Sebart Avanti S Build Thread w/KT 180
01-15-2014, 02:43 PM
#26
My Feedback: (1)
I guess they are narrow to fit a P-100, and anyone planning to fit a larger engine is expected to enlarge the opening.
I would think the vast majority of people building an Avanti will be fitting the larger engine, so why not space the rails for the largest engine size and have "adapter plates" that can be glued (or bolted) in for smaller engines?
As well engineered as this kits is everywhere else, it is surprising that they didn't put more thought into the engine mount rails.
01-15-2014, 04:36 PM
#28
My Feedback: (1)
DrScoles,
What servos are you going to use in your's?
I am setting mine up with all Sbus servos.
S9075SB's for the rudder and flaps
S9071SB's for the nosegear door, brake and retract valves
S9074SB's for all the remianing flight controls
I am planning to make my own bus cable, that way I can make all the wire lengths exact, minimize the number of servo connectors, and use larger wire (16 gauge) for the power feed to minimize voltage drop at the rear servos.
I've had mine for several weeks now, but I decided to glass the wings and stabs because I really despise iron on covering. Everything is glassed and primed now. If the weather will just warm up enough I could get it painted and start assembly.
I am installing the P-120 to start with, but I will probably break down and buy a P-180 for it before too long.
What servos are you going to use in your's?
I am setting mine up with all Sbus servos.
S9075SB's for the rudder and flaps
S9071SB's for the nosegear door, brake and retract valves
S9074SB's for all the remianing flight controls
I am planning to make my own bus cable, that way I can make all the wire lengths exact, minimize the number of servo connectors, and use larger wire (16 gauge) for the power feed to minimize voltage drop at the rear servos.
I've had mine for several weeks now, but I decided to glass the wings and stabs because I really despise iron on covering. Everything is glassed and primed now. If the weather will just warm up enough I could get it painted and start assembly.
I am installing the P-120 to start with, but I will probably break down and buy a P-180 for it before too long.
01-15-2014, 06:25 PM
#29
Hi Kevin,
A man much wiser than me, (who has posts on this thread) once posed a question, "do you think the plywood holding those servos in can withstand 475oz of torque?" You definitely aren't gonna have any servo failures with your set up. I am just below you. 74's for flap, elev, and rudder. 72 on ailerons and I haven't made up my mind on the thrust vector. I am using the 430 gyros for the thrust vector, so it doesn't have to be sbus, just fast. With split elevators, you have almost 1000oz of torque for your elevators! I'm using the 75's on my comp arf corsair, the control surfaces are pretty big. I wish there was a more scientific method for servo selection, we tend to just put stronger and stronger as the companies produce them. I'm more concerned with current draw than having enough torque. I'm relatively new to airplanes, I try to go on the guidance of my more seasoned friends.
You are making your own sbus wires, that never donned on me. How are you coming up with the hub? I would like to make my own. I am using just the signal wire to the rudder and elevator servos with their own regulated power supply, then the flaps, ailerons, and all the other stuff are on another regulated power wire. I have the royal srs with gyro, but I think it's overkill. Trying to go simple and light.
very cool that you can glass the wings, that's a skill I do not possess!
A man much wiser than me, (who has posts on this thread) once posed a question, "do you think the plywood holding those servos in can withstand 475oz of torque?" You definitely aren't gonna have any servo failures with your set up. I am just below you. 74's for flap, elev, and rudder. 72 on ailerons and I haven't made up my mind on the thrust vector. I am using the 430 gyros for the thrust vector, so it doesn't have to be sbus, just fast. With split elevators, you have almost 1000oz of torque for your elevators! I'm using the 75's on my comp arf corsair, the control surfaces are pretty big. I wish there was a more scientific method for servo selection, we tend to just put stronger and stronger as the companies produce them. I'm more concerned with current draw than having enough torque. I'm relatively new to airplanes, I try to go on the guidance of my more seasoned friends.
You are making your own sbus wires, that never donned on me. How are you coming up with the hub? I would like to make my own. I am using just the signal wire to the rudder and elevator servos with their own regulated power supply, then the flaps, ailerons, and all the other stuff are on another regulated power wire. I have the royal srs with gyro, but I think it's overkill. Trying to go simple and light.
very cool that you can glass the wings, that's a skill I do not possess!
01-16-2014, 03:08 AM
#30
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Could you post pictures of the glass work? How many ounces is the glass cloth your using?
Thanks
Thanks
DrScoles,
What servos are you going to use in your's?
I am setting mine up with all Sbus servos.
S9075SB's for the rudder and flaps
S9071SB's for the nosegear door, brake and retract valves
S9074SB's for all the remianing flight controls
I am planning to make my own bus cable, that way I can make all the wire lengths exact, minimize the number of servo connectors, and use larger wire (16 gauge) for the power feed to minimize voltage drop at the rear servos.
I've had mine for several weeks now, but I decided to glass the wings and stabs because I really despise iron on covering. Everything is glassed and primed now. If the weather will just warm up enough I could get it painted and start assembly.
I am installing the P-120 to start with, but I will probably break down and buy a P-180 for it before too long.
What servos are you going to use in your's?
I am setting mine up with all Sbus servos.
S9075SB's for the rudder and flaps
S9071SB's for the nosegear door, brake and retract valves
S9074SB's for all the remianing flight controls
I am planning to make my own bus cable, that way I can make all the wire lengths exact, minimize the number of servo connectors, and use larger wire (16 gauge) for the power feed to minimize voltage drop at the rear servos.
I've had mine for several weeks now, but I decided to glass the wings and stabs because I really despise iron on covering. Everything is glassed and primed now. If the weather will just warm up enough I could get it painted and start assembly.
I am installing the P-120 to start with, but I will probably break down and buy a P-180 for it before too long.
01-16-2014, 04:38 AM
#31
My Feedback: (1)
I chose the servos simply by comparing the specs of the recommended JR servos and using the Sbus servos with specs that came closest to them. Not very scientific, but it should work fine.
My Sbus cable will not have any "hubs" installed. It will be a true three wire bus system running the length of the fuselage with servo wires soldered in place in paralell where needed along the length. The larger power wires will minimize the voltage drop, and the number of servo connectors will be much lower than it would be with the Futaba hubs installed.The servo connectors at the wings will be the only connectors in the airplane that are transferring power to more than one servo. It should also be much less expensive than buying all that extra hardware from Futaba or Robbe. I should end up with only three connectors plugged into the receiver (pwm for throttle and smoke pump, and one Sbus connection).
I did not take any pictures while I was glassing the wings, and it probably wouldn't do any good to take any at this point since they are just gray primer now. I used one layer of 3/4 oz cloth on everything. I weighed a wing and a stab before I removed the iron on covering, and I will weigh them again once painted. I doubt the weight difference will be very much, and my wings wont look like a linen shirt that was left in the dryer overnight.
I will try to post some pics during the painting process.
My Sbus cable will not have any "hubs" installed. It will be a true three wire bus system running the length of the fuselage with servo wires soldered in place in paralell where needed along the length. The larger power wires will minimize the voltage drop, and the number of servo connectors will be much lower than it would be with the Futaba hubs installed.The servo connectors at the wings will be the only connectors in the airplane that are transferring power to more than one servo. It should also be much less expensive than buying all that extra hardware from Futaba or Robbe. I should end up with only three connectors plugged into the receiver (pwm for throttle and smoke pump, and one Sbus connection).
I did not take any pictures while I was glassing the wings, and it probably wouldn't do any good to take any at this point since they are just gray primer now. I used one layer of 3/4 oz cloth on everything. I weighed a wing and a stab before I removed the iron on covering, and I will weigh them again once painted. I doubt the weight difference will be very much, and my wings wont look like a linen shirt that was left in the dryer overnight.
I will try to post some pics during the painting process.
01-16-2014, 06:51 AM
#32
I've been thinking about the s-bus cabling and custom solutions myself. I have the crimping tool, pins and connector stock to make up servo ends, and multi way Ashlok connections along with a bunch of 22ga wire so I can make up almost any custom harness. The issue come when you are running multiple servos off one lead that is waaay back in the tail - probably the longest in the plane. There is heavier wire available, however, usually the insulation is too big to fit into the connector housings.
We have some aviation grade wire at work in various gauges including 18 and 20 ga. I'm planning to try running this stuff for the main feeds and then "Y" off to the servo connectors. The insulation is a thin wall Teflon product so it's dia and weight is pretty much the same. Only issue is it's not nearly as flexible as the fine stranded copper stuff we are used to.
Robbe has these s-bus hubs the provide a high current source but now you're back to running multiple wires:
http://translate.google.ca/translate...fari%26hl%3Den
PaulD
We have some aviation grade wire at work in various gauges including 18 and 20 ga. I'm planning to try running this stuff for the main feeds and then "Y" off to the servo connectors. The insulation is a thin wall Teflon product so it's dia and weight is pretty much the same. Only issue is it's not nearly as flexible as the fine stranded copper stuff we are used to.
Robbe has these s-bus hubs the provide a high current source but now you're back to running multiple wires:
http://translate.google.ca/translate...fari%26hl%3Den
PaulD
01-16-2014, 08:17 AM
#33
In my new Skymaster Hawk I am using the Robbe Futaba battery backer Sbus system. The cabling is 1mm2 approx. 17 swg and uses insulation displacement connectors (IDC) to connect the standard servo cable and plug to the bus. There is no reason why you couldn't use this cabling system without the backer if you wanted to. They make a pwm connector to allow standard servos to connect to the heavy duty bus cable too.
Malcolm
Malcolm
01-16-2014, 08:26 AM
#34
I chose the servos simply by comparing the specs of the recommended JR servos and using the Sbus servos with specs that came closest to them. Not very scientific, but it should work fine.
My Sbus cable will not have any "hubs" installed. It will be a true three wire bus system running the length of the fuselage with servo wires soldered in place in paralell where needed along the length. The larger power wires will minimize the voltage drop, and the number of servo connectors will be much lower than it would be with the Futaba hubs installed.The servo connectors at the wings will be the only connectors in the airplane that are transferring power to more than one servo. It should also be much less expensive than buying all that extra hardware from Futaba or Robbe. I should end up with only three connectors plugged into the receiver (pwm for throttle and smoke pump, and one Sbus connection).
My Sbus cable will not have any "hubs" installed. It will be a true three wire bus system running the length of the fuselage with servo wires soldered in place in paralell where needed along the length. The larger power wires will minimize the voltage drop, and the number of servo connectors will be much lower than it would be with the Futaba hubs installed.The servo connectors at the wings will be the only connectors in the airplane that are transferring power to more than one servo. It should also be much less expensive than buying all that extra hardware from Futaba or Robbe. I should end up with only three connectors plugged into the receiver (pwm for throttle and smoke pump, and one Sbus connection).
01-16-2014, 08:30 AM
#35
Hi Kevin,
A man much wiser than me, (who has posts on this thread) once posed a question, "do you think the plywood holding those servos in can withstand 475oz of torque?" You definitely aren't gonna have any servo failures with your set up. I am just below you. 74's for flap, elev, and rudder. 72 on ailerons and I haven't made up my mind on the thrust vector. I am using the 430 gyros for the thrust vector, so it doesn't have to be sbus, just fast. With split elevators, you have almost 1000oz of torque for your elevators! I'm using the 75's on my comp arf corsair, the control surfaces are pretty big. I wish there was a more scientific method for servo selection, we tend to just put stronger and stronger as the companies produce them. I'm more concerned with current draw than having enough torque. I'm relatively new to airplanes, I try to go on the guidance of my more seasoned friends.
You are making your own sbus wires, that never donned on me. How are you coming up with the hub? I would like to make my own. I am using just the signal wire to the rudder and elevator servos with their own regulated power supply, then the flaps, ailerons, and all the other stuff are on another regulated power wire. I have the royal srs with gyro, but I think it's overkill. Trying to go simple and light.
very cool that you can glass the wings, that's a skill I do not possess!
A man much wiser than me, (who has posts on this thread) once posed a question, "do you think the plywood holding those servos in can withstand 475oz of torque?" You definitely aren't gonna have any servo failures with your set up. I am just below you. 74's for flap, elev, and rudder. 72 on ailerons and I haven't made up my mind on the thrust vector. I am using the 430 gyros for the thrust vector, so it doesn't have to be sbus, just fast. With split elevators, you have almost 1000oz of torque for your elevators! I'm using the 75's on my comp arf corsair, the control surfaces are pretty big. I wish there was a more scientific method for servo selection, we tend to just put stronger and stronger as the companies produce them. I'm more concerned with current draw than having enough torque. I'm relatively new to airplanes, I try to go on the guidance of my more seasoned friends.
You are making your own sbus wires, that never donned on me. How are you coming up with the hub? I would like to make my own. I am using just the signal wire to the rudder and elevator servos with their own regulated power supply, then the flaps, ailerons, and all the other stuff are on another regulated power wire. I have the royal srs with gyro, but I think it's overkill. Trying to go simple and light.
very cool that you can glass the wings, that's a skill I do not possess!
I personally have not seen servos pull out of there position. That being said, I like to put a doubler or even use 256 blind nuts in for servos over 450 in oz.
Nice work Dr.
01-16-2014, 09:07 AM
#37
Well I ordered the Futaba Sbus servos Kevin recommended. I guess those puppies are either in high demand or limited production. Tower backordered 'em and they kept moving the arrival dates back, when they moved the S9074SB's back to February when I checked this morning, I went looking for the servos elsewhere. Tower did had the three small servos Kevin suggested to me but I had to hit Servo City and Amain Hobbies to get the five 9074's, the 9075's were not hard to find.
As for Mike's (can I call you Mike???) question about the thrust vectoring servos. Everything I've read says they should be fast and Comp-Arf even recommends using reverse expo when setting the servos up for the model. I looked at tons of servos and nothing came very close to the SebArt recommended JR DS8717's. They are a heli swashplate servo so maybe you're familiar with them already. IIRC we talked about you going to Sbus while I'm going to use the PowerBox PE so changing two servos won't be an issue. The other thing I've always kind of liked about JR is the deadband, it wears out some gear sets but it's tight. Futaba won't post a spec for that but I'll bet the JR's are tighter whatever Futaba's spec is.
As for Mike's (can I call you Mike???) question about the thrust vectoring servos. Everything I've read says they should be fast and Comp-Arf even recommends using reverse expo when setting the servos up for the model. I looked at tons of servos and nothing came very close to the SebArt recommended JR DS8717's. They are a heli swashplate servo so maybe you're familiar with them already. IIRC we talked about you going to Sbus while I'm going to use the PowerBox PE so changing two servos won't be an issue. The other thing I've always kind of liked about JR is the deadband, it wears out some gear sets but it's tight. Futaba won't post a spec for that but I'll bet the JR's are tighter whatever Futaba's spec is.
01-16-2014, 09:10 AM
#38
My Feedback: (1)
The way I am doing it is to just use the heavy wire for the bus (like a bus bar), then I am soldering on standard 22 gauge servo leads along the length of it where a servo needs to connect. Each one of the leads that is soldered onto the bus wires will have a single standard servo connector on the end of it and one servo will plug into each one (except at the wing connection where the flap and aileron servo will be Y'ed together and plug into one lead).
I will take some pictures when I get around to assembling it.
Last edited by Kevin_W; 01-16-2014 at 09:21 AM.
01-16-2014, 09:21 AM
#39
My Feedback: (1)
Zeeb,
I got all of my servos from Servo City.
Thier prices were slightly better than Tower Hobbies, and I was able to get a 10% discount too. (there is a link on thier order page that explains how to get the discount).
Even though the Sbus servos are a little more expensive than the recommended JR servos (some of which I already have) I ended up spending less than I would have if I had bought the rest of the JR servos I needed plus the SBD-1 adapters for them.
A couple of notes though, the S9071SB servo is a little larger than the mount opening for the nose gear door but there is enough room on the former to open up the slot and make it fit, the S9074SB servo is slightly larger that the opening in the nose gear steering mount, but I was able to open that up with a file in about 2 minutes (the screw holes line up fine).
I got all of my servos from Servo City.
Thier prices were slightly better than Tower Hobbies, and I was able to get a 10% discount too. (there is a link on thier order page that explains how to get the discount).
Even though the Sbus servos are a little more expensive than the recommended JR servos (some of which I already have) I ended up spending less than I would have if I had bought the rest of the JR servos I needed plus the SBD-1 adapters for them.
A couple of notes though, the S9071SB servo is a little larger than the mount opening for the nose gear door but there is enough room on the former to open up the slot and make it fit, the S9074SB servo is slightly larger that the opening in the nose gear steering mount, but I was able to open that up with a file in about 2 minutes (the screw holes line up fine).
01-16-2014, 09:42 AM
#40
Zeeb,
I got all of my servos from Servo City.
Thier prices were slightly better than Tower Hobbies, and I was able to get a 10% discount too. (there is a link on thier order page that explains how to get the discount).
Even though the Sbus servos are a little more expensive than the recommended JR servos (some of which I already have) I ended up spending less than I would have if I had bought the rest of the JR servos I needed plus the SBD-1 adapters for them.
A couple of notes though, the S9071SB servo is a little larger than the mount opening for the nose gear door but there is enough room on the former to open up the slot and make it fit, the S9074SB servo is slightly larger that the opening in the nose gear steering mount, but I was able to open that up with a file in about 2 minutes (the screw holes line up fine).
I got all of my servos from Servo City.
Thier prices were slightly better than Tower Hobbies, and I was able to get a 10% discount too. (there is a link on thier order page that explains how to get the discount).
Even though the Sbus servos are a little more expensive than the recommended JR servos (some of which I already have) I ended up spending less than I would have if I had bought the rest of the JR servos I needed plus the SBD-1 adapters for them.
A couple of notes though, the S9071SB servo is a little larger than the mount opening for the nose gear door but there is enough room on the former to open up the slot and make it fit, the S9074SB servo is slightly larger that the opening in the nose gear steering mount, but I was able to open that up with a file in about 2 minutes (the screw holes line up fine).
I appreciate the tips and will keep watching this thread, but my model is down in Bakersfield, CA. I've got a guy putting it together for me since I've never done a jet. I've got a Tomahawk Design 2.0M ViperJet downstairs that I am working on and contemplating going all Sbus on that, see if I can make the new 18MZ work. Already chasing wiring questions on it as I bought the electric gear mod and it's got electric brakes.
01-16-2014, 01:00 PM
#41
My bobcat is s.bus and has one 6v regulator and one wire supplying juice to all the servos. It has one 9075 on elevator, 9074 on flaps, then the micro sbus on rudder and 9072 no ailerons. It has 30 flights on it. Love how simple the wiring is. Zeeb, the tomahawk viper is an awesome plane, you will enjoy it. If you want, I can send you my 18mz program for the viper… might be a good starting point. Mine isn't s.bus, but simple enough to reassign servos.
01-16-2014, 04:59 PM
#44
Little bit more done today, have the nanny here, so I can sneak away to the garage a bit. For the vectored thrust crowd, we have to cut the rear former out and glue in the supplied one. Coarse sanding drum on the dremel took care of it fairly easily. I also painted the inside of the fuse. I didn't want to due to the slight weight addition, but this plane is too sharp to leave unpainted inside. Again, very happy with the layout, I didn't have to add a single shelf or brace to hold equipment.
01-17-2014, 09:34 AM
#50
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Hi guys, just checking who else with the vectored thrust pipe has got to the point of lining up the turbine and pipe?
mine is almost fitted, I've installed the pipe then was lining up the engine when I noticed the engine was sitting very low compared to the pipe. I tried using spacers to lift the turbine but then the turbine was at an angle relative to the pipe. I've pulled the lot out tonight and worked out that the holes on the bell mouth of my pipe were not directly opposite, meaning the pipe was sitting up at the front. I have redrilled the holes opposite each other and now it is a lot closer. It is possible the bell mouth was attached upside down, but I can't turn the pipe over due to the vector thrust linkages at the rear.
if somebody has the VT pipe sitting around can you measure for me and check if the holes are directly opposite?
thanks
mine is almost fitted, I've installed the pipe then was lining up the engine when I noticed the engine was sitting very low compared to the pipe. I tried using spacers to lift the turbine but then the turbine was at an angle relative to the pipe. I've pulled the lot out tonight and worked out that the holes on the bell mouth of my pipe were not directly opposite, meaning the pipe was sitting up at the front. I have redrilled the holes opposite each other and now it is a lot closer. It is possible the bell mouth was attached upside down, but I can't turn the pipe over due to the vector thrust linkages at the rear.
if somebody has the VT pipe sitting around can you measure for me and check if the holes are directly opposite?
thanks