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Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 7:00 pm
by cnckeith
how do you know it is 'bad' ? how did you test it? etc..

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 7:04 pm
by cnckeith
these types of switches are terrible for a cnc milling machine. these are "farm" equipment travel switches.
while they will 'work' they are not ideal for holding tenths or thousandths. and are specifically not recommended in the Acorn Installation manual on page 59. https://www.centroidcnc.com/centroid_di ... manual.pdf
fram equipment.png

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 7:20 pm
by cdiseker
The place that converted it and supplied the switch had me run through some trouble shooting and he said the switch was bad.
I was supposed to get a replacement overnighted last Thursday. I'm probably going to have to replace the switches on my dime.

With that, I don't know what to look for in new switches.

By the way, thanks for your help.

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 7:28 pm
by cdiseker
I need to be clear on my previous post, the switch in the picture you shared is for the z-axis, the switch that I was told was bad was for the y-axis. However, I cannot get the home all when I first start the machine to cycle through after hitting the limit switch on the z-axis. This is why I can't go forward with the machine and get the rotations to length calculator correctly.

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 8:13 pm
by cncsnw
In the Wizard, choose "Simple Homing". Then you just jog to position and press Start. It will not attempt to move to the switches.

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 8:20 pm
by cdiseker
Will I need to do that every time I power cycle the board and will that work to get through a couple of jobs a day to get jump started?

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 8:26 pm
by cdiseker
Also, will I need to do that for each axis or just at the start?

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 11:39 pm
by cnckeith
Yes, any type of homing is required after a power cycle of the Acorn Board.

from the sound of things, before you get started working on a couple of jobs the machine needs checked out for proper operation.

i would make some test cuts in air then in wax/plastic of simple circles (circular pockets) and squares and measure them to see if you get the expected results before venturing off on any 'real' part making. and then this way you will get some practice as well.

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Wed Mar 27, 2024 11:43 pm
by cnckeith
this does not look like good mounting or wire routing practice for home switches on a cnc mill and will not provide good reliable performance over time.
cnc converstion.png

Re: New Build LMS 3990 Hi Torque Mini Mill

Posted: Thu Mar 28, 2024 5:33 pm
by cdiseker
Hey guys. I'm following (trying) Marty's instructions on how to Fine DRO Adjustment & Measuring Overall Turns Ratio as in his video


I'm using 1-2-3 blocks end to end and doing the math based on the actual distance traveled of 6 inches and cannot get the answer. It sounds like he's repeating himself some or I'm nuts.

As I travel 6 inches the DRO reads 11.9955

Is there a basic formula for this so I can adjust my turn ratios?