Bob Cat Copy Falcon 120 Jet
12-04-2009, 05:42 PM
#3027
RE: Bob Cat Copy Falcon 120 Jet
I don't know about the BVM Bobcat, but the Flacon 120 has this amount of up thrust because of its semi semetrical wing, as it goes faster the more lift it produces it therefore needs the up thrust to keep the nose down and prevent excess climbing.
Mike
Mike
12-04-2009, 06:22 PM
#3029
RE: Bob Cat Copy Falcon 120 Jet
Guys its not down thrust, because the motor is at the rear its up thrust, you must look at the thrust line in relation to the wing angle of attack, down thrust would increase the angle of attack and do exactly the opposite to what we are trying to achive.
Mike
Mike
12-05-2009, 04:54 PM
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RE: Bob Cat Copy Falcon 120 Jet
hey guys i too have been looking for the stock size 20mm carbon wing spar.im getting real close to the maiden. i did find this one, check out this link.
http://rcfoam.com/cart.php?target=pr...category_id=94
http://rcfoam.com/cart.php?target=pr...category_id=94
12-06-2009, 10:00 PM
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RE: Bob Cat Copy Falcon 120 Jet
im concerned it seems realy thick,maby too heavy (4mm). also it dosent appear to be carbon fiber,just carbon. will it still be suitable?
12-07-2009, 07:05 AM
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RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: sweetpea01
I have not bought it yet......still debating on my choices. Thanks for raising those questions I'll look into them. Also waiting for FX to get back to me about the $40 tube as well.
I have not bought it yet......still debating on my choices. Thanks for raising those questions I'll look into them. Also waiting for FX to get back to me about the $40 tube as well.
Common sence RC are the US importer for MS composite. Maybe they can give you a price for the boom?
Thanks
dave
12-10-2009, 01:51 PM
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RE: Bob Cat Copy Falcon 120 Jet
Here are some pics from today !!
Faster than I thought.....have to turn donwn the turbine to make it legal......
Onboard small GPS ......
I have a lot of problems with the didgi-tech landing gear............. with the tires that hold air........going to get something else !!!!!
Derrick
Faster than I thought.....have to turn donwn the turbine to make it legal......
Onboard small GPS ......
I have a lot of problems with the didgi-tech landing gear............. with the tires that hold air........going to get something else !!!!!
Derrick
I have received a landing gear set from Digitech which looks identical to yours. Can I please ask you, did you just go with the standard length that drops straight in to the Falcon or did you have the struts shortened by Digitech ?
Also have you found some replacement wheels to replace the troublesome ones ?
Thanks in advance
Dom.
12-10-2009, 04:04 PM
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RE: Bob Cat Copy Falcon 120 Jet
The digitech gear was too light duty for my Falcon. I did no mods to the Digitech gear.
If you need them shortened, someone with a lathe can do it.
I bought the Comp-arf Eurosport Pro link gear set and Intrairco wheels from dreamworksrc and did mods for it to fit in the wells.Pro-link much better design.....ZERO SLOP !!!
I did this gear change last week.
Pro-link also uses shoulder bolts.
I now have a Ultra-Heavy duty gear for my Falcon.
Derrick
If you need them shortened, someone with a lathe can do it.
I bought the Comp-arf Eurosport Pro link gear set and Intrairco wheels from dreamworksrc and did mods for it to fit in the wells.Pro-link much better design.....ZERO SLOP !!!
I did this gear change last week.
Pro-link also uses shoulder bolts.
I now have a Ultra-Heavy duty gear for my Falcon.
Derrick
12-10-2009, 04:21 PM
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RE: Bob Cat Copy Falcon 120 Jet
Thanks Derrick,
I appreciate the reply.
I will try the Digitechs but will have the mains shortened by 40mm as I think that they are way too long as a stock fit (160mm bottom of trunion to axle) and probably contribute to issues in heavier planes.
I currently have a Springair setup but want the nice look of trailing link gear.
Also do you have any main tanks left and do they slide into the fuselage easily. Are they light weight compared to juice bottles.
I currently have a 1.25L bottle in there which doesn't give me good flight times.
Thanks again
Regards
Dom
I appreciate the reply.
I will try the Digitechs but will have the mains shortened by 40mm as I think that they are way too long as a stock fit (160mm bottom of trunion to axle) and probably contribute to issues in heavier planes.
I currently have a Springair setup but want the nice look of trailing link gear.
Also do you have any main tanks left and do they slide into the fuselage easily. Are they light weight compared to juice bottles.
I currently have a 1.25L bottle in there which doesn't give me good flight times.
Thanks again
Regards
Dom
12-10-2009, 05:40 PM
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RE: Bob Cat Copy Falcon 120 Jet
Yes, I make main tanks to order.
They are About 80oz. They fit into fuse easy !!!!
maybe just a couple ounces heayier than a juice bottle.
I wouldn't use a juice bottle.
I have a friend which the cap can off somehow and unmetered fuel went into the engine.......very scary !!!
Derrick
They are About 80oz. They fit into fuse easy !!!!
maybe just a couple ounces heayier than a juice bottle.
I wouldn't use a juice bottle.
I have a friend which the cap can off somehow and unmetered fuel went into the engine.......very scary !!!
Derrick
12-10-2009, 06:33 PM
#3041
RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: derrickxp8103
Ya its a cool airplane.......I know its probably not the fastest...but my next project will eat anything out there !!! Period !!
Ya its a cool airplane.......I know its probably not the fastest...but my next project will eat anything out there !!! Period !!
Its been some time now, so what period do you want!!!!
Mike
12-10-2009, 06:35 PM
#3042
RE: Bob Cat Copy Falcon 120 Jet
Dom
My Dreamworks gear only lasted 13 flights before one leg bent and the other broke in half, I replaced them with Digitech which have lasted more than double the time, I have to say that the field I fly from is a rough pasture shared with sheep and is not the most freindly of surfaces.
Mike
My Dreamworks gear only lasted 13 flights before one leg bent and the other broke in half, I replaced them with Digitech which have lasted more than double the time, I have to say that the field I fly from is a rough pasture shared with sheep and is not the most freindly of surfaces.
Mike
12-12-2009, 06:23 AM
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RE: Bob Cat Copy Falcon 120 Jet
Guys I want to put smoke in my falcon, only spot for the tank is in the wing. Did I read somewhere that someone had made a wing tank?
Love to hear from someone who has smoke in their Falcon?
Aslo I only have 9 channels so how do I activate my smoke as all channels are being used?
Thanks,
Mav
Love to hear from someone who has smoke in their Falcon?
Aslo I only have 9 channels so how do I activate my smoke as all channels are being used?
Thanks,
Mav
12-12-2009, 10:17 AM
#3045
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RE: Bob Cat Copy Falcon 120 Jet
His tank ad is in the RCU Jet Classified section http://www.rcuniverse.com/market/item.cfm?itemId=580632
You will need to free up a channel to control smoke. The best way is to Y together two common control surfaces or use a Matchbox. If you list what you are already using I'm sure you'll some suggestions.
Joe
You will need to free up a channel to control smoke. The best way is to Y together two common control surfaces or use a Matchbox. If you list what you are already using I'm sure you'll some suggestions.
Joe
12-12-2009, 01:26 PM
#3046
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RE: Bob Cat Copy Falcon 120 Jet
Hi mav many ways of doing this. I fly my falcon with all functions including an extendable nose leg (for take off) and smoke, with just a DX7.
I had run out of channels, so couldnt fit an electric pump and link it to the U/C up selection, as motor would run dry when smoke fuel gone. I went for a pheumatic sysyem. I use an extra U/C air tank and a plastic RADWELD bottle, which holds i think 300mls. I conect a servo and tiny BVM air switch, via Y lead, to the U/C chanel. When the gear is down, servo is well away from the air switch. When gear selected up, the servo stops, just short from operating the air switch. I now flick the Rudder Mix switch on the transmitter, which I slaved to the U/C channel. My mix, gives virtually the same throws on the rudder, but the U/C channel, moves just a touch more and operates the air valve. Obviously the Air switch can be replaced with a microswitch for electric operation. I have used this method with mechanical U/C valves and the excellent jetronics electroinc valves, with great effect.
There is not much info around on smoke, but I posted on here my setup and findings a long time ago, you could do a search. Also on youtube, (falcon120 (I am tim777jet)) you will see my comparison between MT smoke fluid and diesel and also my ground test.There was some talk about any flame getting past the turbine, during accel, igniting the smoke fluid, but have never seen this on my home made turbine, or any one elses. MT fluid is slightly blacker than diesel, so does show up a bit easier than diesl on a whitish sky. Against blue sky, diesel is fine. I just use diesel. Have tried, food colouring dyes and cooking oil and other concotions to no avail. If you want coloured smoke, it can only be done by spraying dye, into the evaporating diesel you are spraying into the jet efflux. It can not be added into the mix, so I have read. Apparently green is the best colour to have, you have to use textile dyes and the mess is terible, once stained you cant get it off. I have not experimented any further with colour, but if you get some results, please post them up.
ref the spray pipe, i have tried spraying the fuel across the jet efflux at 90 degrees, along with it and back up into the tail cone. it seems 90 degs across is best for me. I do not get any residue on the tail, fins booms or engine.
I use I think, a 3 or 4 mm piece of brass tube crushed down at the end @ 0.020thou. I have heard that the Xaco model knife blade is the correct size to squeeze the tube down to.
When I apply the smoke fluid, my 100 psi air, flows into the RADSEAL bottle and pushes the fluid out the brass tube. The RADSEAL bottle fits nicely just in front of the main tank just fwd of my main tank. I fly from a rough grass , very short patch and have no noticeable difference in take off run with the fluid on board. My smoke lasts about 30 secs and tails off as the pressure drops, but good fun, especially when the sky is blue, Hope that helps, cheers tim
I had run out of channels, so couldnt fit an electric pump and link it to the U/C up selection, as motor would run dry when smoke fuel gone. I went for a pheumatic sysyem. I use an extra U/C air tank and a plastic RADWELD bottle, which holds i think 300mls. I conect a servo and tiny BVM air switch, via Y lead, to the U/C chanel. When the gear is down, servo is well away from the air switch. When gear selected up, the servo stops, just short from operating the air switch. I now flick the Rudder Mix switch on the transmitter, which I slaved to the U/C channel. My mix, gives virtually the same throws on the rudder, but the U/C channel, moves just a touch more and operates the air valve. Obviously the Air switch can be replaced with a microswitch for electric operation. I have used this method with mechanical U/C valves and the excellent jetronics electroinc valves, with great effect.
There is not much info around on smoke, but I posted on here my setup and findings a long time ago, you could do a search. Also on youtube, (falcon120 (I am tim777jet)) you will see my comparison between MT smoke fluid and diesel and also my ground test.There was some talk about any flame getting past the turbine, during accel, igniting the smoke fluid, but have never seen this on my home made turbine, or any one elses. MT fluid is slightly blacker than diesel, so does show up a bit easier than diesl on a whitish sky. Against blue sky, diesel is fine. I just use diesel. Have tried, food colouring dyes and cooking oil and other concotions to no avail. If you want coloured smoke, it can only be done by spraying dye, into the evaporating diesel you are spraying into the jet efflux. It can not be added into the mix, so I have read. Apparently green is the best colour to have, you have to use textile dyes and the mess is terible, once stained you cant get it off. I have not experimented any further with colour, but if you get some results, please post them up.
ref the spray pipe, i have tried spraying the fuel across the jet efflux at 90 degrees, along with it and back up into the tail cone. it seems 90 degs across is best for me. I do not get any residue on the tail, fins booms or engine.
I use I think, a 3 or 4 mm piece of brass tube crushed down at the end @ 0.020thou. I have heard that the Xaco model knife blade is the correct size to squeeze the tube down to.
When I apply the smoke fluid, my 100 psi air, flows into the RADSEAL bottle and pushes the fluid out the brass tube. The RADSEAL bottle fits nicely just in front of the main tank just fwd of my main tank. I fly from a rough grass , very short patch and have no noticeable difference in take off run with the fluid on board. My smoke lasts about 30 secs and tails off as the pressure drops, but good fun, especially when the sky is blue, Hope that helps, cheers tim
12-12-2009, 01:57 PM
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RE: Bob Cat Copy Falcon 120 Jet
12-12-2009, 03:12 PM
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RE: Bob Cat Copy Falcon 120 Jet
12-13-2009, 03:20 AM
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RE: Bob Cat Copy Falcon 120 Jet
ORIGINAL: tim777jet
Hi mav many ways of doing this. I fly my falcon with all functions including an extendable nose leg (for take off) and smoke, with just a DX7.
I had run out of channels, so couldnt fit an electric pump and link it to the U/C up selection, as motor would run dry when smoke fuel gone. I went for a pheumatic sysyem. I use an extra U/C air tank and a plastic RADWELD bottle, which holds i think 300mls. I conect a servo and tiny BVM air switch, via Y lead, to the U/C chanel. When the gear is down, servo is well away from the air switch. When gear selected up, the servo stops, just short from operating the air switch. I now flick the Rudder Mix switch on the transmitter, which I slaved to the U/C channel. My mix, gives virtually the same throws on the rudder, but the U/C channel, moves just a touch more and operates the air valve. Obviously the Air switch can be replaced with a microswitch for electric operation. I have used this method with mechanical U/C valves and the excellent jetronics electroinc valves, with great effect.
There is not much info around on smoke, but I posted on here my setup and findings a long time ago, you could do a search. Also on youtube, (falcon120 (I am tim777jet)) you will see my comparison between MT smoke fluid and diesel and also my ground test.There was some talk about any flame getting past the turbine, during accel, igniting the smoke fluid, but have never seen this on my home made turbine, or any one elses. MT fluid is slightly blacker than diesel, so does show up a bit easier than diesl on a whitish sky. Against blue sky, diesel is fine. I just use diesel. Have tried, food colouring dyes and cooking oil and other concotions to no avail. If you want coloured smoke, it can only be done by spraying dye, into the evaporating diesel you are spraying into the jet efflux. It can not be added into the mix, so I have read. Apparently green is the best colour to have, you have to use textile dyes and the mess is terible, once stained you cant get it off. I have not experimented any further with colour, but if you get some results, please post them up.
ref the spray pipe, i have tried spraying the fuel across the jet efflux at 90 degrees, along with it and back up into the tail cone. it seems 90 degs across is best for me. I do not get any residue on the tail, fins booms or engine.
I use I think, a 3 or 4 mm piece of brass tube crushed down at the end @ 0.020thou. I have heard that the Xaco model knife blade is the correct size to squeeze the tube down to.
When I apply the smoke fluid, my 100 psi air, flows into the RADSEAL bottle and pushes the fluid out the brass tube. The RADSEAL bottle fits nicely just in front of the main tank just fwd of my main tank. I fly from a rough grass , very short patch and have no noticeable difference in take off run with the fluid on board. My smoke lasts about 30 secs and tails off as the pressure drops, but good fun, especially when the sky is blue, Hope that helps, cheers tim
Hi mav many ways of doing this. I fly my falcon with all functions including an extendable nose leg (for take off) and smoke, with just a DX7.
I had run out of channels, so couldnt fit an electric pump and link it to the U/C up selection, as motor would run dry when smoke fuel gone. I went for a pheumatic sysyem. I use an extra U/C air tank and a plastic RADWELD bottle, which holds i think 300mls. I conect a servo and tiny BVM air switch, via Y lead, to the U/C chanel. When the gear is down, servo is well away from the air switch. When gear selected up, the servo stops, just short from operating the air switch. I now flick the Rudder Mix switch on the transmitter, which I slaved to the U/C channel. My mix, gives virtually the same throws on the rudder, but the U/C channel, moves just a touch more and operates the air valve. Obviously the Air switch can be replaced with a microswitch for electric operation. I have used this method with mechanical U/C valves and the excellent jetronics electroinc valves, with great effect.
There is not much info around on smoke, but I posted on here my setup and findings a long time ago, you could do a search. Also on youtube, (falcon120 (I am tim777jet)) you will see my comparison between MT smoke fluid and diesel and also my ground test.There was some talk about any flame getting past the turbine, during accel, igniting the smoke fluid, but have never seen this on my home made turbine, or any one elses. MT fluid is slightly blacker than diesel, so does show up a bit easier than diesl on a whitish sky. Against blue sky, diesel is fine. I just use diesel. Have tried, food colouring dyes and cooking oil and other concotions to no avail. If you want coloured smoke, it can only be done by spraying dye, into the evaporating diesel you are spraying into the jet efflux. It can not be added into the mix, so I have read. Apparently green is the best colour to have, you have to use textile dyes and the mess is terible, once stained you cant get it off. I have not experimented any further with colour, but if you get some results, please post them up.
ref the spray pipe, i have tried spraying the fuel across the jet efflux at 90 degrees, along with it and back up into the tail cone. it seems 90 degs across is best for me. I do not get any residue on the tail, fins booms or engine.
I use I think, a 3 or 4 mm piece of brass tube crushed down at the end @ 0.020thou. I have heard that the Xaco model knife blade is the correct size to squeeze the tube down to.
When I apply the smoke fluid, my 100 psi air, flows into the RADSEAL bottle and pushes the fluid out the brass tube. The RADSEAL bottle fits nicely just in front of the main tank just fwd of my main tank. I fly from a rough grass , very short patch and have no noticeable difference in take off run with the fluid on board. My smoke lasts about 30 secs and tails off as the pressure drops, but good fun, especially when the sky is blue, Hope that helps, cheers tim
Thanks for the replies Joe and Tim.
I like the idea of pressurised fluid. Can you explain in more detail how you did your set up? Are you saying your pressurise a separate tank or inject diesel into an air tank? Cool simple idea instead of using a separate pump!!!!!
Mav
