Build thread: New Semroc MX kits

Discussion in 'MicroMaxx (MMX)' started by kuririn, Jun 29, 2018.

Help Support The Rocketry Forum by donating:

  1. Jun 29, 2018 #1

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    For the Maxxers out there, the biggest news in quite some time has been the introduction of several new Micro Maxx powered kits by Semroc, including the (MX) Goblin, Fat Boy, Blue Bird Zero, Hawk boost glider, Cherokee (D), and the Orbital Transport. Good to hear, especially in light of the upcoming closure of Fliskits and their Micro to the Maxx line of kits.

    Since Andrew (Rockets) did such a fine job in his build of the MX Goblin, I'll start with the MX Fat Boy.
    These will be quick, one or two post builds.

    The obligatory parts photo:

    IMG_20180626_132414.jpg


    Assembled the motor mount. Instructions have you tie a knot at the end of the Kevlar shock cord and lock it in place between the thrust ring and motor tube. It dawned on me after assembly that it might be better to tie a loop around the thrust ring. That way the motor will be pushing against the thrust ring and one thickness of the shock cord rather than against a knot. Also the loop knot will be further away from the direct blast of the ejection charge. Will incorporate that into the subsequent builds. Left motor mount to dry in a vertical position. Install in main body tube after drying. (Dry fit first, you may have to sand the centering rings to get a snug fit).

    IMG_20180626_133638.jpg

    Cut out the fins and attached using the fin jigs. I love these! Makes spacing and alignment so easy. I found that the easiest way for me to use these is to dry fit and align the fins with the jigs first. Then I spot tacked both sides of each fins with a drop of medium CA using a toothpick. After drying I removed the jigs and filleted the fins with CA. The capillary action of the CA and the porosity of the wood and paper lends to a strong bond. Glued the launch lug on also.

    IMG_20180626_134710.jpg

    Using the supplied toothpick, pushed it in and marked it. Removed and cut it off at the mark. This will be used later to lock in the Kevlar shock cord to the nose cone.

    IMG_20180626_135203.jpg

    Instructions say to attach the streamer to the Kevlar with masking tape. I have had streamers detach from the shock cord at ejection when I use this method. So this is how I attach all my streamers now:
    First, fold one corner of the streamer down.

    IMG_20180626_140459.jpg

    Then fold the other corner down forming a triangle.

    IMG_20180626_140528.jpg

    Punch a hole and attach a small grommet with a grommet tool. I don't have a rotary punch so I used an ice pick.

    IMG_20180626_140931.jpg

    Then tie it to a loop on the shock cord. This streamer isn't coming off any time soon.

    IMG_20180626_142506.jpg

    Glue the cut off toothpick and the shock cord into the nose cone.

    IMG_20180626_142818.jpg

    And assembly is complete.

    IMG_20180626_143904.jpg

    Comments: The streamer seems quite large for a MX model. My other MMX kits use a shorter, narrower streamer. The large streamer can result in difficulty in getting your wadding and laundry into the body tube. Parts seem to be of good quality. Did I mention that I love the fin jigs?
    EDIT: I missed an important instruction. You are supposed to cut the streamer in half lengthwise, and use just one of the halves. Trimmed down the streamer in my model.

    Will be finishing all models offline using standard CWF, primer, and paint. I prefer doing this all at once rather than piecemeal. Will post a picture of all models in their finest livery at the end.

    Next post: Semroc MX Blue Bird Zero
     
    Last edited: Jun 29, 2018
    blackjack2564 likes this.
  2. Jun 29, 2018 #2

    Rainmaker

    Rainmaker

    Rainmaker

    Well-Known Member

    Joined:
    Jan 4, 2018
    Messages:
    51
    Likes Received:
    9
    Location:
    Austin, Texas
    I've got 8 MMX rockets complete from Semroc and Fliskits. After problems with deployment on a couple, I've left the streamer out on all of them. They don't fly out of sight and the separation alone causes them to float down light enough to land without damage.
     
  3. Jun 29, 2018 #3

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    I agree, most MMX rockets can use featherweight recovery without damage. But it's so much cooler watching them come down with the streamer flapping.
     
  4. Jun 29, 2018 #4

    BEC

    BEC

    BEC

    Well-Known Member

    Joined:
    Feb 19, 2009
    Messages:
    2,321
    Likes Received:
    11
    Gender:
    Male
    Location:
    Auburn, WA
    Not to mention a streamer makes 'em easier to find in the grass....!
     
  5. Jun 30, 2018 #5

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    -Second build: Semroc MX Blue Bird Zero

    The parts:

    IMG_20180626_202625_974.jpg

    Assembled the motor mount and let dry vertically. Used a loop instead of a knot on the Kevlar shock cord.

    IMG_20180626_204410_423.jpg

    Dry fitted the fins to the rocket with the jigs, two for the mains and one for the tiny forward fins. Spot tacked, let dry, then removed the jigs and filleted the fins.

    IMG_20180626_214200_984.jpg

    Glued the body coupler in place, then glued the two main body tubes together.
    Attached the streamer to the shock cord, glued the shock cord to the nose cone with the cut off toothpick.

    IMG_20180629_211221_111.jpg

    And assembly is complete.

    IMG_20180627_023356_895.jpg

    Comments: This is a big model for MMX. The face page of the instructions say the approx. altitude is 215'. I have my doubts, we'll see at launch. Trimmed down the streamer, I was supposed to use half, not the whole thing. Some builders might want to align the tiny forward fins by hand and eyeball, rather than fiddling with the jig. The cuts on the body tubes weren't exactly straight, I squared them off with a sanding block.
    As previously mentioned, finishing to be done offline.

    Next post: Semroc MX Hawk boost glider
     
    Last edited: Jun 30, 2018
  6. Jun 30, 2018 #6

    blackjack2564

    blackjack2564

    blackjack2564

    Crazy Jim's Gone Banana's

    Joined:
    Jan 18, 2009
    Messages:
    8,273
    Likes Received:
    375
    Location:
    Savannah Ga
    nice job there!
    Good to see some new "old" micro's showing up.
    Will have to add some to my collection. Really like the tiny fin guides, nice touch and kit's seem totally complete.
     
  7. Jul 1, 2018 #7

    graylensman

    graylensman

    graylensman

    Well-Known Member

    Joined:
    Feb 24, 2009
    Messages:
    949
    Likes Received:
    1
    That is huge for MMX...but I think I'll pick up that kit. I have very young niece and nephew, and it might be easier for them to watch a bird this big than some of the other MMX rockets.
     
    MarcoPolo likes this.
  8. Jul 2, 2018 #8

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Third build: Semroc MX Hawk boost glider

    The parts:

    IMG_20180627_052149_363.jpg

    Using the alignment jig glue the rudder to the bottom rear of the keel and the stabilizer to the top rear square to the rudder. Careful, there is a tiny 90 degree bend at the end of the keel and the fit of the stabilizer in the slot is tight. It's easy to break off that piece, so sand down the slot if necessary.

    IMG_20180627_053403_603.jpg

    Glue the fuselage top to the keel. Glue the motor tube to the pylon. When dry glue the pylon and motor tube to the top of the fuselage. Glue the nose cone in place.

    IMG_20180627_094344_822.jpg

    Invert the assembly on a level surface and support the stabilizer end with the jig. Motor tube should be level with the surface. Glue the wing tabs into the slots on the keel, with wing tips touching the surface. This easily sets the wing dihedral. Let dry.

    IMG_20180627_095413_907.jpg

    Glue the stabilizer tips to the ends of the stabilizer and the launch lug to the top of the motor tube.

    IMG_20180627_114522_986.jpg

    At this point instructions say to sand all edges round except for the wings, which should be sanded to an airfoil shape for best results. I would think that it would have been easier to do that before assembly, not after. Airfoiled one wing, need to do the other wing and round the other surfaces.

    Anyhoo, I'm calling this assembly complete (except for a little more sanding). Will be finishing this offline with Sharpies instead of paint so as not to degrade flight performance. After finishing, the glider needs to be trimmed with the clay weight.

    Next post: Semroc MX Cherokee
     
  9. Jul 2, 2018 #9

    graylensman

    graylensman

    graylensman

    Well-Known Member

    Joined:
    Feb 24, 2009
    Messages:
    949
    Likes Received:
    1
    >At this point instructions say to sand all edges round except for the wings, which should be sanded to an airfoil shape for best results.<

    By coincidence, this morning I read the chapter on boost gliders in the Handbook of Model Rocketry. Stine mentions that sanding B/G wings with a traditional aircraft airfoil is unnecessary. FWIW.
     
  10. Jul 2, 2018 #10

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Gee, thanks for REALLY confusing me! Since I airfoiled the left wing if I leave the right wing unsanded does this mean that it will do a clockwise circle without clay weight on the wing?;)
    On second thought for the sake of symmetry I'd better do the right wing too. Plus the glider will be lighter, duration may be marginally longer. But thanks for that info. I would tend to believe anything that G. Harry Stine says.
     
  11. Jul 3, 2018 #11

    graylensman

    graylensman

    graylensman

    Well-Known Member

    Joined:
    Feb 24, 2009
    Messages:
    949
    Likes Received:
    1
    Always trying to be helpful! :D

    I just ordered an MMX Hawk today. I'll try G. Harry's advice, and let you know how well it glides.
     
  12. Jul 3, 2018 #12

    GlenP

    GlenP

    GlenP

    Well-Known Member

    Joined:
    Oct 4, 2014
    Messages:
    1,127
    Likes Received:
    31
    If you airfoil, it may change the amount of elevator trim required as compared to a flat wing. Aerodynamically probably not much different, but when you airfoil the wing you are also making it lighter, maybe just a little. Might be hard to tell any difference between a flat rounded wing and an airfoiled wing on the B/G flight time, but if you are lighter it will tend to glide longer.
     
  13. Jul 4, 2018 #13

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Fourth build: Semroc MX Cherokee


    The parts:

    IMG_20180629_000628.jpg

    Assembled the motor mount. Used a loop instead of a knot as in the instructions.

    IMG_20180629_032559.jpg

    Installed motor mount. Assembled fins using the fin jigs. Spot tacked with CA, let dry. Removed the jigs and filleted the fins. Attached launch lug.

    IMG_20180629_032648.jpg

    Inserted toothpick into nose cone, marked, removed and cut.

    IMG_20180629_033338.jpg

    Cut streamer in half lengthwise, attached to shock cord (my method), Glued shock cord and toothpick into nose cone.

    IMG_20180629_072756.jpg

    And assembly is complete.

    IMG_20180629_073333.jpg

    Comments: Dry fit before gluing, the centering rings were tight and needed to be sanded down a little. This is a beautiful design, no matter what the scale. Long aerodynamic body and rounded fins. Should look nice after finishing and decals. As usual, finishing to be done offline with a group shot at the end.

    Next post: Semroc MX Orbital Transport
     
    Last edited: Jul 4, 2018
  14. Jul 8, 2018 #14

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Fifth build: Semroc MX Orbital Transport Part 1

    The parts:

    There were some missing parts! Unbagged the kit, read the instructions, and realized that I should have 3 of the larger alignment tools, 2 of the smaller ones, and 2 thrust rings, one for the motor and one for the glider nozzle to attach to. Instead I had only one of each. E-mailed Randy at erockets, parts were mailed out.

    This is a very complex kit, with many small parts. Will be doing this build in two posts.

    IMG_20180629_105923.jpg


    Assembled the motor mount and let dry, using a loop instead of a knot in the Kevlar. Trimmed off excess Kevlar after dry.

    IMG_20180630_100814.jpg

    Installed the motor mount in the body tube, using the alignment guide to set the depth.

    IMG_20180630_111954.jpg

    Glued the wing fairings to the main wings. There is a tab on the wing that is supposed to fit in the slot on the fairing, but it did not fit, too wide. So I trimmed the tab down with a sharp knife. I suppose glitches like this are to be expected on a first run kit production. Hope they fix it on later runs. Glued together on wax paper with a straight edge to keep both root edges square.

    IMG_20180630_112355.jpg

    Cut streamer in half, attached to shock cord. glued shock cord and cut off toothpick into nose cone.

    IMG_20180630_213301.jpg

    Aligned the wings to the body tube with the three larger alignment jigs, then spot tacked with CA. After drying, removed the jigs and filleted the wings.

    IMG_20180707_060143.jpg

    Measured, marked and glued the two canard wings to the front using two jigs with the third leveling the tube on the aft. Some modellers might find it easier to just extend straight lines from the wing fairings and glue the tiny canards by eyeball instead of fiddling with the jigs.

    IMG_20180707_073042.jpg

    Glued the launch lug and wing tips. Using the two smaller jigs, aligned the two ventral fins, tacked, dried, removed the jigs, and filleted.

    IMG_20180707_085401.jpg

    Assembled the scramjet housings. Note that one of the lugs (exhaust nozzle) was not cut the same length as the other three. Another production glitch. Used a sharp knife to trim to size.

    IMG_20180707_095352.jpg

    Glued the scramjet housings to the wings.

    IMG_20180707_102057.jpg

    To be continued in Part two.
     
    Last edited: Jul 8, 2018
    T-Rex likes this.
  15. Jul 11, 2018 #15

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Update: for some reason I'm having trouble uploading pictures, keep getting an error message. Will try again later today.

    EDIT: Tried again tonight, uploads seem to be working now, so we're back in business.
     
    Last edited: Jul 12, 2018
  16. Jul 12, 2018 #16

    blackjack2564

    blackjack2564

    blackjack2564

    Crazy Jim's Gone Banana's

    Joined:
    Jan 18, 2009
    Messages:
    8,273
    Likes Received:
    375
    Location:
    Savannah Ga
    Same here with pics??
     
  17. Jul 12, 2018 #17

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    I left a post in the Feedback section, hopefully an administrator will see it sooner or later.
     
  18. Jul 12, 2018 #18

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Continued: Semroc MX Orbital Transport Part 2

    Now for the glider. Glue the itsy bitsy disc to the thrust ring. Then form and glue the teeny weeny cardstock nozzle (tweezers are a must). BTW those are regular 3.5" tweezers in the picture. Set aside to dry while trying to maintain your sanity.

    IMG_20180707_144517.jpg

    Using the remaining portion of the cut off toothpick, insert it into the nose cone of the glider. This will be used to hold the balancing clay, if needed.

    IMG_20180707_144637.jpg

    Assemble the glider: The wing dihedral is set by using the glider body tube under the glue joint with the wing tips touching on a level surface. Use wax paper to keep any glue off the tube. When the wing is dry glue to the body. Glue the rudder and the elevons on. There is an elevon angle guide on the alignment tool. Glue the glider hook and aprons to the body. Run fillets on all wing, rudder, and elevon joints.

    IMG_20180707_144714.jpg

    Insert the nose cone and nozzle into the glider but leave unglued at this time, pending trimming after finishing. And assembly is complete.

    IMG_20180707_151458.jpg

    Comments: Instructions say to fill and sand the wood at this point. You may want to do that before this point by filling and sanding the sub assemblies before putting the whole thing together. There are numerous nooks and crannies which make it very difficult to fill and sand the wood, much less prime and paint. The slots and tabs definitely need to be filled before painting.
    There were a few glitches in this build which I attribute to early production oversights. Hope they get straightened out in the future. The alignment tools are terrific. All kits should have them.

    Next post: Family portrait with all the "boys" dressed up.
     
    Last edited: Jul 12, 2018
    T-Rex likes this.
  19. Jul 15, 2018 #19

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Final update:

    Family portrait with the "boys" in their full livery.

    IMG_20180715_002721.jpg

    These builds were a lot of fun without burning a big hole in your wallet. And launch recovery should not be a nail biter either. So you save money both ways.
    Looking forward to building the two stage MX Omega. It's in the Semroc catalog but hasn't been released yet. Thanks for looking in.
     
    T-Rex and rockets like this.
  20. Jul 16, 2018 #20

    graylensman

    graylensman

    graylensman

    Well-Known Member

    Joined:
    Feb 24, 2009
    Messages:
    949
    Likes Received:
    1
    Beautiful! I have the Hawk, Cherokee, and Blue Bird Zero on my bench, waiting to go. What did you use to finish your Hawk?
     
  21. Jul 16, 2018 #21

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    I used a regular black Sharpie for the nose, fuselage, and tail tips, and an orange Sharpie paint pen from Home Depot for the wings and tail. Preliminary glide tests before finishing showed it to be tail heavy, I was hoping the paint might eliminate the need for added clay at the front. Still had to add a little bit of clay to the front of the boom. Glides nicely now, finished weight is somewhere between 2 and 3 grams. In retrospect perhaps I didn't need to airfoil the wings, too much nose lift.
     
  22. Jul 17, 2018 #22

    GlenP

    GlenP

    GlenP

    Well-Known Member

    Joined:
    Oct 4, 2014
    Messages:
    1,127
    Likes Received:
    31
    Did you also airfoil the tail? That is another option, if you want to increase the lift on the tail a little bit to get a better nose-down glide without adding as much clay, probably would still need a little. But, if you already have a good glide, might not want to mess with it
     
  23. Jul 17, 2018 #23

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Nope, thought about it but decided to follow the instructions to the letter for this build. Also thought about a little weight near one wing tip so that it'll fly in a wide circle for recovery, but will wait and see after the first launch if that's needed. BTW neither of those were mentioned in the instructions.

    EDIT: The instructions mention having the glider fly in a circle for easier recovery but does not go into specifics.
     
    Last edited: Jul 18, 2018
  24. Jul 18, 2018 #24

    rockets

    rockets

    rockets

    Sponsor TRF Sponsor

    Joined:
    Nov 18, 2014
    Messages:
    1,131
    Likes Received:
    10
    Location:
    Somewhere in Ohio
    What's your favorite one?


    I like the finish on all of them! :)



    Thanks,
     
  25. Jul 18, 2018 #25

    kuririn

    kuririn

    kuririn

    BARGeezer TRF Supporter

    Joined:
    Oct 3, 2016
    Messages:
    925
    Likes Received:
    105
    Gender:
    Male
    Location:
    Hawaii
    Thanks, Andrew. That's like asking a parent who their favorite child is. I like all of them! And looking forward to more on the way. Laters.
     
  26. Jul 19, 2018 #26

    GlenP

    GlenP

    GlenP

    Well-Known Member

    Joined:
    Oct 4, 2014
    Messages:
    1,127
    Likes Received:
    31
    I am working on a FlisKits TiddlyWink, an MMX Helicopter rocket, and will probably try using Sharpies and paint pens also to keep the weight down. I have a couple of metallic colors and will test them out on some scrap balsa leftovers from the kit. Your glider looks really nice.
     

Share This Page