2d and 3d adaptive violating optimal load on lead in.

[brae86]

hello.

Today i noticed something different when machining something i have machined many times over the past year. It is a basic block with a extruded circle on top of it. I created a new model, used my normal cam method (3d adaptive), popped it the machine, hit run and ......... no good. what i have found is the lead in violates the optimal load by about 1mm. which for me is a big deal as my machine is not capable of taking 1.7mm width of cut at 5mm doc. I have uploaded a screencast of my problem. If i choose a entry point it adjusts the tool path and enters from the side which is a work around for now but should not be necessary.

If anyone can help or shed light on this that would be great. It seems to have only happen in one of the latest updates.

thank you.

[fonsecr]

Hi @brae86,

Can you share a link to your specific example? Thanks.

This makes it easier to review it by the team.

[fonsecr]

Note that the engagement load is mapped to an engagement angle and this is what constraines the cutting - not a fixed stepover. Team will get this verified.

[brae86]

link  is below

http://a360.co/2zdRg2M

password is cake

cheers

[martin.dunschen]

Hi @brae86

I have reviewed the issue you reported and can't find any problem in how the toolpath is calculated, the tool moves to the side as soon as it makes contact with the stock and at no point is the maximum engagement exceeded. 

Is it at all possible that the actual stock you used was slightly bigger than the stock you defined in the software? One advice that has been given in the past is to define the stock in the software slightly bigger so that the first cut is lighter than the specified maximum and optimum engagement.

Hope this helps

Martin

[LibertyMachine]

In order for @martin.dunschen suggestion to be effective, you will need to turn on "Stock Contours". Otherwise, it's just going to calculate off the model, and not the "larger" stock size

[brae86]

Hi Martin,

You may not be able to recreate it but it happens everytime where previously it had never happened before. The issue is on the first lead in cut. The tool goes to its start point which for me is bottom left corner. It then plunges down outside of the stock. Now instead of the tool moving in a straight line to engage the stock, it arcs in towards the centre of the stock and then as it engages the stock it arcs back out to where it should be. So it's first cut is a radius around the edge of the stock which exceeds the optimal load by quite a lot. I have done a few tests and it works out to be about 1 to 1.5mm. Doesn't sound like much but my machine can not handle a 2 to 2.5mm width of cut.

Note I always make my stock in the model slightly bigger then the actual size.
Also as my machine can only probe a X, Y corner the first cut is always going to occur the same.

A work around I am using which seems to vary is to set the start point in the middle of an edge instead of a corner. It works 60% of the time.

If the lead in was straight It would not be an issue. It's the fact that the tool paths arcs in before it cuts which is causing me the problems.

Thank you for your reply I appreciate it.

Brenton

[martin.dunschen]

Hello @brae86

Thanks for the information. I will take another look and compare if the way the Adaptive Clearing approaches the stock corner has inadvertently changed in recent updates. I will keep you posted.

Kind Regards

Martin

[martin.dunschen]

Hi @brae86

I have had another look at this and compared the toolpath for your example with the ones generated with much older versions of the software. I went back as far as January 2016 and the toolpath produced with that version is exactly the same as today, only the lead move is more favorable today being slightly longer. 

Could you post any pictures or even G-code you might still have that shows that the approach to the stock was working differently in the past when you did not have to set an entry position?

Thanks again,

Martin