So I am starting to conceive the frame I want to build in my head and doing some reading on how to go about putting it on paper. One thing I have been reading is that when putting it down on paper you should draw it to a particular size on paper that will multiply in real life. Do any of you really do this? My thoughts is just to draw it out with my measurements on each area of the frame to save on time. Is this a bad idea? Any tips that you could give on how you go about this part of the project would be much appreciated.

I'm still a newbie hobby builder so take this with a grain of salt. I draw the whole thing out full size, front, rear triangles and fork. That allows me to step back and see if it looks "right". Having said that, my third design had the fork measurements all f'ed up so now I lay down a wheel template to double check that part of my work.

a lot of people draw full size. Since that would take a fairly large table, I have never done that. What I have done is draw out the head tube joints full size

I always use graph paper + marking the actual measurements.

I draw out everything full size. I do a lot of curved top tubes and it really helps to dial in the tt slope, bend radius, etc when you have a full size plan to hold a tube against.
the owners seem to like having the blueprint too, fwiw.

Thank you all for your opinions, time to look at my options for drawing this out.

OP; Imho, the best/ideal way to do it these days is to use one of the software design tools and output it to an HP plotter on 32 pound, 42" wide, roll paper. Then you can pin it to a build table with magnets to get your alignment just right. After getting everything cut and fitted, be sure to remove the drawing before firing up the torch (don't ask why I stress this) to tack it together.

-- The advantage of the software is that it does most of the hard math for you to a considerable precision and it has embedded knowledge base of the bits and pieces as well as wheel diameters, canti mount distances, etc., that will aid in your learning process also. Most can also output cut strips to guide you in mitering the tubes to fit.

-- The advantage of a plotter is that it can print almost anything to any size and to about 1/10,000 inch accuracy. As such a plotter is about a $5,000 startup cost, one can probably get by best by just outputting to file and taking the file to a Kinko's shop as almost all of them will have a plotter. One shouldn't miss the value of being able to render the design fully equipped in color for customer reviews/approvals. For that use, a 11x17 inch color printer would do fine and they are relative cheap (about $300-400 for an Epson or similar large format printer or about $10 a page printed by kinko's).

- Nothing in the above should imply that I think one cannot draw up a frame and build from that drawing. I have a good size stack (less one known in absentia as "poof") of rolled up, tattered, badly yellowing paper designs which served very well from the early 1970's on through to about 1990 (including my first build - a very nice 2XL/XL tandem from 1974-ish). Today, I doubt that I would sketch one out on paper as it seems to take a lot longer, seems to lack precision, and I already have a small stock of designs in the computer that can be quickly tweaked to meet needs. Likewise, the dining room table always seems to be in use for something else...

FWIW and hope that helps;
/K

I applaud the full size draftings. The exercise serves many purposes. Spatial relationships, resulting dimensions, and the further understanding of how a bike frame is put together all are gained to a greater extent than a scale drawing. But scale drawings are better then nothing. I would suggest that the OP get a set up to do a number of full size draftings if at all possible as the leaning process won't be complete with #1. Fancy equipment is not needed. Enough floor space, paper large enough (I used brown sign paper BITD), simple adjustable protractor, meter stick, string attached to pencil for a compass.

In time one gets more comfortable with the numbers and a full or scale drawing becomes less important. This is when an on line program (like BikeCad) comes in. Andy.

Doing a full size mechanical drawing of the bike is one of the things I find most fun in the building process. Of course I grew up in the era of eraser bags, so it's a process I'm more comfortable with. One does need to fashion some "tools" like a compass large enough for wheels. Suitable paper is another issue. I buy large poster board from the Dollar Store for 50 cents each, but it does require that you tape two together for a full frame drawing.

Andy; Completely agree. Of course as typical you have said what I meant to say, said it better, and in a third of the space. Kudo's on that. And thanks.

Andy; Re the paper;

Historically I had found white "butcher paper" to be the cats meow for this. Today can search Amazon for "butcher paper roll" (with no quotes) tol yield many listings in all sizes and lengths. Sometimes only one side is unwaxed. There is a $25 pull-off stand listed also which I would recommend. The other but a bit more expensive version of paper is "plotter paper" {search Amazon for "plotter paper roll" -- no quotes. 36" x 300 feet is a good size**. The diff with plotter paper is that it can be had up to about 40 pound thickness and 42 inches wide if needed. It is also much more find grained than butcher paper which can be helpful.

Reddog3; Re a compass for wheels... A cheap, more practical, easy to fold/store, and entirely old-school tool to just use a push pin at the axle center and add a length of string looped around your pencil and then around you go. Remember to twirl your pencil as you good around to keep the line on center. But imho, nothing beats using the specific rim you will later build into the wheels for the specific bike you are building. This can really help with getting canti studs and brake bridges just right as you can visualize the rims specific braking surface.

I would also recommend a 48" (or 72" if doing tandems) metal ruler for layouts. If you have a good table to work full-scale on (a sheet of 5/8" or 3/4" MDF will serve very well), recommend taping down your paper and use an aluminum "dry wall T-Square" indexed off the edge as it provides edge alignment, a precise 90, and a rule on both horizontal and vertical. Most home stores will have them at low cost. Keeping things aligned and baselined on accurate 90 degree vertical take-off lines can really helpful. Most of these stores will also have nice protractors with 1/2 degree or better marks which is good for doing the headtube and seattube take-offs.

Hope that helps some
/K

My "compass" is an 18" steel rule with a hole drilled at the axle, and marking holes drilled at various locations specific to the radius of the mounted/inflated tire being used.

Trammel points are easily available for those who want more exacting circles. Andy.

And cheap! https://www.micromark.com/clamp-on-tr...of-2,8389.html

Brian

I designed my first several bikes in full scale and learned to use a CNC by drafting at + 500%. As a welder, I got a real shock seeing what welding does to frame geometry. Welded stuff can "tighten up" (get smaller) and won't see it unless you do stuff in full scale.

I highly recommend doing the full scale drawing and learning to use layout tools properly. I don't know how many people that build bike frames understand the layout aspect of the job but I don't think it's 100%. That is one of the things that Cinelli did that I fail to to is build to final geometry not theoretical. Doing layout is difficult. Mastering layout is something to be proud of.

If you do choose to print a full scale drawing it would be good to have a couple of reference dimensions to check the scale of the drawing. I am not questioning the above tolerances, I just like to have a string tied to real life.

Andy - Those look awesome. Gotta have 'em. I am thinking they would also be very good for scribing long pairs of parallel lines. Would seem to be natural to use them on a nice stick of 1/2 or 3/4 inch square aluminum tubing or maybe a nicely lacquered beam of oak wood in about the same size.
/K

[QUOTE=ftwelder;15549148]... If you do choose to print a full scale drawing it would be good to have a couple of reference dimensions to check the scale of the drawing. I am not questioning the above tolerances, I just like to have a string tied to real life.[/unQUOTE]

Frank - you have hit a very key point that is under appreciated;

Computers will almost always lie to you and printers lie even worse! Even high-end engineering computers and printer gear requires regular calibration to keep them truthful. I can't justify that grade of tools anyway so...

I always try to work in a horizontal and vertical line along edges of a drawing such that the plot-out or print-out will show them along the waste edges. At least half a meter long with marks at the centimeters and if there is room, a 45 degree line between the tips. Then my best reserved steel rule and protractor (maintained in a sealed plastic tubes) can be laid on the full scale output to proof it before touching the files.

Many folks also believe what they see on a computer screen is highly accurate, but many screens are off by as much as 5-10% to start with and specifically between the horizontal and vertical. Easy to be seen by using the software of choice to draw a perfect square and then copy the square to the side of the original and rotate it 90 degrees. One or the other will suddenly look a lot more like a rectangle than a square. This leads to many errors in the same way as you noted.

Good point. Thanks for popping it up.
/K

I took the time to draw my frame full size, and I would highly recommend it.

I bought a roll of 36 inch wide drafting paper and a few rudimentary drafting tools, set aside a quiet Saturday afternoon, put on some good music, and enjoyed myself immensely.

The drawing helped me to confirm that my calculations were correct and that everything looked and felt right. As I build the frame I hold it up to the drawing to satisfy myself that everything is more or less where is should be.

I drew my last one up on a 900mm x 1200mm sheet of 3mm MDF - the surface is almost as good as paper for drawing plus it holds shape.

If you use mdf you can use flat white latex to paint/cover the intitial drawing and you're set to do another(draw, paint, draw paint, etc., etc.). Gripper is a primer that covers and adheres very well for this purpose.

Brian