Primary Force built from "kit"

[fred cesquim]

i am just about to finish the Primary Force, built from a Brazilian "kit" slightly modified, the kit cutter added flaps, and i moved LG to the wing (can´t stand fuse LG)
balsa was on the heavy side, unfortunately.
wings and tail oracover and automotive paint on fuse and wing trim.
2 part clear coat and full panel lines
powered by an old fox 35
final weight 1.200grams
will have more pictures shortly as soon as the rain stops!

[Terrence Durrill]

    Say Fred,
                  That's a great looking plane.  Love the old Fox .35 stunt engines and have a large collection of this particular engine, many vintages from the original Sand Cast to the 50th Annaversary Edition; at last count it was 28.  I have used the Fox .35 in many different designs over the years.  I got my first Fox .35 in 1956 and these Foxes have been among my favorite engines, even though I have run K&B Greenheads, Vecos, Johnsons, Super Tigres, McCoy Reheads, Enyas, OS MAX, etc, etc..   Let us know how this plane flies.....i'll bet it flies as good as it looks.            

[MikeyPratt]

i am just about to finish the Primary Force, built from a Brazilian "kit" slightly modified, the kit cutter added flaps, and i moved LG to the wing (can´t stand fuse LG)
balsa was on the heavy side, unfortunately.
wings and tail oracover and automotive paint on fuse and wing trim.
2 part clear coat and full panel lines
powered by an old fox 35
final weight 1.200grams
will have more pictures shortly as soon as the rain stops!

Hi Fred,
Nice looking model and I like the color scheme.  The model that is pictured appears to be a Force and not a Primary Force.  I should know, because I designed them both.  I'm not sure if I should be flattered, or ticked off by someone (unless they made a straight wing) selling a kit produced in another country and calling it the Primary Force.  Myself, I'm taking the high-road and wish them good luck in that endeavor but a US company would be hearing from me.

Later,
Mike Pratt

[fred cesquim]

Hi Fred,
Nice looking model and I like the color scheme.  The model that is pictured appears to be a Force and not a Primary Force.  I should know, because I designed them both.  I'm not sure if I should be flattered, or ticked off by someone (unless they made a straight wing) selling a kit produced in another country and calling it the Primary Force.  Myself, I'm taking the high-road and wish them good luck in that endeavor but a US company would be hearing from me.

Later,
Mike Pratt

hello Mike! thanks a lot for the comments. as far as i know this guy laser cut a few "semi-kit" not even with plan, and sold it withou any label at the box, but Primary Force name came at the field and i used (perhaps by mistake) now i am into trouble as the name is painted and clear coated!
will post some more pictures and you can tell if it´s Force, Primary Force or a lookalike of them. Sorry about that, never knew more about it neither that the guy could be braking some copyright here.

[fred cesquim]

    Say Fred,
                  That's a great looking plane.  Love the old Fox .35 stunt engines and have a large collection of this particular engine, many vintages from the original Sand Cast to the 50th Annaversary Edition; at last count it was 28.  I have used the Fox .35 in many different designs over the years.  I got my first Fox .35 in 1956 and these Foxes have been among my favorite engines, even though I have run K&B Greenheads, Vecos, Johnsons, Super Tigres, McCoy Reheads, Enyas, OS MAX, etc, etc..   Let us know how this plane flies.....i'll bet it flies as good as it looks.           

hello Terrence !
thanks for the comments, the FOX was my second engine, and i kind of used as a nostalgia feel, here in Brazil in the 80´s we where forbid to import anything and just a few engines passed through custom´s when someone travelled abroad, and the fox was the most popular! this one have a chrome like appearance, not sure how old it is. i have one nib anniversary edition (no idea wich year) on hold for a gieseke nobler....but that´s for future...

[MikeyPratt]

hello Mike! thanks a lot for the comments. as far as i know this guy laser cut a few "semi-kit" not even with plan, and sold it withou any label at the box, but Primary Force name came at the field and i used (perhaps by mistake) now i am into trouble as the name is painted and clear coated!
will post some more pictures and you can tell if it´s Force, Primary Force or a lookalike of them. Sorry about that, never knew more about it neither that the guy could be braking some copyright here.

Hi Fred,
Yes, the Force is a straight wing constant cord wing with flaps.  It is a really good flyer when built in the mid forty ounce range.  I don't think the fox 35 will be enough engine for it.  I would suggest an OS 40 or 46 with an 11 X 4-1/2 prop.  Also, if you are inclined, a c/f pipe works well on the Force to.  Please feel free to call or email if you have any questions.

Later,
Mikey

[fred cesquim]

hello  Mike, sounds it´s a Force then! have straight wing and flaps
i´ll fly with the fox and see how it goes, if too marginal, i can switch to a 46 that i have and had to repaint the nose (i´m picky with finish lol)
BTW, it´s a gorgeous design, really nice look!
will be back with pictures tomorrow and you can tell mw if it´s a SIG rip-off or a Force copy. either way, i beg apologies for this, never knew it, just got the kit at the field and built it

[Mike Griffin]

Hi Fred,
Yes, the Force is a straight wing constant cord wing with flaps.  It is a really good flyer when built in the mid forty ounce range.  I don't think the fox 35 will be enough engine for it.  I would suggest an OS 40 or 46 with an 11 X 4-1/2 prop.  Also, if you are inclined, a c/f pipe works well on the Force to.  Please feel free to call or email if you have any questions.

Later,
Mikey

Mikey, did you ever kit The FORCE?

[MikeyPratt]

Mikey, did you ever kit The FORCE?

Hi Mike,
Yes, sort of.  I sold laser cut ribs & plywood parts.   The new Force MK II is almost ready to offer as a short kit.  Looks the same but with a few minor changes such are leading edge sheeting & cap strips.  Most of the changes are in the fuselage making it stronger, lighter and very stiff.  The changes should reduce the overall weight down to the low 40's retaining its great handling and good looks. 

Powered with good 40 or 46, or piped 32 or 40 will give you an excellent model that can take you up to the expert class. 

Later,
Mikey

[George Albo]

i am just about to finish the Primary Force, built from a Brazilian "kit" slightly modified, the kit cutter added flaps, and i moved LG to the wing (can´t stand fuse LG)
balsa was on the heavy side, unfortunately.
wings and tail oracover and automotive paint on fuse and wing trim.
2 part clear coat and full panel lines
powered by an old fox 35
final weight 1.200grams
will have more pictures shortly as soon as the rain stops!

That is one nice paint job!!! I like it. How does it fly with the fox?

[fred cesquim]

ready to go! any input on CG location? i am assuming it´s on the spar location.
hopefully will fly tomorrow and be back with news
have checked SIG Primary Force and looks like this one differs a lot indeed...too back i painted the name and clear coted over it hahaha
will try to live wth that!
Mike thanks a lot for the offer of help, any advice on CG and lead out starting position?
i am a moderate flyer, just can perform loopings, reverse flight and 8 figures, but i really want to improve with this plane!

[MikeyPratt]

ready to go! any input on CG location? i am assuming it´s on the spar location.
hopefully will fly tomorrow and be back with news
have checked SIG Primary Force and looks like this one differs a lot indeed...too back i painted the name and clear coted over it hahaha
will try to live wth that!
Mike thanks a lot for the offer of help, any advice on CG and lead out starting position?
i am a moderate flyer, just can perform loopings, reverse flight and 8 figures, but i really want to improve with this plane!

Hi Fred,
The lead-outs should be centered on the spar.  You should start the C.G. at 2.25 behind the leading edge at the fuselage with a maximum at 2.75.  What type of Bellcrank did you built into the wing?  The control geometry is very important to the final flight trim.  With the bellkrank in the neutral position, flaps and elevator in the neutral position, the control horn on the flaps should be set behind the leading edge of the flap .125, and the horn on the elevator be set at .125 before the leading edge of the elevators.  This keeps flap & elevator equal during control movement from the Bellcrank.

Later,
Mikey

[Serge_Krauss]

Fred-

Beautiful building and finishing job. What did you use to achieve the great metallic blue? Thanks.

SK

[john e. holliday]

Plane looks great.  Do as Mikey says and you will have one terrific flying plane.  Need to recover wings on my Primary Force after the demented poodle did her dance on the wing while I was flying another plane.

[fred cesquim]

Hi Fred,
The lead-outs should be centered on the spar.  You should start the C.G. at 2.25 behind the leading edge at the fuselage with a maximum at 2.75.  What type of Bellcrank did you built into the wing?  The control geometry is very important to the final flight trim.  With the bellkrank in the neutral position, flaps and elevator in the neutral position, the control horn on the flaps should be set behind the leading edge of the flap .125, and the horn on the elevator be set at .125 before the leading edge of the elevators.  This keeps flap & elevator equal during control movement from the Bellcrank.

Later,
Mikey

thanks a bunch Mikey!
had to add a lot of lead to achieve CG at 2.75 final weight > 1250gr (44oz?) not sure if this is heavy or not...
Bellcrank is 3" and horns are metal control horns, si i have no way to change pivot position, but they are on hinge centerline.
looks about right regarding movement.
hopefully will maiden on sunday will keep all posted.
if flight with the fox result too marginal, i may surgery the nose to add a 46 LA and repaint nose (as i will need to add some balsa to meet up with spinner)
best regards!

[fred cesquim]

Fred-

Beautiful building and finishing job. What did you use to achieve the great metallic blue? Thanks.

SK

thanks SK!
metallic blue is polyester auto paint and 2 part clear over everything

[fred cesquim]

Plane looks great.  Do as Mikey says and you will have one terrific flying plane.  Need to recover wings on my Primary Force after the demented poodle did her dance on the wing while I was flying another plane.

hello John!
thanks man, have followed Mikey great tips, let´s see how the Fox bring life to the plane!
sorry about your PF x Poodle affair!
best regards
Fred

[George Albo]

thanks SK!
metallic blue is polyester auto paint and 2 part clear over everything

Was that polyester over dope? Butyrate dope?  What clear did you use?

George

[Shug Emery]

The finish looks so right! Very very nice.
Shug

[fred cesquim]

Was that polyester over dope? Butyrate dope?  What clear did you use?

George

the yellow is oracover lightly sanded to improve adherence
fuselage have sylkspan with dope ( in brazil we only have one kind of dope, not sure wich one, but i guess is not butyrate)
then 2 part primer and red / blue are polyester (yellow part on fuse is oracover over the paint.
clear is 2 part auto clear (sherwin willians dupla camada) don´t know similar for America...
and finally polishing

[George Albo]

the yellow is oracover lightly sanded to improve adherence
fuselage have sylkspan with dope ( in brazil we only have one kind of dope, not sure wich one, but i guess is not butyrate)
then 2 part primer and red / blue are polyester (yellow part on fuse is oracover over the paint.
clear is 2 part auto clear (sherwin willians dupla camada) don´t know similar for America...
and finally polishing

Nice job. With your permission I'm going to paint mine the same. I like it!  

[fred cesquim]

Nice job. With your permission I'm going to paint mine the same. I like it!  

thanks a lot George! it´s
 an honour to me! please post pictures when ready!

[George Albo]

thanks a lot George! it´s
 an honour to me! please post pictures when ready!

It will be a little while, but when I do, you'll be the first to know!!!

[MikeyPratt]

thanks a bunch Mikey!
had to add a lot of lead to achieve CG at 2.75 final weight > 1250gr (44oz?) not sure if this is heavy or not...
Bellcrank is 3" and horns are metal control horns, si i have no way to change pivot position, but they are on hinge centerline.
looks about right regarding movement.
hopefully will maiden on sunday will keep all posted.
if flight with the fox result too marginal, i may surgery the nose to add a 46 LA and repaint nose (as i will need to add some balsa to meet up with spinner)
best regards!

Hi Fred,
I was looking at my notes on the first Force and an all up weight was 46 ounces with an all dope finish and powered with a OS 35 S.   Your 44 ounce weight should be fine and within (upper) ranger of the Fox 35.  There are a few tricks you can use to make the fox work better.  Take an 11 X 5 prop and Trim the diameter to 10-1/4" and balance it perfectly.  Use 15% (28% oil) nitro fuel and set the engine to a fast & wet 4 cycle in flight after take off.  This well give the old Fox a little more power.

Later,
Mikey

[George Albo]

Hi Fred,
I was looking at my notes on the first Force and an all up weight was 46 ounces with an all dope finish and powered with a OS 35 S.   Your 44 ounce weight should be fine and within (upper) ranger of the Fox 35.  There are a few tricks you can use to make the fox work better.  Take an 11 X 5 prop and Trim the diameter to 10-1/4" and balance it perfectly.  Use 15% (28% oil) nitro fuel and set the engine to a fast & wet 4 cycle in flight after take off.  This well give the old Fox a little more power.

Later,
Mikey

Good to know, thanks for posting this.
George

[fred cesquim]

dear Mikey and fellows
had 6 flights with this baby
followed all valualble tips from Mikey (thanks a bunch)!
old fox started on the 4th flip, as soon as it get airborne i felt a pretty steady ship flying! as the egine was resting for the last 20 years or so, only wing overs where done and landed by itself thanks to the perfect CG info !
next flight a much more experienced friend of mine made inverted flight, loopings and some square loops, by his smile i could tell he loved the plane. he says the ship is great for stunt!
right wing was a bit high, on inverted flight was low so a bit of a flap twist was needed (indeed the wire was misaligned, not a wing warp) and 5 grams of weith added outside.
other flights i started to do some loops and inverted flight and really loved the plane!
tried 10x6 prop but got back to the 10x5. next flight i´ll try the 11x5 cut to 10.1/4 as suggested by Mikey,  but the fox holds the plane perfectly
thanks a lot for all the support and input here!
now it´s time to go back to the bench with my new project!
all the best
and thanks!
Fred

[john e. holliday]

That is great news.  It does pay to listen to the designer.

[George Albo]

thanks a lot George! it´s
 an honour to me! please post pictures when ready!

Fred, who makes that spinner?

Thanks, George

[fred cesquim]

next time i´ll start a tread before i finish, so i can have such great input before it´s too late!
spinner is Du-Bro, but now i have painted to match the plane colour after a friend comment lol!

[Jerry Reider]

I've got a Primary Force with an OS 46LA with a 12/4 Master Airscrew.  Love it, awesome flying plane, it does everything easily.  The 46LA is probably the best CL engine OS ever made in my opinion.