---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Fri 02/22/13: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:48 AM - Re: Tailwheel upgrade (John Gilpin) 2. 07:47 AM - Re: Tailwheel upgrade (Rick Neilsen) 3. 08:57 AM - Re: Tailwheel upgrade (b young) 4. 09:48 AM - Re: Tailwheel upgrade (Rick Neilsen) 5. 01:39 PM - Re: Tailwheel upgrade (tombaisley) ________________________________ Message 1 _____________________________________ Time: 12:48:09 AM PST US From: "John Gilpin" Subject: Re: Kolb-List: Tailwheel upgrade Yeh, a tailwheel upgrade is really worthwhile. That pizza cutter is pathetic... For my Firefly, I got the one from Aircraft Spruce because it was in stock for immediate shipment and Kolb didn=99t have any in stock at that time. Bad mistake..... The one from Spruce has 1/2=9D hole, while the Kolb shaft is 5/8=9D..... It=99s a specialized machining job to bore it out because there=99s a square boss that won=99t chuck in a lathe. I took it to a really well-equipped machine shop and they found it difficult. They had to load it in the chuck from the driven end, then the work was so buried in the chuck that a conventional boring bar wouldn=99t reach, so they had to fabricate a special extension. Cost $130 for 1 1/2 hrs work...... So if your going to get that tailwheel assembly, get from Kolb and it=99s all ready to go. But to do it again I wouldn=99t get that assembly at all. As Larry has pointed out, that breakaway swivel is a pain.... I also had to machine out the mechanism so that it doesn=99t breakaway. So what=99s the point of paying for all that mechanism at all. Besides, that tailwheel is heavy and designed for much heavier aircraft. Another problem with that product is that the steering arms are much longer than the original, so it gives even less deflection at full lock. The arm is very hard steel and I couldn=99t drill it to shorten the arms. Maybe if you heated and annealed at that point you could drill it.... The original Kolb mechanism is a lot lighter and is adequate, it=99s only the pizza cutter wheel itself that=99s the problem...... I noticed that the bearings in the new tail wheel would fit onto the the original Kolb tailwheel axle. Only problem was that the axle is too short to project all the way through the new wheel. To do it again I=99d have a longer axle welded in place on the original gear, and just replace the wheel. Surely the wheel itself must be available as a replacement part. Hopefully Kolb could source those wheels and manufacture the part to just bolt it onto their original gear. Be a lot easier and less costly.... JG ________________________________ Message 2 _____________________________________ Time: 07:47:24 AM PST US Subject: Re: Kolb-List: Tailwheel upgrade From: Rick Neilsen John I can't speak for the Spruce version but the Kolb version is worth every penny but it to needs to be modified to work well. First get some compression springs. The light springs allow the tail wheel to rotate in a strong cross wind situation that allows it to unlock at just the wrong time. Then you need to cut (shorten) and drill the steering arms so that you can get enough rotation to unlock the tail wheel at full rudder defection. These tail wheels don't unlock till they are turned quite a bit. Also you need to find a good tool store that sells drill bits for hard steel. Rick Neilsen Redrive VW Powered MKIIIC On Sat, Sep 15, 2012 at 11:25 AM, John Gilpin wrote: > Yeh, a tailwheel upgrade is really worthwhile. That pizza cutter is > pathetic... > > For my Firefly, I got the one from Aircraft Spruce because it was in stoc k > for immediate shipment and Kolb didn=92t have any in stock at that time. Bad > mistake..... The one from Spruce has 1/2=94 hole, while the Kolb shaft is > 5/8=94..... It=92s a specialized machining job to bore it out because th ere=92s > a square boss that won=92t chuck in a lathe. I took it to a really > well-equipped machine shop and they found it difficult. They had to load > it in the chuck from the driven end, then the work was so buried in the > chuck that a conventional boring bar wouldn=92t reach, so they had to > fabricate a special extension. Cost $130 for 1 1/2 hrs work...... So if > your going to get that tailwheel assembly, get from Kolb and it=92s all r eady > to go. > > But to do it again I wouldn=92t get that assembly at all. As Larry has > pointed out, that breakaway swivel is a pain.... I also had to machine o ut > the mechanism so that it doesn=92t breakaway. So what=92s the point of p aying > for all that mechanism at all. Besides, that tailwheel is heavy and > designed for much heavier aircraft. Another problem with that product is > that the steering arms are much longer than the original, so it gives eve n > less deflection at full lock. The arm is very hard steel and I couldn=92 t > drill it to shorten the arms. Maybe if you heated and annealed at that > point you could drill it.... > > The original Kolb mechanism is a lot lighter and is adequate, it=92s only > the pizza cutter wheel itself that=92s the problem...... I noticed that the > bearings in the new tail wheel would fit onto the the original Kolb > tailwheel axle. Only problem was that the axle is too short to project a ll > the way through the new wheel. To do it again I=92d have a longer axle > welded in place on the original gear, and just replace the wheel. Surely > the wheel itself must be available as a replacement part. > > Hopefully Kolb could source those wheels and manufacture the part to jus t > bolt it onto their original gear. Be a lot easier and less costly.... > > JG > > * > =========== =========== =========== =========== > * > > ________________________________ Message 3 _____________________________________ Time: 08:57:28 AM PST US From: "b young" Subject: Re: Kolb-List: Tailwheel upgrade I don=92t know what I am missing.... if you drill the arms so you have more deflection, then machine out the fitting so it takes more deflection to break it loose... where is the benefit. I put on a full swivel tail wheel and never looked back. it is wonderful. in normal driving I have never had it break away. if I want it to break, even with the longer arms all I have to do is add a bit of breaking and that forces it over the edge. I am still using the light stock springs with the longer arms and have not noticed any more problems in a cross wind than I had on the pizza cutter wheel. I don=92t know if it just comes down to technique, but in a cross wind I have been conscious of riding the break a bit. I only had one time when I could not hold a line... that was in a 25 gusting to 35 wind at a 90 deg to my direction of taxi. the tail wheel was firmly attached to the ground... I just think it would skid sideward when the gust would hit the tail. only a tire with more grip would have eliminated that problem. boyd young mkiii utah >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> I can't speak for the Spruce version but the Kolb version is worth every penny but it to needs to be modified to work well. First get some compression springs. The light springs allow the tail wheel to rotate in a strong cross wind situation that allows it to unlock at just the wrong time. Then you need to cut (shorten) and drill the steering arms so that you can get enough rotation to unlock the tail wheel at full rudder defection. These tail wheels don't unlock till they are turned quite a bit. Also you need to find a good tool store that sells drill bits for hard steel. For my Firefly, I got the one from Aircraft Spruce because it was in stock for immediate shipment and Kolb didn=92t have any in stock at that time. Bad mistake..... The one from Spruce has 1/2=94 hole, while the Kolb shaft is 5/8=94..... It=92s a specialized machining job to bore it out because there=92s a square boss that won=92t chuck in a lathe. I took it to a really well-equipped machine shop and they found it difficult. They had to load it in the chuck from the driven end, then the work was so buried in the chuck that a conventional boring bar wouldn=92t reach, so they had to fabricate a special extension. Cost $130 for 1 1/2 hrs work...... So if your going to get that tailwheel assembly, get from Kolb and it=92s all ready to go. ________________________________ Message 4 _____________________________________ Time: 09:48:52 AM PST US Subject: Re: Kolb-List: Tailwheel upgrade From: Rick Neilsen Boyd On a cross country the wind picked up don't know the speed now but it was strong. I landed for gas and had to taxi cross wind. Holding full opposite rudder and one wheel breaking a gust would push the tail wheel (stretching the weak springs) to the point where it unlocked three times (doing a 360 to get it to lock again) to the gas pumps then 5-6 more times to get to a sheltered area. The compression springs fixed the unlocking problem but they also didn't allow the tail wheel to rotate enough to unlock ever. The optional tail wheel has much longer arms than the stock "bogey" wheel tail wheel assembly. I then shortened to tail wheel control arms and spring attach points to get enough rotation to get a full deflection unlock. Now I get very positive control of the tail wheel and the wheel will unlock only when the rudder hits the stop. There have been a few times where wind gusts have pushed the tail wheel sideways but I was able to recover without having to do a 360 and I don't have to ride the brakes. Note! I did not "machine out the fitting". Rick Neilsen Redrive VW Powered MKIIIC On Fri, Feb 22, 2013 at 11:57 AM, b young wrote: > I don=92t know what I am missing.... if you drill the arms so you hav e > more deflection, then machine out the fitting so it takes more deflection > to break it loose... where is the benefit. I put on a full swivel > tail wheel and never looked back. it is wonderful. in normal drivin g > I have never had it break away. if I want it to break, even with the > longer arms all I have to do is add a bit of breaking and that forces it > over the edge. I am still using the light stock springs with the longer > arms and have not noticed any more problems in a cross wind than I had on > the pizza cutter wheel. I don=92t know if it just comes down to > technique, but in a cross wind I have been conscious of riding the bre ak > a bit. I only had one time when I could not hold a line... that was i n > a 25 gusting to 35 wind at a 90 deg to my direction of taxi. the tail > wheel was firmly attached to the ground... I just think it would skid > sideward when the gust would hit the tail. only a tire with more grip > would have eliminated that problem. > > boyd young > mkiii utah > > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> > I can't speak for the Spruce version but the Kolb version is worth every > penny but it to needs to be modified to work well. First get some > compression springs. The light springs allow the tail wheel to rotate in a > strong cross wind situation that allows it to unlock at just the wrong > time. Then you need to cut (shorten) and drill the steering arms so that > you can get enough rotation to unlock the tail wheel at full rudder > defection. These tail wheels don't unlock till they are turned quite a bi t. > Also you need to find a good tool store that sells drill bits for hard > steel. > > > For my Firefly, I got the one from Aircraft Spruce because it was in stoc k > for immediate shipment and Kolb didn=92t have any in stock at that time. Bad > mistake..... The one from Spruce has 1/2=94 hole, while the Kolb shaft is > 5/8=94..... It=92s a specialized machining job to bore it out because the re=92s a > square boss that won=92t chuck in a lathe. I took it to a really > well-equipped machine shop and they found it difficult. They had to load it > in the chuck from the driven end, then the work was so buried in the chuc k > that a conventional boring bar wouldn=92t reach, so they had to fabricate a > special extension. Cost $130 for 1 1/2 hrs work...... So if your going to > get that tailwheel assembly, get from Kolb and it=92s all ready to go. > > ** > > * > =========== > =========== =========== =========== > > * > > ________________________________ Message 5 _____________________________________ Time: 01:39:50 PM PST US Subject: Kolb-List: Re: Tailwheel upgrade From: "tombaisley" I take off and land my Firestar 90% from grass, never had a problem with the stock tailwheel, Might not look like much but it's very high functioning Read this topic online here: http://forums.matronics.com/viewtopic.php?p=394834#394834 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.