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CAD lessons for beginners.


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On 27/01/2021 at 07:21, JCL said:

Hi @carlw, before printing my own buildings, I created a calibration block. It’s a 2mm thick vertical box that has holes in it on it from front to back that range from 0.2mm to 3mm thick so I can find the hole size I need to allow wires to be thread through. As you’ll know, a 0.5mm hole in a drawing program will often be smaller when printed .
 

Then on the other half of  the front face, I have indented lines ranging from 0.1mm wide and deep to 0.3mm wide and deep. On the back, the same width lines are raised by 0.1mm to 0.3mm that way, I can check mortar lines and such. I’m going to make sure I print one of these each time I change the settings or change my resin.


For the Mono X at 4mm scale, a 0.2mm mortar width/depth works for me, but for my machine, the 0.3mm mortar width and depth is better. As you say, it depends not only on the make and model of the machine, but even within that, machines that should be identical have small biases, and then there are printer settings and for resin machines, resin make, type and temperature to take into account. All of these things make a difference to the final print.

 

We seem to be working in parallel as I’m creating some buildings in Blender when I get the chance. It will be interesting to see where the two programs diverge.

 

 

Hi JCL,

Thanks for your comments.  I have also done something similar to your test piece,  I found that things like Temp, different bottles of resin even though it was the same Manufacturer and same colour,  Angle of print, ETC.  Make so much difference that some times you just need to test a part and if it doesn't work change it and try it again.

I will make sure I follow along with your work in Blender.

Thanks

Carl

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I hesitate to post a help request as I realise that you must be dreading these. However I am stuck on tutorial 1 and after 3 nights of searching for the answer to 'unstick' me ,I realise I am in a catch 22 situation . Basically  I do not have the required understanding of the CAD technical language yet to comprehend the instructions on the internet on how to correct my problem. I am stuck on the tutorial  at dimensioning the cabinet doors . I can do certain sides but am told that I am 'overconstraining' other dimensions. The constraint icons appear different to those on the tutorial screen . I assume my [new] download of Fusion is automatically placing these and I cannot find how to alter these to allow me  to continue with the tutorial. I am sure this is covered in future tutorials but I am loath to follow my usual bad habit of skipping to the interesting bis. I am dtetermined to be disciplined and learn this properly . Any help would be appreciated. Thanks in anticipation, Ian

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On 11/02/2021 at 19:13, Ian R. Weeks said:

I hesitate to post a help request as I realise that you must be dreading these. However I am stuck on tutorial 1 and after 3 nights of searching for the answer to 'unstick' me ,I realise I am in a catch 22 situation . Basically  I do not have the required understanding of the CAD technical language yet to comprehend the instructions on the internet on how to correct my problem. I am stuck on the tutorial  at dimensioning the cabinet doors . I can do certain sides but am told that I am 'overconstraining' other dimensions. The constraint icons appear different to those on the tutorial screen . I assume my [new] download of Fusion is automatically placing these and I cannot find how to alter these to allow me  to continue with the tutorial. I am sure this is covered in future tutorials but I am loath to follow my usual bad habit of skipping to the interesting bis. I am dtetermined to be disciplined and learn this properly . Any help would be appreciated. Thanks in anticipation, Ian

Hi Ian,

 

I'm more than happy to help.

 

without seeing exactly what you have done it’s hard for me to give you a definitive answer.  But what I suspect has happened is when you have placed the rectangle you have accidentily picked up a constraint from another part of the design.  Possible a midpoint,  did any dashed blue lines appear as you were placing them?

 

Can you post a pic of the different constraints you are seeing?

 

Regards

 

Carl

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Hi all,

 

I have Scheduled a video on YouTube for tomorrow at 18:00 GMT I will be online in the chat feature to talk to anyone who has any questions about it.

 

I have a large complex Item that I require for my Model Railway that isn't available at all in any RTR or Kit format.  This project I believe will be massive for the N gauge community as a whole, but just because I'm drawing this in N gauge doesn't exclude any other gauges as you can easily scale the project in post processing .  Many CAD designer's like to maintain control of the hard work that goes into producing items like this.  I'm happy to take you all along for the ride through the process from start to finished model showing an honest view of design, printing and any refinement's that are required in the process, warts and all.

 

Cheers

 

Carl

 

 

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Dear Carl,

                     Thank you very much for the offer of help. I have some time later today and I will start at the beginning again and then when I hit the problem again will try and show you. Sorry for the delay in replying but my spare time is a bit constrained at present as I am out of retirement and back in the saddle vaccinating. Damned Covid getting in the way of modelling!

                                                                                                                      Thanks again for your help Ian

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Dear carl have managed to re create the problem now. I am stuck in dimmensioning the verticals by the constraints show here . the red lock comes on and sometimes a message about overconstraining. I am afraid I could not take a screen shot so have taken them on my phone and attached. Thanks again Ian

20210214_095201.jpg

20210214_095728.jpg

cad prob 1 .jpg

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Hi Ian,

 

it looks like you have the line I have drawn an arrow to constrained to the mid point,  if you look at lesson 2 i show how to fine the midpoint.  If you have accidentally caught it it wont let you change all the dimensions properly.

If you are trying to Dimension the line i have marked with the green arrow,  it wont let you as you have already defined it top and bottom edges to the face.

Cheers

 

Carl

20210214_095728.jpg.548a91d821fd7e38828246e5798b2a10.jpg

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Thanks Carl,

I was trying the green arrowed line.If I understand properly I have to define the green arrowed line before both top and bottom lines are defined. I went around doing the top and bottom faces of the rectangles first and then thought i would do the verticals to 0.4 next. Will play tonight and read tutorial 2 .  Thanks again ian

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Dear Carl,

  Whoop dee do I have completed tutorial one , thank you. I did come across one or two other problems. The hurdle which slowed me, was, when highlighting the hinge to extrude I had to really zoom in so as to be able to blue the small section. I then found that holding shift did not allow me to blue the other part of the hinge to select profile . I eventually did them seperatly. Also found that zooming necessitated  moving the image around the screen  in order to see both hinges at once at a size which allowed highlighting/ blueing of the segment and this led to mistakes. However the sense of achievement is great Thanks again. Ian

P.S. Just wondering if this size limitation in order to highlight might be a mouse problem ?

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Hi Ian,

 

That’s great to hear that you were able to complete the video.  I totally agree about the sense of achievement as you see project come to fruition.

 

You will find in the videos I zoom in and out quite a bit to be able to select the smaller items like that.  The mouse I use has a center roller wheel,  which is set up for the zoom function.

 

Cheers

 

Carl

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19 hours ago, Ian R. Weeks said:

Dear Carl, Just a quick post to thank you for your efforts. I am [I think ] progressing and thoroughly enjoying your tutorials. Thanks again Ian

Ian,

Im glad to hear that you feel like your progressing and picking up how to use the software.  Just remember if you get stuck im happy to help out.

Cheers

 

Carl

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Thanks to Carl's tutorials - only up to lesson 4 so far, I've created my first piece.

(Last time I used CAD was a basic course in 2D Autocad in the mid 1990s)

It's a base for a hopper wagon and about 25mm across.

 

hopper.jpg.95cf5a2ee418f1400128f772ddf4933f.jpg

 

Looking forward to drawing a few more bits before firing up the printer.

 

Keep up the good work Carl.

Edited by newbryford
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