Saturday, April 17, 2010

The disappearing draftsman, slips and trips, and DS and DIMLO

First, The Disappearing Draftsman. Last week I had an interesting viewpoint explained to me by an engineer I'm working with. He had gone ahead and done his own PID's, but needed me to knock them into shape so that they would be presentable, which took a day to do. I'm not sure how long he spent on them, I would imagine at least 4-5 days.

He explained that he found that he could use Autocad as a faster, easier way of producing a sketch of what he wanted than doing a hand sketch. Plus there was an added advantage that the draftsman was only required to do a short "tarting up". The last place he worked, there was a proper drafting department, and they were probably grumpy that he was doing part of their work.

Here at his new work, there is no drafting dept (only me, 2-3 days a month!). So he has to manage somehow.

I have done a few PIDs, but would hardly call myself an expert, so I was interested to hear his take on how they should be done. He reckons, at the quotation stage, you just insert symbols, and leave it at that. You do not use symbols with lots of hidden attributes so that at a future date you can extract a full Equipment List from the job.

The generation of tag numbers, he said, should be the preserve of the Electrical guys, who make a large database. When they have done their thing, and the job is a go, then you can put the tags on.

Slips and trips: I recently had a reasonably complex design to draft. It was a "bag massager".
I came unstuck in one of my drawings: the 20mm plates welded onto a 100x100 axle, somehow got moved by 100mm, this was only in the detail drawing- the main ass'y drawing was correct.

Which made me think: could this have happened in Inventor? Probably not. But I'm stuck with Autocad, so what could I do to prevent this happening again? My only idea is that I make it policy with any assembly to xref in all the parts.

DS and DIMLO: Yet another engineer, at a different plant, has arrived, and he seems keen on doing his own drawings. That is OK by me, because less time working=more time living. He seems pretty good, just a little polishing required in the dimensions department. Namely, he had large arrows and tiny text on his dimensions.

I explained to him the system I use-but I'm not sure he was at all in favour of it, which is to use 2 lisp routines, DS.lsp to set the text height and DIMLO.lsp to insert, then erase a block that has most dimensions styles a mechanical draftsman might need.

In the past done I have done things differently-see a previous post about zero height text.

Here are the two routines:

DS.lsp:

;This routine sets up for text to be right height
;By Bill Le Couteur
(defun c:DS()
(setq skale (getreal "Please enter the plotted scale: "))
(command "-style" "STANDARD" "ARIAL" "0" "1" "0" "" "" )
(if
(tblsearch "style" "R1")(command "-style" "R1" "ARIAL" "0" "1" "0" "" "" ""))
(if (tblsearch "style" "R1-25")(command "-style" "R1-25" "ARIAL" "0" "1" "0" "" "" ""))
(if (tblsearch "style" "R2")(command "-style" "R2" "ARIAL" "0" "1" "0" "" "" ""))
(if (tblsearch "style" "R5")(command "-style" "R5" "ARIAL" "0" "1" "0" "" "" ""))

(setvar "MIRRTEXT" 0)

(setvar "DIMSCALE" SKALE)
(setq the_textsize (* skale 3))
(setvar "textsize" the_textsize)
(setvar "dimassoc" 2)
(princ))

The nice thing about this is if you have an existing drawing an someone has used the style R5 say, then you can change that at the same time as well.

Here is DIMLO.lsp

;This routine sets up for dims and text;
By Bill Le Couteur
;imports a dummy block containing a set of dimension styles
(defun c:Dimlo()
(command "-insert" "c:/cad/library/symbols/dimension styles" "0,0" "1" "1" "0")
(command "erase" "l" "")
(princ)
)

A very simple routine-I have no idea why Autodesk don't have a magic button that does all this...

Of course, many will argue that you need to set up your prototype drawing nicely, with all the needed scales and the text the right size, and this is correct, except what happens when you change scales? As well, if you purge the drawing your nicely setup scales that are not used are ditched, so if you want to use a 1:20 dimension style, it won't be there.

Sunday, April 4, 2010

Autocad 2011

There is not much point me going into the user interface etc etc as you could go to, say,Robin Capper's excellent blog at http://rcd.typepad.com/rcd/ where he does a good job of giving a run down on R2011. You might have to reverse through to the post, as he seems to be churning them out!

So, I'll just outline my experiences with it and hope that someone gets around a few of the things that I found as I proceeded to waste my Easter weekend drawing a set of instructions for a do-it-yourself cabinet assembly.

On firing up for the first time I noticed: No toolbars. Well, it turns out that they are still there, just hidden-I guess that Autodesk want you to move towards the Ribbon system. Here is a snip of my screen setup, just of the ribbon, shown vertically as I have two screens:


(By the way, there is a snipping tool in Vista-look under Accessories)

How to get your toolbars? Just to the right of the Quick Access Toolbar there is a small triangle.


Press this and locate "Show Menu Bar". Then go Tools/Toolbars/Autocad and tick the ones you want.

Another fun annoyance, was the helpful popups that appeared in the top right hand corner.

On pressing "Don't show me this again" it appeared yet again, and again. A friend told me that they were all different ones and that after a while all sorts would be eliminated. Makes sense, really, because you want your new users to be looked after.

A lot of new changes are not immediately apparent- for instance the loft command has been overhauled to allow for surface creation. Previously, the dialog box came up automatically, now you have to use the Settings option to make it come up.

As usual with new releases, I tread carefully, making sure I do regular backups.

The neatest things I'm finding are:

*The materials system has been overhauled and is looking good.

*Hatching has had a lot of work done on it and seems much better.

*Polylines are a lot nicer to edit - but old habits die hard!

*There is a new display bar on the right of the screen which has the often used orbit button on it, and the "Steering Wheel" which I have not been using but have been driven to because of it's handy little button marked "Center" which is great if you want to reset the orbit center graphically.

Wednesday, March 31, 2010

Title block pain

Just plodding my way through (pardon the pun) a bunch of Hazardous Area drawings and it was pointed out the the company logo had gone all funny. This is on about 40 drawings.

If you had 2 or 3 drawings you would just reinsert the block, redefining the old one. So you would think a script would be the go. This where I found out my ignorance regarding the insert command.

After some digging on the net I came up with parts to make this one:

-insert
A3BORDER_LAND_MECH=
Y
(command)

An explanation:

-insert ......just issues the insert command without the dialog box.
A3BORDER_LAND_MECH....is the name of the title block, and the = means that you wish to redefine it.
Y is the answer to the prompt "Do you want to redefine the block?"
(command) ....is a means of cancelling the script-does not make much sense but it works!

Just one catch-you have to put the location of the directory of the block in file locations in autocad. Go Tools/Options etc.

Just use the cui to make yourself a button and you just click when you want the block redefined.

Sunday, March 21, 2010

From igloos to elephants





More architectural monstrosities-yes I know the curves do not match, yes I know there does seem to be no means of support in some of these...but hey, it's Sunday and I have limited time!
I'm not quitting my day job just yet!
It is strange- this house design is supposed to be about olives (it is near an olive farm), hence the shape of the rooves, but things have ended up resembling upside down boats and elephants.
This is just a massing exercise. Sometimes you wonder what you need walls for out in the country-the only place I can think one might be needed is the toilet/bathroom and say a sound barrier if one had a baby...so the outer walls could be totally glass, but this means lots of dollars.Though if you were to have such a house, cost might not be an issue.

Saturday, March 6, 2010

A draftsman's lot and architectural fantasies

Being a draftsman is a bit like doing a maths exam every day, one where you should not make mistakes at all. But ask yourself: who ever scores 100% day in day out? All we can hope for is that our mistakes are minor and easily fixed.

I remember the story of one draftsman who drew an entire truckload of ducting. On the day it was delivered, he was looking out the window. As soon as he saw it he realised they were all completely wrong.

Another, an architectural designer, was awoken at 2 am in the morning. Apparently the irate person on the phone accused him of bad design of a deck because there had been a party and a large number of people were on the deck and it collapsed resulting in some injuries. A real shock to him, but he was later vindicated as it was found the builder had just nailed the stringer support to the house instead of using coach bolts!

Anyway, I seem to be sliding back into drawing houses for fun-it is great, just as long as you do not intend to build them!

The "flying saucer" one came from a vision I had of standing inside a house and looking upwards and seeing the sky: ie a hole in the roof! Hardly original. Maybe the glob below the hole made of chrome is though (probably not!). The "pears laid on the ground" one is again probably not original, but has the "looking at the sky while inside" thing going as well.


















Saturday, February 20, 2010

Batch processing of Autocad drawings

Some years ago (about 12!) I played around with scripts and lisp routines to automate the plotting of drawings. So when a co-worker asked me if I knew of a downloadable routine that could search a series of drawings for a text string, I thought: I'll just rejig my old routines and there we are.

Not really. He was after a system that would search electrical drawings for numbers. The reason for this is that say you have wire number 39 on one drawing, then you want to know where this wire number is on other drawings (maybe the drawing system is at fault here!). Just to add to the fun, some things are attributes, not text. Probably if you looked, you would find some mtext in there as well.

This is all hanging on your finding a thing that will open several drawings in succession.

I have looked, but most of them you have to pay for. To cut a long story short I found the ideal thing-just for opening up drawings: and for free!

I have tested it out by reinserting and updating a title block.

The number finding thing will have to wait.

The routine can be found here:

http://thatcadguy.blogspot.com/2009/10/batch-processing-autocad-drawings.html

There is a trick to it's use-Navigate to the directory, and then select the first file.
Otherwise, it works brilliantly, (yes, I did leave a comment).

Maybe someone at Autodesk might read this and consider putting it in Express Tools?

Saturday, February 13, 2010

Whats bin did and what's bin hid

If you are a little older, you will recognise the title as one from an LP made by Donavan in the 1960's. I thought I might be forgiven for pinching it.

I have been trying (empasise on trying!) to draw a Flying boat from the 1950's.

The pic shows progress so far.

If you are keen on looking at Flying Boat Pics, then here is a good place

My approach to the fuselage was to draw the individual frame shapes and then loft them, hoping that if I drew the inside as well, I would end up with a hollow aeorplane. Sadly, this approach came unstuck and I had to regress to a solid all the way through one. At the tail I lost patience (never a good plan if you want things to go right!) and drew the tail section as a chunk and tried carving bits off it. Not a good way to go, but I have resigned myself to the idea that this is just a first pass.

The process of getting information, ie PLANS was a bit of a trial. I ended up with a Short Seaford (not Solent) as my pdf of choice.