Re: [Emc-users] more dc servo questions

I included a simplified schematic of a dual h-bridge. You can see that the motor runs in one direction id Q1 and Q4 are open while Q2 nd Q3 are closed. Reverse this and the motor runs the other way. But what if in switching, the timming is "off" and for just a millisecond both Q1 and Q2 are

Re: [Emc-users] more dc servo questions

On Wednesday 22 September 2021 15:31:33 Chris Albertson wrote: > SIn waves are there own derivatives and integrals, except for phase. > So a sine wave acceleration works if the gaol is a sine wive velocity > curve. But I assume the goal here is maximum change in velocity. > You get that by

Re: [Emc-users] more dc servo questions

On Wednesday 22 September 2021 14:48:55 dave engvall wrote: > Hi, > > Fully recognizing that nothing is impossible to the person that > doesn't have to make it work.  With that proviso I will open > mouth and insert foot. To wit: a sine for acceleration should give a > more gentle startup and

Re: [Emc-users] more dc servo questions

On Wednesday 22 September 2021 14:28:40 Chris Albertson wrote: > So you are driving it with something like this? > amazon.com/HiLetgo-BTS7960-Driver... > SN98DC/ref=asc_df_B00WSN98DC/?tag=hyprod-20=df0=1980909

Re: [Emc-users] more dc servo questions

On Wednesday 22 September 2021 13:42:00 John Figie wrote: > John Figie > > But if it overshoots the > > > commanded position and goes into reverse to bring the motor back by > > more than a 1 or 2 % drive while the motor is still coasting fwd, it > > will crowbar the psu, getting it hot

Re: [Emc-users] more dc servo questions

SIn waves are there own derivatives and integrals, except for phase. So a sine wave acceleration works if the gaol is a sine wive velocity curve. But I assume the goal here is maximum change in velocity. You get that by running the motor is full reverse. I doubt we are seing back EMF

Re: [Emc-users] more dc servo questions

Hi, Fully recognizing that nothing is impossible to the person that doesn't have to make it work.  With that proviso I will open mouth and insert foot. To wit: a sine for acceleration should give a more gentle startup and approach to end point. Of course implementation is left as an exercise

Re: [Emc-users] more dc servo questions

So you are driving it with something like this? amazon.com/HiLetgo-BTS7960-Driver... One possible mistake is

Re: [Emc-users] more dc servo questions

John Figie But if it overshoots the > commanded position and goes into reverse to bring the motor back by more > than a 1 or 2 % drive while the motor is still coasting fwd, it will > crowbar the psu, getting it hot instantly, causeing the psu to do a shut > down until it has cooled for 2 or 3

Re: [Emc-users] more dc servo questions

On Wednesday 22 September 2021 11:44:51 John Figie wrote: > Gene, > > I would like to better understand your problem and have been thinking > about this. I have some questions. > > > > I don't think the fact that there is a worm gear matters. The > > > problem, I bet is the large inertia of the

Re: [Emc-users] more dc servo questions

On Wed, Sep 22, 2021 at 8:49 AM John Figie wrote: > Gene, > > I would like to better understand your problem and have been thinking about > this. I have some questions. > > > > > > > > I don't think the fact that there is a worm gear matters. The > problem, I > > > bet is the large inertia of

Re: [Emc-users] DC Servo issues

On Wednesday 22 September 2021 05:18:40 John Dammeyer wrote: > > From: Gene Heskett [mailto:ghesk...@shentel.net] > > > > On Wednesday 22 September 2021 00:27:53 John Dammeyer wrote: > > > I love it when a plan comes together. > > > > > > John > > > > I'm surprised you kept the acme screw. > > >

Re: [Emc-users] more dc servo questions

Gene, I would like to better understand your problem and have been thinking about this. I have some questions. > > > > I don't think the fact that there is a worm gear matters. The problem, I > > bet is the large inertia of the system. > Hmm I am not sure about the inertia. I think if you have

Re: [Emc-users] DC Servo issues

> From: Gene Heskett [mailto:ghesk...@shentel.net] > On Wednesday 22 September 2021 00:27:53 John Dammeyer wrote: > > > I love it when a plan comes together. > > John > > I'm surprised you kept the acme screw. > Cheers, Gene Heskett This is a slow on-going project. Ball screws are on

Re: [Emc-users] DC Servo issues

On Wednesday 22 September 2021 00:27:53 John Dammeyer wrote: > I love it when a plan comes together. Tested out the Bergerda 1.27NM > motor on the Y axis. I was worried that it might not carry the extra > weight as the DC Servos were 1.6NM. > > Well. Silky smooth. For a 2.8A motor it never has