Wider gear options for the IV

32 posts in this topic

Posted

I am already looking for other gear options for my Mark IV after the first test run. I'm pretty handy with metal and would not mind at all building a set. I even have a spare Mark IV airframe to jig it off of. I'm going to search through the threads and see what you all have been doing and if anyone has documented their gear builds. 

Vance

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Posted

The MK IV should already have a wide gear set up on it unless it was changed.  First thing to check is the wheel alignment!!

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Posted

MK IV standard gear was just taller than earlier models but not wider.   Agree completely on wheel alignment.  JImChuk

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Posted

I believe this plane has the exact same gear as the earlier model A that I flew. It is no taller and does not have a step welded on it. I do have a set of the taller gear I got from Joey that could go on this IV easy enough. As far as alignment what are you looking for? Both straight ahead? toed in? 

I have attached two pictures. I'm assuming the white and red Avid is on the standard taller gear?

Thank you

Vance

 

Mountian Avid 6.jpg

post-329-0-54680900-1419981543.jpg

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Posted

The second picture is my Avid MK IV.  It has the standard MK IV gear.  If my memory is right, it's 2" taller than the earlier standard gear.  As far as wheel alignment goes, most say 0 to 1/8" toe out.  JImChuk

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Posted

Well you will be happy to know that your plane is on my desktop on my work computer. It's one of my favorite Avid pictures.

I believe my Avid was a transition between the C and IV.  Have you guys flown both sets and is there a noticeable difference between the two? You are correct on the height difference. I measured it for Joey and it was 2". 

Vance

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Posted

yes, I have flown standard and the wide gear.  My first set of wide gear from Avid did not have a step welded on them. 

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Posted

yes, I have flown standard and the wide gear.  My first set of wide gear from Avid did not have a step welded on them. 

Was there a big difference between the two? I'm taking the wide gear I got from Joey to the powder coater and I have a set of bigger rims and brakes (the same as yours) on my spare plane. I was going to cover them with fabric but after seeing your gear I kinda like that look. It will also match the doors after I take the fabric off of them too. 

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Posted

One thing, if you go to the Avid wider bungee gear, you want to at least infill the triangles on the seat truss with plywood to strengthen it.  The seat truss is a weak point even with the narrow gear.  Even more so with the extra leverage the wider gear will put on it.  JImChuk

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Posted

I have covering on my gear legs now.  I also faired everything I could to get more climb.  I used suberavids trick of sliding the trailing edge material over the round tubes on the jury struts and the tail struts.  I am going to use the old wood strut material on the vee struts on the gear.  The plane will only go so fast with the undercambered wing, but fairing everything you can really does help in climb and in power settings needed to maintain cruise speed.  I wanted to just do some tests to see if it would actually help me out and used white gorilla tape over the front of the fairing material to hold it on.  Suberavid just used zip ties and they are still holding up years later.  I picked up about 150-200 FPM in climb and can cruise at 5600 RPM at the same speed I used to have to run 6000 to cruise at.

These are very draggy planes, but we can do a good bit to get just a lil more performance out of them.  As I am ranging out more and more with the plane, every bit of fuel burn I can save will make a big difference as fuel stops can be far between them.

:BC:

 

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Posted

This is what I am trying

WIN_20171019_193153.JPG

WIN_20171019_193138.JPG

WIN_20171019_193117.JPG

WIN_20171019_193053.JPG

WIN_20171019_193029.JPG

WIN_20171019_193017.JPG

WIN_20171019_193001.JPG

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Posted

I suppose a way to test it is to mount it on a trailer like thing, put a bunch of weight on it, and pull it up and down a semi rough field at various speeds and see if you can wreck it.  I like it though!  JImChuk

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Posted

I like it alot!!! Maybe someday I will make a mod like this but for right now I'll stick with something a little less extreme until I get some time in this bird. Man you should really jig those parts up for people to make their own.

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Posted

I was thinking about first lifting it up by crane and dropping onto car dollies, higher and higher.

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Posted

I built a laminated wood spring gear one time for an ultralight.  I made a mock fuselage and tested the gear on that.  It was set up so the wheels landed on steel plates that sat on round rods, so they could move outwards.  The gear cracked when I dropped it.  I hated to see it break, but I was glad I tried it that way first.  Plane was still good, and I gave up on the idea of a wood gear.  Dropping will give a good idea of straight up forces, a trailer type test will for front to back forces.  Keep at it!  I like it.  JImChuk

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Posted

This is what I am trying

WIN_20171019_193153.JPG

WIN_20171019_193138.JPG

WIN_20171019_193117.JPG

WIN_20171019_193053.JPG

WIN_20171019_193029.JPG

WIN_20171019_193017.JPG

WIN_20171019_193001.JPG

Jared, which model Fox shocks are those? Did you fab the the arms? All .058 4130N tubing? Good looking setup!

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Posted

I am already looking for other gear options for my Mark IV after the first test run. I'm pretty handy with metal and would not mind at all building a set. I even have a spare Mark IV airframe to jig it off of. I'm going to search through the threads and see what you all have been doing and if anyone has documented their gear builds. 

Vance

I have been told (for tail daggers) to move the Front wheels forward 6”. The source was a highly respected person. Any thoughts on that?

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Posted


works fine but ground handling is a bit harder. 

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Posted

Couple of thoughts come to mind.  If one is worried about braking to hard, and going over on their nose, that probably makes sense from that standpoint.  On the other hand, the reason a taildragger wants to swap ends in the often practiced manuever called the ground loop is there is more weight behind the main wheels, and in a swerve, the weight behind the mainwheels trys to get in front of them.  I would imagine that when the designer looks at both sides of the issue, there is a happy medium where neither side is fully happy, but settle on a compromise... JImChuk

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Posted

Ah. I understand. 

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Posted

Shifting the wheels forward can delay the lifting if the tail with the resultant longer take off roll. Nosing over is a skill related problem in a kitfox.

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Posted


I can honestly say I wish my gear was about 2 to 4 inches forward of where they are. Mine are actually 3/4 inch behind my leading edge if my brakes were really good it could be an issue.

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Posted

The Avid main wheels are about 3/4" in front of the leading edge of the wing...  JImChuk

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