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Magnums with Airdale Bush Gear

42 posts in this topic

Posted

Has anyone installed the Airdale Bush Gear on a Magnum?

Thanks,

Ron

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Posted

Has anyone installed the Airdale Bush Gear on a Magnum?

Thanks,

Ron

Haven't seen one yet. How does the gear on the Magnum compare to an Avid? I would think it's a bit more heavy duty for the extra weight but I'm just guessing. :tumbleweed:

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Posted

What is the "gross" on a Magnum? I would think quite a bit more than the standard LSA Avid/Kitfox. Wider, too?

It could probably be made heavy enough, but it would need to be custom.

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Posted

The magnum gross weight is 1750 lbs and the cabin (44") is about 4" wider than the original avid flyer.

I'm thinking it might be a custom job, but I need to look at the Avid+ specs too.

I have the original bungee on it now.

Thanks,

Ron

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Posted

The magnum gross weight is 1750 lbs and the cabin (44") is about 4" wider than the original avid flyer.

I'm thinking it might be a custom job, but I need to look at the Avid+ specs too.

I have the original bungee on it now.

Thanks,

Ron

Ron, cabin width can vary, but what is the width at the lower longerons? My KF is 32 inches there.

ED in MO

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Posted

Ron, cabin width can vary, but what is the width at the lower longerons? My KF is 32 inches there.

ED in MO

Rough measurement at 36".

Man those original legs are short! I measured, roughly 21" from the center of the axle to the bottom of the plane. The hubs are only 54" apart too!

Thanks,

Ron

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Posted (edited)

Rough measurement at 36".

Man those original legs are short! I measured, roughly 21" from the center of the axle to the bottom of the plane. The hubs are only 54" apart too!

Thanks,

Ron

Ron, I have an old Grove catalog and it gives the dimensions for the Magnum gear: 21.5 axle to top of gear, and 66 across outside of axle attach. Weight is 37.2 lb for 1" x 5" gear. This one is 2024-T6, and I know that they are using 7075 now, and believe this newer gear could be lighter.

What I gave you is for the tail-dragger, 1750 gross. The tri-gear is only 16.5 to top of gear.

As a comparison, both of my Kitfox gears are 22" tall, one is 60 inches across, and the KF7 is 68 inches across.

The MK4 gear is about the same as yours except thinner metal. The TD is 66, the tri-gear is only 62 across.

Hope this helps.

ED in MO

edit: The Magnum gear across fuselage is 35", and the MK4 is 32. The MK4 is 3 or 4 lbs lighter.

Edited by Ed In Missouri

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Posted

Ron, I have an old Grove catalog and it gives the dimensions for the Magnum gear: 21.5 axle to top of gear, and 66 across outside of axle attach. Weight is 37.2 lb for 1" x 5" gear. This one is 2024-T6, and I know that they are using 7075 now, and believe this newer gear could be lighter.

What I gave you is for the tail-dragger, 1750 gross. The tri-gear is only 16.5 to top of gear.

As a comparison, both of my Kitfox gears are 22" tall, one is 60 inches across, and the KF7 is 68 inches across.

The MK4 gear is about the same as yours except thinner metal. The TD is 66, the tri-gear is only 62 across.

Hope this helps.

ED in MO

edit: The Magnum gear across fuselage is 35", and the MK4 is 32. The MK4 is 3 or 4 lbs lighter.

Thanks Ed...I knew my measurements were off a little, I had the bottom fiberglass in place. I appreciate the numbers, that will reassure the answers about my measurements when I get them exact.

Well, I did some more looking at it and I'm thinking about making a 3 mount gear leg using the mount under the wing strut (Float leg attach mount).

It has truss support and I think it would really make a strong gear leg with the extra support.

It will look much like the Airdale Bush Gear in height and width, but it will have the third mount leg.

I drew up a plan with rough numbers, and I stole Randy's cool step idea. I drew it to scale with 26" tires. Also planning on using 1.5" tubing.

Let me know what y'all think...

Ron

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Posted

Take care to be sure those three mounts are in line. I have my doubts that they are.

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Posted

I saw a Kitfox 5 at a ski flyin this weekend that had Grove gear on it. Didn't get to look inside to see what it attached to, but the mount and gear were ahead of the regular attachment point for the standard gear. There was a two piece clamp that went around the aluminum gear with a 5/16" (I think) bolt in the front and back of the clamp. I'm guessing it bolted to plates that were welded onto the longerons, but couldn't see that. I have a Grove gear that was set up for nosewheel and wondering about putting it to use. It is shorter in height than a tailwheel gear though. I have the nose gear also, maybe I should just sell it all to someone that wants to go that way. Anyway, if someone has pics of the grove mount I was describing, please post them. Thanks, Jim Chuk

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Posted

I saw a Kitfox 5 at a ski flyin this weekend that had Grove gear on it. Didn't get to look inside to see what it attached to, but the mount and gear were ahead of the regular attachment point for the standard gear. There was a two piece clamp that went around the aluminum gear with a 5/16" (I think) bolt in the front and back of the clamp. I'm guessing it bolted to plates that were welded onto the longerons, but couldn't see that. I have a Grove gear that was set up for nosewheel and wondering about putting it to use. It is shorter in height than a tailwheel gear though. I have the nose gear also, maybe I should just sell it all to someone that wants to go that way. Anyway, if someone has pics of the grove mount I was describing, please post them. Thanks, Jim Chuk

Jim,

I will have to check my book, but believe the KF5 mount is the same as the 6 and early 7, with complicated round ends and radius blocks. The early KF7 had a complicated setup and I have a set. The later and current 7 has a simple clamp radius block setup, and I have a set of those. I also have the set of mounts for the earlier Foxes which bolt to the original gear mounts. How thick and how wide is your gear?

What does your nose mount fit, and how is it made and how does it attach? Can you post a photo or two?

ED in MO

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Posted

Hi Ed, Not sure if you understood my post, I was wondering what the grove gear bolted to. The clamps didn't hook onto the original gear mounts. The clamps were mounted ahead of the original gear mounts. All I could see from the side was the clamps going around the grove gear, and the two bolts going up into the fusaloge. The clamps were touching the fabric which was flat on the belly of the plane where the clamps mounted. It could very well have been a home made design, I don't know. He does have an O-200 in the plane. Maybe that's why the gear is mounted further ahead than the standard gear attachment points???? I'll start a new thread where I will post pics of my nosewheel/grove gear. Take care, Jim Chuk

Jim,

I will have to check my book, but believe the KF5 mount is the same as the 6 and early 7, with complicated round ends and radius blocks. The early KF7 had a complicated setup and I have a set. The later and current 7 has a simple clamp radius block setup, and I have a set of those. I also have the set of mounts for the earlier Foxes which bolt to the original gear mounts. How thick and how wide is your gear?

What does your nose mount fit, and how is it made and how does it attach? Can you post a photo or two?

ED in MO

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Posted

The Grove gear clamp on my IV mounts to the front bungee gear mount and the forward float mount. See the photos in my IV Restoration thread for the locations and how I reinforced them.

link

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Posted

Take care to be sure those three mounts are in line. I have my doubts that they are.

I was skeptical myself, but they do!

post-545-13618477806269_thumb.jpg

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Posted

Hi Ron,

That looks great and will be very strong with the added width and extra mounting point at the top of the gear. Even with the taller gear it will create a wider triangle.

Glad to hear that the three mounting point line up. Obviously the two stock mounting points on each side will line up and be parallel. I was thinking that if the rear mounting point was not exactly in line you could have fabricated an offset mounting point that bolted into the existing rear mounting point to give you a hinge point that was in line. Much better that you don't have to mess with that.

Randy

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Posted

Hi Ron,

That looks great and will be very strong with the added width and extra mounting point at the top of the gear. Even with the taller gear it will create a wider triangle.

Glad to hear that the three mounting point line up. Obviously the two stock mounting points on each side will line up and be parallel. I was thinking that if the rear mounting point was not exactly in line you could have fabricated an offset mounting point that bolted into the existing rear mounting point to give you a hinge point that was in line. Much better that you don't have to mess with that.

Randy

Agreed Randy...that would have been some advanced math on my caveman brain :(

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Posted

Well, it has been a long while, but I thought I would update this post. I decided to design my own gear but have somebody else build it because I wanted it welded right! I can weld, but I thought the landing gear was too critical for me to experiment with! That being said, I had to weld brackets on the front mounts to provide attach points for the cabane V. The gear measures 32" Tall and 73" from axle plate to axle plate. I stole rough numbers from Randy because I liked the AoA on his Avid.

Steve Furjersi at Experimental Aircraft Fabrication inc built the gear for me, and I bought his unique suspension system too. He is a great guy and he really helped engineer a cool gear for my Magnum.

I'm attaching pictures, so take a look, and throw spears if you have them, because I want all of your input!

Thanks,

Ron

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Posted

Hi Ron,

 

That looks really nice.  The hydrosorbs are preferred by a lot of the Cub drivers up here because they seem to asorb a lot and do not have the rebound bounce of the bungees.   I have a couple of friends who have them on their cubs.

 

The one thing that you might review is if the stock lateral frame of your fusalage between the cabane attach points may need some strengthening.  This will recieve a compression load between the attach points now instead of the bending load on the seat truss that it was designed for with the stock bungee gear.  The compresion load in this area seems to be the place most of the avids and KF's have failed when using the cabane gear, although the compression springs stack solid and the hydrosorbs will not tend to do that.

 

Just wondering; are the axles welded in place or are they replaceable?

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Posted

Thanks Randy...you answered a question that I had...I was thinking about strengthening it with glued in plywood panels in the seat truss. Is that enough?

They are not removable axles. I didn't know that was an option...I can see that it would be handy.

Thanks again for sending me the numbers on your gear! I really like the height of the gear, it will probably reduce the risk of me taking the flapperon in the cranium!

By the way, the guy that built the gear didn't want to put the middle leg on my gear because the back leg was so long and he was afraid the center mount would reduce the flex of the back leg. However, he welded the step bar in because he thought the back leg might flex too much without it. Whatever? I'll try it like it is and go from there!

Thanks,

Ron

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Posted

Hi Ron,

 

I don't think glueing in the plywood panels will give the existing cross tube that runs between the cabane attach points enough lateral stiffness in all directions.  That would really only stiffen it in the direction of the seat truss.  It might be better to weld another tube along side it either in front or in back of it and stitch weld it to the existing tube.  This will give it twice the lateral stiffness in the vertical direction and many times the lateral stiffness in the horizontal (front to back) direction.

 

I am not sure I understand why your welder was concerned about the additional connection tube not allowing the back tube to flex; stiffness with minimum flex would be good, along with the third point for load distruibution on the frame; but it looks pretty strong as is and the cross tube from front to back should be enough.  The workmanship looks excellent.

 

I think you will like the additional height of the gear; not only for your cranium but also the AOA help on performance.  Can't wait to hear further updates on your progress!

 

Randy

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Posted

I am really diggin' on Ron's rotisserie, would love one of those for covering and painting!

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Posted

@Randy,

Thanks for the idea, I think I will do that!

@dholly,

I've got severe back issues, so I built the rotisserie so that I can easily rotate the fuselage. I'm really happy with how it turned out. It made welding new gear mounts on the fuse really easy.

Unfortunately I had just moved and had scrapped my scrap metal pile, so I had to buy all new steel. All together I spent about $500 and about 1.5 days building it. I welded some harbor freight swivel casters on the bottom so the whole thing can move in any direction making it easy to get it in and out of the garage. It is the best money spent so far! I have to give credit to Ivan Allen, I stole some ideas from his rotisserie!

Here are some pics...no laughing at my welds :)

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Posted

I spoke at length with the builder of this gear today to see if it's possible to retrofit a similar spring system into my Airdale gear.

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Posted (edited)

I saw a very interesting variation of spring gear in the Pazmany book - If I can get my daughter to help, I will try to post it.

You designers can imagine, without drawing the V-leg portions, making an X out of the gear legs, and putting a compression spring / shock between the upper points on the X and attaching them to the opposite lower leg / to inside of lower longeron.  Got to think about this for a while.....If you try drawing something like this, make the upper part of the X a lot shorter than the lower part.

EDMo 

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Edited by Ed In Missouri

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Posted

Here is another variation of gear, as used on the Interstate Cadet.

post-399-0-38538200-1389674433_thumb.jpg

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