Foxbat Build 2018

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 Foxbat                                           Build

NOte: The Details are presented in reverse order of the Build, Early Details are Presented Last

June o3 Foxbat Flies with a couple Video Links

June 02 Update

Surface Area

Wing  1260 Sq In

Stab/Elevator  179 Sq In

After Build Note:

watch the wing tip panel angles. Build this wing flat, using the included joiners and be prepared for a handful.

To little angle, and turning will be a bugger

Ask If you want to know what I did, this plane really does fly great as I built it but others where not so fortunate 🙂

Looking for a Easy Sailplane Kit Build , with clear and concise Instructions? I would suggest something other then the Foxbat.

There are numerous inconsistencies, dimensions that don’t measure up on the plans. Fit everything before gluing, see if the materials are gonna work for your plan

Methodology is also confusing, and may result in a “shelved” plane within Hours of your start.

That being said , a seasoned Builder can produce a fine plane from what is included in the box, If one plans carefully.

May 11

Some lead detail for the ballast

There are 3 pieces in total

Individual piece weights

Tail Pieces

I tried real hard to keep this as clean as Possible 🙂

Painting is complete, all white fuselage

Tip panels weigh within .4 G each more on weights later,

FYI Left 127.9 Grams right 128.3 Grams Covered

Lead is cast for ballast, 3 pieces.

Servo and push rod install continues.

April 12

Just spent a bit of time covering center panel, doing inside corners all transparent red. Trim iron works well for the smaller pieces

April 08

right wing tip a little clean up

root end, NOTE, the two Tip Joiners where later Modified to give a better turn, Increased Polyhedral

vacuum brush, clean clean , soon time to cover

right tip panel

rudder trailing edge

trailing edge rudder with slight bow

rudder 11.7 Grams

marking rudder , preparing for surgery

Both sides of slot cut

clean up the ends

shape a 1/16 splint

ready to be glued


and another, where is the scale, somewhere there’s a picture, it was 11.8 Grams

Fuselage with canopy

Canopy wing interface, look for clean lines, allow space for covering.

still need a bit of fine tuning, but close

elevator fixed portion

elevator moveable portion


leftovers from the bench, in the past I would save this 🙂

after a sweeping and cleaning, ready for covering

Fin Rudder

Fin Rudder 46.5 Grams covered, no horn , before covering 19.4 plus 11.8 G   —  15.3 G Ultracote










































Mar 22

The busy end , fin post skid, push rods and control horns all meeting at the tail


I don’t like to just rely on some glue to hold CF to balsa, so I have added a tenon, and keyed it to the elevator

Remember to slide the horn over the square tube 1st

a little cg work, 50 G at the nose still missing some stuff,

Mar 14

A couple weeks later and I have some cloth on the bottom of the fuselage and some more sanding done

Mar 02

Center panel with servos exit hole reinforcement, getting set to fit upper sheet

Trailing edge 1/16 inch doubled , will clean up later

Rear wing mount in place, critical for proper setup of wing mount

Forward wing mount from underside

T nuts for wing mount plates, two have the flanges flattened on on side for clearance

computers are everywhere, CAD offers a mirror function, not sure why these 2 canopy pieces are not symmetrical

You can really see here how these are askew

I have glued together the two canopy pieces, and lopped of the forward deck that butts up to the nose block

the angle is not critical, I think 30 degrees or so, I will add some stops on the underside of the canopy later

Mating faces get a piece of ply, I like to use this as not as soft as balsa where the edges come together

Just realized now that the nose block pieces I got don’t have the same length as what is drawn

I have added some bottom corner tri stock, or I can’t accommodate the rounded fuse corners as outlined on the drawing

Rear magnet plate for canopy connection

a couple holes for some magnets at the rear of the canopy

a template like this is helpful for shaping the nose, template was created with a half fold of the paper, with previous revelation, I don’t trust the plans at this point

Magnets in place, nice

canopy located , some balsa to sand here

Spoilers, magnets in corners

Nose shape

Feb 11

Tail surface alignment, I use a stick forward to one of the bulkheads in the fuselage

Left side of stab, my eyes can’t do as good a job as a go – no go gauge

Into the corner here at a forward bulkhead

I have cut some load spreaders as well for where the screws go thru the stab. There is a piece of 1/16 sheet that goes down over this area top and bottom where the stab meets the fuselage

at the rear a piece of CF tube, which I will later glue into the fin

Rear wing mount perch, one hole one t nut, and pre drilled thru the edges a couple holes which I can later use to pin and glue this to the ply doubbler of the fuselage sides

wing rear with mount

wing with 3 bolts

Mounts in place

again, slow set epoxy

T nuts, some tri stock, and some little fillers of ply

Left upper d tube sheet cut to suit spoiler

Glued and pinned sheeting epoxy at spar ends and where the forward screw blocks sit

some filler sheet precut , ready to glue in place

Feb 03

Tail, spread side panels, room for the elevator pushrod, and a rear fastening point for the stab and fin

I moved the rudder pushrod slot forward to allow clearance for the 2-56 end as well as the kwik link

small holes and t pins, that gives me room for adjustment before I open the holes up to suit the screws

This line is square from the center rear

a little overlap of the bottom sheet onto the nose block, I will add a layer of fg cloth at some point later

Jan 25

Jan 24

Getting the fuse square, and aligned over center 🙂

As you may remember , the Design calls for the stab horn in the center of the fuselage, and the space needed was not there as drawn. I have spread the sides apart and filed some clearance for the clevis in the lower longerons at the rear.

Rudder control out the left side, there’s a similar slot on the other side that I will plug later

Not to early to add a servo tray, and will also include a partial bulkhead and the front edge, which will serve as a ledge for the tray and hold the fuselage to the shape on the plans

Jan 20

a couple nice straight edges sent to me by a Friend, Thanks Bruce

I’ll put these to good use

Tip sheeting

trailing edge upper sheet

rib caps

rib caps

both tip panels

More rib caps, I do all the cutting with a single edge razor blade

Lining up the panels, they should be pretty close with the joiners, and this gives me a chance to get the top sheeting in the correct location

short on lumber the Leading edge would be better served with 5/ 16 x 5/16 material rather then the 1/4 stuff supplied.

some servo and rail parts for the spoilers

the lower sheeting needs notches for the servo access door

Dec 05

I am really enjoying this building, there’s enough detail with no information that I get to come up with my own way of doing things.  Something that occurs more often with a scratch Build

The elevator control horn, and it’s location is of particular interest and has consumed me.

All lines on the drawing point to the push rod and the horn being in the center of the fuselage, looking down

a couple pieces 1/8 spruce stuck in between the fuse side, and as you can see the horn clevis etc will not go in there considering there is 1/8 wide spruce longerons to be added at the top edge as well

The tail post on the fin is 1/4 wide, I can always add some material on either side to center it between the fuse sides

adding enough space between the longerons means spreading the fuse sides apart an additional 3/16 inch

This looks like it should work, but there is an extra slot in the fuse side for a second push rod, huum    you tell me.

Aha, you thought I was gonna give up , nope not me not like the 100’s of others that have these wonderful Foxbat Kits, in various stages of build or  have them on the shelf 🙂

See you soon,  same bat time, same bat channel

Dec 02

I added the lower sheeting as I built up the tip panels, and need to shave some material away from the Leading edge Balsa

Both spar ends of the inner panels, at the joiner boxes get a wrap

tip panel leading edges in place and glued

Servos for the Foxbat

Got the replacement sides for the fuselage, and have epoxied them together with the bottoms set against a straight edge

Forward ply doubbler , aligned and set with 24 hr epoxy

Other side, watch for left and light when you add these doubblers, no going back later

Clean, no excess glue, I will stack both sides   together later and edge sand a bit

Longeron bits and pieces from the ply doubler back to the fin tailpost

They get beveled at the forward end as well, to fit snug against the doubler

Back end of fuse, fin tail post, sets flush with the edge, and the spars come to the post

a bit of an offset here where the elevator sits

Lower longeron gets epoxied, and aligned to the lower edge

Hollowed nose block as well as Gauge for root rib angles,  NOTE, these angles are my interpretation of what I found with the KIt, and Info on the Plans, later I Decided the Polyhedral was incorrect and changed the tip panel Joiners, even the center could be a bit more


There’s quite a wow in the fuse side sheeting, watch for that, get it straight on the bottom right from the start

Nov 25

I have relieved the other two inner pieces of the nose block. will cast some lead in there later in case it is needed

Nov 19

I will place the tip panels later and add the lower TE stock.

Cookies Anyone

Nov 18 , More to see

I zeroed the lower spar, and built up the ribs and supplied laser cut shear webs,                                                                                                  To much offset for my liking. The pitch on the drawing for the tip ribs is consistent, and that’s what I will go with. and will cut shear webs after to fit

Back to my original plan, mark the spars and should be tough to get an error

I also drew the outline of the opposite side tip panel. The rear is actually important at some point, the LE is defined by the ribs, and I will just make sure I get the longest rib location correct and work to the tip from there when it comes to the left panel

I have extended the forward lower spar location on the plan so I can pick it up after the lower d box sheet goes down

I had previously cut a taper in the lower sheeting, and cut the rear edge straight. A four foot level up against some, pins and a few pins will hold the lower sheet in place. The pins on the right side will be used when I do the opposite panels to locate the other lower d box sheet

Lower sheet in place, and a stop, for the lower spar

I located the spar the same way I located the lower sheet, and left those pins in place for the other panel. Spar is shown here glued in place, with the level, and 12 lbs of weight on top

All ribs in place, other then the root rib, which I will deal with later.

Sat Nov 18, Hilite of the Nite

Doing plans , not enough room , try this , In this case a tip panel, of course it’s in color, but a different line weight or line style will work to clarify the different panels 🙂 The spar is in the same plane, and all the ribs as well except the root rib in this case and the tip rib.  Of course when you do your design , you can place those as well so they line up.

Bonus Coverage

Now, I am not a fan of precut shear webs, what If there to small my mind asks. A good set of plans has the pitch for the ribs drawn accurately and then I like to place the ribs accurately.

Extra R2 here, as well as the other end, R1 would have worked just fine, I’ll cut some new ribs, I can trace R1 The spoilers do not go beyond the Rib caps, at either end so the notches are not needed

The other end

I see no reason why R1b wouldn’t work here in place of R3, I will use R3b to add the hole for the pin to the Rib later

R1B should also work here in place of R1

Here I have set the root rib and the spar tight against a block, and built up my rib ladder, alternating ribs and laser cut shearwebs




After 5 ribs I am out two rib widths, not the kind of building I like. Better to decide now whether to pace the ribs as shown on the plans or space them with the shear webs, panels will be different .                                                                                                                                                                Spent quite a bit of time cleaning those shear webs, Honestly perhaps I am not the modern Laser Cut Kit Builder, but placing the ribs at the center they are called for and cutting shear webs from a sheet is more my style.          Will it affect things in the end likely not, other then some strange pitch at the end of the panel, perhaps out 1/2 inch or so. Grateful for the Kit, looking like it’s a prototype kit though, and with a few changes will be even better soon






Nov 17 Extra

Root rib from the polyhedral brake, as well as the balsa rib that is inboard, I have centered them on the spar

The plan calls for 1 1/16 TE strips


The TE lines measure 1 3/16 the ply root rib is longer by 1/8 It’s a toss up at this point, I will go with the ribs being accurate, and set the TE more rearward before gluing and make them a little wide as well, perhaps 1/8 to 3/16 inch

Framed, glued, ribs in place and spar pinned down


S3 and S3B could be a bit wider, fore and aft so that the stab ends better lined up with the LE’ and TE’s

Underside, 1/16 x 1/4 spruce spar

Finished, all joints got a bit of a sanding as well, as I felt the Laser cuts where vee’d a bit , and I wanted all joints to be as tight as possible.


47.5 Grams , just off the board, how heavy was yours?

Wing sheeting 12 sheets 1/14 x 4 x 36 17 Grams to 22 Grams a sheet I will use the heavier stuff on the inboard Panel Cut the trailing edges 8 pieces, I believe they are 1 1/16 wide, and bevel the bottom sheet TE so that the top sheet comes down over at the wing TE nicely

Nov 16  Part Two

Pulled some of the pieces from the sheets, just to get a handle on all the Pieces.

There are no Instructions, so I will make sure to go thru all the supplied lumber before I start Hacking

Not a kit for a beginner looking for steps 1 – 100

Rudder pieces, there must be some lumber somewhere to tie into these slots

Spar stuff

Fuselage sides two pieces with keys, and the 1/8 lite ply doubler

Fuselage side join, will have to clean up this area in order to align the edges. Some offset issues with the kerf on the 1/16 balsa cuts for the join

These are spoilers, though a section view on the drawing shows 1/8 material, this appears to be closer to 1/32 ply

AS near as I can tell the Stab horn is at the center of the stab, This means one of these sides has a slot it doesn’t need

I’ve taken all the laser cut pieces for the stab and fin/rudder and cleaned away the retention nibs

Contents of the hardware bag, one of the 2-56 couplers is not threaded

Parts and pieces for the fin and rudder

I previously cleaned up the edges and checked the notches for the ribs

Glued in place, well the frame first and then cut and add the ribs last

That’s it folks, a little drying time and I can hang these up

Yes they do require sanding, tapered trailing edge, LE rounded.

Section views , 3 places for the stab, 1/16 x 14 spar top and bottom

S10 is missing a couple of notches, I’ll add those before I proceed

S7and S6 miss marked here, though it’s quite obvious where they go

Those little pieces known as F7 on the plans where’s Waldo

More ply removed and cleaned up

Nov 15 / 2017

Yes indeed, the Foxbat has landed

The kit is very nicely done and well packed as you can see.

Some of the tabs were not enough to hold the pieces into the sheet, so I will take care when I handle the pieces.

Haven’t unrolled the plans yet, I do see though there is a stash of wood inside there  :):)

143 Inch wingspan, 54 Oz or so RES  Sailplane


Nice, love this silouette