Avid Plus build is on ....

30 posts in this topic

Posted

Well, the build is officially back on track.

A buddy brought over a laser level and it was amazing at getting the Vertical Stab plumb and the Horizontal Stab perpendicular.

I filled and redrilled the Stab Struts and bolted it together and it's still perfect.

How long can I keep this "Give a Shit" attitude goin' ?

It's a long journey comin'

Stay tuned ....

Jim R

 

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Posted


Very cool.

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Posted

Is this the same as a "fat avid"/

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Posted

Hey Chris Bolkan

It's not a Fat Avid yet but will be.

Its a new (and yet very old) Avid Plus or Fat Avid fuselage and rudder and Avid Mk IV Heavy Hauler everything else. Wings,            H Stab, Elevator, Pedals, Sticks and Control Column. 

I bought it in 2014 and due to my love for flying my Challenger coupled with an unavoidable 4 year break, am starting it now.

Hey TJay

Re Fuselage Wing Mount Tubes 

Carry Through Tubes?

The front Wing Mount Tube has a wall thickness of .054 inches.

The rear Wing Mount has to be modified on the Fat Avid Fuselage upgrade due to the centres of the front and rear tubes being jigged and  welded too close together by about 1/4 inch at the factory.

This mod was done before I purchased the plane.

The single wall thickness of the original tube is .035 inches.

It has a tube pushed in and welded so that it allows for repositioning of the rear pivot tube for the wing.

Together, the two tubes have a thickness of .109 inches.

Here are pictures of the front (non modified) and rear (modified) tubes.

 

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Posted


That was one of the fuses sold by [old] Airdale as a "Fat Avid" fuselage upgrade. It is not a true Airdale Avid Plus, which were sold as complete kits (only 7 known to exist). The Fat Avids re-used all the parts off your existing Avid Flyer B, C, D (Mk-IV), or Bandit with the exception of doors, balanced rudder and instrument panel. Of course, a Fat Avid fuselage could always be ordered with additional parts/options however, in every instance, MTOW was set by the parts bolted onto the fuse. Every one is unique.

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Posted

Thanks Doug

You're my favourite source for Avid model info.

I believe you have a Plus or is it a Fat Avid like mine?

JR

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Posted

Congrats Jim, you will love that fuselage.  That is what JackAk and I have.  The jig for the wing carry through tubes were off on all of these I guess.  Jack and I heated and bent the front carry through tubes forward per Steve Widner's direction. I made a template off my Avid MKIV to locate the front pin tube in the correct position, also reinforced it after it was in place.  A somewhat different solution than was done on yours but either works in the end.  You will be amazed at the additional amount of room.

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Posted

I think that is the fuselage I have too. I love the room. Super fun to fly and well behaved.

I think the control arrangement leaves a lot to be desired. While the mechanism under the seat and cables is convenient, Mine leaves a lot to be desired wrt flapperon slop.

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Posted

I think there are pics of the mod that John Stoner did on his KF III that put the mixer under the seat and gave it the proper differential.  You do have to disconnect the rods to fold the wings but that's a pretty small price to pay for a system with no slop and that worked well.  It was a pretty easy mod to do as well.

:BC:

 

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Posted

Thanks Doug

You're my favourite source for Avid model info.

I believe you have a Plus or is it a Fat Avid like mine?

JR

After talking to Steve W and Jerry M, we concluded I own Avid Plus Kit 007. Last complete A+ kit produced/sold. At one time I think I was able to trace all but 2 of the 7 kits. BTW, my carry thru tubes are exactly 27-1/2" CL to CL, must have been built on a different jig than the Fat Avid fuselages. I've tried to locate the jig used for A+ kits, no luck tho.

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Posted


That is so cool that you guy were able to get a hold of these airplanes. Some pretty cool history there.

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Posted

Progress and inevitable questions:

I've got the Control Column Extended, Riv-Nuts and Cockpit and Cargo Bay Floor Panels installed, Rudder Pedals and Control Column Installed  and (almost) all this stuff bolted down with "Inspectable Methods and Hardware"

I am now facing the thing I've been dreading, that being the Aileron / Flap Mixer hardware.

There is very little to go on from the MK-IV manual

There was a "Bag Full" of specialty parts that came with the plane.

Would anyone have or could direct me to ....

1) A photograph of what you have working for your Mixer Assembly in your Avid Plus or Fat Avid?

2) Any recommendations for the Flap Deploy Lever that could improve what looks like a terrible system. (I understand the lever and the mixer operation but don't get how the flap position gets held in place)

I've included several photos of how I've interpreted the assembly from the drawing I have for the MK IV.

None of the Mixer components are held together with the correct hardware but is sufficient for testing.

I seem to have interference issues with the Rod Ends extending out the LHS of the Control Column.

The Pivot Bolt that secures the two Rod Ends at the bottom of the LHS Stick (one points left to Bell Crank one points right to Tie Rod to RHS Stick) seem to drag inside the column when moved full lock to lock without Bell Crank connected.

I used the recommended AN3-10A bolt with the two AN960-10 washers and the AN364-1032A nut and was wondering if this makes sense.

I have all the hardware on the fastener (AN3-10A) that holds those two Rod Ends to the Stick but if I assemble the bolt with the washers on the bolt and nut it spaces the nut out too far and the nut hits the tube.

To use the recommended hardware I have to place both washers under the bolt head (to maintain correct bolt length) and no washer on the nut side.

This allows the Rod Ends to move back and forth without hitting the entry into the Control Column without the Bell Crank attached, however, as soon as the Bell Crank is attached and the stick is moved full lock side to side and pulled back for the elevator lock to lock it the rod and assembly just jams and drags and sticks etc.

I'm sure this isn't normal.

What am I missing here?

Thx for any help ....

 

 

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Posted

bolt "R" is shown vertical not horizontal.  That will probably make a difference.  The flap lever is held in place by the friction washer but it seems most make some sort of detent or ratchet system as they are used to other aircraft that are made that way.  I like not having detents and the ability to use what ever exact amount I want to use just by pulling or pushing the lever.  in reality I pretty much use full or none on the flaps but in certain gusty or crosswind scenarios I might use varying amounts depending on what "feels" right and gives me the roll control I want or need.

:BC:

 

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Posted

I'll take some pictures of mine. The easiest way to fix the flap handle problem is to install a linear actuator. Works well and does not slip when set.

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Posted

The yoke "H" needs to be loose enough to move freely so that it acts as a universal joint in addition to Leni's comment. I'm fine with the friction flap handle when properly adjusted holds great and allows precise adjustment albeit somewhat rather stiff. 

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Posted

Thanks guys for the help.

AKFlyer hit the mark with the bracket being out 90 degrees due to Bolt R and also got me to think about what else I looked at and didn't see.

The other thing that solved the binding was inserting the pivot bolt for the bottom stick and 2 clevis' and washers (another R bolt) in from the front of the Control Column like the drawing shows and not from the easier back side like I did.

More of the jamming, binding, sticking issues disappeared when I started thinking about actual "control throws" and when I started thinking about the flap travel realistically and its start and finish points all that jamming wasn't within any usable range of motion.

Where that leaves me is sorting out the Flap Control Lever and Linkage.

I have no idea what "Useful Travel" is for this, either linearly back and forth at the rod ends driven by the arm from the shaft or the degrees of rotation at the handle.

I've attached a couple of pictures of the installed parts I have that came with the kit but think I am missing some components for the factory friction disk system without really knowing what it looks like or how it works.

 

Chris Bolkan

If you could send me a picture of your Flap Adjust system that would be great.

I like the idea of a Linear Actuator for its adjustabilty.

Is that what you are using?

If so, where'd you get such a creature?

 

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Posted

I was not able to get enough friction on the flap handle to hold it against the wind pressure and ended up building a detent system for my flaps, which is a much better way to go and allows you to add incremental flaps when loads take you out of your trim range. Find a light spring that fits in your flap handle and an aluminum rod to fit inside on top of the spring.  Then slot the flap handle and thread the rod to take a 3/16 bolt that will engage your detent arc.  Punch the rod to disengage and let up to engage the detent.

I set mine up to move the flaps from 0 to 26 degrees, but at full 26 degrees it sometimes blocks out the tail so I have to let it off a notch and you instantly get full tail authority back.

Also, I ended up releaving a large part of the torque tube where the rod end comes out so it does not have any chance to hit it and limit the travel of the inner tube (aelerons).

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Posted


Also shortened the "T" shaped arm to get additional throw on the flap lever. Otherwise the flap handle has about as much throw as a switch. Notice in the third picture.

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Posted

I'll take some pictures of mine. The easiest way to fix the flap handle problem is to install a linear actuator. Works well and does not slip when set.

I got the flu and just got back from the dead. I guess I forgot that I took quite a few photos of the mixer assembly in my fat avid thread on this site. Let me know if you want any additional pictures. I should be able to get out of the house soon!

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Posted

Hey Guys 

Thanks for the help so far.

It's getting better results (this mixer / control column binding thing) but I'm working on it again today.

When it STILL doesn't work tonight, I'll post detailed pictures and dimensions of what's sticking and where.

I'm trying to be fairly fussy on this stuff as the next step is to schedule the MD-RA  (Ministry Delegate - Recreational Aircraft) to perform the Pre-Cover Inspection and don't want to give them too much to look at that don't adhere to the assembly drawings.

So far the drawings call for drilled bolts with nyloc nuts in a couple places, some bolts are just too long, stuff like that, that I'll need to explain to the inspector with explanations why I had to change it.

I hope. 

Any-hoo

Thx so far and 

Stay tuned .....

 

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Posted

Tonight's Facebook Post

Tomorrows Another Day.

 

 

Apparently,

According to the manual,
 
When all this stuff's assembled,
And all the bolts are tight,
And all the rods connected,
And everything's done right,
The steering sticks, the manual says
Should move,
Fore - Aft,  / Left - Right
But because the sticks both jam and bind
And because I've all but run out of rhyme.
And because on this crap,
I've spent too much time.
I'm gonna say ....
 "F#$k it"
(for tonight).

 

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Posted (edited)

Generally speaking, the bolts cannot be "tight".  locked by locknut or castle nut with the cotter pin, but I found that they have to be able to move a little bit to work without binding.  I also adjusted the washer stacks as needed to try to get the best alignment of the parts.  There is a lot of variability with the pieces so you have to adjust things as needed.

Edited by SuberAvid

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Posted

Here are a couple of photos of my linkage. The linear motor under the passenger seat adjusts the flaps. Things may not look exactly like yours because the original builder of my plane did a lot of cutting and trimming of things I think he shouldn't have, but it is what it is. None of what he did affected location or basic geometry of any of the control system.

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Posted

 Good News .... Finally

The Control Column and linkage is all in and not binding at all.

I had to change several things

1) I had to run the "Stick to Stick" tie rod on the rear side of the Stick Stubs that extend into the Control Column. This puts the Mixer linkage exiting the Column forward of the Stick Stubs. I see this as the biggest variance to the design.

I don't understand why it works exacly opposite to how it's drawn .... but it works.

2) NONE of the bolts inside the Control Column are Hex Head anymore and have been changed to lower profile AN Slot Head Clevis Bolts.

3) The length of the stud that comes from the Male Heim Joint in the Male / Female Hiem Joints that connect the Bell Crank needed to be adjusted to a specific length, too long and it started to drag too short, the same.

Thanks Randy for your input on putting it together and to you and Chris Bolkan for your versions of the Flaperon Mixer Control methods and pictures.

I love the automation of the Linear Actuator but the simpicity of the. ratcheting system.

These are the build conundrums I like

More to come.

It takes a village to build an airplane.

Thx

   

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Posted

A ratcheting system or a linear actuator will work fine. Friction as originally designed???? Not so much.

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