Miyano parameter Problem

[AFX]

hi i have a miyano JNC-I-35 cnc Lathe, runnig 3t-f controls. the problem i am having is it was lewfting sitting with no power and the battery died so it lost all parameters. we got it running again but the z travel is off by about 25-26% i was wondering if anyone knew how i could solve this. im sure it's a parameter just not sure what should be what.

-Thanks in advance
-Tim

[Al_The_Man]

If it positions consistantly every time, it could be the command multiplier for the Z, par. 0016.
Do you have the manual, it describes the parameters.
Al.

[AFX]

ok i found a 3t-f manual and found that it says for 0016 to be set to 2 which is what the machine is set to.... how would i go about figuring what the maching is looking for....

[Al_The_Man]

Actually you can tell if it is the multiplier by commanding a relative move and see if it travel the distance commanded, if it does, it is not the multiplier.
Al.

[AFX]

ok i had a little time to play with this miyano again today and here is what i was able to do... i touched off to a part and moved 1" away from the spindle. and measured how much it actually moved and the actual movement was .75"
but when looking at this parameter list there is no multiplier that would be able to correct this... there is...
1 = .5
2 = 1 (current Parameter)
4 = 2
10 =5
20 =10

if i did this correctly wouldn't i need a multiplier of .75?


Edit: Spelling

[Al_The_Man]

Actually there is two parameters that set the least input increment, it should explain in the manual the two Par. are 7 & 8 bits 5,6,7 which is the CMR and 15 & 16 DMR.(command multiply ratio).
And the Least input increment = CMR (Command multiplier)
It really is a way of saying between the two you can set the pulses/degree of movement.
I can post a bettter explanation or example if you cannot find it in the manual.
BTW all entries values are in binary equivalent of the setting value.
Al.

[AFX]

i found it in the manual but im still a bit confused...
so i take paramater 16 and multiply it to bits 6,5,4 of parameter 8 to get the command multiplier?

currently param. 16 is set to 2 (ratio of 1)
param. 8 is set to 1 1 1 (multiplier of 4)
and the movements are off my 25% a 1 inch command yeilds a .75 movement.

i think i could use a little more explaination.

[Al_The_Man]

The way the DMR/CMR is set up is first the servo distance/rev (grid interval), the smallest command incr. decided, and the encoder pulses/rev known.
the first parameter is 0007 for the X.
DMRX & GRDX
Example servo driving a ball screw .25 turns/rev with a 2500 counts/turn encoder.
With the above, the smallest detected incr. will be .0001, we require .00005 so .0001/2 = .00005 so the DMR =2
GRDX (capacity of ref. counter) = Grid Interval/ required detection unit =.25/.00005 = 50000
so the values for DMRX & GRDX converted to the binary number assigned as per the manual chart
P0007 = 0011 0100
We require also a command increment of .00005
exsisting command incr. = .0001 so we use a CMR of 2.
.0001/2 = .00005
In this case CMR & DMR both equal 2.
Therefore CMRX P0015 is 4
Make sure you also have the correct number in the GRDX GRDY.
All the above Parameters also affect your feed/speed and servo gains, so make sure you note the original settings.
Al.

[AFX]

ok, I think I got this figured out but just one question looking over your formula's it looks like cmr and dmr will always be the same... I noticed they where set to different numbers on this miyano. also they tables have totally different values... if possible could you post an example where the cmr and dmr are different values?

[Al_The_Man]

Ok take another example is where a lathe has two identical motors encoders and ball screws, the normal way of setting up a lathe is the readout and command in the X is by diameter designation (/2), whereas the Z is direct linear measurment.
The ball screws are .4"/motor rev. The encoders are 2000p/rev, the counting for unit Z is to .0001"
With 2000p encoders the DMR will be 2 and the CMR 1 (encoder pulses x ratio) giving the reference counter capacity of 4000 (.4"/4000=.0001")
With the X, if we use the same DMR & CMR it will indicate radius distance.
So to change it to Diametric, CMR 1 and DMR 4 changes our ref. counter to (2000x4 ( our encoder pulses by our ratio)) = 8000
What this does effectively, is change the smallest command unit to 0.0001"/2= .00005" or .4"/8000
Hope this is a bit clearer.
Al.
.

[AFX]

ok well i figured it out parameter 0008 was 01110111 and now it is 01010111
the change of a 4x multiplier to a 3x multiplier.
thanx al for all the help i have a much better understanding of the encoder parameters now.
as a side note i have an old mori seiki that i back-up the parameters via dnc... my quick question is, the mori is yasnac and the control is a bit different then all the fanuc machines we use.... is there an easy way to dnc the parameters via fanuc 3 and 6? cause i tried and it didn't work for me.

thanx again for all the help so far!

[Al_The_Man]

What input device do you have? If the parameters are lost completely, you have to load the communication para. by hand first, then select edit mode and parameter screen and flip the parameter switch on, on the MB then INPUT.
turn the parameters switch back and power down and back up.
Al.