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The half nut must stay closed through an automatic sequence. I felt a constant cut area seemed more sensible and machine friendly. If further passes are needed to achieve the required size or fit the operator can set these. He (or she) also has the option of a rapid move in X to clear the thread area for test. A further rapid move takes the tool back to the Null position.
Richard

Ah.? So you do exactly the same thing mine does for following the flank.? The only difference is mine doesn't do the extra move in the Z threading direction before it waits for the index and does the pass. ?

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Mine returns to that new calculated Z position and then waits for the index to start the next one.? Given how fast the spindle turns it's not a big deal to wait one extra revolution.

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I was under the impression you still closed the half nut to start each threading pass.? Maybe that's a different Arduino based system.

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And mine lets the operator decide how deep to make the first pas and then how deep for each of the subsequent main threading passes plus the number of spring passes.? Or, given the pitch can calculate how deep to make each pass and therefore the number of passes.? First pass and spring passes are still up to the operator.

John

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From: [email protected] [mailto:[email protected]] On Behalf Of Richard
Sent: October-19-20 4:55 AM
To: [email protected]
Subject: Re: [digitalhobbyist] No compound

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My X infeed per pass is based on a constant area calculation where obviously the depth of the very first pass dictates the area of the first cut and therefore subsequent cuts.
When commencing an Auto Thread sequence the operator either accepts the default first pass depth for that pitch of thread or adjusts it to a value appropriate to the material and tool. When the cycle runs each subsequent pass depth increment reduces (by calculation) to ensure the constant area. Limits have previously been set for Z. A cutting pass will end at the Z end limit and after X is retracted the carriage will then return to the Z start limit.
If the system is set to cut on the flank, having calculated the required total depth for a pass a Z increment is calculated by multiplying that pass depth by 0.566. At the start of a pass Z is moved by this amount and X is moved into depth. Once these moves finish the Z axis then starts its threading move on the zero count of the encoder.
I did not think it was "clever" but maybe I am missing something?
Richard

On 19/10/2020 09:10, John Dammeyer wrote:

Well if you are following the hypotenuse of the 28.5 degree triangle then for each pass X is a bit deeper and Z is closer to the headstock if the thread is cut towards the headstock.? Simple trig.

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But if you keep the Z starting position the same then to start the cut a bit further along the thread the spindle has to rotate a different amount while the Z axis motor is accelerating so the tool enters the work over by that Z amount.

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So I'm curious how your system tracks the flank of the thread.

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John

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From: [email protected] [mailto:[email protected]] On Behalf Of Richard
Sent: October-19-20 12:52 AM
To: [email protected]
Subject: Re: [digitalhobbyist] No compound

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Wow John you have got me worried now! I did not think that it was "clever math" so I had better go back and check what I did.
Richard

On 18/10/2020 17:30, John Dammeyer wrote:

Hi Ralph,

So you have written the 'clever math' to do this.? Super.? Looking forward to a detailed explanation on how you've done that.

John

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From: [email protected] [mailto:[email protected]] On Behalf Of Richard
Sent: October-18-20 1:38 AM
To: [email protected]
Subject: Re: [digitalhobbyist] No compound

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Actually John I think that Ralph was directing the question to John Lindo!

Further to the comment you made that I repeat below, sorry John you are incorrect. I am using the Russian ELS on on Arduino Mega and I have "modified" the software. I have constant area cutting and the operator can pick plunge or flank cutting. After reaching the calculated depth for the Metric or Imperial thread further passes are possible at increments chosen by the operator. I also have the capability of clearing the tool away from the job? in X for testing then subsequently moving it back to the original position if further cuts are needed. As the system is encoder controlled the speed can vary whilst cutting.
Richard

On 17/10/2020 23:31, John Dammeyer wrote:

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Unless the math is really clever on the Arduino based electronic gearing systems they can't do it either.

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