Bushmaster type gear

[KSG]

Researching bushmaster gear for my extended 22", dual seaplane doors, sticks, and widened etc. experimental short wing I came across gear using the original t.p. gear mounts. The gear then angled forward for a taildragger. With the extended tail there were references to the axle location being up to 6" aft of a pacer location to offset the extra tail weight. Some pictures appear to show this while others are original pacer gear. Producers have cub style gear which may be slightly aft in pictures but hard to tell. Fisherman has bushmasters but he seems to keep them on floats. The t.p. gear mounts are wider at the fuselage to give better triangulation when I extend the gear 3" and will involve less material and time to fabricate since the upper half will remain the same, just new legs coming down. Any info or comments would be appreciated. This is not a flipped around t.p. gear.

[Steve G]

Researching bushmaster gear for my extended 22", dual seaplane doors, sticks, and widened etc. experimental short wing I came across gear using the original t.p. gear mounts. The gear then angled forward for a taildragger. With the extended tail there were references to the axle location being up to 6" aft of a pacer location to offset the extra tail weight. Some pictures appear to show this while others are original pacer gear. Producers have cub style gear which may be slightly aft in pictures but hard to tell. Fisherman has bushmasters but he seems to keep them on floats. The t.p. gear mounts are wider at the fuselage to give better triangulation when I extend the gear 3" and will involve less material and time to fabricate since the upper half will remain the same, just new legs coming down. Any info or comments would be appreciated. This is not a flipped around t.p. gear.



KSG

I put Trimmer/Super Cub style gear on my Bushmaster, I believe it's a stronger style vs Tri-Pacer/Pacer style gear. Are you going to push your engine forward or stay with the stock mount? I would think engine placement would also be a consideration on axle location.


Steve

[KSG]

Steve I agree that the trimmer/super cub gear is stronger but I live in the Midwest so less drag is the way to go for me. Plane will be on floats a lot also. Did you extend your motor mount? If you did how well does it work? Most of the comments have been to leave it stock. The gear location is a balancing of too much tail weight or tippy as in tip over on its nose. My clipper never wants to nose over so with the extension moving the axle back a couple inches seems prudent.

[Steve G]

KSG

Still building so no feedback on engine mount. I plan to push it fwd 3-4 inches. What floats are you going to use?

[KSG]

Zenair amphibs 1900 or most likely 2200. I haven't heard any major negative comments on them and the price is right. Some of the other kit floats cost as much as an rv 7 kit! Floats are the reason for the stretch. Steve will you be using floats? If you are which way are you going? I am using lightweight accessories with the battery and solenoids moved foreward, the prop will be lighter also, either catto or sensenich adjustable composite if they ever finish the longer blade model. No vac system. With the front weight reduction I was concerned about w-b but I'll try the stock mount on the completed airframe weigh it up see how it turns out before I make the cowl.

[Steve G]

I have a set of Edo 2440's, I looked at the Zenair floats at Oshkosh one year, decided to pass. My stretch is longer than yours, I have D&E wings with the 66" cord and an IO-360 Lycoming. What engine are you using?

[KSG]

DE ribblet wings! Cool. I am using extended t.p. wings with ailerons larger and moved out, larger flaps. Engine will be 320 electronic ignition, with Lyon cylinder mods and cam. 4 into1 header. Word is 200 hp or more. The IO360 is quite a bit heavier if it is an angle valve do you still think the longer mount is necessary?

[Steve G]

Parallel valve w/ P Mags and accessory mount alternator. You can talk to five different Bushmaster builders/fliers and get six different answers on engine mounts. I have a 28" stretch + bigger rudder & elevators with longer cord.

[KSG]

Steve you are so right on all the different ways to build. They all seem to work though! Starting with a good design from piper. Are the tail pieces the Sullivan style squared corners? If I build tailpieces I'll use the squared style just so it looks different with a little more authority. Ignition will be MSD crank fire. I have had great luck with MSD and easy to adapt to aircraft. I tried to call DE a few times with no response are they hard to contact?

[Steve G]

I spoke/emailed with Scot at D&E years ago... no problems. Bought their struts for the wings too. MSD good stuff... I'm an old gearhead and am always looking at ways to work automotive technology into experimental aircraft. Not using squared tail, basically a Piper style just bigger footprint.

[KSG]

Steve amen to the gear head. This project I'm trying to keep costs reasonable, and be experimental. The short wings are such a good foundation for these projects that it's hard to justify starting from scratch. How much slower in cruse and how much more lift do you estimate with the ribblet airfoil vs piper. I was originally looking at doing a short wing with the ribblet airfoil but couldn't find enough info to go that way. Did you use the extruded D pieces for the flaps and ailerons? If so how was the weight? They look very strong and a great way to go.

[Steve G]

I hope the Riblett airfoil won't be a cruise penalty. I think the jury is still out on Cub vs Riblett airfoil, but Bob Barrows used the Riblett airfoil for his new Bearhawk LSA and he's a pretty sharp guy. Used the extruded D pieces, no weight on wings yet, they are heavier, but higher gross too. Everything has a cost. I'm hoping for a 1250lb empty weight and looking at a 2500lb gross. Why did you go with sticks vs yokes? Was it difficult to fab/install?

[KSG]

I find sticks more intuitive and don't bump into my knees while maneuvering the aircraft. The sticks will come out of the panel so you don't have to get over them to get out. I have completed the ratio and throw mockup but haven't actually fabed yet. Won't be able to put anything below the horizontal tube above knees due to the stick throw coming out of the panel. Using a modified T.P. Piece coming out of the floor. Bearhawks have some nice performance numbers.

[Airwrench]

Take a look at this one, we used the 66" riblett on it. http://www.mykitlog.com/Rick%20Davis

[KSG]

Airwrench. I have looked at that plane for quite a while but I haven't seen any pireps on the wing vs. piper. Maybe I have to look at the site harder. What is your opinion of a riblett airfoil on shortwing spars? My use is floats in the Midwest so super short perf. Isn't the goal. I really like the maneuverability of the short wing.

[Airwrench]

KSG, The riblett wing should work well for you, even on the 13' spar, but the 66' riblett ribs were set up for a taller spar than the Piper spars. I believe that they could be utilized though, with the right positioning of the rib attachment. Low speed performance was about equal to that of the Piper wing, and cruised a bit faster, as I recall. They are heavier, but that equates to stronger also. The "D" channel for the flaps and ailerons worked out very well also.
As far a landing gear are concerned, you may want to consider the spring gear rather than tube gear. The cub type gear is a lot of drag, as is the pacer type gear. The spring type gear would give you the least amount. Since this is the landing gear thread, remember that there is a difference between aerodynamic CG and landing gear CG.
BTW the "J" channel in the floor is a float reinforcement on the early models.
- Steve

[Steve G]

KSG,

I agree with Airwrench on the aerodynamic advantages of spring type gear vs Cub style. Spoke with Robbie Grove about this years ago, he has some plans/drawings to put one on a pacer airframe, save your money they are not cheap, but he builds really good stuff. Now if you want your cake and eat it too, go with a composite spring style gear. Light, strong, last forever... corvette's have had composite springs for years. Put one on my 72 corvette 25 years ago... no issues. Just remember to build it for torsional loads too. I think the VariEze aircraft have composite gear, I'd talk with that group if I were to build one.

[KSG]

Thanks for the input. Grove gear is really nice but for once I'm trying to stay on budget.ya I know it won't work but I'm trying. How much faster would you estimate the grove gear is? Here is an off the cuff idea, how about using the spring gear for the front float mount. Floats would need strong crosstie to stop outward motion. Might be able to eliminate the diagonal float mount since the spring gear will take the for and aft loads. Just add the downwards mounts and cross cables at rear. Gear is heavy 50 pounds I'd guess but less cables and mount pieces saves some of that. Easy swap over. I'm surprised that the thicker and wider riblett airfoil is faster and slow speed is similar. My eyeball engineering was way off on that. If I do a riblett it will be with the larger de spars.

[Steve G]

My first concern: Prop to water clearance, the gear would have to be very tall to get the prop away from the water. Second: I would be afraid to take the diagonal out just to lose a few pounds. There's a pacer out there with spring gear, Rupp Pacer I think. Have you tried a search on the forum?

[KSG]

Steve I have seen the rupp racer with the spring gear and rv cowl. Cool plane. The mounts at the floats would have to be raised to accommodate the spring gear. If the spring gear can take bouncing over bumps and holes why not water? It would be different that's for sure. I had gone away from the spring gear idea but you guys got me thinking about it again.

[Bushmaster]

http://img.tapatalk.com/d/14/03/10/napy3eba.jpghttp://img.tapatalk.com/d/14/03/10/u7e9etyr.jpg



Bushmaster

[Bushmaster]

Pawnee hydro sorbs, 3 on each side, safety cables just in case.


Bushmaster