What Does Do Not Scale Drawing Mean

• #4

Marv and gw are absolutely right. this is a general rule of building things.
Sometimes a print volition have dimensions but non ones you want or feel you demand .This is time to pull out the pencil and paper or calculator, and do the math to determine other dimensions. Practice non read them with a scale. If yous are really jammed in a corner and need to utilise a scale as a last ditch no other way to get a measurement bank check known given dimensions both horizontal and vertical to see what error or distortion is in the print. Even this may not requite an exact dimension if the print was not drawn to true calibration.
Equally far equally scaling up yous should be fine.
Also exist aware that doubling the size of the engine yous will accept an engine that uses 8 times the fabric thus weighs 8 times as much will utilise viii times the fuel and put out 8 times the ability. but going from 5cm to ten cm should not be a big deal.
Tin

• #6

considering information technology would became an 8cc, or not? ???

no when you lot calibration upwardly :
linear measurements are proportional ie 2x
area is proportional to the foursquare of the number 2^ii= 4x
volume is proportional to the cube 2^iii =8x
Can
Oh and yea a duh doubling a two cc motor would give a 16 cc motor where was my head whoops.
edited to right mental gas!!!

• #7

That one confused me for a while until an oldster referred to what I call "a 6" ruler" equally a "6-inch-scale". Then it clicked

"Exercise not scale" means "exercise not slap a ruler on this cartoon and effort to have measurements off it"

• #8

The word calibration in the English linguistic communication is a bit ambiguous.
Scale: an instrument for measuring mass.
Scale: The protective plates on a fish.
Calibration : rust chaff corrosion on metal such as mill calibration.
Scale the marks on and instrument such every bit a ruler or scale or a thermometer.
Scale: The marks on a map representing a stated real distance.
Scale: ratio of the distance on a map , drawing or model that represent the same distance in the real world object.
And there are a few others also.
Do not calibration means practice not mensurate the mass of the drawing :big:
Tin

Oh and yea a duh doubling a 2 cc motor would give a 16 cc motor where was my caput whoops.

• #10

Drafting scales are still available mostly used past students most unremarkably in a trianglular shape with 6 to 12 scales on it. I have three different ones:
metric for engineering or architectural use
architectural imperial fractions. ie one" to the foot calibration or iii" to the human foot calibration
and engineering in decimal inches.
I am still ane of those former timers that leanred drafting in Jr loftier and loftier schoolhouse on newspaper before the heavy use of computer drafting. The offset release of automobile cad was autumn of 1982.
Tin can

• #11

I took two years of mechanical drawing in high school in 1955 and 1956. 1 of my classmates was female and that was considered and then unusual that she was mentioned in the local paper. The time in the form that the tension was highest was when we had to employ pens with Republic of india ink to consummate the drawings. No errors were tolerated.

Jack

• #12

Rulers are made of plastic or wood, scales are metal or in a few old rare cases
a triangular device with ivory faces.
...lew...

• #13

Lew---Triangular scales were besides available in inexpensive, white plastic. I know, considering as a starving drafting apprentice in 1965, making $53 for a fourty hour calendar week, that was all I could afford. I couldn't afford one of the "nice" triangular scales untill I'd been working v years. ;D ;D We worked on a lot of big gold mining projects, self unloading ships (grain carriers on the Great Lakes) and on the Athabaska tar sands project. Nigh of our General Arrangements were done at 1/4"=12", detail work was done at ane"=12" calibration, and "accident ups" were done at 1.5" and 3" to the human foot scale. We HAD to draw everything to scale, only we had to calculate every dimension. This was in the pre reckoner days, when everything was washed with "Smoleys Iv Combined Tables of Logarithmic Functions". The "Checker" (Near hated human being in the drafting role) would check your drawing for scale, and your calculations with a slide dominion, and if things were out of scale, y'all would exist looking at a consummate redraw. Likewise many "redraws", and you were taken bated by the main engineer for a "Little Talk" and it would be suggested that peradventure your talents lay in a field other than mechanical drafting.---And God help the machinist/fabricator who was caught scaling anything off a drawing. His career alter would be immediate and irrevocable. Now in the wonderfull world of computers, when i of the press options is "Scale to fit paper size when printing" information technology would be an even worse option to consider scaling a drawing.----Brian

• #14

To save time when a product is revised and a dimension is inverse just the written dimension would be inverse rather than redrawing the drawing. ie it was found that a hole should be drilled 3.5" from an edge, where originally information technology was three.6", the dimension would be changed but the hole would even so be drawn at 3.vi" from the border.
Regards,
Gerald.

• #15

Steamboatmodel---That may have worked in the horse and buggy days when I started out. At present notwithstanding, the client will enquire for the cad file of the cartoon as a .dxf file to be sent to the burning tabular array or the cnc shop. And when ya get old similar me, you can no longer remember which dimensions yous "fudged" and which ones you didn't, so you pretty well have to brand information technology a coating policy to never fudge whatsoever dimensions. Nothing is uglier than a fabricator who had just made a $2000 cnc part so finds out that some of the math information in the cad file was DIFFERENT than what the dimension said.

• #16

How-do-you-do Brian,
It was mostly work that was done in firm that the drafting dept. didn't have time to redraw the cartoon. It was quite common for u.s.a. in the store to get drawings/prints that would have changes done to dimensions in ruby ink with initials and a date, and be told they needed the parts yesterday and proper drawings volition come latter. It got to the point that I would photocopy all the drawings that came in similar that and file them with a re-create of the workorder and a printout of the cnc program. It was much better once nosotros got to the point that all the drawings were done in cad, but I always had a fight to have them keep the drawings current with changes on the production floor.
Regards,
Gerald.

• #17

Gerald,
I work from copies of original Lima Locomotive Works drawings and information technology is very mutual to have changes noted on the drawings or even several different mods to castings for different applications. I think some of this might have been washed in a different colour but I only take B&Westward copies. I e'er double check whatsoever note in a different mitt writting as information technology was not done past the original draftsman.

There have been times when a dimension is not specified, and so I like the original blueprint maker take to use my all-time judgement as how to make the part. If I have to use a scale on the drawing I always check near dimensions both vertical and horizontal to check for paper stretch or scan mistake.

Errors In Lima drawings are fairly rare but they practise exist and each one I find takes more research to figure out how to deal with conflicting information.

Thanks Dan

• #eighteen

I enjoy Drawings much more than since I am retired and don't have to worry about Bosses, Customers, and deadlines. When I was working drawings were sometimes a existent Pita.
Regards
Gerald.

• #nineteen

Steamboat---Yeah, in the pre-computer days, I used to do it all the time too. Equally long as it was marked upwards every bit a "Revision" and a engagement and reason were included, we felt pretty safe with it. On a lot of our repeat orders that were "nearly" the same information technology was not uncommon to make a sepia or mylar, change one-half the dimensions on a sheet, put a big note on it "NOT TO SCALE" and issue it to the shop flooring. Time was money.---Still is!!! ;D ;D ;D

• #20

I have never seen a "Diesel" model engine larger than 5cc, nonetheless 10cc glow plug are popular.
There must be a reason for it.
A 16cc "Diesel" may be a behave to starting time by flicking the prop, and if it bites information technology may take the finger out.
Mauro

Source: https://www.homemodelenginemachinist.com/threads/do-not-scale-drawing.8311/

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