However . . . . The modern standards were not put in place till 1972
The original British Standard 308 was first issued in 1927. Still have my BS 308A : 1964 Abridged edition 'for the use of students'. Finally replaced in 2000 by BS 8888.
However . . . . The modern standards were not put in place till 1972
Pattern making is a whole new ball of wax, and "pattern" drawings have to be made for hand-made patterns, and all of those dimensions are larger than the "as-machined" dimensions.
.
You can make patterns from the part sizes. That is why they make "pattern makers rules" as the reading of say 6" on that will be 6.060" if it's one for a pattern that is intendedto be made in iron. If finished surfaces are indicated then the pattern maker will know to add a machining allowance to those too.
That's interesting, but A.W. was an American and the Americans were slow to do this. Almost unbelievable.The original British Standard 308 was first issued in 1927. Still have my BS 308A : 1964 Abridged edition 'for the use of students'. Finally replaced in 2000 by BS 8888.
There are some recent discussions about engine drawings.
I hate to admit it, but I am ignorant of almost all drawing terms, except "front view", "side view", "bottom/top view", and "isometric".
I have heard some mention that dimensions should not be repeated.
I don't really follow this line of thinking.
I generally put the dimensions in an arrangement that makes it easy to take them off of a drawing, when making manual patterns.
I often have a string of dimensions, and then an overall dimension, which is redundant, but I don't want to have to pull out a calculator while I am reading drawings.
Here are the drawings I made for the green twin.
I did not follow anyone's rules about making engine drawings, and am basically ignorant of any and all engine drawing rules.
I just do my own thing with drawings; I have always ignored almost every rule I was ever taught in drafting class.
So somebody should look at my green twin drawings, and tell me what you like or don't like about them, or how to make them better.
Are there some gaffs in the green twin drawings?
I never have problems using my own drawings.
I guess this is prove that ignorance is bliss.
https://www.homemodelenginemachinis...green-twin-oscillator-drawings-by-patj.34341/
I guess I somewhat mimic the style of Kozo Hiraoka, but it is not an intentional thing, but more of just a desire to make the drawings very clear and concise looking.
I am pretty sure I don't use the standard callouts for holes and things, bascially because I am ignorant of those standards, and I don't think that affects the usability or readability of engine drawings.
Have I repeated dimensions in the green twin drawings?
Honestly, I have no idea; I just make the drawings, I don't critique my own work.
.
Did a look through your drawings for the engine.
The only think I could see that wasn't laid out with dimensions was the flywheel.
There was no information on how to develop the spokes - - - - as they're likely ellipsoidal and then with the curves into the hub and the rim.
Wouldn't be a problem 3-D printing but not a lot of information if anyone wanted to be doing this some other way.
(Would be very difficult to dimension as well..)
Me - - - I would suggest keeping on keeping on.
I noticed in your post #3 of your drawing that a number of dimensions are within (over) the outline of the part - whilst sometimes unavoidable or because it simply makes more sense to do so - is best avoided and all dimensioning should be outside the part being dimensioned.
It is also quite common practice to make the outline "bold" to define the realm of the "part" vs the realm of the dimensions.
View attachment 146516
I am not claiming this to be correct or "THE" way to do it (in fact there are a few errors in it).
FYI
Regards, Ken I
Please - - - - comment wasn't supposed to be read as a criticism - - - - actually great drawings - - - that's what made the spokes stick out - - - - it was the only thing that didn't have some kind of measurements associated with them - - - lol.I got so deep into the fog of the green twin design that I pretty much lost track of some things, such as putting a lot of dimesion on the flywheel, especially at the spokes (the diameter, rim, hub and such are dimensioned).
At first it was going to be a barstock build, but I really had little experience with that other than some practice pieces.
Then we decided to make castings, but really had no concept of how to do that either.
I really just learned as I went, and I must say I learned a lot.
The flywheel along with the entire green twin engine design was developed from three oblique photos, and so everything was extrapolated from photos that were not straight-on.
The entire green twin build is an approximation of the real engine, but I am pleased with how close I got, and I never expected to get very close to the original design, and never really expected to be able to make the engine at all, since I had never made an engine before.
It was all part of a challenge from my Canadian buddy, who showed me three photos, and sort of dared me to make a 3D model.
It was a very whimsical thing, starting as just an exercise to improve my 3D modeling skills.
I never really expected it to turn into two real engines, much less get published.
It was sort of like climbing a mountain.
I kept reaching plateaus, and could see the next plateau ahead, and so I just kept climbing, not really knowing how high I could make it, or whether I would ever make it to the destination.
.
I think that's completely fine. I don't see it here, but there's always someone who's going to dislike something. Rules are fine to break for better clarity. If you are happy with your project and the way the drawings look, more power to you. You've put a ton of work to validate the design.As a general statement, I guess I like the looks of stacked dimensions, but that is a very unscientific approach, and is more like an emotional/feelings thing.
I look at drawings sort of like I look at old engine designs; ie: I want the drawings and engine build to look "visually correct", with "visually correct" being defined as looking visually correct to me.
Different strokes for different folks I guess.
.
Gordon, guilty as charged but I fully agree with you - so elsewhere on my drawing there are usually notes about tollerances dependent on the number of decimal places - with the caveat that untolleranced 2 decimals (metric) when given for co-ordinate data does not imply tollerance (unless stated otherwise).Since the advent of CAD drawings folks seem to have a lot of really weird dimensions. When I see a dimension like. 1.336 I immediately assume that the dimension is critical.
If making them better you should use mmThere are some recent discussions about engine drawings.
I hate to admit it, but I am ignorant of almost all drawing terms, except "front view", "side view", "bottom/top view", and "isometric".
I have heard some mention that dimensions should not be repeated.
I don't really follow this line of thinking.
I generally put the dimensions in an arrangement that makes it easy to take them off of a drawing, when making manual patterns.
I often have a string of dimensions, and then an overall dimension, which is redundant, but I don't want to have to pull out a calculator while I am reading drawings.
Here are the drawings I made for the green twin.
I did not follow anyone's rules about making engine drawings, and am basically ignorant of any and all engine drawing rules.
I just do my own thing with drawings; I have always ignored almost every rule I was ever taught in drafting class.
So somebody should look at my green twin drawings, and tell me what you like or don't like about them, or how to make them better.
Are there some gaffs in the green twin drawings?
I never have problems using my own drawings.
I guess this is prove that ignorance is bliss.
https://www.homemodelenginemachinis...green-twin-oscillator-drawings-by-patj.34341/
I guess I somewhat mimic the style of Kozo Hiraoka, but it is not an intentional thing, but more of just a desire to make the drawings very clear and concise looking.
I am pretty sure I don't use the standard callouts for holes and things, bascially because I am ignorant of those standards, and I don't think that affects the usability or readability of engine drawings.
Have I repeated dimensions in the green twin drawings?
Honestly, I have no idea; I just make the drawings, I don't critique my own work.
.
Enter your email address to join: