Pietenpol-List: Elevator cables

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Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: "Domenico Bellissimo"
Stumped again. I'm rigging the tail control cables, using cable clampsfor now, and am having a problem with the elevator cable tensions. Thetension is varying from slack at neutral to too tight at full up or downdeflection. I've tried different angles between the center horn and theelevator horn, but still have the same problem. Any one know off hand whatthe problem is? I've measured the attachment fitting to hinge points, andthey seem fine, so is there something obvious I'm doing wrong? The topcables are also hitting the leading edge of the tail, as expected. Theonly way I could avoid this is to route the top cable over the top of thelongerons. It would work, but I don't think I'll do it. I did route therudder cables to below the elevator vice above. Doesn't need pulleys underthe seat that way. I put the fuselage on its main wheels a week ago. 8.5x 6 tires look real nice. Lots of rubber necking in the cars driving by. Wayne Sippola, Winnipeg ________________________________________________________________________________
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Re: Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: "John McNarry"
Wayne,Positioning the bell crank per the drawing will make the to elevator cablehit the top of the stabilizer. I'm sure most people have had the sameproblem. What I did to my bell crank was position it higher up so the cablecould come out of the side of the aircraft at a better angle. It will stillhit a little but not as much. You will nee to protect that area on the topof the stabilizer with a flat piece of nylon, or teflon. I also entrappedthe cable so it wouldn't slide sideways, because it also does that too. Nowthe problem with the tightness and slackness of the cables...it's acompromise. You'll find the control cable prior to the bell crank will alsovary in tension. I heard some people have put in good bungee cords to takeup the slack. I don't think you want it tight( better a little slack), forone the tension will ruin the pulleys in no time and two your stick willfeel tight and not right. Did you put two pulleys, side by side just at theback of the seat at the lowest point to help the cables change direction?Hope this helps. If not it will at least open the discussion to others.Regards,Domenico BellissimoToronto________________________________________________________________________________
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Re: Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: Wayne Sippola
Wayne I had a long talk with a builder at Brodhead a few years back, I noticedhis cables didn't go slack and asked him about it. He said it was in theshape of the elevator horns and the bellcrank. The lever length both sidesof the pivot points must be the same and more importantly, if the elevatorhorns to elevator hinge line form a triangle, then the bellcrank must alsohave the same points. The result should be the bellcrank, cables andelevator horns form a parallelogram. The arc swing from centerpivot to cableattach points the same on both elevator horns and bellcrank.Don't worry about the clock it doesn't keep track of time either ;-)John Mc----- Original Message -----
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Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: Isablcorky(at)aol.com
Graham wrote:>Does the tension vary between upper & lower cables at full deflection?It sure does on 41CC. Matter of fact, the A&P who did the last annual on it got worried about it and wanted me to take out the "slack" on the lower cable. That is, until I pointed out to him that this was normal and if I took out the slack when the elevator was in one position, the cable would be overly tensioned when in the other.>If so can this be avoided.Yes; change the geometry of the elevator "idler" bellcrank behind the seat as well as the relative lengths of the bellcrank arms with respect to the bellcrank on the elevator. John Dilatush did this on "Mountain Piet" and the cables maintain an even tension throughout the full range of travel, both ways. You can see this in the second photo up from the bottom (and its caption) here: http://www.flysquirrel.net/piets/John_piet.html>Any way of stopping the top cable from rubbing on the L,E of tail plane?See answer to above question ;o) However, it's only a perceived defect or flaw. In operation, everything works just fine and slipping a piece of aquarium air hose over the cable where it touches the LE of the horizontal stabilizer, or applying some clear leading edge tape to the HS, will allay your fears and protect the LE paint and fabric if that's what you're worried about. 41CC has neither and is none the worse for wear so far. A picture of the setup on 41CC, with the elevator in the 'up' position (lower cable fully in tension, no slack) is at the 4th photo from the bottom here: http://www.flysquirrel.net/piets/incide ... t.html>Had considered raising the height of the bell crank in fuse but>this could gear down the amount of travel avail for the elevtor.It really isn't a problem and everything will work fine if you just build it to the plans. That is, unless you're an engineer (like John Dilatush), a perfectionist, a tinkerer, or just don't like for a classic 4-bar linkage to operate with one of the linkages slack ;o)What's funny is that it is so easy to say all this stuff now that I have an airplane to fly. Back before I did, I'd worry and fret and fuss and think and sketch and build cardboard and string and popsicle stick parts (all of which are good things to do, mind you), but now when I read about somebody fretting about things like this when they could have already completed the part and gotten it covered, getting them that much closer to actually flying, I want to say the same thing everybody told me back then: "just hurry up and build it, because flying these airplanes is so much fun!"Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net_________________________________________________________________Dont miss your chance to WIN $10,000 and other great prizes from Microsoft ________________________________________________________________________________
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Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: "Jack Phillips"
A couple of questions for anyone in the group. The plans show the cables going from the control stick back to the bell crank going thru a wood member and changing direction at the same time thus rubbing on the wood every time the controls move. Seems to me a couple of pulleys placed where the direction change occurs are in order. Also, does the difference in angle between where the cables attach to the bell crank and the cables going out to the elevators have any adverse effect? What is the concensus amongst those who have gone thru this stage? Chuck________________________________________________________________________________
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RE: Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
I didn't like the "spruce bearing" in the plans and added a pulley as shownbelow. You can see the elevator pulley at the extreme right side of thepicture. I also added pulleys for the rudder cables as shonw in about themiddle of the picture. The remainder of what you see is part of my trimsystem:Jack PhillipsNX899JPRaleigh, NC _____
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Re: Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: Jack Phillips
Jack, thanks for the picture. I gives me ideas of how to handle my system. I see only one pulley which I assume is for the cable that comes from the pulley at the front of the control stick. Does the other cable not need one or did you put the pulley that is for the cable at the rear of the stick further back so that only one change of direction was needed? How about the second part of my question. Does the different angles have any effect? Chuck ----- Original Message -----
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RE: Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: cncampbell(at)windstream.net
I think everyone has done what Jack did=2C put a pulley (I put two) on that lower cross member for the elevator cables. I played with the angle of the center bellcrank and could not find that it made any difference whatsoever what angle it was placed. One would think that it should "point" towards the pulleys so that it could never "break over center." I was never able to get it to go over center for either the forward or rear cables no matter how I positioned it=2C so I just kind of positioned it halfway between the two when the stick is centered. A lot of my terminology won't make sense unless you have tried it. Once you do=2C it will become clear.Gene Rambo
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RE: Pietenpol-List: Elevator cables

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Good pics, Jack. One should note the 'keepers' that you added to the pulley,so that the cables can't slip off.Gary Boothe Cool, Ca. Pietenpol WW Corvair Conversion, Running! Tail done, Fuselage on gear (23 ribs down.) _____
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Post by matronics »

Original Posted By: "Gary Boothe"
I'm a new guy, woodshop teacher, building a Piet with 12 students. Our fuselageis making progress. What tailwheel is recommended for the Piet. We plan onusing 600-6 tires and springs instead of bungee cords. Would appreciate any helppossible. Flyboy from Berwick PARead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/pont ... __________
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Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: "Charles Campbell"
I used a 1" x 1" pc of UHMW and drilled two "fairlead" holes thru it. Weighs lessthan one of the pulleys alone....never mind the brackets. Lighter here andthere (x100) is good!--------PAPA MIKERead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
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Re: Pietenpol-List: Re: Elevator cables

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Original Posted By: "899PM"
I'm sorry. What is UHMW?----- Original Message -----
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> Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By:> rockriverrifle(at)hotmail.com
the problem here is that the angle change there is 45 degrees or better. That is technically too much for a fairlead=2C which should not change a cable more than 5 degrees (? some small number)=2C not that I always follow that rule. In this case=2C two large cables that are extremely critical making a big angle change=2C I would go with a pulley.Gene Rambo> Subject: Pietenpol-List: Re: Elevator cables
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Re: Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: Gene Rambo
Thanks, Gene, I'll do that. I'm about ready to get the control system welded up and when I install it in the airplane I'll use a couple of pulleys to change the direction of the cables. I read somewhere from a fellow in Australia, I think, who says they are required to use a pulley anytime a control cable changes direction. Good rule, I think. ----- Original Message -----
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Re: Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By:> Gene Rambo
Gene is correct on change of direction for fairleads being a small angle. If I remember correctly 3 degrees is the commonly accepted limit before a pulley is in order.-john-John HofmannVice-President, Information TechnologyThe Rees Group, Inc.2424 American LaneMadison, WI 53704Phone: 608.443.2468 ext 150Fax: 608.443.2474Email: jhofmann(at)reesgroupinc.comOn Jan 6, 2011, at 2:06 PM, Charles Campbell wrote:> Thanks, Gene, I'll do that. I'm about ready to get the control system welded up and when I install it in the airplane I'll use a couple of pulleys to change the direction of the cables. I read somewhere from a fellow in Australia, I think, who says they are required to use a pulley anytime a control cable changes direction. Good rule, I think.> ----- Original Message -----
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Re: Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: Roman Bukolt
Very nice! I love big wire wheels... it just looks right!--------Brad "DOMIT" SmithFirst rule of ground school: This is the ground... don't hit it going fast.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Re: Elevator cables
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Post by matronics »

Original Posted By:> Gene Rambo
Thank you Ally. Looks like a great place.Sent from my iPhoneOn Jan 6, 2011, at 2:06 PM, "Charles Campbell" wrote:> Thanks, Gene, I'll do that. I'm about ready to get the control system welded up and when I install it in the airplane I'll use a couple of pulleys to change the direction of the cables. I read somewhere from a fellow in Australia, I think, who says they are required to use a pulley anytime a control cable changes direction. Good rule, I think.> ----- Original Message -----
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Re: Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: "899PM"
UHMW? Please give a definition,if you would. I am at this very point with the Sky Scout. Was planning this evening on pulleys, just as jack did; or a piece of 1"thick Teflon with holes in it used as a guide. We use the Teflon in farming as "rubbers" for elevator chains on harvesters. Maybe that is what UHMV is?Thanks and fly SAFELY,Ray KrauseWaiex 51YX, Jabiru 3300 (1197), Sensenich wood prop, AeroCarb (#2 needle modified), Dynon D-180, Garmin SL 30 NavCom, Garmin 327 transponder, Garmin Aera 560, nav and strobe lights: 234 hrs. Building Sky Scout... slowly.----- Original Message -----
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RE: Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Hi Guys,Check this out...http://www.redwoodplastics.com/products ... rWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
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RE: Pietenpol-List: Re: Elevator cables

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Original Posted By: owner-pietenpol-list-server(at)matronics.com
Google it. -----Original Message-----
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Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: Frank Metcalfe
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Pietenpol-List: Re: Tail wheel

Post by matronics »

Original Posted By: "kevinpurtee"
Remember....we are building EXPERIMENTAL. My guess is, the UHMW with the holesthru it will far outlast myself and anyone else on this list.--------PAPA MIKERead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Tail wheel
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Post by matronics »

Original Posted By: "Gene & Tammy"
Hi - There are lots and lots of variation in tailwheels. Look on westcoastpiet.comfor a sampling. I personally use the 6" matco from aircraft spruce - hasworked well for me.The plane and your kids look great.Take care,Kevin--------Kevin "Axel" PurteeNX899KPAustin/Georgetown, TXRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
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Re: Pietenpol-List: Re: Tail wheel

Post by matronics »

Original Posted By: kevinpurtee
Where is everyone getting their tailwheel springs?Gene In Beautiful West Tennessee-----Original Message-----
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RE: Pietenpol-List: Re: Tail wheel

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Which kind, Gene? I've got a leaf spring from a Piper PA-12 that you arewelcome to. If you are referring to the coil spring for the BHP design,some use a John Deere spring. I got my spring from McMaster-Carr. As Irecall, it was about $13.00 Jack PhillipsNX899JP "Icarus Plummet"Raleigh, NC-----Original Message-----
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Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: "Gboothe5"
I have no doubt that UHMW would be an excellent material for a fairlead - low friction,self-lubricating, abrasion resistant, etc.I think the issue in this case is the amount of deflection in the control cable,which in this case, as scaled from the plans, is about 30 degrees, which ismuch more than should be handled by a fairlead. The issue is the amount of localizedflexing that the cable will be subjected to. I would think that if a UHMWblock was shaped to a radius equal to the appropriate sized pulley, the netresult would be the same as using a pulley.Having said that, there have been countless Air campers built as per the plans,using a hole in a block of spruce, and as far as I know, none have fallen outof the sky as a result of that practice. But sometimes it just makes sense toincorporate newer methods and techniques that are based on safety.Read this topic online here:http://forums.matronics.com/viewtopic.p ... __________
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RE: Pietenpol-List: Re: Tail wheel

Post by matronics »

Original Posted By: owner-pietenpol-list-server(at)matronics.com
If you're talking the coil spring...John Deere. I couldn't order online, butfound the part# and a local dealer who mailed it to me. (gotta dig for thepart #)Gary Boothe-----Original Message-----
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Re: Pietenpol-List: Re: Tail wheel

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Original Posted By: Gboothe5
Thanks Gary but I have a friend that is looking for a flat tail spring for his J3 Kitten.Gene-----Original Message-----
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Re: Pietenpol-List: Re: Tail wheel

Post by matronics »

Original Posted By: Jack Phillips
Thanks Jack. I just called Rich and let him know about McMaster-Carr.Doing good here.Gene-----Original Message-----
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Re: Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: "Bill Church"
Thanks, I agree 100%. Two pulleys are not that difficult to install.Ray Krause----- Original Message -----
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Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: Jim Markle
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Pietenpol-List: Tail wheel

Post by matronics »

Original Posted By: "Flyboy"
A couple of questions for anyone in the group. The plans show the cables going from the control stick back to the bell crank going thru a wood member and changing direction at the same time thus rubbing on the wood every time the controls move. Seems to me a couple of pulleys placed where the direction change occurs are in order. Also=2C does the difference in angle between where the cables attach to the bell crank and the cables going out to the elevators have any adverse effect? What is the concensus amongst those who have gone thru this stage? Chuck ________________________________________________________________________________Subject: Pietenpol-List: Tail wheel
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Post by matronics »

Original Posted By: "Charles Campbell"
> To: pietenpol-list(at)matronics.com> >> > I used a 1" x 1" pc of UHMW and drilled two "fairlead" holes thru it. Weighs less than one of the pulleys alone....never mind the brackets. Lighter here and there (x100) is good!> > --------> PAPA MIKE> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 810#325810> > > > > > > ============================================> > > ________________________________________________________________________________
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> Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: John Hofmann
> To: pietenpol-list(at)matronics.com > > > I used a 1" x 1" pc of UHMW and drilled two "fairlead" holes thru it. Weighs less than one of the pulleys alone....never mind the brackets. Lighter here and there (x100) is good! > > -------- > PAPA MIKE > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.p ... 810#325810 > > > = > > > ________________________________________________________________________________
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Pietenpol-List: Re: Elevator cables

Post by matronics »

Original Posted By: "Bill Church"
> > To: pietenpol-list(at)matronics.com> > > > > > I used a 1" x 1" pc of UHMW and drilled two "fairlead" holes thru it. Weighs less than one of the pulleys alone....never mind the brackets. Lighter here and there (x100) is good!> > > > --------> > PAPA MIKE> > > > > > > > > > Read this topic online here:> > > > http://forums.matronics.com/viewtopic.p ... 810#325810> > > > > > > => > > > > > > > > href="http://www.matronics.com/Navigator?Piet ... enpol-List> href="http://forums.matronics.com">http://forums.matronics.com> href="http://www.matronics.com/contribution"> ... nics.com/c> > > > ________________________________________________________________________________Subject: Pietenpol-List: Re: Elevator cables
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> > Pietenpol-List: Re: Elevator cables

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Original Posted By: "Jack"
> > To: pietenpol-list(at)matronics.com> > m>> > > > I used a 1" x 1" pc of UHMW and drilled two "fairlead" holes thru it. Weighs less than one of the pulleys alone....never mind the brackets. Lighter here and there (x100) is good!> > > > --------> > PAPA MIKE> > > > > > > > > > Read this topic online here:> > > > http://forums.matronics.com/viewtopic.p ... 810#325810> > > > > > > => > > > > > > > > href="http://www.matronics.com/Navigator?Piet ... enpol-List> href="http://forums.matronics.com">http://forums.matronics.com> href="http://www.matronics.com/contribution"> ... nics.com/c> > ============================================================================================================================================> ________________________________________________________________________________
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> Re: Pietenpol-List: Re: Tail wheel

Post by matronics »

Original Posted By: KM Heide CPO/FAAOP
This is the part number, as posted by Bill Church, for the John Deere springin case anybody else is looking for the info. John Deere sells a spring that'sa perfect match for the specs; its part number is T 143444, and it costs about$9.00. Its outer dia. is 1.5in.; full length( no load ) is 6.73" Bill C -----Original Message----->From: Gboothe5 >Sent: Jan 7, 2011 10:14 AM>To: pietenpol-list(at)matronics.com>Subject: RE: Pietenpol-List: Re: Tail wheel>>>If you're talking the coil spring...John Deere. I couldn't order online, but>found the part# and a local dealer who mailed it to me. (gotta dig for the>part #)>>Gary Boothe>>-----Original Message----->From: owner-pietenpol-list-server(at)matronics.com>[mailto:owner-pietenpol-list-server(at)matronics.com] On Behalf Of Gene & Tammy>Sent: Friday, January 07, 2011 7:54 AM>To: pietenpol-list(at)matronics.com>Subject: Re: Pietenpol-List: Re: Tail wheel>>>>Where is everyone getting their tailwheel springs?>Gene In Beautiful West Tennessee>>-----Original Message----- >From: kevinpurtee >>________________________________________________________________________________Date: Fri, 7 Jan 2011 13:44:10 -0800 (PST)
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