This doesn't belong in the Feedback forum. Perhaps it could be moved?

As a solution to your first problem, consider:

1. Create two parallel circles of differing diameters (what will be the top & bottom of your tapered cylinder).
2. Select both circles.
3. Do a Sandbox | From Contours
4. Explode the newly created sandbox group.
5. Delete surfaces at the top circle.
6. Draw one line across the top circle, from vertex to vertex to (re)create a top to your frustum.
7. Erase the new line, leaving the new top/disk.
8. Manipulate (move/rotate) the top & bottom circles however you like.

I have nothing to offer as a solution to your second problem.

[ c ]

for the first question:

if you're using a PC, try holding down the Alt Key + Move tool when you move the top cylinder. That initiates a command called 'autofold' which will unlock the blue axis

If you're using a MAC - use the Apple (command) Key for 'Autofold'

For the Second Question:

i uploaded a tutorial to the 3D Warehouse which might help:

http://sketchup.google.com/3dwarehouse/details?mid=55697620d6776a795aac7b0aab31c32a&prevstart=0

-mike

thank you so much!

this tutorial is exactly what i was searching for... maybe i should spend much more time with eyes wide open in the 3d-galery...; )

 but, questions continue.

1 )as mentioned in the tutorial, the move-tool could be also used to  change diameters of a circle!?

but all i can do with it, is to move/multiply edges/surfaces a long the axes. i m working on a mac... 

i tried a couple of things with all these buttons but everything  stayed the same size, only postions were changing.

2) trying to delete the circles of the tampered mast, deletes also most parts of the frustum!? independent if the circles are selected by eraser- or select tool.

3)you asked me to move this topic to another forum, how do i do that? 

thx hannsen

1) most circles are drawn with 24 sides and 24 vertices. If you zoom in toward the edge of the circle you can see the corners of the vertices more clearly. Of the 24 corners of the circle, all but 4 of the corners will move the entire circle when you click on them with the move tool. But 4 of the corners (located at the N/S/W/E sides) of the circle will allow you to move the radius in or out. you can tell the difference based on whether or not the circle is highlighted blue. if you're hovered over a point, and the circle is NOT highlighted blue then you'll be able to move the radius.

2) use the eraser tool. But if you're on a MAC, be sure and hold down the Option key while you're erasing the edge.

-mike

back to the properly appointment of this forum...

thanks a lot guys, you do a great job here!

the tutorials, answering all these upcoming questions, it s a real big help for me and definetly all the other users. 

toda raba from tel aviv

hannsen