I have a stretched PA 20 (Exptl Cert.) essentially a Producer. Want to install borer prop and am looking for extended gear... or, can I get away with a set of bush wheels? Currently have 6" 8.50's on 1.5" axles. Any advice on prop tip clearance to add to the bunch I already have?
wher are you? Eddie Trimmer has a nice extended gear that he uses I will try post a pict.
Wup
I'm in Eagle River Alaska.... been meaning to get out to Willow one of these days and talk to Eddie.... need to see bud holt too about some float parts... where are you? Are you with bushwheels?
John
I am in Joseph OR, Home of the Alaskan Bushwheel..... so yes I am with ABI. I can't find the picture yet but if your that close you will probibly see it before I find the pict.
Wup
Skraeling,
Good to hear that you fly a Producer - that is essentially what we call a Bushmaster here in BC, Canada. I got one (experimental) with regular 18 gear and 1.5" axles. I just had a set of 3" extended gearlegs made up, beefed up, with 1.25" axles and weld-on step . They will be put on in the spring together with 29" GarAeros. I run a Sensenich cruise prop but for the Borer the 3" ext legs will be on. The plane is on skis this winter.
Hans
If you have the standard pacer wide gear and 8.50's - the 82 inch Prop will work ok - just limit your runnups on gravel etc. Do them on the roll. Bigger tires do help minimize prop nicks. Being experimental you don't have to worry about approvals, but that is the prop that I use on the certified "Producers" - Steve
Well, as usual I got side tracked.... thanks for the encouragement.
Steve: According to my special conditions for the Exptl Cert the FAA has to sign off on any major change... prop change qualifies, so I was concerned about it (don;t know why :>) ). George Drummond (Merrill Field Prop) says: flight level, one tire flat and just clear. What about gear flex and wheel landings? I think a set of Bushwheels or some such might be the ticket.... or a set of extended gear.... or both! No point in leaving all my money to the kids!
Wup: Don't worry about the photo of the ext. gear... I'll get out to Willow one of these days ......
I am about to get involved in a Producer/Busmaster type Pacer project and was pondering PA-18 vs spring steel gear (C-170 ?).Comments would be welcome (I think). Thanks.
WLT
My understanding from the really experienced C-170 guys is that the gear may not be up to "extended" ski applications. " Every airplane with a broken gear has been on skis at some time in its life." This quote from Tom Downey whom I gather to be a pretty experienced C-170 guy. You might consider C-180 gear legs or the Cub gear. I'm not an expert, just what I've read on the C-170 forum. I have had my 170 on skis and the legs do flex a LOT. Mike Vivion owns a C-170, and seems to really know his stuff, maybe he will chime in.
Bill
A friend of mine put spring gear on a Clipped Wing Cub. Less drag but looks kinda funny to me. It is aluminum and gun drilled for brake lines, I think Grove makes it. I have a cataloge at the shop I'll look it up.
Steve Pierce
"When everything seems to be going against you, remember that the airplane takes off against the wind, not with it."
Henry Ford
Bill Rusk's comments are all true re: spring gear. A Scout is a very different handling machine on the ground than a Cub, which is not all bad, just very different.
The problem with most 170 gear is that it's REALLY old, like some of the rest of us. Depending on use, it could be just fine. If it's been on skis much, or certainly been on wheel skis, I'd be careful. At the very least, if you intend to use any used spring gear, have it magnafluxed, or some other non destructive testing, to try to assess its integrity.
Even that isn't an absolute assurance that there won't be problems with old gear, though.
I have early 180 gear on my 170, which goes on wheel skis in winter. The 180 gear is stiffer, and I like it better, but might be too stiff on a lighter airplane.
The other issue with spring gear is that it's heavy. You have to build a gearbox into the fuselage for attachment, which requires structure, then you add to that the weight of the gear legs themselves, and I suspect you'll add 20 to 30 pounds of weight to the frame, over Cub type gear.
Personally, I think the Cub/12 type gear works fine, and has a lot of advantages. It is draggy, though, and the spring gear would be a lot cleaner aerodynamically.
This is just stuff to think about. I think you could get specific weights, etc from others on the list.
If I were going to go the spring gear route, I'd take a look at Scout gear, and gear box. If you could find that setup, a lot of the engineering has already been done, and the gear would be newer.
MTV
Hello Skraeling! We are using a Cub type gear on our Bushmaster that allows us to remove the 22 suspension structure to allow for sticks and a seat on tracks. We can build it with any extension you would like ie. 3 or 6 inch, and an axle that cannot be broken. If we can help, please allow us.
Mike: Do you have any drawings you'd be willing to share re the modification?
removed
In regards to spring gear adapted to a tube fuselage it would good to look over a Scout or other production a/c that has it installed. I know years ago the Christen Eagle had trouble with the longerons cracking from the torsional loads and the Pitts Special was never certified with it because it would not pass drop test for the catagory they were shooting for. I know these airplanes dont see the service that a Bushmaster would. A cub type gear and any damage suffered would probably be easier to repair.
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