What do you think of FORMOST 150 ?
03-14-2008, 09:38 AM
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RE: What do you think of FORMOST 150 ?
ORIGINAL: bahamadude
How much does she weigh ?
What is the winspan ? I keep getting conflicting numbers
How much does she weigh ?
What is the winspan ? I keep getting conflicting numbers
Wingspan is 76" or 1930 mm
Weight : don't know yet, the manufacturer announces 6500 gr but that figure is misleading as it is referring to the nitro model.
All details are in the Digitech Webshop, the Turbine Formost is there available with the turbine conversions included !
http://shop.digitech-turbines.com/pr...i0hejf8mmaoao1
Nicolas.
03-16-2008, 02:06 AM
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RE: What do you think of FORMOST 150 ?
FLIGHT REPORT : 15/03/2008
----------------------------------------
I had my first four flights yesterday (Saturday).
What a great airplane this is ! It flies like an F3A patternship, floats like a trainer, and has a very lock-in feel at the controls.
Our grassfield was in very bad shape after a long winter, grass was much too long, full of rabbit holes and bumps etc. An endurance test for the landing gear, that was obvious. The trailing link struts took the shocks with ease, but the retract units "Excellence" have pivot blocks of a much too soft aluminium grade. The nose pivot block is already due for replacement since the first flight. I should have gone the proven paths and selected the Jet-1 landing gear (without wheel brakes for me, no need to have those on our grass field).... If you fly only on tarmac, these Excellence retract units would be sufficient, but for us european pilots.... [:@]
Anyway.
It didn't stop me from flying some more. Immediately after take off on the first flight, I had to trim all the way "UP". I had set my CG as per the plan but did so with completely empty tanks. The RX battery is in the nose and the lipo ECU battery was velcro strapped on top of main fuel tank. Most likely, the full UAT tank in the front was too much for the good CG. Next weekend, I will move some weight backwards or replace the RX battery in the nose for a lighter one.
Plane takes off easy, despite the very long grass, accelerates fast once airborne, no flaps used the first flight, and steering on all controls was very crisp. The plane is overall very forgiving as well and totally not critical, never saw one moment the Formost had a stall tendency, even when flying very very slow, almost at walking pace.
The SimJet 1200 (& thrust class) is a great match for this one. Exactly the right thrust I need, but I can imagine well vertical performance could be even better with more thrust. (...Wren SuperSport ?...) My verticals were not endless but more than enough. The fuel tank of 2 liters is a perfect choice, I would not install a bigger one, as you could observe that the Formost felt better during the second halves of each flight, when about one liter of fuel was gone already. Flight times were more than enough and ended in the worst case with about half a liter of fuel left, but I'll install the special JetCat/Orbit fuel clunk so I can drain the main tank to the last drop. The weight does make a difference, not only in vertical performance but surely in slow flight characteristics. It is very similar to a nitro trainer model. The Formost "feels" the difference in wing load. It is more obvious on this one than any other jet I had before. So : build light, don't install heavy turbines, choose the best weight/performance combo without the need of installing bigger tanks hence more weight to carry along, and be selective with your battery packs ! With my SimJet, I had a flame-out at low altitude on acceleration during the second flight, and although I expected an emergency landing down-wind, I could easily make a full circuit to my full surprise and even almost passed our airfield of 140 meters length... Very impressive how it floats !
The flame-out had most likely to do with a change of acceleration parameters I had set for a bit faster spool-up, on recommendations of a SimJet representative. I know now that this Formost doesn't need a fast spool up... I changed the acceleration delays back to normal after my belly landing just behind the runway (to save my poor retract pivot blocks) and the third and fourth flight were done with a flawlessly running turbine.
My SimJet has some 3 degrees down-thrust (I put some washers under the front mounting bolts) as I understood this is common practice on this type of jet. I still have to check later on if this was a good idea, I didn't really pay attention to it how the trim reacted in flight at full power.
Flight speed was very good, not too fast and enough power left to play all the time with the throttle control. Banked low fast fly-by's are very impressive, I could hear the Ohhhhs and Ahhhhs behind me when we were taking the flight photo shots on the fourth flight.
Third flight was to check the high G's.
Sharp turns, short loops,... The Formost takes them all with ease, and is rock steady in all maneuvres. Wings feel very strong, I am happy I did the CF reinforcement on the mid wing panels and the tailboom foam injection.
Cuban eights in very small airspace, slow rolls, rolling circles, loops,... this plane does it all with ease and challenges my skills as a pilot. It's a docile racing horse, walking around when you want it and displaying fast top aerobatics when you ask it to. I have to go back to training, and this is the perfect plane for that !
Only, the knife edge was only just sufficient. Rudder deflection or rudder size could be better, or perhaps it had to do with my CG being too nose heavy ? Will check that next time.
The third and fourth flight, I tested the flaps (flaperons). I used them on take-off and landing and during some slow maneuvers (testing the stall point at high altitude). I will definitely continue to use them, they add more lift and stability (without changing the elevator trim... =right now with my nose heavy plane). I do not see the necessity of having split flaps/ailerons per wing panel, there has never been a tip stall tendency when flaperons were deployed and I would highly prefer the present light set-up more than two more servos with the added advantage of eventual crow-braking. Keep it light and simple !
I had quite some aileron and elevator deflection and had, as an option, programmed the last minute a D/R switch on my TX for less deflection. You'd never know at high speeds... But I didn't need it, even more, I would keep the max deflection at all times like it was. No exponential, no D/R. The max deflections never felt like overkill and even rolls at full speed were not too fast. Just right.
I will publish my settings of present CG and deflections later today.
Must say again, what a great combo this is, the Futaba FASST and the brushless servos Futaba BLS451 with a 5 cell RX battery ! Unmatched very crisp controls and rock steady. I am flying now this Formost with the very basic Futaba 6EX FASST transmitter and I am really very pleased and impressed with it. The transmitter is also used to the absolute basics (just reversed some channels and set it to flaperons (CH1+CH6), nothing else was programmed or used), I will even throw out the D/R as the Formost does not need anything of all the fancy TX features.
As a summary, I must say that the airframe met with all expectations, if not exceeded it. We have done a lot of work to find the best (repeatative) solutions for the Turbine conversion, and I can say the Formost past with honours all the tests. This is an every weekends' totally hassle-free jet, absolutely great fun to fly and very rewarding and forgiving for a pilot. I am intended to fly it continuously in the weekends -except for recharging and refuelling-
I must solve the issue with the sloppy retract units for our highly demanding grass field (= read : to replace them with top quality gear !) and finding the correct CG, and I am ready for enjoying perhaps the best value for money I ever had in this hobby.
Will post flight pics later today... Sorry : no videos from my side, perhaps others can film their Formost, I am still in the Hi-8 stage (read : 90ies) !
This Formost is highly recommended... but after buying this very affordable kit absolutely don't economize the same way on all needed accessories but buy top notch gear to complete it (top servos, top landing gear,...), or don't make short cuts on the needed modifications or reinforcements (described earlier in this long thread). Because THAT is where your frustration will come from. And definitely not from the Formost !
Enjoy, and if you ever buy or fly one... let us all know here on RCU how it went !
A very happy "Almost-Formost-150-160-190-190TC-Europa-V1-V2-V3" [&:] owner,
Nicolas.
----------------------------------------
I had my first four flights yesterday (Saturday).
What a great airplane this is ! It flies like an F3A patternship, floats like a trainer, and has a very lock-in feel at the controls.
Our grassfield was in very bad shape after a long winter, grass was much too long, full of rabbit holes and bumps etc. An endurance test for the landing gear, that was obvious. The trailing link struts took the shocks with ease, but the retract units "Excellence" have pivot blocks of a much too soft aluminium grade. The nose pivot block is already due for replacement since the first flight. I should have gone the proven paths and selected the Jet-1 landing gear (without wheel brakes for me, no need to have those on our grass field).... If you fly only on tarmac, these Excellence retract units would be sufficient, but for us european pilots.... [:@]
Anyway.
It didn't stop me from flying some more. Immediately after take off on the first flight, I had to trim all the way "UP". I had set my CG as per the plan but did so with completely empty tanks. The RX battery is in the nose and the lipo ECU battery was velcro strapped on top of main fuel tank. Most likely, the full UAT tank in the front was too much for the good CG. Next weekend, I will move some weight backwards or replace the RX battery in the nose for a lighter one.
Plane takes off easy, despite the very long grass, accelerates fast once airborne, no flaps used the first flight, and steering on all controls was very crisp. The plane is overall very forgiving as well and totally not critical, never saw one moment the Formost had a stall tendency, even when flying very very slow, almost at walking pace.
The SimJet 1200 (& thrust class) is a great match for this one. Exactly the right thrust I need, but I can imagine well vertical performance could be even better with more thrust. (...Wren SuperSport ?...) My verticals were not endless but more than enough. The fuel tank of 2 liters is a perfect choice, I would not install a bigger one, as you could observe that the Formost felt better during the second halves of each flight, when about one liter of fuel was gone already. Flight times were more than enough and ended in the worst case with about half a liter of fuel left, but I'll install the special JetCat/Orbit fuel clunk so I can drain the main tank to the last drop. The weight does make a difference, not only in vertical performance but surely in slow flight characteristics. It is very similar to a nitro trainer model. The Formost "feels" the difference in wing load. It is more obvious on this one than any other jet I had before. So : build light, don't install heavy turbines, choose the best weight/performance combo without the need of installing bigger tanks hence more weight to carry along, and be selective with your battery packs ! With my SimJet, I had a flame-out at low altitude on acceleration during the second flight, and although I expected an emergency landing down-wind, I could easily make a full circuit to my full surprise and even almost passed our airfield of 140 meters length... Very impressive how it floats !
The flame-out had most likely to do with a change of acceleration parameters I had set for a bit faster spool-up, on recommendations of a SimJet representative. I know now that this Formost doesn't need a fast spool up... I changed the acceleration delays back to normal after my belly landing just behind the runway (to save my poor retract pivot blocks) and the third and fourth flight were done with a flawlessly running turbine.
My SimJet has some 3 degrees down-thrust (I put some washers under the front mounting bolts) as I understood this is common practice on this type of jet. I still have to check later on if this was a good idea, I didn't really pay attention to it how the trim reacted in flight at full power.
Flight speed was very good, not too fast and enough power left to play all the time with the throttle control. Banked low fast fly-by's are very impressive, I could hear the Ohhhhs and Ahhhhs behind me when we were taking the flight photo shots on the fourth flight.
Third flight was to check the high G's.
Sharp turns, short loops,... The Formost takes them all with ease, and is rock steady in all maneuvres. Wings feel very strong, I am happy I did the CF reinforcement on the mid wing panels and the tailboom foam injection.
Cuban eights in very small airspace, slow rolls, rolling circles, loops,... this plane does it all with ease and challenges my skills as a pilot. It's a docile racing horse, walking around when you want it and displaying fast top aerobatics when you ask it to. I have to go back to training, and this is the perfect plane for that !
Only, the knife edge was only just sufficient. Rudder deflection or rudder size could be better, or perhaps it had to do with my CG being too nose heavy ? Will check that next time.
The third and fourth flight, I tested the flaps (flaperons). I used them on take-off and landing and during some slow maneuvers (testing the stall point at high altitude). I will definitely continue to use them, they add more lift and stability (without changing the elevator trim... =right now with my nose heavy plane). I do not see the necessity of having split flaps/ailerons per wing panel, there has never been a tip stall tendency when flaperons were deployed and I would highly prefer the present light set-up more than two more servos with the added advantage of eventual crow-braking. Keep it light and simple !
I had quite some aileron and elevator deflection and had, as an option, programmed the last minute a D/R switch on my TX for less deflection. You'd never know at high speeds... But I didn't need it, even more, I would keep the max deflection at all times like it was. No exponential, no D/R. The max deflections never felt like overkill and even rolls at full speed were not too fast. Just right.
I will publish my settings of present CG and deflections later today.
Must say again, what a great combo this is, the Futaba FASST and the brushless servos Futaba BLS451 with a 5 cell RX battery ! Unmatched very crisp controls and rock steady. I am flying now this Formost with the very basic Futaba 6EX FASST transmitter and I am really very pleased and impressed with it. The transmitter is also used to the absolute basics (just reversed some channels and set it to flaperons (CH1+CH6), nothing else was programmed or used), I will even throw out the D/R as the Formost does not need anything of all the fancy TX features.
As a summary, I must say that the airframe met with all expectations, if not exceeded it. We have done a lot of work to find the best (repeatative) solutions for the Turbine conversion, and I can say the Formost past with honours all the tests. This is an every weekends' totally hassle-free jet, absolutely great fun to fly and very rewarding and forgiving for a pilot. I am intended to fly it continuously in the weekends -except for recharging and refuelling-
I must solve the issue with the sloppy retract units for our highly demanding grass field (= read : to replace them with top quality gear !) and finding the correct CG, and I am ready for enjoying perhaps the best value for money I ever had in this hobby.
Will post flight pics later today... Sorry : no videos from my side, perhaps others can film their Formost, I am still in the Hi-8 stage (read : 90ies) !
This Formost is highly recommended... but after buying this very affordable kit absolutely don't economize the same way on all needed accessories but buy top notch gear to complete it (top servos, top landing gear,...), or don't make short cuts on the needed modifications or reinforcements (described earlier in this long thread). Because THAT is where your frustration will come from. And definitely not from the Formost !
Enjoy, and if you ever buy or fly one... let us all know here on RCU how it went !
A very happy "Almost-Formost-150-160-190-190TC-Europa-V1-V2-V3" [&:] owner,
Nicolas.
03-16-2008, 06:27 AM
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RE: What do you think of FORMOST 150 ?
Nicolas,
Congratulations on your maiden, I am glad your efforts payed off.
I lost my Boomerang yesterday due to wing failure. I am still waiting on my L 39 but I might just pick up a Formost 150 as a replacement for my Boomer.
Thkank you.
jef
Congratulations on your maiden, I am glad your efforts payed off.
I lost my Boomerang yesterday due to wing failure. I am still waiting on my L 39 but I might just pick up a Formost 150 as a replacement for my Boomer.
Thkank you.
jef
03-16-2008, 08:16 AM
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RE: What do you think of FORMOST 150 ?
Nico,
Check the max rpm. It could be less than the max allowed by the ECU. You can yank it up to 165.000 to obtain about 19lbs of thrust.
Chris
Check the max rpm. It could be less than the max allowed by the ECU. You can yank it up to 165.000 to obtain about 19lbs of thrust.
Chris
03-16-2008, 11:22 AM
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RE: What do you think of FORMOST 150 ?
ORIGINAL: cairoman
Nico,
Check the max rpm. It could be less than the max allowed by the ECU. You can yank it up to 165.000 to obtain about 19lbs of thrust.
Chris
Nico,
Check the max rpm. It could be less than the max allowed by the ECU. You can yank it up to 165.000 to obtain about 19lbs of thrust.
Chris
Nicolas.
03-16-2008, 11:27 AM
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RE: What do you think of FORMOST 150 ?
Photos : Take-off, my fourth flight.
---------------------------------------------
Saturday. Finally one single day of good weather !
Grass was much too long, airfield was really muddy, but we enjoyed a perfect wind and a nice temperature (16°C).
---------------------------------------------
Saturday. Finally one single day of good weather !
Grass was much too long, airfield was really muddy, but we enjoyed a perfect wind and a nice temperature (16°C).
03-16-2008, 11:50 AM
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RE: What do you think of FORMOST 150 ?
(13-14-15/25)
These three photos are very interesting : look how well the entire wing flexes in these high-G maneuvers...
These three photos are very interesting : look how well the entire wing flexes in these high-G maneuvers...
03-16-2008, 12:04 PM
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RE: What do you think of FORMOST 150 ?
(24-25/25)
Note that I passed myself at about 1,5 m high (5 feet), the plane touches down about 100 m further. Excellent gliding at slow speed, this is a floater ! Not used to it yet...
Note that I passed myself at about 1,5 m high (5 feet), the plane touches down about 100 m further. Excellent gliding at slow speed, this is a floater ! Not used to it yet...
03-16-2008, 06:30 PM
#300
RE: What do you think of FORMOST 150 ?
Nicolas,
Very nice....
One question, in looking at the photos it almost looks like the wings are deflecting in both the inverted flight and normal flight, or is it a strange camera angle?
Question, did you extend the depth of the CF spar into the outer wing panel?
From the photos it looks like the outer wing panels are flexing.
I measured the insertion depth to be 6.12” (155 mm) on mine, I increased it to over 12" (304 mm) by using the aluminum tube as a hole saw and drilling through two more ribs.
I bought a 16mm OD x 1220 mm Lg CF spar.
Additionally I plan on making a vertical sheer web to support the spar where it passes through the center fuselage as it is exposed and unsupported.
Very nice....
One question, in looking at the photos it almost looks like the wings are deflecting in both the inverted flight and normal flight, or is it a strange camera angle?
These three photos are very interesting : look how well the entire wing flexes in these high-G maneuvers...
Question, did you extend the depth of the CF spar into the outer wing panel?
From the photos it looks like the outer wing panels are flexing.
I measured the insertion depth to be 6.12” (155 mm) on mine, I increased it to over 12" (304 mm) by using the aluminum tube as a hole saw and drilling through two more ribs.
I bought a 16mm OD x 1220 mm Lg CF spar.
Additionally I plan on making a vertical sheer web to support the spar where it passes through the center fuselage as it is exposed and unsupported.