DC conversion on lathe.
Moderator: Harold_V
Re: DC conversion on lathe.
Yes, I like the advantages of a PWM controller. But the KBMM-125 you linked to is an SCR controller, not a PWM controller. Since the motor comes with a working SCR controller, I don't understand the need to replace it with another SCR controller?
Re: DC conversion on lathe.
Ooooops! I screwed up again and guess should have read a little closer! Page 1 SCR Controller. One of these days I'm going to find someone to give me adult supervision. LoL
Re: DC conversion on lathe.
The man who doesn't make mistakes is either lying or dead. And if he's dead, there's a good chance it's because he made a mistake...
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- Posts: 71
- Joined: Sat Aug 16, 2008 11:38 am
- Location: Dartmouth, MA
Re: DC conversion on lathe.
I wrote an article on this type of conversion on my web site. Do a search on the web site to find it
www.rvbprecision.com
www.rvbprecision.com
Re: DC conversion on lathe.
Some very nice mods there!rbertalotto wrote:I wrote an article on this type of conversion on my web site. Do a search on the web site to find it.
http://www.rvbprecision.com
Re: DC conversion on lathe.
I just saw an interesting mod for the lead screw. Instead of making idler gears a guy added a reversible DC motor on the right end of the lead screw. He used a 50 rpm motor and of course a DC controller. That way just take the lead screw out of gear and use the motor for fwd/rvr motor for shuttling the carriage or cutting left hand threads.
Re: DC conversion on lathe.
Welcome to the wonderful world of Hardinge lathes!LX Kid wrote:I just saw an interesting mod for the lead screw. Instead of making idler gears a guy added a reversible DC motor on the right end of the lead screw. He used a 50 rpm motor and of course a DC controller. That way just take the lead screw out of gear and use the motor for fwd/rvr motor for shuttling the carriage or cutting left hand threads.
~RN
Re: DC conversion on lathe.
I think you'd need a rotary encoder and a stepper motor to synchronize the lead screw to the chuck rotation in order to cut threads. It would be a fast and easy way to change thread pitches though!LX Kid wrote:I just saw an interesting mod for the lead screw. Instead of making idler gears a guy added a reversible DC motor on the right end of the lead screw. He used a 50 rpm motor and of course a DC controller. That way just take the lead screw out of gear and use the motor for fwd/rvr motor for shuttling the carriage or cutting left hand threads.
Re: DC conversion on lathe.
Ahhhh yes! I see what you mean. The chuck would not be in sync with the chuck. Think I'll scrap that idea and just worry about the basics. LoLTorch wrote:I think you'd need a rotary encoder and a stepper motor to synchronize the lead screw to the chuck rotation in order to cut threads. It would be a fast and easy way to change thread pitches though!LX Kid wrote:I just saw an interesting mod for the lead screw. Instead of making idler gears a guy added a reversible DC motor on the right end of the lead screw. He used a 50 rpm motor and of course a DC controller. That way just take the lead screw out of gear and use the motor for fwd/rvr motor for shuttling the carriage or cutting left hand threads.
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- Posts: 71
- Joined: Sat Aug 16, 2008 11:38 am
- Location: Dartmouth, MA
Re: DC conversion on lathe.
Powering the lead screw isn't for threading. It is to remove all gear vibration and the resulting pattern this imparts on the part being turned.
It also allows you to change the speed of the cut while under power resulting in a much better surface finish...
And a bonus is it is MUCH quieter so you can hear the scope of the ball game on the radio......
Check out my conversion here
www.rvbprecision.com
It also allows you to change the speed of the cut while under power resulting in a much better surface finish...
And a bonus is it is MUCH quieter so you can hear the scope of the ball game on the radio......
Check out my conversion here
www.rvbprecision.com
Re: DC conversion on lathe.
As a novice this doesn't make sense to me. Change gears working with the speed of the lead screw determine TPI. Am I wrong here?rbertalotto wrote:Powering the lead screw isn't for threading. It is to remove all gear vibration and the resulting pattern this imparts on the part being turned.
Re: DC conversion on lathe.
You are correct. The change gears synchronize the speed of the chuck with the speed of the carriage travel, and hence, the TPI.
What rbertalotto refers to is when using a very, very fine "TPI" -- thousandths per revolution -- as a feed for turning. Any slight vibrations can show up as visible imperfections in the finish.
What rbertalotto refers to is when using a very, very fine "TPI" -- thousandths per revolution -- as a feed for turning. Any slight vibrations can show up as visible imperfections in the finish.