---------------------------------------------------------- RV9-List Digest Archive --- Total Messages Posted Sat 03/12/05: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:10 AM - Re: Trim-- electric vs. manual (Charlie England) 2. 08:16 AM - Re:Re: Pitot Static Testing with Dynon (Leland) 3. 09:35 AM - Re: Trim-- electric vs. manual (Carroll Neblett) 4. 10:14 AM - Re: Trim-- electric vs. manual (Richard E. Tasker) 5. 11:28 AM - Re: Trim-- electric vs. manual (Steve Sampson) 6. 11:28 AM - (owner-rv9-list-server@matronics.com) 7. 11:33 AM - Re: Trim-- electric vs. manual () ________________________________ Message 1 _____________________________________ Time: 08:10:54 AM PST US From: Charlie England Subject: Re: RV9-List: Trim-- electric vs. manual --> RV9-List message posted by: Charlie England Ross S wrote: >--> RV9-List message posted by: "Ross S" > >I installed the electric trim because I didn't want the big knob in the >cockpit and figured the electric would be lighter. .... so for a few extra >bucks it would be win win. > >Reality struck when I started flying. In my opinion, the electric is not >nearly as good as the manual. > >The electric is not sensative enough to get exatly the correct hands off >pitch position. If you just bump it one direction it goes too far, and then >bump it back and that is too far. I realize that you can buy a speed >control to slow it down, but on the other hand it is already too slow. When >you want to trim for landing or takeoff, it takes an eternity to get into >position. I usually end up coming in hot and don't have time to screw with >it and I land without trimming the plane. It just plain doesn't have the >operational benefits of manual trim. > > >Solutions: > >1.) One of you guys needs to come up with an electric trim with a dash >mountet knob with a fair amount of resistance (maybe like the volume control >on my GMC pickup that has detents every few degrees) that needs to be turned >about ten turns for full deflection. > >or.. > >2.) Make a speed control that will ramp up in speed the longer you hold it >down. Then you could still control it with the coolie switch on the grip, >but you could have fine control and speed both. > >-Ross > >Ross Schlotthauer >RV-7 flying but not finished >www.experimentalair.com > A true servo will do exactly what you describe in 1) above. That's how R/C model airplane servos work; they attempt to adjust the sense potentiometer on the motor to match the control potentiometer. I had roll trim in a Thorp T-18 built in the mid 70's that used an R/C servo & a volume control on the instrument panel. BTW, you don't want detents on the control; you will likely have similar problems to the overcontrol problem you have now with the pushbuttons. Anyone know whether the 'servo' Van sells is really a servo motor or is it just a dc motor & geartrain? Charlie ________________________________ Message 2 _____________________________________ Time: 08:16:37 AM PST US From: Leland Subject: RV9-List: Re:RE: Pitot Static Testing with Dynon --> RV9-List message posted by: Leland Another lister suggested pitot-static testing of the Dynon probe by putting a balloon over it. I tried doing this yesterday and the balloon trick worked well. It is necessary to tape over the drain holes in the back and for the balloon to encompass the entire probe tip. I used a large balloon that was easy to inflate so as not to over pressure the ASI. Leland > > >>Time: 10:52:47 AM PST US >>From: "Steve Sampson" >>Subject: RE: RV9-List: Pitot Static Testing with Dynon >> >>--> RV9-List message posted by: "Steve Sampson" >> >>Leland - how long did you hold the pressure for? (It sounds like a great >>cartoon with you and your tounge stuck in the RV!) >> >>In one sense I never did manage to test it. I have tested it to the pitot by >>disconecting it and subsequently a high speed taxi in which it accidently >>flew a few yards. >> >>Steve. >> >> >> >> > > > ________________________________ Message 3 _____________________________________ Time: 09:35:00 AM PST US From: "Carroll Neblett" Subject: Re: RV9-List: Trim-- electric vs. manual --> RV9-List message posted by: "Carroll Neblett" Replying to Charlie's question about the elevator trim servo - The 8A trim "servo" that Van's uses is just a DC motor with a gear train. It does include slider pot, but it's only a position sensor, not a feedback pot. When I received the servo kit with my empennage, I couldn't believe it was for aircraft use (or that it was worth $200+). I've been a R/Cer for years too, and $50 R/C servos appear to be much better designed and made, but they are also more complex; and anyone that's flown R/C for many years has probably had a servo or two fail. On the plus side for the servo provided by Van's is that there's not much to fail - since it's just a DPDT switch that applies reversible DC to a small motor. Carroll Neblett ----- Original Message ----- From: "Charlie England" Subject: Re: RV9-List: Trim-- electric vs. manual > --> RV9-List message posted by: Charlie England > > Ross S wrote: > >>--> RV9-List message posted by: "Ross S" >> >>I installed the electric trim because I didn't want the big knob in the >>cockpit and figured the electric would be lighter. .... so for a few >>extra >>bucks it would be win win. >> >>Reality struck when I started flying. In my opinion, the electric is not >>nearly as good as the manual. >> >>The electric is not sensative enough to get exatly the correct hands off >>pitch position. If you just bump it one direction it goes too far, and >>then >>bump it back and that is too far. I realize that you can buy a speed >>control to slow it down, but on the other hand it is already too slow. >>When >>you want to trim for landing or takeoff, it takes an eternity to get into >>position. I usually end up coming in hot and don't have time to screw >>with >>it and I land without trimming the plane. It just plain doesn't have the >>operational benefits of manual trim. >> >> >>Solutions: >> >>1.) One of you guys needs to come up with an electric trim with a dash >>mountet knob with a fair amount of resistance (maybe like the volume >>control >>on my GMC pickup that has detents every few degrees) that needs to be >>turned >>about ten turns for full deflection. >> >>or.. >> >>2.) Make a speed control that will ramp up in speed the longer you hold it >>down. Then you could still control it with the coolie switch on the grip, >>but you could have fine control and speed both. >> >>-Ross >> >>Ross Schlotthauer >>RV-7 flying but not finished >>www.experimentalair.com >> > > A true servo will do exactly what you describe in 1) above. That's how > R/C model airplane servos work; they attempt to adjust the sense > potentiometer on the motor to match the control potentiometer. I had > roll trim in a Thorp T-18 built in the mid 70's that used an R/C servo & > a volume control on the instrument panel. BTW, you don't want detents on > the control; you will likely have similar problems to the overcontrol > problem you have now with the pushbuttons. > > Anyone know whether the 'servo' Van sells is really a servo motor or is > it just a dc motor & geartrain? > > Charlie > > > ________________________________ Message 4 _____________________________________ Time: 10:14:08 AM PST US From: "Richard E. Tasker" Subject: Re: RV9-List: Trim-- electric vs. manual --> RV9-List message posted by: "Richard E. Tasker" It is just a motor with a gear train, although you could convert it to a real servo with the "True Servo Conversion for M.A.C.-R.A.C Sort-of-servos" (next to last on the page) http://www.periheliondesign.com/moreproducts.htm Dick Tasker Charlie England wrote: >--> RV9-List message posted by: Charlie England > >Ross S wrote: > > > >>--> RV9-List message posted by: "Ross S" >> >>I installed the electric trim because I didn't want the big knob in the >>cockpit and figured the electric would be lighter. .... so for a few extra >>bucks it would be win win. >> >>Reality struck when I started flying. In my opinion, the electric is not >>nearly as good as the manual. >> >>The electric is not sensative enough to get exatly the correct hands off >>pitch position. If you just bump it one direction it goes too far, and then >>bump it back and that is too far. I realize that you can buy a speed >>control to slow it down, but on the other hand it is already too slow. When >>you want to trim for landing or takeoff, it takes an eternity to get into >>position. I usually end up coming in hot and don't have time to screw with >>it and I land without trimming the plane. It just plain doesn't have the >>operational benefits of manual trim. >> >> >>Solutions: >> >>1.) One of you guys needs to come up with an electric trim with a dash >>mountet knob with a fair amount of resistance (maybe like the volume control >>on my GMC pickup that has detents every few degrees) that needs to be turned >>about ten turns for full deflection. >> >>or.. >> >>2.) Make a speed control that will ramp up in speed the longer you hold it >>down. Then you could still control it with the coolie switch on the grip, >>but you could have fine control and speed both. >> >>-Ross >> >>Ross Schlotthauer >>RV-7 flying but not finished >>www.experimentalair.com >> >> >> > >A true servo will do exactly what you describe in 1) above. That's how >R/C model airplane servos work; they attempt to adjust the sense >potentiometer on the motor to match the control potentiometer. I had >roll trim in a Thorp T-18 built in the mid 70's that used an R/C servo & >a volume control on the instrument panel. BTW, you don't want detents on >the control; you will likely have similar problems to the overcontrol >problem you have now with the pushbuttons. > >Anyone know whether the 'servo' Van sells is really a servo motor or is >it just a dc motor & geartrain? > >Charlie > > > > ________________________________ Message 5 _____________________________________ Time: 11:28:41 AM PST US From: "Steve Sampson" Subject: RE: RV9-List: Trim-- electric vs. manual --> RV9-List message posted by: "Steve Sampson" While on the subject of electric trim has anyone had the following problem? When I key the radio it upsets the trim indicator lights. Steve. RV9a #90360 -- Internal Virus Database is out-of-date. Checked by AVG Anti-Virus. ________________________________ Message 6 _____________________________________ Time: 11:28:41 AM PST US From: owner-rv9-list-server@matronics.com --> RV9-List message posted by: ________________________________ Message 7 _____________________________________ Time: 11:33:54 AM PST US From: Subject: RE: RV9-List: Trim-- electric vs. manual --> RV9-List message posted by: My 2 bits worth on the trim thing. My RV9 has been flying a year now and has electric elevator trim. Yes it is sensative but I've grown used to it and am very comfortable with it. I chose that route because, lighter weight, simpler to install and probably more reliable. A tech guy at Mac(when it was still Mac) suggested that rather than using the speed control deck they sell, to just build a larger control horn on the trim tab itself. This will increase the radius of travel hereby slowing the control responce. I have flown in the factory RV9 about 4 hours with Mike Seager and the manual control really is very nice. Dennis Thomas --- Gerry Filby wrote: > --> RV9-List message posted by: Gerry Filby > > > > Van's own RV9 has the manual trim (and electric > flaps) ... > hmmm, wonder why ... > > g > > > > > > --> RV9-List message posted by: "Ross S" > > > > > I installed the electric trim because I didn't > want the big knob in the > > cockpit and figured the electric would be lighter. > .... so for > > a few extra > > bucks it would be win win. > > > > Reality struck when I started flying. In my > opinion, the > > electric is not > > nearly as good as the manual. > > > > The electric is not sensative enough to get exatly > the correct > > hands off > > pitch position. If you just bump it one direction > it goes too > > far, and then > > bump it back and that is too far. I realize that > you can buy a speed > > control to slow it down, but on the other hand it > is already > > too slow. When > > you want to trim for landing or takeoff, it takes > an eternity > > to get into > > position. I usually end up coming in hot and > don't have time > > to screw with > > it and I land without trimming the plane. It > just plain > > doesn't have the > > operational benefits of manual trim. > > > > > > Solutions: > > > > 1.) One of you guys needs to come up with an > electric trim with a dash > > mountet knob with a fair amount of resistance > (maybe like the > > volume control > > on my GMC pickup that has detents every few > degrees) that needs > > to be turned > > about ten turns for full deflection. > > > > or.. > > > > 2.) Make a speed control that will ramp up in > speed the longer > > you hold it > > down. Then you could still control it with the > coolie switch > > on the grip, > > but you could have fine control and speed both. > > > > -Ross > > > > Ross Schlotthauer > > RV-7 flying but not finished > > www.experimentalair.com > > > > > > >From: "Bill Repucci" > > >Reply-To: rv9-list@matronics.com > > >To: > > >Subject: RE: RV9-List: Trim-- electric vs. manual > > >Date: Fri, 11 Mar 2005 15:26:49 -0500 > > > > > >--> RV9-List message posted by: "Bill Repucci" > > > > > > >Too bad the electric trim doesn't work off the > manual cable like some > > >production airplanes. That way you could still > adjust the trim manually > > >if the actuation motor went Tango Uniform. > > > > > >Back to the basement for me. Busy drilling and > pounding. > > >Bill > > >www.repucci.com/bill/baf.html > > > > > >-----Original Message----- > > >From: owner-rv9-list-server@matronics.com > > >[mailto:owner-rv9-list-server@matronics.com] On > Behalf Of Carroll > > >Neblett > > >To: rv9-list@matronics.com > > >Subject: Re: RV9-List: Trim-- electric vs. manual > > > > > > > > >--> RV9-List message posted by: "Carroll Neblett" > > > > > > > I've bought and built the electric elevator > trim, but have never > > >been > > >fully comfortable with elevator control being > subject to an electrical > > >problem (and the trim servo doesn't appear to be > of very impressive > > >quality). > > > It may be a stupid idea as I've never seen > or heard of it on any > > >aircraft, but I've often wondered what would be > wrong with having > > >electric > > >trim on one side and manual trim on the other. > This would give the > > >convenience advantage of electric trim (if there > is any) and the safety > > >advantage of manual trim. In the event of a > runaway electric trim, it > > >could > > >be offset with manual trim, but I have no idea > what the drag and roll > > >effects would be of having extreme and opposite > trims on the left and > > >right > > >elevators. > > > If having both trim types would be > aerodynamically practical, it > > >shouldn't add much cost, especially if Van's > would allow the empennage > > >kit > > >to be ordered with two "left" elevators. > > > > > >Carroll Neblett > > >(waiting on wings) > > >----- Original Message ----- > > >From: "Richard Scott" > > >To: > > >Subject: RV9-List: Trim-- electric vs. manual > > > > > > > > > > --> RV9-List message posted by: Richard Scott > > > > --> > > > > > > > > For those with flying 9's, I would like to > know how the plane flies at > > > > full > > > > up and full down trim. Can you keep it level? > Can you overcome the > > >trim > > > > adequately to climb with nose down trim and > vice versa? In other > > >words, > > > > if > > > > you get a runaway trim situation, can you > continue to fly safely until > > >you > > > > can land, even if that means flying half an > hour or more? You can't > > >in my > > > > '41 Interstate Cadet, but trim in that is > manual. > > > > > > > > If it is too hard to overcome the trim, then > for me the question of > > > > manual vs. electric trim is simple: You'll > never have a manual trim > > > > runaway on you (of course the cable could > break, but so could wires). > > > > > > > > Richard Scott > > > > 9A wings > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > ========================================================== > > Gerry Filby > gerf@gerf.com > === message truncated ===