I would like to draw a carbide tip insert, the flat type.

To do this I have to scale the bottom of a solid shape/object without scaling the top. The sides of the top triangle must be 16.1 mm and the bottom be 13mm.

How do I do it?

If a draw the object in lines I don't get a solid so I have to work with a solid.

You have several choices, this two are IMO the best ones:
1: (easiest) draw both triangles at the desired dimensions and positions, then convert both to polygons with "polygons from curves" tool, then use skin solid tool, you can still play with the polygons points, dimensions, position, elevation, etc. to modify your solid

2: Make trigonometrical calculations for draft angle, (if both triangles are centered), then draw one of the triangles and extrude it with the right draft angle settings

If i get well, this is what you need to do (kind of):

[ATTACH]4078[/ATTACH]

Use the skin solid tool if you have it. Draw two triangles and skin both triangles. You'll get a nurb solid.

I will try again until I succeed. Thanks for the advice.

^ re: item 5. Maybe try this...

Plan A: When using the Inscribed Polygon tool (Circle Inside) with 3 sides for a triangle...
The general formula of Diameter = L x tan(60) x 2 / 3, where L = the length you like to have. Lets take an example of L = 10" if we want the length to be 10". In the Diameter box, type 10*tan(60)*2/3 and press Enter.

Plan B: When using the Circumscribed Polygon tool (Circle Outside) with 3 sides for a triangle...
The general formula of Diameter = L x tan(60) / 3, where L = the length you like to have. Lets take an example of L = 12" if we want the length to be 12". In the Diameter box, type 12*tan(60)/3 and press Enter.

Please try and see if it works... have fun there... bye

Martin,
Of course, the draw by length with a 120 degree angle in between is the answer. Obvious. I just did not think that way. Looking for too difficult methods.

I have drawn it yesterday by extruding at an angle, over and over and over and measuring with dimensions until I got the 13mm side to 13.002. Long but I got there. I used booleans to make the chip breaker groove.

The only difference from your design is that the tips and corners are not beveled, but super sharp. It is a Seco TP3500 triangle tip, designed for all types of metal and designed to be at positive angle and can take off axis materials, Stainless included. Very expensive but ultra durable. I am planning to make my own index-able type of tools, but for manual operations, not CNC. With a few well designed tools you can replace a box full of the older generation of brazed on tools. This tips can be mounted flat on top of a blank on it's own but you will require at least an edge (shoulder) to prevent the tip from shuttering or turning on the holding screw axis. What is also different is the screw hole is tapered, evenly through, not with a step. For my hobby use the tips will take the beat and will work out cheaper on the long run.

I am just drawing the designs to see how to make them, but because I am drawing to scale I am able to see where and how much material must be taken away, if enough will be left to support the downward pressure as my lathe toolpost can only take up to 13 mm (therefore I can work with 12mm tool steel square bar) and I must also ensure that the clearance is enough, but to the minimum, etc. With this ViaCAD I can do it now and get it on paper in a plan as well. If I can get a cheap source of labour I will most probably ask somebody to do the milling for me, or maybe I will do it myself on someone's milling machine.

However I am also trying the other methods because this is the only way to learn the program properly.

Thanks Bill,
I have adjusted the code for 13 mm sides:


This gave me a 26mm sided one,
So I just use the formula 6.5/cos(30)
and then there is a perfectly sized triangle.

Iebeau, What you have said now is what I would like to see in thr solid native designing as well. Think of how easy designing will be. Blender, 3DS and Rhino can. Think of the possibilities if Via or Shark can as well.
This is the reason why I mentioned selective scaling as a new suggestion.

I am still thinking ViaCAD pro is very fast building a reputation as a professional CAD software for both the hobbyist and the professional. When you deliver your 2D plan to someone, he is not voncerned whether it was designed by Autocad, ViaCAD, Solidworks or open source cad programs or even by hand. As long as the plan fulfills his requirements.