# Reversible lathe.  Worth the effort?



## ramaroodle (Nov 1, 2018)

Since it was only $9 with same day delivery and I love tinkering I ordered a DPDT switch so as to make my lathe reversible.  That being said, has anyone noticed a real advantage of being able to reverse direction for sanding?  Seems like you'd have to look through a microscope to see the fibers laying down in the opposite direction.


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## Gary Beasley (Nov 1, 2018)

Maybe not forr pens but when Im sanding bowls the endgrain cuts a lot faster if I reverse direction a time or two. Some people even run reverse when turning the inside of a large bowl and work the opposite side of the bowl.


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## ramaroodle (Nov 1, 2018)

Gary Beasley said:


> Maybe not forr pens but when Im sanding bowls the endgrain cuts a lot faster if I reverse direction a time or two. Some people even run reverse when turning the inside of a large bowl and work the opposite side of the bowl.



Thanks.  By the way, since you do stabilized blanks....why does the brilliant blue cactus juice dye turn blanks green?? (at least mine turn green)


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## dogcatcher (Nov 1, 2018)

I have an old Delta, as in the 1960's that reverses, I like to sand in both forward and reverse.  Reverse also comes in hand when using taps and dies.


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## More4dan (Nov 1, 2018)

My metal lathe has a reverse switch but also has a lockout in the circuit so the lathe has to be stopped before it will reverse. Bad things will happen if you bump the switch wile turning at speed. Might be worth a covered switch so you have to do it on purpose.





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## ramaroodle (Nov 1, 2018)

More4dan said:


> My metal lathe has a reverse switch but also has a lockout in the circuit so the lathe has to be stopped before it will reverse. Bad things will happen if you bump the switch wile turning at speed. Might be worth a covered switch so you have to do it on purpose.
> 
> View attachment 181612
> 
> ...


Looks kinda like a space shuttle switch.  Good advice. Thanks.


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## TonyL (Nov 1, 2018)

I use reverse for sanding. Even though I have plenty of respiratory protection, I like it. It wouldn't kill me to sand forward if I didn't have a choice.


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## Gary Beasley (Nov 1, 2018)

ramaroodle said:


> Gary Beasley said:
> 
> 
> > Maybe not forr pens but when Im sanding bowls the endgrain cuts a lot faster if I reverse direction a time or two. Some people even run reverse when turning the inside of a large bowl and work the opposite side of the bowl.
> ...



Well,I havent done the dye but the cactus juice resin is amber and wood has warm tones so it would be easy for the dye to turn green at low concentrations.


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## magpens (Nov 2, 2018)

Andy,

In my opinion it is worth being able to reverse the rotational direction of the lathe. . I am thinking mainly of a metal-working lathe.

You never know when you might want to turn the back side of something from the other side of the workbench !! 

 Or you might, when drilling at low speed, have the drill bit seize up and the lathe stalls. . You might be able, by reversing the rotation, to back out the drill bit ! . Who knows ?
Or maybe you'll inherit a set of left-handed drill bits !!


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## skiprat (Nov 2, 2018)

Adding a reverse switch is not a clever idea if you have screw on chucks:wink:


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## randyrls (Nov 2, 2018)

More4dan said:


> My metal lathe has a reverse switch but also has a lockout in the circuit so the lathe has to be stopped before it will reverse. Bad things will happen if you bump the switch wile turning at speed. Might be worth a covered switch so you have to do it on purpose.



Danny;   YES!!!!!   To the original poster:
If you switch direction while the lathe is spinning, you will burn out the MOSFETs in the controller.  It is an expensive mistake.

Also, this only works on a DC motor.  You probably already know that, but sometimes the simplest things trip me up.

I have added set screws to my chucks so they don't unscrew as Skiprat said.  Make sure they "land" on a flat spot, not where the spindle is threaded.


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## ramaroodle (Nov 2, 2018)

skiprat said:


> Adding a reverse switch is not a clever idea if you have screw on chucks:wink:


I figured that.  Would only use it at low speeds for sanding pens on a pen mandrel.

Thanks everyone for the feedback.  Doesn't seem like many folks feel the need for that option.


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## magpens (Nov 2, 2018)

Valid point, Skip !  I don't.


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## monophoto (Nov 2, 2018)

Bob at RJBWoodturning has a video on modifying a midi lathe (the PSI Turncrafter) to add a reversing switch.  Since I have the same lathe, I found it very helpful in doing the hack on my lathe. 

The major issues that have to be addressed are:
1.  Finding a suitable DPDT switch.  As others have noted, you NEVER want to change the direction of the lathe instantaneously, so using a switch that has a 'center off' feature provides an extra margin of protection.  I found my switch at Home Despot.  Incidentally, there is also the matter of how the switch has to be wired.  I opted for a switch that had screw connections, but you can also find switches with soldered connections, or switches with lugs that use special 'Stakon' wire connectors.
2.  Mounting the switch.  I've seen a video in which the switch was mounted in the controller box, but I was concerned that there isn't a lot of 'wall space' to work with.  So I located a small plastic box on e-Bay that I used to house the switch. The box I bought was actually manufactured to mounting/connecting exterior video cameras and came with a weather seal where the top attached to the bottom.  I mounted a 2" round magnet (from Harbor Freight) on the back of the box so that it could be stuck anywhere on the lathe base.
3.  Bob identified that the motor cable on the Turncrafter lathe plugs into the controller using a standard IEC connector set (the same connector set used to plug the power cord into a computer).  You can purchase extension cords with male and female connectors from Amazon - I opted for an 18" cord thinking that would be long enough - it works, but in retrospect, I should have used a longer cable so that I have more flexibility in where I stick the switch box on my lathe.  With the shorter cable, I have to stick it to the foot of the lathe at the tailstock end - that's fine because it's hidden, and I have to really want to reverse the lathe before I reach around to flip the switch.  But the downside is that the tailstock locking handle sometimes bumps into the switch handle.  Just a minor inconvenience rather than a show stopper.

The point about screw-on chucks is a valid concern.  However, for sanding, that's usually not a problem since you normally want to run the lathe fairly slowly.


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## ramaroodle (Nov 2, 2018)

Thanks Louie

1. Got a DPDT 3 position same day delivery @ Amazon  (*Make sure the switch is 3 position and NOT MOMENTARY*)
2  Wiring instructions here




3. I modified my lathe to use a treadmill variable speed motor so I'll probably mount it on the side between one of the 2 black boxes on the left so as not to inadvertently trip it. 




Now, the question is, do you find it a useful addition?


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## monophoto (Nov 2, 2018)

ramaroodle said:


> Now, the question is, do you find it a useful addition?



Yes.

I don't use it on every project, and I use it only for sanding.  But if I'm doing a face grain turning, or a spindle with an end-grain problem, it's really helpful to be able to reverse the direction of rotation.

The cost of around $20 was very reasonable for the value that it brought.


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## ramaroodle (Nov 2, 2018)

monophoto said:


> ramaroodle said:
> 
> 
> > Now, the question is, do you find it a useful addition?
> ...


Excellent!  Thanks.  I'm not really a bowl turner other than a couple of experiments so it's mainly for pens.  Most of them seem pretty darned smooth by the time I get to 400-600 but options are always goo especially when the switch is only $7.


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## monophoto (Nov 4, 2018)

Further to the explanation of how I did my reversing switch,  here is a picture that shows the finished installation.

Note that the switch box is held onto the base of the lathe using a magnet.  It is actually on the right rear leg, which means that I have to reach around/over the tailstock to flip the switch.  That helps prevent inadvertent reversals. If I had used a longer cable, I could have located the switch somewhere else.

Also, note that the tailstock locking handle appears to be touching the switch box.  If I unlock the tailstock, and slide it all the way to the right, I can't move it back or lock it because of interference between the switch and the tailstock handle.  I can live with it, but it is a nuisance that I could have avoided by using a longer cable that would allow me to mount the box somewhere else on the lathe base.  That's a variation on the 'measure twice' rule!


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