BVM Balsa Bobcat, build photos..
#26
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Location: Leyland, UNITED KINGDOM
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It is actually 1 Bobcat 2 Falcons and 2 of the nitroplanes bobcats (same people that make the falcon but smaller)
I didn't do the original paint work myself but each year I tart it up a bit. After 3 years the paintwork unfortunately isn't as smooth and slippery as it was. Still looks great.
I dont use anything for takeoff but with the P80se there's a lot of residual thrust and not much drag. I can literally do 2 circuits on idle. Where did you end up with your COG? I moved mine back by over an inch from factory settings after a year. Huge improvement on inverted and anything involving inverted, especially slow rolls.
Martyn
ps Awesome pic!
I didn't do the original paint work myself but each year I tart it up a bit. After 3 years the paintwork unfortunately isn't as smooth and slippery as it was. Still looks great.
I dont use anything for takeoff but with the P80se there's a lot of residual thrust and not much drag. I can literally do 2 circuits on idle. Where did you end up with your COG? I moved mine back by over an inch from factory settings after a year. Huge improvement on inverted and anything involving inverted, especially slow rolls.
Martyn
ps Awesome pic!
#27
Thread Starter
Hi Martyn,
Yes the P80 has a bit of residual thrust, which is why the air brakes were designed I guess.. I know that many of these are flown with P120s, or even 160s!!! which would be interesting...
I did remove the 180 grams of ballast I had in the nose, which will put it behind the factory CG dots, but have not checked its balance against the marks since then. It still requires a wee bit of down elevator to maintain inverted so perhaps a bit more rearward is in order.. ..
BV tends to be very nose heavy conservative with his factory CGs.. I remember the old Balsa Bandit I built. It needed full up trim on its test flight.. Aggravated by the forward fuel tanks which also made it sluggish in the flare if landed with full tanks.. .. It took us a while to ge the CG right on that one..
Roger
Yes the P80 has a bit of residual thrust, which is why the air brakes were designed I guess.. I know that many of these are flown with P120s, or even 160s!!! which would be interesting...
I did remove the 180 grams of ballast I had in the nose, which will put it behind the factory CG dots, but have not checked its balance against the marks since then. It still requires a wee bit of down elevator to maintain inverted so perhaps a bit more rearward is in order.. ..
BV tends to be very nose heavy conservative with his factory CGs.. I remember the old Balsa Bandit I built. It needed full up trim on its test flight.. Aggravated by the forward fuel tanks which also made it sluggish in the flare if landed with full tanks.. .. It took us a while to ge the CG right on that one..
Roger
#28
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i still need a fair chunk of down on inverted but it is much better.
I was considering a VT80 for mine some time ago, mainly to reduce weight (700g lighter). What flight time are you getting?
I already get 9mins flight time +2mins for gear check pass and landing (11 total) with its 2L wing tanks and a 0.5l main tank + hopper. 9mins is usually 0.75L left to go
I was considering a VT80 for mine some time ago, mainly to reduce weight (700g lighter). What flight time are you getting?
I already get 9mins flight time +2mins for gear check pass and landing (11 total) with its 2L wing tanks and a 0.5l main tank + hopper. 9mins is usually 0.75L left to go
#29
Join Date: Jan 2008
Location: Medellin, COLOMBIA
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Good afternoon guys,
We are setting up a BVM Bobcat XL and we need a copy of the manual. We cannot find an email to contact BVM directly. Does any body have a PDF copy of this manual that can be shared with us?
Regards,
Omar
We are setting up a BVM Bobcat XL and we need a copy of the manual. We cannot find an email to contact BVM directly. Does any body have a PDF copy of this manual that can be shared with us?
Regards,
Omar
#32
My Feedback: (11)
Here is the email to the pretty Lady 4 pics down on the BVM customer website.
[email protected]
That's Uncle Bob's daughter. She is the best in the business.
[email protected]
That's Uncle Bob's daughter. She is the best in the business.
#34
Thread Starter
[QUOTE=omarhazbon;12305951]Thanks a lot ravill!
I just send Patty an email.
Regards,
Omar[
/QUOTE]
Yes indeed. Patty is very helpful. She has been my goto person at BVM for many many years. BVM is sure to have a copy of the manual available, although maybe not in PDF form..
BTW if you only need the Bob cat set up information, you can get this here. http://www.bvmjets.com/Pages/tips1.htm
Roger
I just send Patty an email.
Regards,
Omar[
/QUOTE]
Yes indeed. Patty is very helpful. She has been my goto person at BVM for many many years. BVM is sure to have a copy of the manual available, although maybe not in PDF form..
BTW if you only need the Bob cat set up information, you can get this here. http://www.bvmjets.com/Pages/tips1.htm
Roger
#36
Thread Starter
No worries Omar..
Be aware that BVMs recommended control throws are usually very powerful. I would suggest having a lower setting on dual rates available..
His CG also tend to be very conservative forward.. My Bobcat CG is at least 20mm behind the BVM recommended.
Good luck.
Roger
Be aware that BVMs recommended control throws are usually very powerful. I would suggest having a lower setting on dual rates available..
His CG also tend to be very conservative forward.. My Bobcat CG is at least 20mm behind the BVM recommended.
Good luck.
Roger
#38
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No worries Omar..
Be aware that BVMs recommended control throws are usually very powerful. I would suggest having a lower setting on dual rates available..
His CG also tend to be very conservative forward.. My Bobcat CG is at least 20mm behind the BVM recommended.
Good luck.
Roger
Be aware that BVMs recommended control throws are usually very powerful. I would suggest having a lower setting on dual rates available..
His CG also tend to be very conservative forward.. My Bobcat CG is at least 20mm behind the BVM recommended.
Good luck.
Roger
BTW, my BC does not have the CG holes in the booms
#39
My Feedback: (3)
I've got a balsa bobcat that's been sitting around for years all painted and pretty much ready for a turbine. It does not have flaps. I put it together thinking it would be a fun weekend jet but other priorities got in the way. I would like to finish it and want some opinions on the best power plant for it. I was looking at the kingtech K160? Too small?
Thanks!
Thanks!
#41
Martyn and Roger,
I had a Falcon with a MW54 and fixed gear that weighed about 14 lb. (no ballast)
how does the Bobcat compare, in weight and size?
Have you weighed the Bobcat without the initial nose ballast?
I had a Falcon with a MW54 and fixed gear that weighed about 14 lb. (no ballast)
how does the Bobcat compare, in weight and size?
Have you weighed the Bobcat without the initial nose ballast?
#42
Thread Starter
Hello roger, I have had two Bob cats, an older one and an XL. I just got a Composite BC and I have totally forgotten the throws and set up since I was out of the hobby for over 5 years. I'll look up BV site for these info. But can you give me details of your particular set up including throws, Final CG and the turbine down thrust angle which is very important for set up if I remember correctly...Cheers!
BTW, my BC does not have the CG holes in the booms
BTW, my BC does not have the CG holes in the booms
For test flying, I set this Bobcat up with the standard factory recommended throws, BUT I also set rate switches so that I had a selection of three rates… 100,% 80%, 60%.
From memory, I test flew with Ali, Elev and Rud all at mid rates of 80%. This had .more than adequate control.
Nowadays I use flight modes on the flap switch.
For take off (no flap) and general flying I like the elevator and ailerons at 80% and 60 % respectively, with about 20% expo.
For landing, I like elevator at 100% no expo, and ailerons at 80% no expo. This gives a bit more control in the circuit.
I have the rudder set at 80% with 20% expo for all flying..
My CG is 3/4" behind the dots. and the motor thrust is set using the factory mounts.. I am unsure if this has any down thrust.. To be honest, My Bobcat does pitch up a little under power, or maybe this is speed related pitch change, But I just live with it.. It is only minor and likely to do with the twin boom lay out.
Last edited by roger.alli; 02-14-2017 at 04:39 PM.
#43
Thread Starter
I've got a balsa bobcat that's been sitting around for years all painted and pretty much ready for a turbine. It does not have flaps. I put it together thinking it would be a fun weekend jet but other priorities got in the way. I would like to finish it and want some opinions on the best power plant for it. I was looking at the kingtech K160? Too small?
Thanks!
Thanks!
#44
Thread Starter
My Bobcat std weight is 8.25 kg, dry ready to fly (no ballast). 18.5 lbs. I think the Bob cat is a wee bit bigger than the Falcon 120. At 14 lbs it should be a great performer.. light = good..
#45
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#47
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Thx Roger, great info.
I set up my planes with 30-35% expo and full throw, I like them to feel like when I fly small full scale planes that I had flown. No flight modes.
Looking at your engine, it looks like you may want to try a couple of 1mm washers, or two, under the front turbine mount, this should give you better inverted flight and no pitch up with full throttle. If you try it, plz let me know how it goes.
I may use an 80 or 120 on mine, have not decided yet......
I set up my planes with 30-35% expo and full throw, I like them to feel like when I fly small full scale planes that I had flown. No flight modes.
Looking at your engine, it looks like you may want to try a couple of 1mm washers, or two, under the front turbine mount, this should give you better inverted flight and no pitch up with full throttle. If you try it, plz let me know how it goes.
I may use an 80 or 120 on mine, have not decided yet......
#48
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Hello Roger,
Thank you for the advise. I will use your CG location, it will probably take-off and land slower.
Patty send me the manual in PDF, Thanks a lot for the email.
Regards,
Omar
Thank you for the advise. I will use your CG location, it will probably take-off and land slower.
Patty send me the manual in PDF, Thanks a lot for the email.
Regards,
Omar
#49
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Thanks a lot for your help.
Regards,
Omar