From: owner-krnet-l-digest@teleport.com[SMTP:owner-krnet-l-digest@teleport.com] Sent: Thursday, July 09, 1998 7:18 AM To: krnet-l-digest@teleport.com Subject: krnet-l-digest V2 #114 krnet-l-digest Thursday, July 9 1998 Volume 02 : Number 114 ---------------------------------------------------------------------- Date: Wed, 08 Jul 1998 20:02:29 -0700 From: Micheal Mims Subject: Re: KR: RC Servo trim motor At 09:08 PM 7/8/98 -0400, you wrote: >Mike, >I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm for R/C >servo motor controllers that would be perfect for this application. One even comes in kit form, >>> This is good stuff! I want to add one to the ailerons too. The servos I have are about 5 years old and used very little. I bought them thinking I would get back into RCing when I was flying in Alaska. They are Futaba units. I guess I am being cheep but these guys are nice and small and look almost brand new. I charged the batteries today and the servos still work! :o) zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 20:04:05 -0700 From: Micheal Mims Subject: Re: KR: more good reading At 08:13 PM 7/8/98 -0500, you wrote: >Why? > > Why was it good reading or? zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 20:17:42 -0700 From: Micheal Mims Subject: Re: KR: when do you? At 08:43 PM 7/8/98 -0700, you wrote: >How much alcohol did you use per ??? > >Is it better if you just drink it before you start? > > Just a little bit. :o) I don't know how much really, just enough to thin it so it would go on better with a brush. zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 20:48:09 -0700 From: Peter Hudson Subject: Re: KR: when do you? Alan Moat wrote: > So, when do you apply epoxy to the interior and exterior of the > fuselage? > Alan Moat Alan, as a general rule later is better...BUT... I had a leaky roof dump a bunch of water in my "boat". After the bailing bucket and a month or so in the desert I decided to fix up the water damage and seal the whole interior before anything else like that happened again. I had all the controls in but no wires or instruments. I figure a little sanding to attach things like wire harness mounts won't be an issue. So my answer is put in any structural bits first then seal it and don't worry to much about the misc attach blocks. - -Peter- ------------------------------ Date: Wed, 08 Jul 1998 21:24:14 -0700 From: Peter Hudson Subject: Re: KR: RC Servo trim motor Micheal Mims wrote: > What would one do to drop the voltage to the right amount > and how would you control the motor from the cockpit? Rocker switch? > Micheal Mims > SP290,.. Filling and sanding now! Mike, A radio shaft voltage regulator to get 5 volts will work fine (it may need a capacitor ..trial and error on the size but probably about .1 pico F for starters) control options: a) buy a servo driver (signal pulse width determines servo position) from a model mag (~$30) and use it as a trim wheel (use a second servo for an indicator!). b) use a rocker switch or "coolie hat" in the stick, remove the controller board and and wire straight to the motor. Use the built in pot to drive a position meter. c) take out the pot as well; and remove the little nub which limits servo travel. Attach the output wheel to a little homemade jackscrew to slow it all down. Then use the rocker switch without an indicator. (or put a pot somewhere else in the system) I'm not sure yet which way I'm going to go but I like a) and c). Option a) is easy but option b) will improve the output torque enough to match the mack servo and it's slower action might be nice. - -Peter- ------------------------------ Date: Wed, 08 Jul 1998 23:24:08 -0500 From: Trent Flemming Subject: Re: KR: Count ME In, Purchased the Spruce Hello Haris Glad to here that i'm not the only one just getting started. Some of the fellow are almost done. I didn't want the mailing list to die with them. Where are you located? Good Luck Measure twice and cut once! Trent Flemming At 09:52 PM 7/6/98 EDT, you wrote: >I am just getting started. > >Haris Ashraf > > ------------------------------ Date: Wed, 08 Jul 1998 23:25:58 -0500 From: Trent Flemming Subject: Re: KR: Re: Count ME In, Purchased the Spruce Hi Bob, Thanks for the reply. I hate to spend a bunch of money on spruce and then worry about messing up right off the bat. Thanks again. Trent At 06:07 PM 7/6/98 -0700, you wrote: >Bob, > I used Aeropoxy Structural Adhesive for all my spruce stuff. It has similar >properties to T-88, but I think it >is a bit cheaper? At any rate it comes in two cure rates FAST (20min) and SLOW >(1HR). I used the SLOW >when I was in Phoenix. If it gets over 100 deg, it starts to get real thin, >and tends to behave more like water like than >it does at more normal temperatures. I found that more of it wicked into the >wood under hot conditions, and/or it >just would run around. This was OK normally, but I was doing the firewall >triangle gussets, and would have been >better off to wait for a cooler day, or later in the evening to do that >portion. > > Generally speaking, using the SLOW cure rate for hot temperatures worked >great for me. I usually mixed only >a small 3oz dixie cup worth at a time. (50/50 mix). > -- Regards > Ross > >Bob Sauer wrote: > >> Welcome >> I am at Smithville, TX with about the same temps/humidity. Used T-88 very >> successfully. I have the boat, spars and tail group completed on my KR2S. >> Presently installing hardware for controls. ANYBODY= NEED INFOR ON EPOXY >> for high temps and humidity. Any suggestions??? >> >> Bob >> >> ---------- >> > From: Trent Flemming >> > To: krnet-l@teleport.com >> > Subject: KR: Count ME In, Purchased the Spruce >> > Date: Monday, July 06, 1998 10:58 AM >> > >> > Hello group, >> > >> > I recieved my Spruce the other day from Alpha Aviation in Greenville, TX. >> >> > I have a question regarding glue, I bought some T-88, but was wondering >> > what everybody used for the fuselage. Our East Texas weather has been >> > running in the Mid 90's to Low 100's (hot) and the humidity has been >> between >> > 50% and 80% most of the time. Is T-88 the glue (epoxy) for me or should >> I >> > use Aerolite Glue. >> > >> > Also is there anyone else on this list that is just getting started on >> there >> > KR project. >> > >> > Thanks for the help. >> > Looking forward to meeting some of ya'll and seeing some nice KR's at the >> > Perry Flyin. >> > >> > FYI >> > >> > My Name Trent Flemming >> > Location East Texas (Longview) >> > Project KR-2S >> > Percent Completed Just a large dent in the wallet for Spruce. :) >> > >> > Thanks again >> > > > > > ------------------------------ Date: Wed, 08 Jul 1998 21:35:53 -0700 From: Peter Hudson Subject: KR: Back in the game. Hi gang, Well the big project at work has gotten throught the critical design review on schedual at great expense to my KR. Then it was time to re-bond with my wife which entailed a trip to England. Now I'm back on the KR...Checking my building log it was a 5 month lay off :( Assuming my trip to England wasn't quite as successful as Mike's trip to the Bahamas I should be back in the game for a while! Current status is the plane's upside down and I just mounted wheel pants then added foam and glass to fair in the brakes and gear legs. They're pretty sexy all faired in. It's good to be sticky again. - -Peter- ------------------------------ Date: Wed, 08 Jul 1998 23:32:48 -0500 From: Trent Flemming Subject: KR: Oops, Sorry, Will Check Address next time ------------------------------ Date: Wed, 08 Jul 1998 21:42:43 -0700 From: Micheal Mims Subject: Re: KR: Back in the game. At 09:35 PM 7/8/98 -0700, you wrote: >Hi gang, > >Well the big project at work has gotten throught the critical design >review on schedual at great expense to my KR. Then it was time to >re-bond with my wife which entailed a trip to England.>>> All right! Back in the saddle again. Hey I need to drive up your way sometime to visit. Maybe some weekend eh? Anything else to see up your way? zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Wed, 08 Jul 1998 21:47:19 -0700 From: Micheal Mims Subject: Re: KR: Count ME In, Purchased the Spruce At 11:24 PM 7/8/98 -0500, you wrote: >Hello Haris > >Glad to here that i'm not the only one just getting started. Some of the >fellow are almost done. I didn't want the mailing list to die with them. Humm,...I am not sure how I like " I didn't want the mailing list to die with them" ! Nobody said anything about having to die! :o) zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Micheal Mims SP290,.. Filling and sanding now! mailto:mikemims@pacbell.net http://www.geocities.com/CapeCanaveral/Hangar/4136/ Irvine Ca Fax 949.856.9417 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Thu, 9 Jul 1998 00:20:56 EDT From: HAshraf@aol.com Subject: KR: Elevator size and pitch sensitivity. I was thumbing through Dynamics of Flight by Etkins and here are some points I thought about. Please note that these are just my opinions and I am by no means an aircraft stability expert [yet :-)], so please do not take any offence. There has bees some discussion about the size of elevator vs the pitch sensitivity. The size of the elevator is only part of the equation. For static stability reasons it is the tail volume (Vh) that counts. The tail voulume of a KR-2 is around 0.30 and KR2S is 0.36 (very rough calculations). Strojnik book LAD (page 172) recommends 0.45-0.65. Obviously KR2 has a very low tail volume. However, he also gives example of a Cherokee which has a tail volume of 0.37, C150=0.40. So, in the tail volume department, KR2S has a big enough tail. Vh = (area of elevator+stab)*(moment arm of tail)/(wing area*mean chord) moment arm is measured from a.c cg. For pitch sensitivity reasons we need to look at the tail damping as a function on of motion about the pitch axis (Cmq), which is proportional to (moment arm of tail)**2. Therefore, extending the fuselage is a much better solution. The argument of the tail sensitivity due large elevator does not make a lot of sense to me as there are planes with all moving tails that are not very pitch sensitive. It can be argues that they may have a reduced movement of the elevator per stick movement (small lever arm). That can be accomplished in a KR by increasing the size of elevator horn or reducing the distance between the points where the control cables attach on the control stick. Area wise the elevator is not too big. In any case a smaller elevator will need a larger movement to rotate the plane at takeoff and could stall. Therefore, reducing elevator size is a non trivial matter. Haris Ashraf ------------------------------ Date: Thu, 09 Jul 1998 00:26:38 -0500 From: Trent Flemming Subject: Re: KR: Count ME In, Purchased the Spruce Sorry, I just meant that i haven't seen many people on the list that are just getting started as i am. I figure when those who are way ahead of us newcomers are finished with your plane, you will proably not frequent the list. Therefore a good source of information will die. I hope that will not be the case. I have already gained much appreciated knowledge from the seniors here. Excuse the Freshmen (me). Trent At 09:47 PM 7/8/98 -0700, you wrote: >At 11:24 PM 7/8/98 -0500, you wrote: >>Hello Haris >> >>Glad to here that i'm not the only one just getting started. Some of the >>fellow are almost done. I didn't want the mailing list to die with them. > > >Humm,...I am not sure how I like " I didn't want the mailing list to die >with them" ! Nobody said anything about having to die! :o) >zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz >Micheal Mims >SP290,.. Filling and sanding now! >mailto:mikemims@pacbell.net >http://www.geocities.com/CapeCanaveral/Hangar/4136/ >Irvine Ca >Fax 949.856.9417 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > ------------------------------ Date: Wed, 08 Jul 1998 23:29:01 -0700 From: Ross Youngblood Subject: Re: KR: N541RY Progress report Bobby Muse wrote: > At 06:20 PM 7/5/98 -0700, you wrote: > > >Here are things I have to check: > > > >1 ) TIMING > > I dumped Bob Hoover's "Finding TDC" sermon on the web from > > the KRNET VW link. This will allow me to verify TDC. I also > > made a XEROX of the timing wheel in the Great Planes manual > > and hope to validate that I have some good static timing this > >evening. > > > > -- Regards > > Ross > > > > > > Ross, Where did you find Bob Hoover's "finding TDC"? > > Bobby Muse(N122B) > mailto:bmuse@mindspring.com > Wimberly, TX Go to http://www.krnet.org, along the LEFT hand side towards the bottom, there is a VW link. This takes you to the Bob Hoover VW Sermon website... then do a search. He has EVERYTHING you want to know about care and feeding VW's just about. ------------------------------ Date: Wed, 08 Jul 1998 23:31:45 -0700 From: Ross Youngblood Subject: Re: KR: Re: Bummer... 1/2 Compu-Fire dead Just a note on this thread... the Compu-Fire is not a DUAL system, just two seperate modules for front and back cylinders... Somehow this became a thread on dual magneto's.... Just in case someone was wondering what I was doing. BTW, I found the reciept and shipped the unit off for warrenty repairs... -- Ross Bobby Muse wrote: > At 11:35 AM 7/8/98 -0400, you wrote: > >Email (repy) to cary@storm.ca > > or ve3ev@rac.ca > >Web page http://www.storm.ca/~cary/ > >KR2 area http://www.storm.ca/~cary/kr2.shtml > > > >---------- > >> From: Ross Youngblood > >> Well, I'm bummed. > >> > >> The good news is this explains why my two cylinders seemed to be running > >> cold, and why it > >> was so hard to start. Maybe I can sell the Compu-Fire unit to someone > >> with a 1/2 VW engine :). > >> It ran really good with only two cylinders but it's probably not the > >> best way to begin the break-in > >> cycle. > > > >You could have come to a bad end. A real bummer there. > > > >Sorry: I couldn't resist. > > > >Perhaps you can shed some light for me on the engine response when checking > >left then right ignition. I use "Bendix" mags. When I check the left or > >right mag, the engine shakes like Model 'T' on a cordoroy road. I know my 6 > >cyl Continental shakes a bit, but thought the Revmaster might have been > >protesting too much. All CHT and EGT readings are close to each other and > >well within the green. The rpm's drop about the same for each. Just how > >much of a St. Vitus dance should I expect? > > > >- Cary - > > > >(BTW, great for making milkshakes) > > > > Cary, > I have a 2100d Revmaster and I when which from Right to Left, I can > barely tell a difference and I'm idling at about 600rpm. Maybe you're > idling too slow? or have bad plugs or ignition wires? > Check wire routing. I have all my left mag wires going to the top > plugs and the right mag wires ging to the bottom plugs. > > Bobby Muse(N122B) > mailto:bmuse@mindspring.com > Wimberly, TX ------------------------------ Date: Wed, 08 Jul 1998 23:33:46 -0700 From: Ross Youngblood Subject: Re: KR: Count ME In, Purchased the Spruce Almost done? It really sounds like this? Cool! (Ten years later...) - -- Ross Trent Flemming wrote: > Hello Haris > > Glad to here that i'm not the only one just getting started. Some of the > fellow are almost done. I didn't want the mailing list to die with them. > Where are you located? > Good Luck > > Measure twice and cut once! > > Trent Flemming > > At 09:52 PM 7/6/98 EDT, you wrote: > >I am just getting started. > > > >Haris Ashraf > > > > ------------------------------ Date: Wed, 08 Jul 1998 23:41:28 -0700 From: Ross Youngblood Subject: KR: Re:KRNET mailing list die? Nope! Trent, Actually this mailing list is unlikely to die. Last year a collection was taken at the KR gathering in Perry OK to support this list, and we recieved enough money that I setup a seperate account for KRNET stuff only. (In case I decide to change my ISP etc.) I also had our domain name registered so the website can remain www.krnet.org as long as we pay the $50/yr fee (We are paid up for one more year). If I ever get really tired of managing the list, I can just hand it over to someone else who wants to do the admin chores via email. Other than the occasional 3800 emails in the inbox... it's not a bad job. The real thanks needs to go to Mike Graves who setup the mailing list nearly two years ago. I think it started from some folks who used to chat around on the AOL kr chat area. At any rate, when I joined there were about 60 people on the list. Now we have around 210 or so plus 35 folks on the digest which is emailed when we get about 40K worth of normal krnet emails. (From once a day to once every three-four days). Now that you mention it... it might not be a bad time to start whining for funds again. The bill comes due in September for the next year. -- Regards Ross Trent Flemming wrote: > Sorry, > > I just meant that i haven't seen many people on the list that are just > getting started as i am. I figure when those who are way ahead of us > newcomers are finished with your plane, you will proably not frequent the > list. Therefore a good source of information will die. I hope that will not > be the case. I have already gained much appreciated knowledge from the > seniors here. Excuse the Freshmen (me). > > Trent > > At 09:47 PM 7/8/98 -0700, you wrote: > >At 11:24 PM 7/8/98 -0500, you wrote: > >>Hello Haris > >> > >>Glad to here that i'm not the only one just getting started. Some of the > >>fellow are almost done. I didn't want the mailing list to die with them. > > > > > >Humm,...I am not sure how I like " I didn't want the mailing list to die > >with them" ! Nobody said anything about having to die! :o) > >zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > >Micheal Mims > >SP290,.. Filling and sanding now! > >mailto:mikemims@pacbell.net > >http://www.geocities.com/CapeCanaveral/Hangar/4136/ > >Irvine Ca > >Fax 949.856.9417 > >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > ------------------------------ Date: Wed, 08 Jul 1998 23:56:22 -0700 From: Ross Youngblood Subject: KR: It's starting to be that time again (My July Whine) Whine Time! Well Randy... you can start your Whining again. Since I am going off to Arlington, and who knows when I will get back to normal life, it seemed like a good idea to post a request for donations, to support KRNET for another year... Donations are voluntary. Since the minimum annual ISP bill to support the KRNET account is $180/yr plus $50 for the krnet.org domain name. We have additional storage that we pay for to store the back issues of the archives $5/mb/year, but I can always cut that to save $$$ if necessary. The basic donation we arrived at last year was $10.00, and this year I can send you a CD-ROM with all the past KRNET archives on it for another $10.00. I'm not too excited about the disk idea this year, but thought it would be nice to give you somthing tanagable in return for your money.... it might be worth the extra $10.00. I don't think I will have time to build anything fancy on this disk like color photos, search engine... not enough time and I am guessing on the S&H fees. So that newbies will not be confused... the KRNET ARCHIVES are NOT back issues of the newsletter. Just the last year or so of KRNET posts on CDROM arranged as vol-01.n00-100 somthing, for last year and vol-02.n00-1xx somthing for this year (so-far). Send you check or money order to: KR-NET c/o Ross Youngblood 1109 NE Burke Pl Corvallis,OR 97330 Please make sure you provide your mailing address where you want the CD-ROM shipped. I can test the disks on my PC & my Laptop, but neither is a Macintosh. However, they read fine on my UNIX workstation so assuming MAC's are pretty smart, you should be able to read them on the MAC as well. I will post one more whine in August... then if necessary again in September... Gee, its just like Public Broadcasting! Thanks for everyones support! It's still fun! - -- Ross ------------------------------ Date: Thu, 09 Jul 1998 07:04:35 -0400 From: Tom Andersen Subject: Re: KR: RC Servo trim motor Mike, If you put one on your ailerons, it's possible to use an R/C autopilot with both servos and so have a wing leveler and pitch holder. The new PAL unit $50 mounts on the bottom of an R/C plane and uses differences in light between sky and ground to provide stability in two axis. I hear it works great and only weighs two ounces. There's another unit, the BTA from Israeli developers who actually mention in their ads it has been used in experimental aircraft. It's much more sophisticated and has three-axis control with solid state gyros. It's cost is about $350. I think the PAL system on the ailerons only would be nice as a wing leveler, and with the elevator trim connected, you could fly even a regular KR-tail hands off! - -Tom Micheal Mims wrote: > At 09:08 PM 7/8/98 -0400, you wrote: > >Mike, > >I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm > for R/C > >servo motor controllers that would be perfect for this application. One > even comes in kit form, >>> > > This is good stuff! I want to add one to the ailerons too. The servos I > have are about 5 years old and used very little. I bought them thinking I > would get back into RCing when I was flying in Alaska. They are Futaba > units. I guess I am being cheep but these guys are nice and small and look > almost brand new. I charged the batteries today and the servos still work! > :o) > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > Micheal Mims > SP290,.. Filling and sanding now! > mailto:mikemims@pacbell.net > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > Irvine Ca > Fax 949.856.9417 > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ------------------------------ Date: Thu, 09 Jul 1998 07:19:41 -0400 From: Tom Andersen Subject: Re: KR: Elevator size and pitch sensitivity. Haris, No doubt a longer tail by about 14" would be good on the KR-2S. Unfortuanately, I didn't understand all these facts when I started my plane, I was trying to be a good little builder and follow the plans exactly. With the 14" extension, a KR-2S would be 28 inches longer in the tail and about 5-6" longer in the nose. Many threads have been written about reducing elevator travel, but the problem there seems to be getting sufficient control at lower speeds. There is more authority than is necessary on such a short-coupled airplane. It's a stretch to compare the KR to the Cherokee, since the Cherokee has three times the weight and a thicker airfoil. Look at the tail on the Teenie Two and the new Sonex. Granted, the Teenie two has only 59 sq ft of wing, but the elevator is very small, probably only 30-40% of the size of the KR-2. - -Tom HAshraf@aol.com wrote: > There has bees some discussion about the size of elevator vs the pitch > sensitivity. The size of the elevator is only part of the equation. For static > stability reasons it is the tail volume (Vh) that counts. The tail voulume of > a KR-2 is around 0.30 and KR2S is 0.36 (very rough calculations). Strojnik > book LAD (page 172) recommends 0.45-0.65. Obviously KR2 has a very low tail > volume. However, he also gives example of a Cherokee which has a tail volume > of 0.37, C150=0.40. So, in the tail volume department, KR2S has a big enough > tail. > > Vh = (area of elevator+stab)*(moment arm of tail)/(wing area*mean chord) > > moment arm is measured from a.c cg. > > For pitch sensitivity reasons we need to look at the tail damping as a > function > on of motion about the pitch axis (Cmq), which is proportional to (moment arm > of tail)**2. Therefore, extending the fuselage is a much better solution. > > The argument of the tail sensitivity due large elevator does not make a lot of > sense to me as there are planes with all moving tails that are not very pitch > sensitive. It can be argues that they may have a reduced movement of the > elevator per stick movement (small lever arm). That can be accomplished in a > KR by increasing the size of elevator horn or reducing the distance between > the points where the control cables attach on the control stick. Area wise the > elevator is not too big. > > In any case a smaller elevator will need a larger movement to rotate the plane > at takeoff and could stall. Therefore, reducing elevator size is a non trivial > matter. > > Haris Ashraf ------------------------------ Date: Thu, 9 Jul 1998 06:55:04 -0500 (CDT) From: Steven A Eberhart Subject: Re: KR: RC Servo trim motor Looks like we are on to something here. We did a grass roots pole a while back and a large percentage of KR builders are/were R/C modelers. My only concerne about putting the servo controller in the cockpit and the servos in the tail/ailerons is the possibility for noise interference. giant scale R/C is pushing the limits on how far you can/should move the servo from the control source. Reason being, the signal going to the servo is a pulse train with 1.5 ms nominal control pulses repeated every 18 ms or so. The leading edge of a square wave generates a tremendous amount of RF noise due to the very rapid voltage change on the leading edge of the square wave. With an antena as long as we are talking about, from the cockpit to the tail, I think we may very well have an interference problem with all of the rest of the electronics. THis is the reason I was thinking about using a plastic fiber optic cable for the run between the servo controller and the servo. THe interfaces to the fiber should be verry simple and not require any modification of the servo controller or servos. They simply plug into the fiber transmitter and receiver. Steve On Thu, 9 Jul 1998, Tom Andersen wrote: > Mike, > If you put one on your ailerons, it's possible to use an R/C autopilot with > both servos and so have a wing leveler and pitch holder. The new PAL unit $50 > mounts on the bottom of an R/C plane and uses differences in light between sky > and ground to provide stability in two axis. I hear it works great and only > weighs two ounces. > There's another unit, the BTA from Israeli developers who actually mention in > their ads it has been used in experimental aircraft. It's much more > sophisticated and has three-axis control with solid state gyros. It's cost is > about $350. > I think the PAL system on the ailerons only would be nice as a wing leveler, > and with the elevator trim connected, you could fly even a regular KR-tail > hands off! > -Tom > > Micheal Mims wrote: > > > At 09:08 PM 7/8/98 -0400, you wrote: > > >Mike, > > >I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm > > for R/C > > >servo motor controllers that would be perfect for this application. One > > even comes in kit form, >>> > > > > This is good stuff! I want to add one to the ailerons too. The servos I > > have are about 5 years old and used very little. I bought them thinking I > > would get back into RCing when I was flying in Alaska. They are Futaba > > units. I guess I am being cheep but these guys are nice and small and look > > almost brand new. I charged the batteries today and the servos still work! > > :o) > > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > > Micheal Mims > > SP290,.. Filling and sanding now! > > mailto:mikemims@pacbell.net > > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > > Irvine Ca > > Fax 949.856.9417 > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > - ------------------------------------- http://www.newtech.com/nlf One test is worth a thousand expert opinions but a thousand opinions are easier to get. When once you have tasted flight you will always walk with your eyes turned skyward, for there you have been and there you will always be. --Leonardo da Vinci ------------------------------ Date: Thu, 9 Jul 1998 09:13:06 EDT From: Krwr1@aol.com Subject: Re: KR: RC Servo trim motor WildBill here I used servo motors on my trim tabs for the whole time I flew the KR,, U just put a couple D cells with a 3 way toggle switch. The batteries last for years. The servos should be heavy duty, like landing gear retract servos. WildBill ------------------------------ Date: Thu, 09 Jul 1998 09:21:36 -0400 From: Tom Andersen Subject: Re: KR: RC Servo trim motor/manual backup Steve, I know there's already fiber units out there which plug into the standard servos. I'll keep my eyes peeled... A secondary method I thought about is to wire directly to the servo motor and use a DPDT switch with a current-limiting device in the circuit. Some ultralight guys do this with a 9v battery, which has internal resistance, thus limiting the current and slowing the actuation speed. For trim position feedback, (which is required), route the nyrod tube to the cockpit with a marker on the end. Even if your trim servo fails, you can just grab this trim rod and move the trim, giving a manual backup system. This is probably the best of both worlds. I think that with the nyrod setup, there may be a bit of drag in the tube, but there are better materials for this purpose which have less drag. This method eliminates the use of the failure and wear-prone potentiometers in the servos and servo drivers, and this allows a simple DPDT switch to be mounted in the control grip. It's a heck of a lot more precise than any manual trim control, and has manual backup. It's the cheapest of all R/C servo conversions, but this precludes the use of the servo in any autopilot. Having said that, this is the method I will probably use because there's no sensitive electronics and provides the backup. - -Tom Steven A Eberhart wrote: > Looks like we are on to something here. We did a grass roots pole a > while back and a large percentage of KR builders are/were R/C modelers. > > My only concerne about putting the servo controller in the cockpit and > the servos in the tail/ailerons is the possibility for noise > interference. giant scale R/C is pushing the limits on how far you > can/should move the servo from the control source. Reason being, the > signal going to the servo is a pulse train with 1.5 ms nominal control > pulses repeated every 18 ms or so. The leading edge of a square wave > generates a tremendous amount of RF noise due to the very rapid voltage > change on the leading edge of the square wave. With an antena as long as > we are talking about, from the cockpit to the tail, I think we may very > well have an interference problem with all of the rest of the electronics. > > THis is the reason I was thinking about using a plastic fiber optic cable > for the run between the servo controller and the servo. THe interfaces > to the fiber should be verry simple and not require any modification of > the servo controller or servos. They simply plug into the fiber > transmitter and receiver. > > Steve > > On Thu, 9 Jul 1998, Tom Andersen wrote: > > > Mike, > > If you put one on your ailerons, it's possible to use an R/C autopilot with > > both servos and so have a wing leveler and pitch holder. The new PAL unit $50 > > mounts on the bottom of an R/C plane and uses differences in light between sky > > and ground to provide stability in two axis. I hear it works great and only > > weighs two ounces. > > There's another unit, the BTA from Israeli developers who actually mention in > > their ads it has been used in experimental aircraft. It's much more > > sophisticated and has three-axis control with solid state gyros. It's cost is > > about $350. > > I think the PAL system on the ailerons only would be nice as a wing leveler, > > and with the elevator trim connected, you could fly even a regular KR-tail > > hands off! > > -Tom > > > > Micheal Mims wrote: > > > > > At 09:08 PM 7/8/98 -0400, you wrote: > > > >Mike, > > > >I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm > > > for R/C > > > >servo motor controllers that would be perfect for this application. One > > > even comes in kit form, >>> > > > > > > This is good stuff! I want to add one to the ailerons too. The servos I > > > have are about 5 years old and used very little. I bought them thinking I > > > would get back into RCing when I was flying in Alaska. They are Futaba > > > units. I guess I am being cheep but these guys are nice and small and look > > > almost brand new. I charged the batteries today and the servos still work! > > > :o) > > > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > > > Micheal Mims > > > SP290,.. Filling and sanding now! > > > mailto:mikemims@pacbell.net > > > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > > > Irvine Ca > > > Fax 949.856.9417 > > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > > > > > > > ------------------------------------- > http://www.newtech.com/nlf > > One test is worth a thousand expert opinions but a thousand opinions are > easier to get. > > When once you have tasted flight you will always walk with your eyes > turned skyward, for there you have been and there you will always be. > --Leonardo da Vinci ------------------------------ Date: Thu, 09 Jul 1998 09:44:51 -0400 From: Tom Andersen Subject: Re: KR: RC Servo trim motor Steve, The servo in the aileron is definitely doable with the KMI unit directly connected to the PAL autopilot unit to create aileron trim and wing leveler. The lead wouldn't be longer than 4'. That would be within reason and inexpensive, no? - -Tom Steven A Eberhart wrote: > Looks like we are on to something here. We did a grass roots pole a > while back and a large percentage of KR builders are/were R/C modelers. > > My only concerne about putting the servo controller in the cockpit and > the servos in the tail/ailerons is the possibility for noise > interference. giant scale R/C is pushing the limits on how far you > can/should move the servo from the control source. Reason being, the > signal going to the servo is a pulse train with 1.5 ms nominal control > pulses repeated every 18 ms or so. The leading edge of a square wave > generates a tremendous amount of RF noise due to the very rapid voltage > change on the leading edge of the square wave. With an antena as long as > we are talking about, from the cockpit to the tail, I think we may very > well have an interference problem with all of the rest of the electronics. > > THis is the reason I was thinking about using a plastic fiber optic cable > for the run between the servo controller and the servo. THe interfaces > to the fiber should be verry simple and not require any modification of > the servo controller or servos. They simply plug into the fiber > transmitter and receiver. > > Steve > > On Thu, 9 Jul 1998, Tom Andersen wrote: > > > Mike, > > If you put one on your ailerons, it's possible to use an R/C autopilot with > > both servos and so have a wing leveler and pitch holder. The new PAL unit $50 > > mounts on the bottom of an R/C plane and uses differences in light between sky > > and ground to provide stability in two axis. I hear it works great and only > > weighs two ounces. > > There's another unit, the BTA from Israeli developers who actually mention in > > their ads it has been used in experimental aircraft. It's much more > > sophisticated and has three-axis control with solid state gyros. It's cost is > > about $350. > > I think the PAL system on the ailerons only would be nice as a wing leveler, > > and with the elevator trim connected, you could fly even a regular KR-tail > > hands off! > > -Tom > > > > Micheal Mims wrote: > > > > > At 09:08 PM 7/8/98 -0400, you wrote: > > > >Mike, > > > >I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm > > > for R/C > > > >servo motor controllers that would be perfect for this application. One > > > even comes in kit form, >>> > > > > > > This is good stuff! I want to add one to the ailerons too. The servos I > > > have are about 5 years old and used very little. I bought them thinking I > > > would get back into RCing when I was flying in Alaska. They are Futaba > > > units. I guess I am being cheep but these guys are nice and small and look > > > almost brand new. I charged the batteries today and the servos still work! > > > :o) > > > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > > > Micheal Mims > > > SP290,.. Filling and sanding now! > > > mailto:mikemims@pacbell.net > > > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > > > Irvine Ca > > > Fax 949.856.9417 > > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > > > > > > > ------------------------------------- > http://www.newtech.com/nlf > > One test is worth a thousand expert opinions but a thousand opinions are > easier to get. > > When once you have tasted flight you will always walk with your eyes > turned skyward, for there you have been and there you will always be. > --Leonardo da Vinci ------------------------------ Date: Thu, 9 Jul 1998 09:18:05 -0500 (CDT) From: Steven A Eberhart Subject: Re: KR: RC Servo trim motor On Thu, 9 Jul 1998, Tom Andersen wrote: > Steve, > The servo in the aileron is definitely doable with the KMI unit directly connected to > the PAL autopilot unit to create aileron trim and wing leveler. The lead wouldn't be > longer than 4'. That would be within reason and inexpensive, no? > -Tom Should be fine, my 1/3 scale Sky Terrier will have the servos for flaps, spoilers and ailerons mounted in the wings (one servo for each control surface), THe flap cabels will be about 2', spoilers, 3' and ailerons about 4'. All I plan on doing is put rf chokes in each wiring lead. I am not sure about the rudder and elevator yet. I may experiment with the fiber optic cable idea here and put the servos and separate battery pack in the tail. I like your idea of trying the 3 axis solid state gyro auto pilot. May play with that on the model after I get it flying the way I want. The main reason for the model is I need some answers to the effects that the 10 degree forward swept wing will present. I have been talking to Dr. Selig about this and he didn't like some of my early thoughts about how to deal with the pitch up tendance of a forward sweep wing in a stall (center of lift moves forward when the root stalls first). His comment was that the model was a prudent design tool to use in investigating all of the flight aspects of the forward sweep wing. You know me, always ready to put criticism to rest with an experiment to get the REAL answers. One big (SP ?) as there are a bunch of questionable spellings in the above. In fact I may put this disclamer in my signature line :-) Steve Eberhart - -------------- If you have the Coroners report, why keep beating the poor dead horse. --Steve Eberhart, 1998 > > Steven A Eberhart wrote: > > > Looks like we are on to something here. We did a grass roots pole a > > while back and a large percentage of KR builders are/were R/C modelers. > > > > My only concerne about putting the servo controller in the cockpit and > > the servos in the tail/ailerons is the possibility for noise > > interference. giant scale R/C is pushing the limits on how far you > > can/should move the servo from the control source. Reason being, the > > signal going to the servo is a pulse train with 1.5 ms nominal control > > pulses repeated every 18 ms or so. The leading edge of a square wave > > generates a tremendous amount of RF noise due to the very rapid voltage > > change on the leading edge of the square wave. With an antena as long as > > we are talking about, from the cockpit to the tail, I think we may very > > well have an interference problem with all of the rest of the electronics. > > > > THis is the reason I was thinking about using a plastic fiber optic cable > > for the run between the servo controller and the servo. THe interfaces > > to the fiber should be verry simple and not require any modification of > > the servo controller or servos. They simply plug into the fiber > > transmitter and receiver. > > > > Steve > > > > On Thu, 9 Jul 1998, Tom Andersen wrote: > > > > > Mike, > > > If you put one on your ailerons, it's possible to use an R/C autopilot with > > > both servos and so have a wing leveler and pitch holder. The new PAL unit $50 > > > mounts on the bottom of an R/C plane and uses differences in light between sky > > > and ground to provide stability in two axis. I hear it works great and only > > > weighs two ounces. > > > There's another unit, the BTA from Israeli developers who actually mention in > > > their ads it has been used in experimental aircraft. It's much more > > > sophisticated and has three-axis control with solid state gyros. It's cost is > > > about $350. > > > I think the PAL system on the ailerons only would be nice as a wing leveler, > > > and with the elevator trim connected, you could fly even a regular KR-tail > > > hands off! > > > -Tom > > > > > > Micheal Mims wrote: > > > > > > > At 09:08 PM 7/8/98 -0400, you wrote: > > > > >Mike, > > > > >I uploaded two ads to my web site http://home.att.net/~tomkr2s/index.htm > > > > for R/C > > > > >servo motor controllers that would be perfect for this application. One > > > > even comes in kit form, >>> > > > > > > > > This is good stuff! I want to add one to the ailerons too. The servos I > > > > have are about 5 years old and used very little. I bought them thinking I > > > > would get back into RCing when I was flying in Alaska. They are Futaba > > > > units. I guess I am being cheep but these guys are nice and small and look > > > > almost brand new. I charged the batteries today and the servos still work! > > > > :o) > > > > zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz > > > > Micheal Mims > > > > SP290,.. Filling and sanding now! > > > > mailto:mikemims@pacbell.net > > > > http://www.geocities.com/CapeCanaveral/Hangar/4136/ > > > > Irvine Ca > > > > Fax 949.856.9417 > > > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > > > > > > > > > > > > > ------------------------------------- > > http://www.newtech.com/nlf > > > > One test is worth a thousand expert opinions but a thousand opinions are > > easier to get. > > > > When once you have tasted flight you will always walk with your eyes > > turned skyward, for there you have been and there you will always be. > > --Leonardo da Vinci > > > > - ------------------------------------- http://www.newtech.com/nlf One test is worth a thousand expert opinions but a thousand opinions are easier to get. When once you have tasted flight you will always walk with your eyes turned skyward, for there you have been and there you will always be. --Leonardo da Vinci ------------------------------ End of krnet-l-digest V2 #114 *****************************