Avid Mk-IV Documentation and Materials

[FlyingPiper 1]

I have a 1996'ish Avid Mk-IV builder's manual, the "Avid Yearbook" from that era, a ton of vintage Avid-Comm newsletters, and even a small stack of new Avid Flyer postcards (not written upon).  I no longer own the Avid, and I've not seen a response yet from the buyer that he wants this stuff.  Anyone interested?

Randy

 

[allonsye 85]

Did you post up on the Avid FB page, Homebuilt.com page and kitfox pages?

[FlyingPiper 1]

No, but I'll give that a whirl.

Thanks, Randy

 

[OLDMNSX 3]

I would like to have it. I recently purchased a partially started and many missing parts kit.  How much do you want?

Thanks, Brad

[FlyingPiper 1]

I want this stuff to go to someone who really wants it and will use it.  Brad, that sounds like you.

If you agree to pay for the shipping, it's all yours.

Randy

 

[OLDMNSX 3]

That would be SUPER. Thank-You. I can send you my FedEx account number then all you have to do is drop it off at any FedEx shipping center. I'll email you a letter that you can take with you. Please PM me your email address. 

[Rex Reeb 1]

I too just acquired a new to me missing a ton of parts and no documentation project. Hell, I need help figuring out what all I have! I do have a new Fuselage and wings with .063in thick spars, STOL Ribs, and new fiber glass tanks. I'm not sure what model and or combo he was in the process of building when he stored it then passed away. Any help on how to I.D. parts and what the best things to modify or not modify etc would be great.

Thanks!

[1avidflyer 1983]

A model Avid is 36" wide at top of seat and a welded in motor mount.  MK IV has gusseting around the rear spar carry though, also the door latch is about 1/3 back from the front bottom of the door.  B and C models have the door latch in the front bottom corner of the door.  MK IV had a rounded rudder, earlier models were straight in the back.  It seems more of the later planes ended up with the thicker wall spars, (.083") and 1' spacing on the ribs.  Heavy hauler wing that way.   Stol wing had 18" spacing on the ribs and .063" spars.  This will give you a start.   JImChuk

Edited 10 Sep 2020 by 1avidflyer

[Rex Reeb 1]

Thank you Jim! That is a good start. Looks to be a "C" Model. and is as described with the STOL wing 18inch spacing on .063.

Question, can it be updated to Mk4? Meaning can I add the gussets ect? Is it worth the effort, and what is the benefit? The plane is completely unassembled at this time and the airframe is not powdercoated. What is the benefit of .083 vs .063? Is it worth tearing down the wing and rebuilding with the .083 and possibly adding extra spars for the 12'' spacing? Sorry for all the questions but I'm looking to get rolling and want to get to the best mods if any before I start putting her together. Also any other mods you guys might recommend? I would like to use a Rotax 912 series engine. Looks like this causes some CG issues, any advise there would be great as well.

Thanks again!

[1avidflyer 1983]

If the plane is unassembled, it should not be hard to strengthen the fuselage for the MK IV upgrades.  I wouldn't tear the wings apart, rather build a new set with bigger stiffeners.  Ribs can be built if you can't buy some from the new Avid outfit.  They seem to have gone into hibernation.  Reason I wouldn't tear the old wings apart, they are worth more then the price of new materials for new wings, and you can sell your original wings to someone who wants to replace their clipped speed wings.,   If you are really into changes, you could stretch the fuselage, and that would take care of the nose heavy ness.  For that mater, some have hung Subaru engines on a standard airframe, and it did fly, although I'm sure they had plenty of weight in the tail.  The 912 will be lighter then the Subaru for sure.  I also have widened the fuselage on the last few re builds I've done.  3 or 4" extra width at your shoulders makes for a much nicer ride when you have a passenger.   Strengthen the seat truss, as well as under the doors to keep that just a little bit to hard landing  from ruining your day.  JImChuk

[Rex Reeb 1]

Thanks yet again Jim, I would love to stretch and widen it, what is the best informational resource for that? Any good threads with pics? I have access to tools and talent in the steel fab dept. (A buddy of mine that is a race care builder). One of the old wings do have some rib damage, but the original owner bought another wing for parts (I assume). Also is there any resources regarding the building of new wings? I like the idea of the .083 spar strength and the sheet ply leading edge I've come across on the forums. I'm in Arizona, if you know of any local builders, that would also be a great help.  Thanks again..... Sorry for all the newb questions, I've owned and built several aircraft in the past and was a production manager for a small Weightshift trike company for several years, so ability isn't the problem, just wanting to get rolling in the direction of a flying bird.

 

Rex

[1avidflyer 1983]

 .083" spars may be real hard to find, but Kitfox uses .065" clear up to their heaviest models.  I think they gain the needed strength with a better/stronger stiffener.   I priced spar and stiffener  a few years back, and Just aircraft was a bit cheaper then Kitfox.  As far as ribs, they should be fairly easy to build, make a pattern piece, and use it as the guide to cut out the others on a router table with a bit like this.   You can even make a router table of sorts with a piece of plywood, have a hole for the bit to go through, and screw the router to the underside of the plywood with the plywood sitting on a couple of saw horses.  Use T88 epoxy for the glue.  I've made rib tail replacements like this.  (see picture)  I got the plywood from aircraft spruce, 1/4" is 12 ply, 1/8" is 5 ply.  Here is a link to the plywood.    JImChuk   https://www.aircraftspruce.com/catalog/wppages/finnishbirch.php

[1avidflyer 1983]

Never stretched a fuselage, but here are the widening pics I did on a Kitfox 4.  (I think I've posted this picture 100 times)  JImChuk

[Rex Reeb 1]

That's pretty neat! Did you make some stringers to fair it in going aft? Also, I really wanted to go 4 stroke like a 912 series engine, How bad is the Nose Heavy situation with that motor? I was thinking about a Yamaha based conversion since Teal lives an hour from me and I love the idea of 140 plus hp, but I know they out weigh the 912 by a fair number, So I think as it is right now I'm going to leave the length alone and possibly add internal stiffeners the the original wing and just repair them, fastest way to a nice capable airframe. I don't want to get bogged down with too many re engineering projects on my project lol. I think the 912 mount or if I go 2 smoker a 670 mount will be enough. I think I may widen as you did though, that it cool and I'm a larger guy. Any recommendations on a spar stiffener?  Dang Jim, I'm learning more from you than hours of huntin the forums! Thanks!

[1avidflyer 1983]

The Kitfox uses wood stringers, on my Avid, which used steel tube stringers, I added piece of tube about 18" long back to the orginal stringers.  Would have gone further, but the Avid MK IV had a baggage compartment door on the side, so I stopped before that.  These pics of of my Avid Flyer.  Went 3" wider on it.  Also you see the infill on the seat truss and under the doors.  I like the under the doors infill better on the Kitfox though.  Live and learn they say.  Did the Avid first.  JImChuk

[Rex Reeb 1]

Very nice, Mine does not have the tabs for the storage compartment. I was thinking of adding it though. What did you use to paint it with?

 

[1avidflyer 1983]

Epoxy paint on the fuselage.  Don't remember the brand on the Avid, the Kitfox was PPG Omni something or another.  JImChuk

[Rex Reeb 1]

Ohhh kay.... I've been doing a lot of research and am pretty sure I in fact do have a "C" model. I will widen as you have Jim, I have the material already and the fab ability. I will also strengthen the Truss area and the lower door sill like you did on your Fox. Is there any more structural gusseting that you would do? I see they gusseted the rear spar carry through and that should not be difficult. What thickness did you use? Did you use all the same thickness gussets?  Thanks again, sorry for all the questions, new to a compete and custom build. Looking forward to making it my own.

[1avidflyer 1983]

I used .040" 4130 chrome moly sheet for all the gussets.  There is also a small gusset at the front bottom of the door on the MK IV that isn't on the C model.  Do you see it?  Also half way up the back of the door, and at the top back of the door.  Easy to add, and I suppose they put them in for a reason.  JImChuk

[Rex Reeb 1]

Thanks again Jim, looks like I have a good starting spot. I do have another question, is there a pattern to cut windscreens and floor boards? I don't have any of that reference material on hand. Thanks! 

[1avidflyer 1983]

Only pattern I've ever used was the old windshield clamped to the new piece of lexan.  Mark the outline and drill all the holes without moving the "pattern", unclamp the two pieces, cut it out and you are pretty near done.  Never have needed to make new floorboards, but would do the same thing if I needed to.  If you don't have the old windshield or floorboards, maybe I could trace out a rough out line on some paper and send it to you.  Either Kitfox or Avid marked out the rough shape of the windows and windshield on the lexan they provided with the kit I believe.  But with no pattern at all, you just start with a big enough piece, and cut away everything that shouldn't be there.... Trying to be funny there, but it really is what one does. Fit, mark, and trim.  Fit, mark, and trim.  Eventually you get to the point where you say, "ya, that's right" or you scream and holler and say "that was to much" and you start over with a new piece.  JImChuk

[Rex Reeb 1]

I figured that's were this is going lol. Come to think of it, there is a guy building one an hour or so from here and I know hes going to be doing a windshield soon. I'll trace his, but thank you for the offer! Oh yeah, I was looking over the gusseting and widening mods and was curious as to why the outer door frame mod doesn't extend to the bottom of the rear carry through. Looks like an easy doubling/ strengthening opportunity with very little weight penalty, My thought would be to do that part first then add the gusset to tie it all together, or is there a clearance issue I'm failing to see?