Plans discrepencies

[David M Johnson]

I know I'm kind of new at the whole build thing but I was hoping I could get everyone's opinion. I purchased a set of plans for a Bill Simon Shoestring. from a reputable source, the plans didn't come with Rib templates. When it came time to start the wing on the plans it showed a main rib and a tip rib for the wing I thought this won't be too bad I'll reverse engineer the ribs and build the wing.  Here is where it went sideways. After I got the ribs cut out in paper I laid them up to the wing plan and they are 3/4 of an inch TOO LONG! I went back to the fuse plan and measured and the rib sizes are different.  So my question is A. Does this happen for other plans and B. since this isn't a scale plane is there anything wrong with a larger wing versus the smaller wing.

David Johnson
I specifically did not state who these plans were purchase through because I value the source and I realize this is in no way their fault.

[Bill Morell]

A standard procedure for making the ribs would be to have taken the # of ribs for the wing and the same # of sheets for each rib and stacked them together between the root and the tip and start carving. Pretty much a safe way to do it. Drill 2 holes through the stack and bolt them together. Holds everything in place.

[Phil Coopy]

It happens.  I bought a set of 1/4 scale SE5a plans ($58)  advertized to be accurate and had them blown up to 1/3 scale (another $64). In the in the process of construction I found that, as I used lots of photographs for detail accuracy,  there were a ton of things out of place, rib spacing, incidences, outline, wing placement.etc. And these were supposed to be fine scale plans. Finally I have bought a set of Replicraft plans from Tony Kiger ($128) to work from.  These plans are used to construct accurate full scale replicas.
When you get into scale competition those judges are really sharp, especially when it comes to WW1 planes.  I have built scale for years and I have learned over time that there are a lot of bad plans out there. I bought a set of 1/4 scale Citabria Pro plans from Balsa USA and it turned out that they  were closer to 1/5 scale....they bought them back.  It is always good to research the photo documentation before settling on a set of plans.  Best to work from full scale plans.

Phil (sometimes on the dark side)

[Wynn Robins]

I pays to check each plan before you start cutting anything - I have around 100 plans on file - and a lot of them (probably over half) you would need to meaure and check everything prior to starting - I have some that show each rib - but if you cut them from the plan - you are in for  big surprize....

Stack sanding is a good idea - also measure each section of the plan to see which is the most accurate - it does get frustrating!

[Randy Powell]

I've built two Bill Simons' Shoestrings. The first was built according to Flying Models plan (inaccurate). The second was built with changes to the plan suggested by Bob Hunt. This included using templates for a Skylark wing (what Bill originally used) and a couple of other minor changes to bring it more in line with the original.

And yes, it's not uncommon, especially for some magazine plans in the 60s and early 70s, to be pretty inaccurate.

[Jim Thomerson]

I think the British are more concerned with details than we are when it comes to Old Time, Vintage, etc.  There was a fairly lively, unresolved, discussion in Aeromodeller, about discrepancies between the airplane as photographed in the construction article, and the airplane as shown on the plan.  I'd say match up to one or the other or make a combination of the two.

[Bill Little]

I've built two Bill Simons' Shoestrings. The first was built according to Flying Models plan (inaccurate). The second was built with changes to the plan suggested by Bob Hunt. This included using templates for a Skylark wing (what Bill originally used) and a couple of other minor changes to bring it more in line with the original.

And yes, it's not uncommon, especially for some magazine plans in the 60s and early 70s, to be pretty inaccurate.

I can vouch for that Randy.  The magazine plans were inaccurate as often as they were accurate back in the day.  I have also noticed recently how many times the pictures do not match the plans, as well.

One thing is, as far as OTS, Classic, or now Nostalgia 30, plans of the original and magazine plans both yield an eligible model.   And the kit (if made) was usually another version altogether! LOL!!  I am reminded of Ed Southwick's Skylark: Kit, magazine plans and his own plans.  All different, all legal.

Big Bear

[john e. holliday]

It is amazing how things get distorted even in kits.  I've had of the Sterling Skylark kits.  The second one was used as a pattern with all new wood.  hen I got the Ken Smith Kit and also got to see the actual plane.  What a difference.  Another icon taken too early that could fly such big planes and have such a big heart.  That also encludes his lovely wife also. 

[Brett Buck]

It happens.  I bought a set of 1/4 scale SE5a plans ($58)  advertized to be accurate and had them blown up to 1/3 scale (another $64). In the in the process of construction I found that, as I used lots of photographs for detail accuracy,  there were a ton of things out of place, rib spacing, incidences, outline, wing placement.etc. And these were supposed to be fine scale plans. Finally I have bought a set of Replicraft plans from Tony Kiger ($128) to work from.  These plans are used to construct accurate full scale replicas.

    Off topic, but - that's one of those examples of "too pretty to cover"! Fantastic.

     Brett

[pat king]

I have re-drawn some old airplanes and boats on CAD from the original plans and/or plans and kit parts. Most of the old plans vary from poor to almost totally useless. Most of the old kits do not match the plans. Some of the old kit parts do not even match each other. Sterling plans are tough because they do not have full size views of the airplane and they do not have full size templated of the parts. There is almost no way to scratch build from Sterling plans. I am currently working on a Ringmaster Sportster (Kit S 22) design. It is certainly no better than any other Sterling kit. CAD and laser cut parts make for great building, old kits and many old plans make for a lot of fit and fill to get something that looks decent.

Pat

[Dick Pacini]

I had one design published, the Spirit of Saginaw III, which came out in the January 1973 issue of Flying Models Magazine.

A few months ago, I ordered two sets of my own plan from Carstens. How surprised I was to see that about an inch or so was cut off from the rudder and fuselage.  My thoughts were that the printer shifted the drawing.  I then looked at one of my MANY copies of that magazine issue and discovered that the reduced plan in the magazine was the same way.  For a moment, I considered that the printer lopped off the end because of the size and that he may have put that small section in a different part of the plan, but no, it was just omitted.

As I examined the plan, I noticed that the tail end of the fuselage was a separate piece that was doweled in with toothpicks.  For the life of me, I couldn't remember, thinking perhaps that I had used a harder piece of balsa on the end to minimize dings.  Then it hit me.  I whipped out my tape measure and measured from the nose to the joint.  Sure enough, 36 inches.  The extra part that was doweled on was a piece of scrap used rather than buy 48 inch long balsa, just to build a 37 inch fuselage.

It only took 37 years for me to discover the error.  I imagine a few plans were ordered because I have heard of a couple of planes being built.  In fact, I saw one at a contest in Ohio I attended, where I flew the original. The kid was very excited that I was there and he was so proud of his plane.  That made two of us.

I still have the original model, although the fuselage is broken in half and the engine seized up solid.  Maybe someday I will repair and fly it.  It was my best plane ever.

[Clancy Arnold]

Do not blame only the kit makers or part time draftsmen!

My last FAI CL Scale model was built from enlarged factory provided three view drawing.  The location of some major features varied significantly from the plan view to the front view.  I had to measure the features in the photographs to see which was correct, or closest to correct.  That is probably why the photographs take precedent in your Scale Documentation. 

I know you are talking about Stunt Models but the problem exists in more than one area of modeling.

Clancy

[John Miller]

One of the problems converting old designs to CAD involves trying to fix the many problems or inaccuracys in the original plan. Sometimes the plan is of the first or inceptual version, and the artical photos are of the second, or third generation, built from modified plans. Some times the mods make it onto the plans, often or not, the mods do not make it, leaving a lot of interpretation to do.

Other problems involve having a time table that just doesn't leave enough time to make all the checks and counterrchecks needed to have no, or very few errors. Most of those who do CAD drawings expect to be making changes after the prototype is built. The drawing is never finished until then any way.

Another issue is involved into trying to fix the designs now apparent flaws, within the limits allowed, so the resulting model will fly right. A case in point, Sterlings Spitfire stunter. There was so much wrong with the incidences, no wonder few were able to get a good flying plane out of one of the kits. The best flying versions were usually built by top builders, who routinely fixed the flaws as they built.

[Geoff Goodworth]

David, sorry to come into this one so late but I've been on holiday and away from a computer.

The Simons Shoestring plan has more differences than you and Randy have noted. I'm still away and do not have all the discrepancies that I documented for the Shoestring plan and build article. One that I can remember is that if you follow the plan, the span is 58", not the 57" mentioned in the build article. certainly, as you have found, the rib sections shown on the elevation are quite different to the rib lengths on the plan view.

I took quite a few measurements from a photo of Bill Simons holding the model almost vertical and can give you a pretty accurate set of numbers for the wing, after I get home. Email me if you want the info.

Cheers, Geoff

[David M Johnson]

I know I'm kind of new at the whole build thing but I was hoping I could get everyone's opinion. I purchased a set of plans for a Bill Simon Shoestring. from a reputable source, the plans didn't come with Rib templates. When it came time to start the wing on the plans it showed a main rib and a tip rib for the wing I thought this won't be too bad I'll reverse engineer the ribs and build the wing.  Here is where it went sideways. After I got the ribs cut out in paper I laid them up to the wing plan and they are 3/4 of an inch TOO LONG! I went back to the fuse plan and measured and the rib sizes are different.  So my question is A. Does this happen for other plans and B. since this isn't a scale plane is there anything wrong with a larger wing versus the smaller wing.

David Johnson
I specifically did not state who these plans were purchase through because I value the source and I realize this is in no way their fault.

And in looking at the N30 page I ran across this From Bob Hunt

Just a bit more explanation on all of this: FM thought they were receiving the plans for the actual Stunt Machine. The man who actually drew the plans for publication apparently did not know that such things as wing airfoils and moment arms and such were important. Gene apparently did not check the work of the draftsman and so an inaccurate design was published. (That same draftsman did the plans for FM for Bill Simons' Shoestring and it was grossly inaccurate and Bill Simons' Aircobra, and it was also grossly inaccurate!)   

I suppose the argument could be made that since the "published" Stunt Machine was not accurate to the original, then the "real" Stunt Machine (The actual design that Gene flew...) is not copyrighted. I guess I could buy that argument. It still does not change the fact that the design is the intellectual property of Gene Schaffer and should not be offered for sale without Gene's knowledge and permission. Guys, there is simply too much of this going on in the modeling world and it is making me sick! We do not have the moral or legal right to sell plans for someone else's work. At least not without written permission. And, if the model was published, even the designer does not have the rights to reproduce a given model, unless he or she obtains the rights back from the publication in question.

There is a plans service that is based in Australia that is offering Genesis plans for sale. I receive nothing from those sales, nor did I authorize the person in question to sell them. He is stealing from me. I won't be party to doing the same thing to a fellow modeler, whether he is reachable or not.

Later - Bob Hunt