Probably overpowered, but then I think a Cub should be flying on a low throttle and not screaming like a banshee !
The panels of Lite-Ply and Balsa were all laser cut and all pieces had small tabs left uncut to h9old them in the sheets. Quick nick with knife and poarts are free AS YOU WORK. Note as you work ... no parts are marked except by the instruction sheet provided. So I find it best to only remove what is necessary for that session ... dry fit to check then glue up.
Note that I am also tracing the parts onto cheap 'Floor insulation foam' for a lightweight foam version later .... also it keeps templates in case of repairs of original.
I prefer PVA wood glue for these jobs ... has a bit of give to it, dries reasonably light but is a slow set solution ... If something needs tacking while drying - a blob of Superglue applied will tack an item.
Start organising first parts for fuselage ..
Here's where first confusion starts ... it says 9 bulkheads but there are 10. Then you realise that the big ones E5 + E7 should be glued together to form one front cabin / wing dowel bulkhead. The slot in fuselage side is 2x width of all others !!
All bulkheads now in place and PVA setting up before adding other side ...
More later ....
(For those eagle-eyed ... yes I am building on a thick sheet of foam sitting on a chair !! My office desk is covered in model bits ... my model den is a store for all sorts ... running out of space !! Actually the foam is good as I can pin through .. it's stable ... I can move it ... etc. The model is not that big anyway ... )
This is no kit for someone without 'ingenuity'..... too many things not explained or shown properly.
For some items I actually took a magnifying glass to study the photos !!
OK ... fuselage is jigged on workmate and left overnight :
Now this may sound strange - but longerons that are along top and bottom of fuselage sides I slide in after ! Why ? I use PVA glue and trying to work two fuselage sides and formers and longerons at same time ? PVA allows me to flex the structure next day to insert longerons and straighten up structure ...
OK they've been added BUT how far do they run ? Study of photos and motor bulkhead indicate they run right to front of fuselage sides. But at rear ? No info - so I decided to curt a little short to allow rear sides to come together matching the fuselage bottom.
Adding longitudinal's ... these have a hard angle change near cabin and may be better to dampen first at that point - mine cracked but use of CA and PVA have restored these ..
Next is fuselage bottom .... now this is sized BETWEEN full width and inside fuse sides width !! But I have used the PVA to fill and set in place using it's form to ensure fuselage is straight.
We now come to the nose section and this really is a DIY sort it yourself area ... you have 2 firewalls, 2 battery 'tables' .... Nothing in instructions about there being two of each. So I assume the 2 firewalls are a sandwich affair to give depth for motor mount etc.
First I PVA'd in place and taped correct ... then second I epoxied in behind for strength ...
I have added 2 foam strips inside the nose to align the battery 'table' after having checked with a my 3S 2200 for room needed ...
The foam is only temp and will be replaced with full depth foam to completely line that area to add to the thin balsa ... without incurring weight.
She's now sitting there glue setting up and ready for tomorrows cont....
Note about scale additions .... given the foam we have nowadays - I can add the engine and exhaust bits etc. without weight penalty using scrap foam. The UC and struts will be via Bicycle wheel spokes bent to shape ...
I already have suitable wheels on hand ...
This definitely a kit for only experienced builders.... and the lack if direct reference between photos and text dies not help. The sheet pics where you identify parts needs magnifying glass to read the id's.
In the instructions it shows to fit the tail sheet cover..... great but tail needs to be accounted for.... I've been tempted to use foam in places but resisted as really it needs to build as supplied in a review.
I'm slowly getting there... now have dashboard and nose cover in place. Photos to follow.
It will I'm sure be a fine model once finished.... but ugh! the manual!
There's no plans..... just a brochure style instruction sheet. Its ok for 90% of the job...... but various area are left to builder to figure out.
Yes and i throw those on the floor also after i have looked at it a couple times. I think its bad when a kit company can't even put full size plans in the kit. You might want to cut some cardboard tenplets in case you need wing ribs or a new fuse later. I copy some kits this way if i know i want another of the same plane later. I have my seacruiser plans and kit they stoped making long ago so before i put it together i will templet every thing . Its a great flying seaplane or i would not go through the trouble. I have had those brochure pages before with pictures that are hard to see and even harder with my old eyes . joe
I use cardboard for all my templets its cheap and i can store it easy in one box or folder but any kind a templet is good. I never know if i will use balsa or foam on a build but the cardboard templet will work on both. She is looking good even with the bad construction book Nigel . BTW I keep forgetting you guys dont have dollar tree stores across the pond . I get my foam for 1 dollar a sheet and a nice big sheet of thin cardboard for 50cents a sheet for my templets . Its easyer for me to save thin cardboard than foam sheets .I use a little thin ca around the edges so my razor knife slides around the templete very smooth without hurting my pattern. joe
I recently built the Hobbyking big stick lazer cut plane and enjoyed it so much that I decided to try the J3.
I searched for build blogs and found yours. My kit is still in the packaging as I was not planning to start until our summer in the Mediterranean ends and it cools down a little.
However, I will follow your progress with interest in the hope that this will help given the challenge of the very poor quality information supplied.
Side panels at rear of windows fitted, tail plane and fin fitted ... I elected to fit BEFORE installing the infill piece at rear of fuselage ..
Covering in progress ...
The undercarriage has double ply plates glued inside fuselage ... bit soft for screws - but as I said - I will use the kit contents. I use bicycle spokes of 2.1mm gauge to form the legs ... and 1.5" wheels....
Wheels retained by plastic end caps on wire.
Next is motor mount and this needs to be extended on the firewall to match a) specification 780mm fuselage length, b) cowl supplied. You can build a ply box or as I did - I had a spare adjustable metal mount - I took the motor mount part and bolted to two wood blocks and glued to existing firewall ...
The matter of the battery hatch ... I was going to use pinned hinges to fit this but in the end elected to try Duct Tape hinge - applied BOTH sides and cover with film.
The model will never be subject to wet fuel so the tape should be good for a reasonable period. I can always revert to pinned hinge later if needed.
The cowling is supplied as a rough cut moulded clear plastic affair ...
Check fit for cutting, trim back edges, cut centre prop shaft hole using reamer :
Look at picture supplied of J3 for ideas of cooling..
Spray paint INSIDE the cowl - this gives better paint protection against scuffs etc. Plus you can use any cheap paint suitable for plastic and the plastic will give the gloss look.
You can see I've cut with soldering iron some cooling slots ...
I am also making up some dummy engine bits in foam to add to cowling to give it some character ..
Drinking straws will provide exhaust pipe ....
Suitable prop looks like a 7x6 ... as I elected to NOT go the 2200kv motor they recc'd ... I don't really want a screamer motor on it ... so went with the 1400kv unit and slightly larger to give a better sound and throttle response ...
a) Photos have no ID to direct link to text.
b) Parts pictures too small to read with anything except exceptional eyesight !
c) Tail fairing over stab is supposed to be fitted BEFORE tailplane - but where are the parts ? I will use scrap balsa for this.... AFTER fitting Tailplane
d) Rudder line is out of line with fuselage rear ... that needs building out to match - I will use scrap balsa.
e) No ideas / suggestions / dimensions for main undercarriage
Started on the wing ... boy is this a nightmare sorting out the pictures to text ... turns out that text does NOT follow same sequence !!
Second that having used one of the wing spars for fuselage longerons ... meant I had to thin down the longeron to use as spar !!
First - cover flat surface with clear plastic ...
Then start laying out ribs and main spar. The ribs are flat bottom and this helps a lot ...
BEWARE .... there are 3 different ribs in this and they are not too clear about this ... the centre rib is the shorter of all ... This is one rib per wing at centre.
Then comes the next rib that has NO inset into the trailing edge to sheet - this one has me totally confused !!
Then #3 rib and all out to end are ribs with the cut out both sides of trailing edge to allow sheeting.
Now usually dihedral braces cap the main spars .... but here we have no indication ... so I decided to kill 2 birds with one stone ......
I used scrap lite-ply from the kit to fashion a wider better brace to go across the front indented leading edge ....
This provides a number of benefits :
a) It sets dihedral at leading edge.
b) It infills the area that butts up to cabin top bulkhead.
c) Provides stiff secure outer plate for wing pegs to exit into cabin bulkhead.
The existing braces will be used to brace at the main spar and rear spar areas by my cutting my own slots. The rear will have to be slimmed down more of course.
Here's braces .. then general as the wing is jigged to check dihedral etc.
Top one is kit version ..
Slot cut next to main spar, with my DIY brace glued in place at front indent ..
Checking butt joint of wings on flat surface ..
How to sand the joint exactly 90 degrees !! Use the desk corner as a template. Run sanding block along desk edge ...
Setting up leading edge along desk edge to ensure straight wing ..
Wing now jigged to correct dihedral (one wing flat on desk - other propped up 12mm at 280mm out from centre) ..
Wing halves will have further work done before joining - to avoid that room sweeping span !!
Joint gaps will be filled with PU glue (generic version of Gorilla Glue) and wing is to be bolted down with two rear bolts anyway and two front pegs ... so joint will be supported by that and also by wing struts ...
Overall the wing is a strong construction but fit of parts is very loose ... the slots and keys are just not matched at all. I remember Pilot Models (Japanese) in the 1980's that die-cutting was so good that you could build a model like this in the hand ... but forget it here ... I've already used up a large roll of masking tape to hold things in place while glue sets etc. !
In fact at times I resorted to my pet hate ... CA to tack things so I could get on !
Overall ? I'm using kit material wherever possible ... the scraps providing fillers and jig pieces etc. Only part I added myself was the foam bearers to set the battery tray in position ... I wanted as light as possible beams to set it up square in the nose.
Today went on the hunt for fishing trace wire and crimps ... you'd think Latvians who are fishing crazy - we do have fabulous fishing here ... even my private canal at back of house is teeming with fish ! ... you'd think there would be lots to choose from ... NO - nothing !
I want 3mm alloy tube to make the struts etc. - Nothing.
I have always owned a cub ,most on floats .I had the e-flight 25 size one and two hanger 9 cubs plus a sig 1/3 scale cub on 4ft floats that i sold last saterday.I only have a new in the box hanger 9 cub left and one nitro motor for it but i will see how much a e- motor will cost before i commit to the nitro motor. I think the best flying one i owned was a goldberg kit cub with a OS 61 four cycle and floats. joe