Scale Viewport - what does 1:30 really mean?

[Anonymous]

My drawing is in feet and inches. I am asked to scale a siteplan 1:30 and its suppose to fit in a titleblock the size of 30x40.

Now what does 1:30 really mean?

When I use the pulldown to scale the viewport and pick the "1:30" option, it is waaay too big to fit in the given titleblock.

So does the required 1:30 really mean 1" = 30'? which is actually 1/360 in cad?

Thanks in advance!

[Anonymous]

You are correct. It does mean 1"=30' which is 1/360xp.

luigiwu wrote:

> My drawing is in feet and inches. I am asked to scale a siteplan 1:30
> and its suppose to fit in a titleblock the size of 30x40.
>
> Now what does 1:30 really mean?
>
> When I use the pulldown to scale the viewport and pick the "1:30"
> option, it is waaay too big to fit in the given titleblock.
>
> So does the required 1:30 really mean 1" = 30'? which is actually 1/360
> in cad?
>
> Thanks in advance!
>

[Anonymous]

No, 1:30 is a unitless ratio and means just what it says, 1 "anything" equals 30 of the same "anythings" - so 1 inch = 30 inches, 1 mm = 30mm, etc.

1" = 30'-0" is the same as 1" = 360", or 1:360. That is tweleve times smaller than 1:30, so if your siteplan fills your sheet at 1:360, it is not surprizing that a view twelve times larger does not fit.

Type 1:360 or 1"=30' in the viewport scale control on the Viewports toolbar or 1/360 in the "Custom scale" property in the Properties dialog.

--

David Koch
Member of the Autodesk Discussion Forum Moderator Program

[Anonymous]

As it is written, you are technically correct. He was asked to do a
site plan at 1:30. I interpreted that he was verbally asked to do this.
Interpreting what is actually wanted as compared to what is asked is
sometimes necessary, as we have all found out. For a site plan, in
imperial units, this would imply 1"-30'. In imperial unit site plans, a
scale of 1:30 is not a common scale.

David_W._Koch wrote:

> No, 1:30 is a unitless ratio and means just what it says, 1 "anything"
> equals 30 of the same "anythings" - so 1 inch = 30 inches, 1 mm = 30mm, etc.
>
> 1" = 30'-0" is the same as 1" = 360", or 1:360. That is tweleve times
> smaller than 1:30, so if your siteplan fills your sheet at 1:360, it is
> not surprizing that a view twelve times larger does not fit.
>
> Type 1:360 or 1"=30' in the viewport scale control on the Viewports
> toolbar or 1/360 in the "Custom scale" property in the Properties dialog.
>
> --
>
> David Koch
> Member of the Autodesk Discussion Forum Moderator Program

[Anonymous]

No doubt that 1"=30'-0" was the desired scale. Your advice to use a 1/360XP ZOOM factor was quite correct.

Unfortunately, imperial "engineering" scales do not appear on the viewport scale pulldown [or in the properties dialog], but 1:30 does. You can type in 1"=30', however.

He was confused about this and I merely tried to explain what "1 to 30" really means. Too many people use incorrect verbal shorthand when describing scales and that, unfortunately, often leads to just this sort of misunderstanding. [I still cringe every time I hear someone refer to 1/8" = 1'-0" [1:96] as "eighth" scale, which implies 1/8 size, or 1:8, which is 1 1/2" = 1'-0".]

--

David Koch
Member of the Autodesk Discussion Forum Moderator Program

[Anonymous]

This was a great question. I have not had the time to try and figure out what all those scales meant. Thanks for the help. ---------- I have one additional question though. David, you said that you can " type in 1"=30' " Can I do this in the properties box with a viewport selected. I tried it in the custom scale and it did not seem to work. Thanks for your help.

[Anonymous]

No. In the Properties Palette, you would need to type 1/360 in the Custom property. The only place you could type 1"=30' is in the ViewportScale control, which, alas, is not included on the out-of-the-box toolbars in the ADT menu file. You can add it to a custom toolbar of your own.

Note also that the number displayed in the Properties Palette, Custom property for a viewport is formatted in accordance with your current units setting. For architectural units, you would have to be using 1/256" precision, to get something other than 0" for 1" = 30'-0", and then you get 1/256", as it rounds the display. In my opinion, this property should display in a decimal format regardless of the units selected.

--

David Koch
Member of the Autodesk Discussion Forum Moderator Program

[Anonymous]

Thanks. I agree that the custom scale line in the properties box is not very intuitive. It would be very nice if you didn't need to figure out a special way of inputting common scales like 1"=50'

[Anonymous]

Oops. I forgot to which group I was posting. The ViewportScale control is, of course, available in the ACAD menu for ADT3[.3], on the VIEWPORTS toolbar. Fortunately [for my post, unfortunately for the lack of functionality], the ADT3.3 Properties dialog behaves the same way as the ADT2004 Properties Palette with regard to typing in engineering scales directly and for displaying the viewport magnification in the current units setting.

--

David Koch
Member of the Autodesk Discussion Forum Moderator Program