Welding CAD critique?

[Andy from Workshopshed]

My last post about cad fell on sarcartic ears but I do still value input from you chaps.

Here's my first attempt at CAD in about 20 years, it's a very simple frame that I know really does not need a drawing, although the sketch I was provided on the back of an envelope was not really sufficient.

It's for a metal frame to be screwed into the inside of a wooden frame of a shed window to provide some basic security, I've told the chap to put more verticals in place but he has a defect with his wallet where the money does not come out very easily hence why I'm doing it as a training exercise for cost.

All feedback welcome although I'm mainly looking for comments on the drawing itself.

 

[snowcat]

I prefer to have the material grades and sizes listed separately, and referenced within a key, Its OK to label them on a simple drawing but get several grades and material sizes and multiple drawings lay ed out and it becomes it impossible to read....

These days I'm mostly designer and mfr so I mostly work from a 3D model, and rarely bother working In Pspace, I normally just switch layers on and off and reference all dims within the model.

 

[FranV8]

The drawing looks fine. If I was being picky, here's what I'd say:

- The title box is a little too simplistic. Normally it has who the author is, a symbol to denote third or first angle projection, scale, tolerances to work to unless otherwise stated etc. If you come up with a comprehensive one, or get one from somewhere else, then you can re-use on all your drawings, no matter how simple or complex.
- If you're using them externally, why not add a graphic or styled name to denote who you are trading as.
- Revisions - I've normally seen the convention that letters are used, e.g. rev. A, B etc.
- Drawing numbering and titling - seperate boxes for each, and come up with a system. One day you may have hundreds or even thousands of drawings to reference in your system!
- Being really picky, I have to guess where you're positioning the bar (8mm dia) - is it flush with the front face, or the rear face, or centred? Could be an opportunity for another elevation to show that without any doubt.

Hope this helps!

Francis.

 

[Andy from Workshopshed]

Thanks guys, good feed back. Picky is good Francis, you are correct I was just been lazy missing out the other elevations but at least one is needed to show where that bar is position.

One question, should the projection lines for the dimensions be away from the item? I left mine touching by mistake.

 

[FranV8]

Hi Andy,

Yes, I believe the projection lines should have a gap between them and the measured point. I can't tell you if them's the rules or not though. It was BS308 but that seems to have been superceded.

Dimension numbers should also be above the lines to which they refer, and orientated as such, i.e. a vertical measurement has the text orientated at 90 degrees, it should not intersect the measurement line.

When I did a bit of CAD, we used the number of digits after the decimal point to show how much more or less critical the tolerances were, this was noted in the drawing title box, but could be just a convention the company I was working at at the time tended to use.

Still in the main very good start - so please don't take this as a load of criticism.

 

[Andy from Workshopshed]

Thanks again. I'd agree on the tolerances and decimal places that sounds familiar. I'll have to see if the CAD tool has a setting for those dimension numbers as that's just the default setting.

 

[jimi_boom]

One thing I would be critical of is your weld symbols.

You don’t need to have one on each corner; in my experience i would simply have a text line saying typ 4 posn

The same goes for the one holding the central bar in place

I also agree with the earlier posts if there is a parts list then this would help in assembly if it was to be done by an outside contractor, and if this was the case parts drawings would then have to be produced tying in nicely with an earlier comment about drawing numbers on sheets etc. also this would enable you to put any weld prep that may also be needed.

This is just my opinion, but if you want a good source of knowledge for this kind of thing try roymech(a guy with way too much time on his hands, but helped me through my degree) and also engineering tips is another one i use regularly, as well as the good old machinist hand book.

 

[rocket01]

What software did you use to do that drawing out of interest. I use autoCAD (although an old version) I'm sure it adds the dimensions in the correct places, orientation etc, although that might be me doing it subconciously as I've been using it for 8 years.

 

[Wedg1e]

AutoCAD's 'Format/Dimension Style' lets you fanny around with the lines, arrows, leaders, text size, colour of everything, standoff distances etc.
I usually use some colour in my dims. to contrast with the part itself, which is fine for the output of the laser printer but can get lost if you fax or photocopy it.

 

[@Turbo]

scale?

is it an autocad file? if so split it into viewports for the different elevations.