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Carriage Stop for G4003G
- Thread starter Canyonman44
- Start date
Whether you crash into the chuck or into a rock solid carriage stop it is still an unwanted crash that will likely cause damage. To prevent crashes why not just have a limit switch on a clamp that is strategically placed to stop the lathe before a crash occurs? This would only be as a backup for a freak lapse of attention at the wrong moment.
However if threading to a shoulder is involved, there are some mechanisms that disengage the half nuts at the right point on every pass. Even so, I find it simpler in this case to run in reverse and thread out from the shoulder with the tool at the back.
A solid clamp on the ways (with or without a micro adjustment) is best used for limiting movement of the carriage by hand so you can feel it stop without crashing it.
Last edited:
- Joined
- Jan 16, 2020
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- 54
Congrats! Do I have to call you SIR now?
- Joined
- Apr 28, 2014
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- 3,590
I agree with with your comments - mostly. The exception is a lathe that's designed like mine.
It could really use a brake and a prox switch modification.
Even with the power cut off it would have continued to spin to a stop.
Here's my crash - the half-nuts had jammed and I couldn't get them disengaged quick enough:
Goofs & Blunders You Should Avoid.
Yes, what could go wrong, please don't tell me this happened in a civilised country. I did notice some kind of Chinese ideographs on the lower forklift near the end of the video.
www.hobby-machinist.com
As it was I didn't find out until later on that the spring pin in the clutch had mangled and seized solid. So it wouldn't have functioned properly anyway.
Perfect storm.
here are a couple of ideas. https://thecogwheel.net/2019/04/04/carriage-stop/
tomstechniques.com
I have the one that comes with my lathe. It is steel and I use it for a hard stop to keep from crashing. I wish to make an adjustable one. I am leaning towards the Cogwheel version and also to make it that it will handle a 2" indicator with positive stop in both directions so I can use it left or right.
With the one in the first link that mksj posted, it should not be too hard to wire the switch shown to a relay to stop the lathe.
Micrometer Carriage Stop
tomstechniques.com
I have the one that comes with my lathe. It is steel and I use it for a hard stop to keep from crashing. I wish to make an adjustable one. I am leaning towards the Cogwheel version and also to make it that it will handle a 2" indicator with positive stop in both directions so I can use it left or right.
With the one in the first link that mksj posted, it should not be too hard to wire the switch shown to a relay to stop the lathe.
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- Jan 2, 2016
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- 1,953
I saw a cool setup on a 4003G, that mounted on the rod that activates the switch, and another piece mounted at the head end such that when the carriage contacted the non movable part, it forced the power lever to the off position. I thought I saved some pics, but cannot find them now.
I also found out by accident that if you do not have the banjo for the change gears real tight, the gears will push each other out of engagement if the carriage gets blocked.
I also found out by accident that if you do not have the banjo for the change gears real tight, the gears will push each other out of engagement if the carriage gets blocked.
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- Jan 16, 2020
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- 54
Hi Mike, We were talking somewhere about a jig a guy made to cut repeatable way cuts. I'm kinda paddling in the deep end, but I think it's
Ken
Ken
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- Feb 17, 2013
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- 4,406
Canyonman -
If your lathe uses a VFD (or contactors that use a low voltage/low current signals) to control the motor, you might be able to rig up a carriage stop with a switch.
I originally posted on my (hard) carriage stop on
www.hobby-machinist.com
Last year I added a microswitch. I'm pretty sure I posted about that modification somewhere on the forum, but I've not been able to find it. So here are a couple of photos to give you an idea. The microswitch opens the "run while closed" VFD circuit when the carriage depresses the plunger. Note that the switch is activated by the side of the plunger as it moves inward. This allows some overtravel without crunching the switch, as might be the case if the switch were located at the end of the plunger. I have a braking resistor on the VFD, so the spindle stops pretty quickly (about ¼ turn at 100 RPM). The ¼" phone plug goes into a "shorting" type jack, so that when the plug is removed, the "run" signal maintains continuity. When I bought the phone plug and jack I added a dust cover to my order. Note that it's a "stereo" phone plug. That's because the signals going to the VFD need to be isolated from ground. Because it's mounted to the metal casing of the lathe, the outer shell of the jack is grounded. The switch is connected to the tip and the first ring of the plug.
All you have to remember when using such a switch is to set the reverse/stop/forward switch to "stop" before moving the carriage away.
If your lathe uses a VFD (or contactors that use a low voltage/low current signals) to control the motor, you might be able to rig up a carriage stop with a switch.
I originally posted on my (hard) carriage stop on
Carriage Stop
A couple of recent projects on my lathe made me aware that really I needed a carriage stop of some kind. I had an old one made for another lathe (no idea where or when I got it), but it wouldn't fit my 12x24. I measured the lathe ways and designed a new stop body that would re-use the already...
www.hobby-machinist.com
Last year I added a microswitch. I'm pretty sure I posted about that modification somewhere on the forum, but I've not been able to find it. So here are a couple of photos to give you an idea. The microswitch opens the "run while closed" VFD circuit when the carriage depresses the plunger. Note that the switch is activated by the side of the plunger as it moves inward. This allows some overtravel without crunching the switch, as might be the case if the switch were located at the end of the plunger. I have a braking resistor on the VFD, so the spindle stops pretty quickly (about ¼ turn at 100 RPM). The ¼" phone plug goes into a "shorting" type jack, so that when the plug is removed, the "run" signal maintains continuity. When I bought the phone plug and jack I added a dust cover to my order. Note that it's a "stereo" phone plug. That's because the signals going to the VFD need to be isolated from ground. Because it's mounted to the metal casing of the lathe, the outer shell of the jack is grounded. The switch is connected to the tip and the first ring of the plug.
All you have to remember when using such a switch is to set the reverse/stop/forward switch to "stop" before moving the carriage away.