Drawing a scale

[Gamewizard]

Hi ,

 

Can anyone help me with drawing a scale plan ?

 

I basically have a free hand sketch of a room, (crime scene) and measured dimensions in cm on it. It contains a window, cupboard, walls, and a piece of evidence in middle of the room with measurements, the position of the evidence is shown by measuring two points from a baseline of the room(triangulation method) But I dont know how to make a scale for it

 

I looked on the internet but cannot find anything useful. Has anyone done something similar or same for thier forensic module? Please help

[cypress]

Hi ,

 

Can anyone help me with drawing a scale plan ?

 

I basically have a free hand sketch of a room, (crime scene) and measured dimensions in cm on it. It contains a window, cupboard, walls, and a piece of evidence in middle of the room with measurements, the position of the evidence is shown by measuring two points from a baseline of the room(triangulation method) But I dont know how to make a scale for it

 

I looked on the internet but cannot find anything useful. Has anyone done something similar or same for thier forensic module? Please help

 

Triangulation measurements are from two baseline points as you indicate. The traditional method involves a distance and angle from each of the two points. The angle is generally relative to magnetic north. This method allows for measurements to be made quickly using a compass and a measuring tape.

[Gamewizard]

Triangulation measurements are from two baseline points as you indicate. The traditional method involves a distance and angle from each of the two points. The angle is generally relative to magnetic north. This method allows for measurements to be made quickly using a compass and a measuring tape.

 

Yes I know I have done that but now what I need is the scale plan of the room which I dont know how to do Have you done a similar sort of thing before ?

[michel123456]

You need a ruler..

You are using centimeters.

You will draw at scale 1/50. It means each meter in reality will be drawn on paper 1/50 of it: 2 cm. (100cm/50=2 cm).

2 cm on paper=1m in reality.

1 cm on paper=50cm in reality

1mm on paper=5cm in reality.

 

And

5cm in reality=1mm on paper

10 cm in reality=2mm on paper

 

Your drawing will fit on a regular sheet of paper A4.

 

If the room is small (a bathroom for example), you can work at bigger scale 1/20

 

At that scale, 1meter in reality is 5cm on paper.

1cm on paper is 20 cm in reality.

1mm on paper is 2cm in reality.

 

Does that help?

 

Usual scales are 1/500, 1/200, 1/100, 1/50, 1/20, 1/10, 1/5, 1/1 for large buildings or plots (1/200) to detailed plans (1/20). Other intermediate scales are sometimes used according to the profession.

 

 

You can also buy an architect's scale but that may not help much if you are not used to it.

Edited December 19, 2010 by michel123456

[cypress]

Ah, sorry, my mistake. Yes, this is common in drafting and engineering surveys. Select a paper size then decide the largest dimension from the sketch. On that basis select a scale, one meter actual = 5 cm for example so that the drawing fits on the paper in the desired size.

 

Next draw a plan view ( a view from the top). Elevation views (side views) are also drawn if needed to show detail. What part of this process are you having difficulty with? as you can tell I am having trouble understanding the precise nature of your issue.

 

If the difficulty is in translating the measurements from radian to cartesian coordinates, draw on your plan view first the two reference points using the scale determined above and so that they have the correct relation to each other and to magnetic north (usually the top of your paper). Then use a protractor and drafting compass and scale to find the intersections from your points. If the measurements are in three dimensions and your reference points are not on the same height plane, then you will have to use trigonometry to generate references and result vectors on a common plane. If this is your issue I can help you with some drafting short cuts.

 

Once your references are on a common plane, only one measurement from the reference is needed.

[Gamewizard]

You need a ruler..

You are using centimeters.

You will draw at scale 1/50. It means each meter in reality will be drawn on paper 1/50 of it: 2 cm. (100cm/50=2 cm).

2 cm on paper=1m in reality.

1 cm on paper=50cm in reality

1mm on paper=5cm in reality.

 

And

5cm in reality=1mm on paper

10 cm in reality=2mm on paper

 

Your drawing will fit on a regular sheet of paper A4.

 

If the room is small (a bathroom for example), you can work at bigger scale 1/20

 

At that scale, 1meter in reality is 5cm on paper.

1cm on paper is 20 cm in reality.

1mm on paper is 2cm in reality.

 

Does that help?

 

Usual scales are 1/500, 1/200, 1/100, 1/50, 1/20, 1/10, 1/5, 1/1 for large buildings or plots (1/200) to detailed plans (1/20). Other intermediate scales are sometimes used according to the profession.

 

 

You can also buy an architect's scale but that may not help much if you are not used to it.

 

Yes it does thank you ! I had my measurements in metres and cm, so what I did was i converted all of them to cm first. So i think the next thing for me to do is dicide on the scale? I will do that in the meantime, and if I have problems then I will get back to you thanks again !

[michel123456]

Yes it does thank you ! I had my measurements in metres and cm, so what I did was i converted all of them to cm first. So i think the next thing for me to do is dicide on the scale? I will do that in the meantime, and if I have problems then I will get back to you thanks again !

 

So you already made a scale of 1/100.

At this scale you can draw a whole house on a simple sheet of paper.

this is probably too small for your job.

You can double all your results, and get a scale of 1/50.

Edited December 21, 2010 by michel123456

[Gamewizard]

So you already made a scale of 1/100.

At this scale you can draw a whole house on a simple sheet of paper.

this is probably too small for your job.

You can double all your results, and get a scale of 1/50.

 

Sorry how would I double up my results ?

[michel123456]

Sorry how would I double up my results ?

 

By two.

 

Obviously, I was not clear.

Let's say you measure is 1,20 meter.

At scale 1/100, you draw on paper a line 1,2 cm long.

At scale 1/50 you draw a line of 2,4 cm long.

[Gamewizard]

By two.

 

Obviously, I was not clear.

Let's say you measure is 1,20 meter.

At scale 1/100, you draw on paper a line 1,2 cm long.

At scale 1/50 you draw a line of 2,4 cm long.

 

Okay, but my measurements in cm are 181.3cm, 121.6cm, 155cm, 144cm, 428.4cm, 130.6cm, 270cm, if i try to double them (multiply by 2) i get very big numbers. for example for the first one 181.3cm, i get 362.6cm which i dont know how i can draw because its too large, there is obviously something wrong here but i cannot figure out what.

[michel123456]

divide by 100 first.

181,3 cm becomes 1,813 cm (approximatively 1,8 cm)

Edited December 25, 2010 by michel123456

[Gamewizard]

divide by 100 first.

181,3 cm becomes 1,813 cm (approximatively 1,8 cm)

 

Okay, having done that, I have got these values now. 2.4cm, 2.8cm, 3cm, 3.6cm, 8.4cm, 2.6cm, 5.4cm. Is that correct?

The first 4 of the measurements are to show the position of the evidence (triangulation). I have other measurements as well which are in cm and im assuming i have to do the same thing to make them smaller as well?

 

and then do I draw all the lines of the room and inside measurements according to these measurements above ? and then only put the scale i used under the drawing which is 1/50 ?

[michel123456]

Absolutely correct.

[Gamewizard]

Absolutely correct.

 

 

Thank you

[michel123456]

Thank you

 

Now that you have understood the basics of scaling, take a look here. It's not mine but if your drawing look like this, it is very good beginning. Note the square background is not a must.

Edited December 30, 2010 by michel123456