How to make a ledge

[ianhughes7UFVF]

Hi

I am trying to make a 3d printed frame. The Top Plate is going to be 10mm thick but I want to make it in segements.

This is my first idea:

8 segments, but I needed to make ledges on each side of the individual sections one on the bottom and one on the top of each to be able to join them.

So the sketch I adjusted to look like the last picture, so it will give me a 10mm cut out on one side and a 10mm extension on the top of the other side.

I extrude the section 10mm but carn't seem to make a ledge on the bottom side properly. The cutout needs to be 5mm up.

Hopefully you can understand what I am asking. I have attached the design for you to look at.

Its basically so I can glue each section together with some retention.

Kind Regards

Ian

[ianhughes7UFVF]

Hi

I test printed the V7 off to see what they were like. They came out fine.

The joint was comfortable on one side and easy on the other. I haven't glued them yet, but it will go together snugly.

But they slot and locate alot lot better than the first go. Definitely on the right track here.

One slightly tangental question. With the R2 build up I showed earlier, I have a 3d file that was once an iges file that I have inserted into fusion. Its coloured gold but before I was able to change its appearance to white to suit the project. Now I carn't seem to change its appearance, it stays half gold and half white. Any ideas why fusion won't let me change it?

Kind Regards

Ian

[ianhughes7UFVF]

Hi

I also took the original ring pieces to work and glued them together two at a time without the bolts and then just finished the circle.

It came together really wheel with a little inaccuracy.

I glued two quaters, clamping them in a vice to keep them flat. The result is really solid. I will add the bolts in after re drilling the holes as I think I will use them to join other bits onto.

Kind Regards

Ian

[lichtzeichenanlage · Accepted solution]

First I want to say, that I like the way how you're maintaining this thread. I love to see your results.

I checked your export and I've assigned a color per component and in general it works. But there are two issues. The first one is, that there are lots of faces overlaying each other. In those areas you see a mixture of assigned colors (blue/gold, green/gold etc.).

Your design does not have solid bodies but faces. Some faces are flipped and you have to invert them (unless you want to see the color in the inside of your R2D2). This can be done like this:

Does this make sense?

[ianhughes7UFVF]

Hi

Thanks for the direction in regards to the Skin.

This is a cad piece that is downloadable from the astromech R2 builders site and was an iges file someone did quite a while ago.

I would like the skill to be able to make something like it myself one day 🙂

The faces arrangement seems to be common with the file design, and any others done by the chap who provided them.

Thanks for the means to correct the colours. I have never used the patch screen and the reverse command so this is another new thing for me.

Thanks again.

Kind Regards

Ian

[ianhughes7UFVF]

Hi

The Top Plate needs to connect to a Cross Plate that will have the legs connecting to it and the rest of the lower section of the Frame.

I started to Cad up the Cross Plate. I probably broke every rule in the book, but I am trying to work from a sketch in fusion.

This is what I came up with.

I intend this to be a skinless R2, that has more movement abilities. Such as side to side pivot, forward and back movement, complete leg rotation. I added the lower hole for the side to side. I want two holes on each side to allow rotation of the legs, but the sketch wasn't letting me place them center of the 30mm sides. I have to work that one out.

The Center slot is for a 160mm spacer that will join this cross section to a duplicate cross section.

Hopefully you can see where I am heading. This is like a shoulder section that will support top plate, legs and lower section.

Feel free to decimate the effort. I am not used to sketching in fusion and may have been rather messy.

Kind Regards

Ian

[chrisplyler · Accepted solution]

This is almost an hour long. You don't have to watch all of it if that's too much. You can skip ahead where you feel you already understand something.

[lichtzeichenanlage]

@chrisplyler: Almost an hour... I haven't watched it yet (time..) but... respect for the effort.

[ianhughes7UFVF]

Hi

I watched the whole hour and thoroughly was absorbed in your explanations, corrections and consideration of what I did.

I am absolutely impressed by how well and clear you explained everything. I appreciate your time.

I was creating the Cross Section as I went, and as I was going, wished that I had been able to do half and mirror it, as I saw as you were going the mistakes I made.

What I learnt was:

1. Make a component first (I should now this rule by now, and cursed the fact that I got half way through and remembered to do it)

2. Use the origin points of the component rather than the parent origin (I have struck 3d cad files that they used the mother origin and the component is away from it  and it makes it difficult to join in external files)

3.Use Construction lines and constrain them as you go (I didn't do this at all, but can see the definite correctness of the method)

4. Create a construction box and then use the midpoint command to join them.

5. Coincident allows you to connect one line to another (Using the Sketch commands more is definitely on my agenda)

6.Using the Horizontal/Vertical to constrain lines

7. Use midpoint to locate lines

8. Trimming lines out

9. Defining Dimensions regulary.

To list a few.

I wish these screencasts were downloadable as I would have yours on my desktop and refer to it constantly.

I do apologize for my mistakes in the design which you corrected perfectly.

Next I need to go back and redo the sketch from scratch following you presentation and learn to use all these commands correctly.

Kind Regards

Ian

[lichtzeichenanlage]

Finally I did remember that there was a interesting video about 3D printing and bonding...

[chrisplyler · Accepted solution]

@ianhughes7UFVF

I want to make sure you understand that you don't have to do everything exactly as I did.

You don't HAVE to make a construction line box. You could have drawn the exterior lines from one to the next using lengths and angles, for example. If you start from the origin with one line defined with a length and an angle, it will be fully defined and turn black. If you keep adding lines onto the end of the previous line, with lengths and angles, then of course they should all be fully defined and turn black also, right? I just noted by taking a few measurements in your file that the angles and lengths seemed arbitrary, and the distances from some imaginary outside corners seemed to be whole numbers (30mm mostly in this case) and so I though a construction box with corners to measure off of was useful.

You don't HAVE to use Midpoints to locate things. You can locate things in a variety of ways. You could dimension both sides and make them equal. You could dimension the whole outside box, dimension the whole inside box, and then dimension the spacing between them as = 1/2 * (outside box - inside box). It's just that using the Midpoint constraint was the quick/easy way in this case.

You don't even HAVE to use construction lines at all. You could do everything with real lines. It's just that construction lines help differentiate the design purpose, which can sometimes get pretty complex. Also they don't contribute to profiles, so using them helps reduce the number of chunks you'll have to select when you go to extrude or whatever.

Each project will be different, and each sketch idea you start out to draw might make sense in different ways. Lesson number two, if I was to make another hour long vid, would be about parameter/function usage, and specifically how it relates to drawing sketches. If you know, for example, that you're going to want that shoulder bracket to be flexible in length side-to-side, you've got to think about whether you want the diagonal braces to stretch, to move with the outside, to hold their position relative to the middle, or maybe to hold position at the bottom but stretch out to a larger angle at the top. You've got to think about that sort of stuff. There is a variety of constraint setups that lock that shape down while it's static, but if you're going to stretch out that overall 390mm length, you're going to want to set up the position of that interior angle brace in a specific way to get it to do the specific thing you want. See what I mean? You might have to set up an interior construction line and have that interior brace built off the midpoint of it, so that at the outside perimeter stretches out, so does that construction line, and so that brace built on the midpoint moves half the distance that the outside perimeter moves. Or maybe instead of using a construction line, you dimension each of the two lines defining that interior brace in such a way that they = 1/2 of the exterior dimension. Or whatever...the point is you'll want to start thinking about that kind of stuff. You'll have to picture the stretching geometry in your head and imagine how you want each bit to move or not move, and then how to dimension/constrain it to achieve that goal.

[ianhughes7UFVF]

Hi

Thanks for all your time and advice. Hopefully I can apply it.

Ironically, the next thing I was thinking about was a 3d printed bracket, which presents a slightly different issue.

So far, I have been working on a flat plane but this is on two planes.

My logic would suggest that I sketch the one side, that has the rounded ends, adding a line in at the bottom that I can extrude the other angle out once finished to create the next part.

I haven't tried this yet, but is that what you would do and then can that second side be selected to add holes in. Those holes would be in line with the other ones.

I realize this is the next level for me.

Kind Regards

Ian

[ianhughes7UFVF]

Hi

It looks as though I was half way there. I should have tried it and possibly come up with your result.

Although I would have forgotten to use the project tool to get the holes in the right place. Although I was intending them to be 30mm apart center to center.

I decided I needed to start from the outside in with the design as I intend to have some pivoting and movement, so this bracket will start to be a set of joiners from a leg mount plate to the cross section plate.

I will post as I go as the cross section plate is going to be modded more.

Thanks again.

Now I can play 🙂

Kind Regards

Ian

[ianhughes7UFVF]

Hi

I started to create the outside Hub Plate and then I used your concept to create the hinge.

Its slightly different.

I inserted the hinges into the Hub plate drawing which seems to stop me exporting the combined file.

I have attached the Plate file. Hopefully I have sketched it correctly.

Next I need to make some brackets that join the hinges to the main Cross Section Plate.

Kind Regards

Ian

[ianhughes7UFVF]

Hi

Things change as I go. I did a test print of the Hub Mount Plate and found it is fundamentally too small.

Its 80mm diameter and it was going to connect to a 167mm plate. I had planned to make another midway plate that would connect it up, but it seems that it would be easier to scale everything up to the 167mm size accordingly.

And here setting my Parameters at the start would have been a brilliant idea.

I will start the drawing from scratch as I need to make some concept changes to it anyway.

Kind Regards

Ian