Problems drawing small items

[andrewm]

I am having problems drawing small items in Sketchup. I need some screwheads for a door handle:

At the moment I am using slightly raised cheese heads which will probably look OK once the whole assembly is on a door but having tried to create a raised head screw I am not giving up.

What I have tried is to draw a half cross section of the head and then use follow me to drag that around a circle.

If I do it at a large scale (a 4m diameter head!) then it works fine and I get this:

However if I do exactly the same at the millimetre level to get a 4mm diameter head it goes wrong when I do the follow me. It is slightly unpredictable what I get but it is usually something like this:

Can anyone shed any light as to why?

Andrew

edited: to change images to jpegs.

 

[Jake]

Rounding errors?

Last time this came up, Dave recommended drawing at the large scale and then scaling down to the intended size afterwards to avoid a similar problem.

 

[SketchUp Guru]

Andrew, SU does have difficulty with creating tiny faces. Remember it was designed for drawing buildings. The solution is as Jake mentioned, Scale up the object and work on it. Then scale it back down. I typically use scale factos of 10 or 100 because I can then scale back down using 0.1 as the factor. For scaling back down from 100, I think you need to do it in two steps of 0.1.

I've found another trick useful and you might for these screws. Your screws should all be components. All screws that are the same size should be the same component. Assuming you have done that, make another copy of the screw component and move that one to some distance from the model. Scale that one screw up, edit it as needed and then delete that large screw component.

Even though SU won't fill in the tiny faces if you work on the properly sized component, it will fill in those faces if you are editing a scaled up copy of the component.

By the way, once you have gotten the screw component as you want it, save the component for later use. Select the component, right click and save as a component you can find later.

BTW, it might just be me but all I get of your images is black rectangles. Could someone turn on the lights please?

 

[andrewm]

Rounding errors?

Last time this came up, Dave recommended drawing at the large scale and then scaling down to the intended size afterwards to avoid a similar problem.

I knew I had seen something about this but none of my seaches came up with anything useful. I'll give it a go.

Andrew

 

[Newbie_Neil]

Hi Dave

BTW, it might just be me but all I get of your images is black rectangles. Could someone turn on the lights please?

No, it's not just you.

Cheers
Neil

 

[SketchUp Guru]

No, it's not just you.

Oh good. I thought I was going blind.

 

[andrewm]

BTW, it might just be me but all I get of your images is black rectangles. Could someone turn on the lights please?

Hmm, odd it works here and worked from work so it is not a problem with permissions. Did you see my picture in this post?

Edit after a bit of investigating: Ahhh, I think the problem may be that the images are .png images. These seem to be the default format the Sketchup uses and are probably better for this than jpegs (less artifacting). But, I bet you are using Internet Explorer which has some known issues with .pngs, I think that there was a security issue so they may have been disabled in one of the patches. I have not found a way of re-enabling them. I am using Opera and they appear just fine and they appear in Firefox too.

I will convert to jpeg if I can.

Andrew

 

[Newbie_Neil]

Hi Andrew

Hmm, odd it works here and worked from work so it is not a problem with permissions. Did you see my picture in this post?

Yes, no problem at all.

Cheers
Neil

 

[tibbs]

Can't see it either - using IE6/XP Pro.

It must be something to do with it being a .PNG - I can see it if I save it to a file & then view it with Paint or Windows Picture & Fax Viewer - don't you just love Windows ( err NO, not really :evil: )

The image in your other thread was a .JPG which shows up fine.

Richard

 

[andrewm]

Definately a IE problem. For those of you still using outdated browsers :wink: I have changed the images in the original post.

Andrew

 

[gidon]

Andrew
Have a look at this post for more discussion:
https://www.ukworkshop.co.uk/forums/view ... hp?t=10016
Cheers
Gidon

 

[andrewm]

Andrew
Have a look at this post for more discussion:
https://www.ukworkshop.co.uk/forums/view ... hp?t=10016
Cheers
Gidon

This does appear to be the problem. When I get a spare half hour at lunchtime I shall give it a go and report back.

Andrew

 

[andrewm]

Well, I seem to have managed to get what I wanted by scaling so many thanks for all the help. However I notice that although I started with a smooth raised head when I put the slot it it became faceted face and has remained that way ever since even through the scaling operation.

It now looks like this:

Andrew

 

[gidon]

Have you tried scaling it a bit more (100x)?
Display Hidden Geometry isn't on is it?
Cheer
Gidon

 

[SketchUp Guru]

The broken lines on both the screw head and the arc on the yellow piece indicate to me that you have hidden geometry turned on. Turn that off and you should be fine.

Edited to add, with all the faces in that screw head, your're heading toward file bloat. If you don't need the detail, tou might consider reducing the number of segments in both the circle for the Follow Me path and the arc that creates the profile.

 

[andrewm]

The broken lines on both the screw head and the arc on the yellow piece indicate to me that you have hidden geometry turned on. Turn that off and you should be fine.

Well spotted Dave. That is exactly what it was. I hadn't realised that hidden geometry showed anything at all if there was no components hidden. You learn something new every day.

Quite agree about the file bloat. For what I am doing this little screw is utterly irrelevant. It just became a matter of principle when I found that I couldn't do it. Now that I have learnt how to get the raised head I will probably return to a simple cheese head screw and get on with what I was doing.

Andrew

 

[SketchUp Guru]

FWIW

The third example might be a little extra work (maybe even extreme) but it shows what happens when you use components.

 

[andrewm]

FWIW


The third example might be a little extra work (maybe even extreme) but it shows what happens when you use components.

Dave, On the assumption that this is a drawing that you 'just knocked up' to illustrate a point and not one that you had laying around how did you create these? I seemed to spend an age trying to create the slot and wondered if there was an easier way.

Andrew

 

[andrewm]

Have you tried scaling it a bit more (100x)?
Display Hidden Geometry isn't on is it?
Cheer
Gidon

Sorry Gidon, missed your post, wasn't ignoring you. Got notification of Dave's. Yes, as indicated hidden geometry was on. As for scaling I started at 1000x (and reduced in three steps of 0.1x so should be enough. Drawing a 8m diameter screw head is interesting

 

[Nick W]

...how did you create these? I seemed to spend an age trying to create the slot

My guess would be, create a box longer and taller than the slot. Position it in the correct place over the head. Select, run Intersect With Model. Delete unwanted bits of box.