Peter The SX3 or Super X3 sold by Grizzley (G0619) does use the digital control. The X3 sold by Harbor Freight and also Grizzley (G0463) use a speed potentiometer. My first attempt will be to use the VFD outputs of the Gecko G540 which provides an opto isolated pwm to analog reference. In its case it is limited to 12 volts so my first job is to determine the safest place to measure the voltage across the pot and then measure it. I was a radar technician in the mid 60's and then went back to get my BSE. So I am very leery of floating references. As you say these voltages may be anywhere from 7 to 15 volts. I can probably use the G540 pins as long as they are between 5 to 12 volts. I will post my findings. Physical inspection of the control boards in the two machines reveals different animals in types and quantity of components. Hopefully I will not have to reverse engineer them to get them to work.
Hubert Peter Homann wrote: > Hi Hubert, > > You need to be careful connecting to the pot inputs of a lot of these type of > speed controllers. The usually put a DC voltage of anywhere between 7V to 15V > across the potentiometer. The kicker is that this voltage is generated via a > zener shunt regulator and the control voltage is actually 7V-15V below the > mains voltage. > > You need to ensure that any pc control connection to this is isolated. I > have > a number of products including the DC-03 that take a pwm signal from the PC > and convert this into an isolated dc control voltage that is suitable for > controlling many types of DC motor controllers and VFDs. > > http://homanndesigns.com/store/index.php?main_page=product_info&cPath=1&products_id=21 > > > As to the X3, I thought it used a brushless motor and the speed controller > was > digital with buttons for speed up/down and not suitable for accepting an > analog control input that replaces a manual speed potentiometer. > > Cheers, > > Peter > > > Hubert Bahr wrote: > >> Just some thinking out loud!! Is it possible to put a rotation detector >> on a spindle, use it as an input to EMC and then have EMC drive some >> type of digital to analog converter to change the speed until it agrees >> with the desired setting? Based on some past discussions on the list, >> I believe the answer to be yes. If so, what type of rotation detection >> is needed? What is the best way to convert the EMC output to be a >> control force for the spindle? >> I am talking about a spindle on the X3 Seig Mill. I am planning to >> convert the current gear drive to a two range belt drive, and since the >> current controller appears to use a pot to adjust the speed and a switch >> to change direction I believe I could use some type of control voltage >> and a relay to replace the pot and switch. I would appreciate any >> suggestions as I explore deeper. >> >> Hubert >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart your >> developing skills, take BlackBerry mobile applications to market and stay >> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >> http://p.sf.net/sfu/devconference >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> ------------------------------------------------------------------------ >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 8.5.421 / Virus Database: 270.14.9/2426 - Release Date: 10/09/09 >> 18:43:00 >> >> > > ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
