing, for the 120 corrugations of the Joe body, when curled into a tube. I cheated a bit and used a BT-101 for the Service Module, slipping over the corrugated plastic body rather than being flush).
     
    Last edited: Apr 27, 2017

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