Using Wizoscript

[albie0803]

I would like to share how I have put Wizoscript to use in my workplace.

We make gears and normally for drawings, gear teeth just need to look right, not actually be right, as we use gear generating machines to actually make them, but occasionally we need to CNC mill gears from a model so it has to correct.

Introducing my Involute curve generator.
My scripting ability is very small so a lot of it is done manually but the important bit gets done for me.

I have an existing part file with the following circles laid out on it.
Gear OD
Gear PCD
Gear Root Dia
Gear Base Circle
And a Node point.

Make sure the Involute part is open without the sketch activated.

Running the wizoscript brings up a form which asks for the Module, Teeth and Pressure Angle. It will then ask for the addendum. It defaults to the correct standard but allows you to edit it if desired.

Wizoscript will then build a single B-Spline Involute curve on the Gear sketch.

The magic’s done, from here on its all manual work.

I now open the sketch and constrain the node point on the 2nd largest circle (PCD) to the B-spline and adjust the dimension to the reference line to half the desired tooth thickness.

I then mirror the B-Spline around the reference line, giving me the correct tooth shape.

I turn the outside (OD) and 2nd smallest (RD) circles back to solid and trim them and the B-Splines as needed.

One tooth shape!

I’m sure a lot more of it could be scripted but it does what I need, and therefore is useful.

So have a go, even if it’s just to do that 1 tedious step. It can make the difference!

 

[Lew_Merrick]

Albie (is this correct?) -- I too learned gear generation as a machinist. I agree that a Spline Curve is fundamentally different from an Involute Curve. And, the truth is that the Model or Drawing needs only to look "about right" overall. -- Lew Merrick

 

[albie0803]

Lew, yes its me, the spline curve is generated with enough points to give quite a good curve. If it needs to be better we cut it a little short and finish it with a gear grinder. We have done reasonable sized gears so a slightly rough finish was good enough.

 

[ajayre]

Many thanks for posting this! It's great to know how people are using WizoScript to solve problems.

Andy

 

[Lew_Merrick]

Lew, yes its me, the spline curve is generated with enough points to give quite a good curve. If it needs to be better we cut it a little short and finish it with a gear grinder. We have done reasonable sized gears so a slightly rough finish was good enough.

Ah, but do you hob them or profile machine them? I learned to hob gearing...

 

[albie0803]

We have Sykes hobbers and sunderland planers as well as new CNC hobbers and grinders.

This bevel gear was completely cnc cut using the above process and the crownwheel was cut 0.5mm deeper to clean up the existing teeth using a generated tooth form.

 

[Lew_Merrick]

Whereas I have tried to be a major booster and supporter of Andy Ayres efforts with respect to WizoScript, there is an area where I find things "lacking." What exists in the "WizoScript Reference" is:

AddParameter
Creates a parameter with a value:
Parameter AddParameter(string Name, Type, double Value)

Creates a parameter with an equation:
Parameter AddParameter(string Name, Type, string Equation)

To that I have added (in my notes) that "Type" boils down to: (1) "ParameterTypes.Distance," (2) "ParameterTypes.Angle," (3)"ParameterTypes.Count," (4) "ParameterTypes.Scale," or (5) "ParameterTypes.Unit." I have found nothing about "Description" It is (IMO) rather worthless to define a (and I really hate saying this) "Parameter" without defining it clearly! It is an area where "completeness" and "polishing" are needed.

 

[ajayre]

It's called "Comment" because that is what it is called in the AD API. See page 32 of the WS reference manual.

Foo = MyPart.AddParameter('Foo', ...)
Foo.Comment = 'Bar'

Andy

 

[Lew_Merrick]

Andy -- Thanks!! If I do not document things, they "lost" way too fast.