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I bought the StewMc dread plan believing it was a full scale plan. It is clearly advertised by StewMc as "Full scale". Some critical dimensions are shown on the plan and I checked a half dozen or so of these with my scale ruler laid on the paper they measured exactly what the dimension said. Great, the plan was printed properly (I know printing can be a culprit even though the CAD file is correct.) so its full scale, I thought.

Most parts are not dimensioned, but that is OK, I can use the plan scale to make patterns, I thought. It has a section A-A of the 10th fret neck shape and a section B-B of the 1st fret neck shape. Templates of the 10th and 1st fret neck shape is typical for shaping the neck. The problem is, making a template using this StewMc plan would have put me WAY off. The neck section at the first fret measured 1 21/32" wide when it should have measured 1 27/32" wide (the nut is 1 25/32" wide dimensioned on the plan but the 1st fret section was smaller than the nut!) totally useless. Likewise, the 10th fret section measured 2 1/32" wide when it should be 2 6/32". These are significant errors that could have ruined a neck had a template been made and used from the plan.

That is not all. The X brace and other braces are not dimensioned, but like above can easily be measured or used as a template from the plan for width, height and shape. Unfortunately, the width shown on the plan view is 10% smaller than that shown on the section view. Which is really intended? Brace lengths in plan view are shorter than the profile. Who knows what the profile is really intended to be. The plan has 3 neck heel profiles which are intended to be the same, but they are not - they vary depending on which part of the plan you take it from. None of this would really matter much for the experience builder that would use his own shapes anyway, but for the novice it is of more concern.

The plan has a "full scale" side shown full length in profile, but no dimensions are given (it even has a "cut line" shown). I had intended to use it for cutting the side to the right profile before bending like Doolin and others do (I'm using a Doolin style bender which anchors the butt end of the sides, thereby fixing them. They don't float around like the Fox style bender.) But now the side view is of no value. It can't be used.

I called StewMc hoping they might make corrections and send me another plan. No luck. At first they said the plan was "just a guide to show how things go together" and not intended to be to scale. When I pointed out that it is advertised and sold as "Full Scale" the tech went and checked and then said I was right. He was no help, but did admit that the plan had some significant errors after I lead him through it. They credited me my $12.45 but I wanted an accurate plan. I do not expect perfection. But this plan has too many errors to be trusted. Period. My whole purpose here is to give other newbies like me a warning. This plan is sometimes to scale and sometimes not, and is inconsistent when showing the same part in different views.

Ed

Ed

I understand your frustration. I purchased the Beard plans for my
Resonator build and found I had to be careful with dimensions in the printout. However, Beard gave written dimensions that were more accurate.

A blueprint is seldom a true scale plan unless the plan states it. This will be stated in the menu box on the print. If you don't see SCALE it isn't . Also if it is a copy the chances of it being scale is even less. For those of us that work with blue prints everyday they are representational views only . I have used this plan and it does the job. The side profile per the actual martin shape will get you in the ball park but there is no way you can make it perfect without jigging.
I have yet to see a perfect plan . Simple things like mold shape can alter the math involved , and it won't take much. Use the plan as a guide and you should have a good result.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Take it from an old tool and die maker - NEVER assume a drawing is to scale.
Use the noted dimensions, and double check their math and yours!

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"Act your age, not your shoe size" - Prince

Something I had beat into me at a young age: never scale from the plan! Doesn't mean I don't ever do it; sometimes I like to cut parts out to make templates but I always measure carefully first.

Well, nobody actually beat me but you get the idea.

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Steve Smith
"Music is what feelings sound like"

When I draw up plans for an instrument, I never make it to a 1:1 scale. I usually make it much smaller. It saves paper and I'm never tempted to measure anything from the sheet.

I have not seen the StewMac dred plan but I am concerned that you said that most parts are NOT dimensioned. It would make it hard to build from the plan if that were so. However, I seldom follow a plan exactly anyway since exact reproduction is not my goal. It sounds like the guitars profile is correct so you can trace that and make mold and bender templates. This is the one area that I regularly copy a drawing because I don't know how to get the shape of the guitar from the dimensions.

The idea of not scaling to the plan is a good one to bring up.

I made some molds from an L-00 plan. I measured several parts of the drawing and they came out pretty close. Close enough for me to believe the plan had printed to scale. I then made up my templates based on the shape from the plan and as it turned out, the body is just a bit short. I'm glad I caught it when I did. Liking the shape and size of the template, I went ahead and built my molds with it. As I'm building I just have to make sure I'm working from the dimensions provided and orient everything so the scale works out.

Oh and someday I'll have to figure out what case will work.

But I would have been in huge trouble if I had gone through the bracing and making other templates right from the drawing.

The title block ("menu") says "Scale: Fullscale". I make my living handling engineering drawings daily and when there is no scale this part of the title block will typically say "Scale: N/A" or "Scale: Not to Scale". This plan is advertised as full scale and marked on the actual plan as such.

As I originally stated, I really don't expect perfection. But to have a 1st and 10th fret neck shape section that is seriously undersized is a significant deficiency. To be usable I would have to cut it out, take it to a copy machine and fool around with blowing it up by trail and error to get it sized right to make a template.

The side profile says "SIDE PATTERN Cut unbent side to this shape. Then bend and trim to full length as noted by dotted lines." As previously stated, it even has cut lines. It is obvious that the plan's designer intended just what he said in writing on the plan. Namely, the side profile was to be an actual scale pattern for shaping an unbent side (what I want to do!). But StewMc told me today this is not to be used as the plan states. If I had the CAD file I could have it fixed in a day.

Todd, makes a good point. The braces width at the base is clarified by the brace table. Unfortunately, the brace profiling is not.

I like StewMc. I'm not intending to rail against them or make a big stink. I am only warning new builders that this plan has some deficiencies to watch out for.

Ed

Another from that trade & I was always taught never to scale or take measurements directly off of a drawing, even if it had a scale written on it. Mind you most engineering drawings have DNS (do not scale) in the scale section of the title block. But if a rule was ever seen hovering over a drawing where I did my apprenticeship, you could bet your life it would be followed by a stream of loud obscenities from the foreman!
If the drawing has a table of sizes as Todd mentioned, then that is what you should work to and as John mentioned, remember, the drawing is only a graphic representation of where things go.

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Nick Oliver

http://www.oliver-guitars.com

Mike,
I appreciate your honesty. At least you admit that you scale off the drawing for the body size and shape and make outside molds and bending molds from the full scale drawing, not from dimensions. The StewMc plan has no dimensions for the body so it is hard for me to believe all these posters that say they never scale from a drawing. My guess is that most of folks saying not to scale from a drawing actually do exactly what you said. They use a dimensionless body shape from a "full size scale" to make their molds and bending forms. How important are these items? You can't build a guitar without a shape and I've never seen one fully dimensioned. The same goes for brace locations. Most people likely scale the plan for brace locations too, among other things.

If you want to build a bridge like the plan, it is not dimensioned, you must scale it. The peghead shape is not fully dimensioned. The sound hole location is not dimensioned. No locations for top braces are dimensioned. etc. etc.

I have long known to go with written dimensions (dimensions govern) instead of scaling a drawing. But instrument plans seen to be lacking many dimensions forcing the use of scaling or just ignoring the plan altogether. Many experienced builders are likely doing the latter most often.

Thanks for being real, Mike.
Ed

I can certainly see Ed's point.

For certain you should 'not' scale from a drawing, that point is clear, and we all know that Stewmac is a really good company to deal with and it is my experience that they always do what they can to keep their customers satisfied so this should not be seen as an attack on them. But the problem is that their business model sees them very much targeting the new and inexperienced to the craft and they do that by presenting clever ways to overcome some of the more challenging aspects of the craft so that the whole process can be broken down and less daunting to the beginner.

In a strong way that model cultivates a reliance and trust in Stewmac in the minds of those who are taking their first steps, and it is those same people that would be most likely to assume that if Stewmac said that a plan is to scale, then its to scale and they can take what ever measurements that want from the drawing....an incorrect assumption to make in the bible of engineers yes, but these people are not engineers and in fact may not have ever had any experience working with their hands before. In a craft that relies heavily on a successful out come to inspire continued participation by the target of their business model, you would think Stewmac would pay very close attention to ensure they eliminate the pit falls for the inexperienced by making sure that at least 'their' plan, which is sold as "Full Scale" would be just that in 'every' detail.

They probably need a heads up I reckon Ed..

Cheers

Kim

I can understand your frustrations Ed but the reality is that a set of plans marked as full scale have proven to be problematic (the reason for your heads up), what most here were trying (not maliciously or in an "out of touch with reality" way) to point out is that you can get burnt by so called 1:1 or full scale plans, never never take things for granted. If you have access to a dread then measure that up or if you don't then take your plans along to a music shop & sit a dread off the rack on top of the plans & check your outlines. Alternatively R.M. Mottola has a wonderful bit of software called G Thang (FREE!) that has a dread outline in it with all the radius's & their centres included in & all the dimensions you need to form a dread outline.

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Nick Oliver

http://www.oliver-guitars.com

I had a bit of a head scratcher when my SM OLF SJ plans were 1/2" narrower in the lower bout and 1/4" narrower in the upper bout, (but length was OK) than stated on the website.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I too have a machinist toolmaker back ground. Never assume the print is correct . Fullscale as I was taught meant full sized the word scale had to be alone. Often these things are based on the company you work for and how the drafting department worked. The size was also noted as A, B, C etc
A print gets you close but you are the guy building it.

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

You should contact Stew Mac about this. All in all though, as others have said, take any plans with a grain of salt.

I would have to agree with Ed... why bother drawing it at all if you're not going to be 100% accurate? Especially the side and neck templates. We're not dealing with mathematical shapes that can be recreated from a table of measurements, so if it's not the right size, you're going to have to copy and scale it until it is the right size (wasting a bunch of paper and ink in the process), or just ditch the plan and draw your own shapes anyway. And if the body drawing is not accurate, then what are you going to make your side bending templates and molds from? Guitars are too big for most printers, so it's going to cost extra to get the size right, or again ditch the plan and draw your own shape.

I haven't used any plans thus far, but I do all drawings at actual 1:1 scale (tape 4 or 6 papers together). 'course, real life usually turns out a bit differently so I always measure in whatever way gets the important relations correct, but you still need something to set the ideal unless you're just going to freehand bend the sides with no reference at all and assemble freeform and see how it comes out. Actually I've kinda been wanting to try that. I already shape the back arch/taper by hand just by referencing against the flat bench top (with sides glued to soundboard), and shape the neck by feel rather than templates.

With respect to a set of plans, there are two parties involved, each of whom has a distinct responsibility. The supplier of the plans has the responsibility to make sure the plans are DRAWN accurately, and to provide measurements that can be used by the other party to correct for inaccuracies that arise from the nature of printing an accurate set of plans on an imperfect medium.

It is the responsibility of the builder to assume the plans are not accurate, and make adjustments accordingly.

I have a set of the SteMac plans in question but have not built from them or even studied them, so I can't personally speak to whether they have fulfilled their responsibility here. If they haven't, I think the OP has a legitimate complaint.

Ed, Thanks for the heads up. You have gotten a lot of advice about doing what you have already done. Namely checking the plans for inaccuracies and inconsistencies and you have done that and found the plans wanting in that regard.
I see no reason a plan for a guitar couldn't be as advertised and described. In fact most things for sale should be that way. I don't believe that what you are saying is a deficiency in your plan reading or the nature of plans in general or a unreasonable expectation from you. All of these things have been suggested.
A guitar plan doesn't have to have fine tolerances but it could be done in such a way as to be able to scale from the drawing for certain things, and to use the dimensions given for others. Where this is the case it can be noted. And while absolute accuracy is not possible on paper relative accuracy and reasonable accuracy is.

I have a GAL plan draw by Kerry Char. Nice plan, fits the bill, can be used to scale of off. I have not found it lacking. It has the alternating black and white 1" bars that go across the top of the plan and down the side to check for any paper stretching or shrinking. I would use a guitar scale ruler for fret positions and bridge location, etc. but you can work right off of the plan for most things. Of course checking and verifying the things you can.
Link

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Cut to size.....Beat to fit.....Paint to match.

I got a Classical and Flemenco plan from LMI, god like 15 years ago maybe, and they make great wall art in my shop thought the florescents wash out the color in time

Coincidentally to this thread though I am actually using one of the plans now. A 1943 Marcelo Barbero Flemenco.

Still I can't imagine ever trusting a printer or a draftsman to a tee on any plan and will proceed with caution and hopefully backed by years of experience.

Yes, Link, they were all suggested above by posters. I checked the printing accuracy, checked the non-dimensioned neck shapes before using, etc. as you pointed out. Thank you.

I am honestly surprised by the majority of posters. I count 5 people above who say not to sale plans, but just use the written dimensions on the plans. If I or others followed this advice, here is a partial list of what you can not do with this StewMc dread plan unless you scale from it, because dimensions are not given at all or not fully given:

1. Can't get the body shape to make inside or outside templates, can't cut top or back to shape
2. Can't thickness or cut to length the fretboard (taper and fret locations are given)
3. Can't profile braces
4. Can't locate braces on the top or the back
5. Can't make a bridge
6. Can't make cut the sides to shape as instructed on plan
7. Can't shape or thickness neck
8. Can't make tail block
9. Can't cut dove tail
10. etc.

I believe that expecting a plan, advertised as full scale, to be able provide the above items is reasonable. Surprisingly, many posters do not. That is OK. We all have different opinions.

I am smart enough to take measurements from existing guitars so that I don't need this plan to accurately build a dread. I bought the plan to make things easier on myself and believing it would do that. It does not unless someone scales from it. Following the advice of experienced posters, most people should not buy this plan. If it is one of the better plans out in the market, then the market is in sad shape for guitar plans IMHO.

My whole purpose here was to tell new builders to watch out for deficiencies in this plan. I now see that some folks don't believe that these are deficiencies. It is OK with me if some of us agree to disagree on this point. It does not upset me.

Ed

I’m with Ed on thinking a plan set, whether for building a roll top desk, a robotic arm or a guitar, should provide sufficient dimensionally accurate information needed to complete the project.

Fortunately, for my first guitar I was lucky enough to have Brune’s 1937 Hauser plan set to work from. They’re plotted full size (1:1) on stable translucent velum; everything on them is drawn accurately to scale and additional critical dimensions such as plate thicknesses are given at numerous points where such information couldn’t be taken off by scaling the drawing. I think the only thing I found lacking on the plans to build a dimensionally accurate copy of the original, both inside and out, was the amount of doming, if any, for the back.

Joe

Thanks for the realistic suggestions, Todd.

As I stated, I don't need the plan to build a dread. I am flexible enought to get along without it. I can get enough information from existing guitars and help from kind folks like you and fudge in the rest to complete it. I'm using a 25.5" scale and a 1.75" nut so my now complete fretboard is entirely of my doing, not the plan. And since portions of the plan are accurately scaled (portions are not) I can scale much of the the info mising from the list I created. Note that I said "IF I or others don't scale" it creates the list. While this scaling goes against the recommendation of a number of people herein, it is close enough, when checked for reasonableness, to be usable. I had hoped my list would point out to those who say "never scale a drawing" that this unflexible approach does not seem very realistic to me. If one is willing to do some scaling and checking, this plan becomes very usable. I am willing to do some practical scaling and checking. Without the checking, this plan could burn someone. It is that someone whom I was trying to help with the heads-up. But somehow this struck a nerve with some folks. (I know the neck shapes are too small and I couldn't get StewMc to stand behind the drawing's instructions on the side profile.

I ordered the Dreadnought plan directly from Martin a year or two back and received the StewMac plan from them.

As far as body shape and most other measurements, I don't have any problems with the plan. It has alreaady been mentioned that there are lots of little variances even in the factory made guitars. The same goes for the templates and molds that are being sold to builders. I have seen four D templates from different sources, all with slightly different shapes and none that matched the shape of the mold that I purchased from a supplier a few years back, so I made a template to match my mold. I would recommend making both the mold and template (the StewMac plan would be fine for this), but if one didn't want to make both, purchase either the template or mold and make the other to match.

Whew...so Ed, are ya sorry yet that you tried to be helpful? I'm thinking there are a lot of (silent) newbie builders out there that benefited from your post.

Yes dont assume that a drawing is printed exactly correct or drawn to scale, but were talking about a guitar not machined parts going into the space shuttle. For the shape of the body, or the placement of braces, who cares if its off by 1/32". As hand builders we introduce a fair amount of tolerance into the process. Some things you should make sure to be precise and shouldnt be using a drawing as your template.

That said, Ive drawn parts up in CAD and plotted and printed 1:1. Its always been dead nuts when I measure it up.