Mountain Models J3 Cub build
#1
New Member
Thread Starter
Join Date: Apr 2007
Location: Manitowoc, WI USA
Posts: 19

Hi All
I decided to attempt a build log on my Mountain Models J3 Cub for two reasons. One, this kit is described as being easy enough to be a first balsa build and second, to help keep the pressure on the build so it doesn't fall too far down the priorities list behind work and family.
This is my first attempt at kit building so we'll see how user friendly this kit really is.
Also, please be patient for updates, I work nights, sleep days and have 4 children between 14 years and 18 months. MY time is usually limited to the middle of the night on friday or saturday.
First Impressions of kit
Good quality wood, beautiful laser cutting, just as expected given Mountain Model's reputation. Printed plans were good, but quality of printed instructions/photos was poor. Text was legible but photos were mostly useless grey blobs with vertical streaks. I just downloaded the instructions from MountainModels.com and printed off a copy on my printer. I'll trade poor instructions for a good kit. I'm only going to use the instructions once. I'm planning on flying this bird many more times than that.
Actual build
I laid the plans out w/wax paper and got out the CA. One pointer here, you really do need fine tip extensions. I'm not sure if I have poor wax paper or what, but my parts had a tendency to stick to the paper. I've heard that parchment paper works better, so I'll have to try that.
If you follow the directions the kit goes together well. A few of the pictures are not real clear but I did manage to figure them out. While the kit is marketed as a beginner builder, some of the parts are not marked and it would be helpful if you know the difference between a former and a stringer. Sometimes I found myself guessing the part shape and then trying to find a part that matched. I think I got them all right. The parts are tabbed so they only really fit if they're in the correct spot.
One more pointer, so far.
When you get to installing F2 and the firewall, you might want to mist the fuse sides with water as bending them in while dry caused one of mine to crack. I misted them and they flexed much easier. I also then skipped ahead a few steps to install 1/8" front stringers and front sheeting to help align the front while the fuse sides were still wet and flexible, seems straight now.
That's all for now. Time for work.
I decided to attempt a build log on my Mountain Models J3 Cub for two reasons. One, this kit is described as being easy enough to be a first balsa build and second, to help keep the pressure on the build so it doesn't fall too far down the priorities list behind work and family.
This is my first attempt at kit building so we'll see how user friendly this kit really is.
Also, please be patient for updates, I work nights, sleep days and have 4 children between 14 years and 18 months. MY time is usually limited to the middle of the night on friday or saturday.
First Impressions of kit
Good quality wood, beautiful laser cutting, just as expected given Mountain Model's reputation. Printed plans were good, but quality of printed instructions/photos was poor. Text was legible but photos were mostly useless grey blobs with vertical streaks. I just downloaded the instructions from MountainModels.com and printed off a copy on my printer. I'll trade poor instructions for a good kit. I'm only going to use the instructions once. I'm planning on flying this bird many more times than that.
Actual build
I laid the plans out w/wax paper and got out the CA. One pointer here, you really do need fine tip extensions. I'm not sure if I have poor wax paper or what, but my parts had a tendency to stick to the paper. I've heard that parchment paper works better, so I'll have to try that.
If you follow the directions the kit goes together well. A few of the pictures are not real clear but I did manage to figure them out. While the kit is marketed as a beginner builder, some of the parts are not marked and it would be helpful if you know the difference between a former and a stringer. Sometimes I found myself guessing the part shape and then trying to find a part that matched. I think I got them all right. The parts are tabbed so they only really fit if they're in the correct spot.
One more pointer, so far.
When you get to installing F2 and the firewall, you might want to mist the fuse sides with water as bending them in while dry caused one of mine to crack. I misted them and they flexed much easier. I also then skipped ahead a few steps to install 1/8" front stringers and front sheeting to help align the front while the fuse sides were still wet and flexible, seems straight now.
That's all for now. Time for work.
#3
New Member
Join Date: Jan 2009
Location: south Jersey
Posts: 1

I look forward to reading your reports. I've been considering this kit, so I'm anxious to see how it goes.
I've been away from the hobby for about 20 years. I'm impressed with all the changes, especially with how well electrics have improved. But, all the ARF stuff kind of disapoints me. To me, building kits was always one of the joys of the hobby. Although, I have to admidt, ARFs certainly get you in the air quicker.
Good luck with your build.
I've been away from the hobby for about 20 years. I'm impressed with all the changes, especially with how well electrics have improved. But, all the ARF stuff kind of disapoints me. To me, building kits was always one of the joys of the hobby. Although, I have to admidt, ARFs certainly get you in the air quicker.
Good luck with your build.
#5

Your build is coming along nicely, looking forward to your progress, I agree you really have to keep an eye on the instructions and the plan as with any kit, these MM kits go together so smoothly and quickly ya kinda get caught up in building then ya realize oop's I shouldn't have glue that yet! it happened to me as well , I built this one last year in the Fun build over on RCG, It's a great flying plane.
Glenn
Glenn
#6

I learned to fly on a MM Tyro and am close to finishing up the Hellcat. I agree with your assessment that the kits are good quality but the directions could be better (In print quality and clarity). Both of my kits were design by Mike Molt rather than Brain. When you consider that these kits are designed by an individual with a passion for the hobby you can easily overlook the rough edges. However, you might want to pass on your suggestions to MM so that they can revise the manual, these guys tend to be very open to suggestions.
I look forward to following your build and your flying experiences as my Tyro needs replacing and I'd like it to be a MM kit, maybe the J3 Cub, who knows.
I look forward to following your build and your flying experiences as my Tyro needs replacing and I'd like it to be a MM kit, maybe the J3 Cub, who knows.
#7
Member
Join Date: Sep 2007
Posts: 167

I envy you JPC! The J-3 was my second balsa build; first all balsa build. Took most of last winter to build mine. what a joy it was
I agree that it is a real stretch to suggest it as a first balsa build unless one is somewhat of a craftsman and used to working with all the light weight easily broken fiddley bits. Instruction pics are poor quality, but the superb fit of the parts and the better quality pics online make it a moot point. Besides, it makes you slow down and plan several steps ahead to confirm the procedures and correct assembly of parts. Covering was tedious, but not overly difficult; trickiest part was the transition on the forward part of the fuse from stringers to sheeted area around cockpit. That took some trial and error to get right.
Some pics and comments on my build and maiden here: http://www.wattflyer.com/forums/showthread.php?t=17656
BTW, just noticed you're in Manitowoc. Lived there in '59 and '60. Had my first and only go at a control line model there; about a 3 second flight. just barely escaped with my life, model wasn't mine
fly well,
M

Some pics and comments on my build and maiden here: http://www.wattflyer.com/forums/showthread.php?t=17656
BTW, just noticed you're in Manitowoc. Lived there in '59 and '60. Had my first and only go at a control line model there; about a 3 second flight. just barely escaped with my life, model wasn't mine

fly well,
M
Last edited by mararra; 01-16-2009 at 04:01 AM. Reason: BTW
#8
New Member
Thread Starter
Join Date: Apr 2007
Location: Manitowoc, WI USA
Posts: 19

Hello everyone
First, let me say "Thanks" to you for your interest and kind words. I wasn't sure if anyone would even watch this thread. Now I feel even more pressure to do a good job
Secondly, unfortunately, there is not much to report at this time. The "lovely" weather this last week turned much of my attention to keeping everything from freezing solid. Wind chills of -30 make flying weather seem terribly far off. Anyway, I did manage to get some work done, mostly some finishing touches on the fuselage, bottom hatches and such. Straight forword stuff, just some minor sanding. It does appear that my concern about covering is well placed. I guess I'll cross that bridge when I get to it. I finshed the landing gear and boy, did I underestimate how tedious and time consuming that was going to be. I'm used to prebent ARF gear.
As I looked at the fuse this last week, it struck me how large the cockpit windows seem to be and how the plane really needed some cockpit detail. Maybe that's just a personal thing, but I ordered a Williams Bros. bust and I plan to install at least a basic cockpit area. The small weight gain will be offset by the enhanced appearance, at least in my mind.
Until next time.
First, let me say "Thanks" to you for your interest and kind words. I wasn't sure if anyone would even watch this thread. Now I feel even more pressure to do a good job

Secondly, unfortunately, there is not much to report at this time. The "lovely" weather this last week turned much of my attention to keeping everything from freezing solid. Wind chills of -30 make flying weather seem terribly far off. Anyway, I did manage to get some work done, mostly some finishing touches on the fuselage, bottom hatches and such. Straight forword stuff, just some minor sanding. It does appear that my concern about covering is well placed. I guess I'll cross that bridge when I get to it. I finshed the landing gear and boy, did I underestimate how tedious and time consuming that was going to be. I'm used to prebent ARF gear.
As I looked at the fuse this last week, it struck me how large the cockpit windows seem to be and how the plane really needed some cockpit detail. Maybe that's just a personal thing, but I ordered a Williams Bros. bust and I plan to install at least a basic cockpit area. The small weight gain will be offset by the enhanced appearance, at least in my mind.

Until next time.
#9

Great build so far, JPC.
I love the feeling of sitting down to a work table and picking back up where where I stopped working the previous week. I've only done one kit build, but I would say I enjoyed that process just as much as flying on a calm morning. Well, ALMOST as much!
For me, covering the finished bones was the hardest part. The learning curve for covering is very steep. But Ron (Skysharkster) has put together some great threads here in the builders forum to help out.
Thanks for the pictures and PLEASE keep 'em coming!
I love the feeling of sitting down to a work table and picking back up where where I stopped working the previous week. I've only done one kit build, but I would say I enjoyed that process just as much as flying on a calm morning. Well, ALMOST as much!

For me, covering the finished bones was the hardest part. The learning curve for covering is very steep. But Ron (Skysharkster) has put together some great threads here in the builders forum to help out.
Thanks for the pictures and PLEASE keep 'em coming!

#11

Where did you find such a great pic? I may have to borrow that for my CW Cub.....

#13
#16
New Member
Thread Starter
Join Date: Apr 2007
Location: Manitowoc, WI USA
Posts: 19

Hi Everyone
Most of my build time this last week was used on the cockpit/pilot. I also finished the tail feathers.
As for the cockpit, I simply created a floor from 1/32" balsa sheet painted flat black. Most of the time was spent painting the pilot bust. I must say it has been a long time since I've attempted to paint detailed figures. He turned out well enough. At least now the plane looks a little more "finished" and it only added 7 grams. I can live with that.
Until next time
Most of my build time this last week was used on the cockpit/pilot. I also finished the tail feathers.
As for the cockpit, I simply created a floor from 1/32" balsa sheet painted flat black. Most of the time was spent painting the pilot bust. I must say it has been a long time since I've attempted to paint detailed figures. He turned out well enough. At least now the plane looks a little more "finished" and it only added 7 grams. I can live with that.
Until next time
#17
Member
Join Date: Sep 2007
Posts: 167

Lookin good, JPC
lookin at your stab and rudder reminded me of a problem I had. On the second flight the tailwheel wire tore out of the rudder. Make sure you have it well bonded. I think I ended up replacing the wire with a plastic assembly that attached to the fuse .....not positive but it's too cold out in the storage shed to go check it out
stay warm,
M


stay warm,
M
#20
#22
New Member
Thread Starter
Join Date: Apr 2007
Location: Manitowoc, WI USA
Posts: 19

Hello Everyone
Just a quick update of last weeks progress. I started the wing assembly. The fit of the pieces is incredibly tight. I broke a couple pieces attempting to press them together. The directions do say that you can sand the tabs to make them fit better. I chose to leave the tabs alone and open up the slots slightly.
By reading through the directions first, I realized the opening in W8 rib was the aileron servo mount. Since I knew that, I slightly enlarged the openings to fit my servos. It was much easier to do before assembly than after.
All in all, the wing assembly is straight forward, simply follow the directions.
One quick note, I was having trouble gluing the parts to my wax paper. For whatever reason, the wax paper was always stuck. I switched to parchment paper and the results are dramatic. If it sticks at all, it pops off with the lightest touch and doesn't shred like the wax paper did.
Just a quick update of last weeks progress. I started the wing assembly. The fit of the pieces is incredibly tight. I broke a couple pieces attempting to press them together. The directions do say that you can sand the tabs to make them fit better. I chose to leave the tabs alone and open up the slots slightly.
By reading through the directions first, I realized the opening in W8 rib was the aileron servo mount. Since I knew that, I slightly enlarged the openings to fit my servos. It was much easier to do before assembly than after.
All in all, the wing assembly is straight forward, simply follow the directions.
One quick note, I was having trouble gluing the parts to my wax paper. For whatever reason, the wax paper was always stuck. I switched to parchment paper and the results are dramatic. If it sticks at all, it pops off with the lightest touch and doesn't shred like the wax paper did.