Replies

1. 
   StanleyNiemiec | Mar 22, 2003 10:25pm | #1

   I continually reverse the rotation of the spindle on my shaper (3HP/220/single phase) all the time by changing the wiring on the motor.  I have a reversing drum switch on my list of things to get to facilitate rotational direction but somehow have not purchased it.  If by changing the wiring (switching the appropriate wires) works on your lathe, then a drum switch will make it easier and faster. 

   The only negative effect reverse rotation might have on a lathe seems to me to be the threading of the headstock and whether the reverse rotation will cause the screw on face plates to loosen/come off while you are working.

1. 
   dscola | Mar 22, 2003 10:36pm | #2

   Hi There,

   Thanks for your response. Do you have a magnetic starter on your shaper?As far as the thread direction,  I have a way to secure my chucks and face plates.  Spoke to a couple of supply shops,  the drum switches run about 60 dollars Canadian funds. I think it is fair considering.

   David

1. 
   StanleyNiemiec | Mar 22, 2003 11:35pm | #3

   Yes I believe I have a magnetic starter but I would not stake my life on it.

   I have a control box on the shaper where I change the wires that is attached to the motor so that I do not go into the switch mechanism.

2. 
   JPGrout | Mar 24, 2003 06:32am | #4

   David I have a 3HP Delta shaper and the reversing switch is right on the motor. Just a toggle switch, costs maybe three bucks. I believe I have a wiring diagram for doing this. If I can find it and figure out how to attach it to this forum I will, other wise I could email it to you.

   Joe

2. 
   booch | Mar 25, 2003 04:32pm | #5

   Reversing drum switches are motor duty rated. If it has a HP rating (check the label or the catalog spec. If so then it is made to start the motor. End of story on that setup. The contacts are beefy if you crack it open. Lots of copper to absorb the arcing or minimize it.

   http://www.squared.com/us/products/nema.nsf/07a0210021262d45862564b5006e4f84/928d19dba98b9f3d852565d90051a566/$FILE/1515g.pdf

   Is a Square D link to show the info and wiring on a drum switch. There are many varieties for single phase, 220 volt and 3 phase applications. All are 600 volt AC rated (yes you can run 110 volts thru a 600 volt switch) Ratings are maximum.

   If you want to use the drum for direction only that is ok. It is a bit redundant but OK.

   As for the threading problem you will obviously have to police that. Spinning the lathe opposite of tightening will cause the headstock and tail to push apart and possibly disengage ... you know the death and destruction inherant in that. However, the tailstock being oppositely threaded makes this necessary. (Is it really threaded that way? My rockwell is right threaded outboard and left threaded inboard so I only need one direction) A suggestion is to label the switch. (Outboard , Inboard ) or something that makes it obvious to the operator.

   I put a drum switch like you describe on my shaper. It really helps with the multi cutter setups as I get it all assembled then realize it is upside down (duh). All that is needed is to reverse the rotation and the shaper setup works fine.

   Jack of all trades and master of none - you got a problem with that?
1. 
   JPGrout | Mar 25, 2003 08:46pm | #7

   I am still of the opinion that as Tom stated above,a DPDT toggle switch is fine. You are not going to reverse the rotation while the shaper is running and quite frankly any attempt to do so even if it were possible would be dangerous. The following attachment is from FWW #64

   
1. 
   TKanzler | Mar 25, 2003 09:40pm | #8

   I can't open the file you've linked to, but here is a quick diagram I ginned up to illustrate how these little switches are connected.  They basically put the two leads from the start winding, which are the two you reverse when you change the rotation in the motor junction box, to the common terminals on the switch (the ones in the middle).  Bring a short jumper from the connection point of each of the two start winding leads, which may be a stud, a wire (or two, or three), or something else, to the terminals on one end of the switch, and add jumpers to the terminals at the opposite corners.  Switching the switch effectively connects the common terminals (with the start windings) either straight through to what they were originally connected to, or reverses the polarity.

   My apologies for not acknowledging your earlier post, wherein you recommended this little switch.  I read the thread a day or two before posting, and didn't recall that it had been mentioned before.Be seeing you...

   
1. 
   TKanzler | Mar 25, 2003 10:09pm | #9

   Here's a smaller version.Be seeing you...

1. 
   JPGrout | Mar 26, 2003 01:13am | #10

   Thanks Tom the image I placed is a tiff file. I guess not every one has those huh?  Sorry This is like the first time I tried this on prospero  Thanks for pointing that out  Joe

2. 
   dscola | Mar 26, 2003 05:54am | #11

   WOW!

   I was not expecting such a response.  I would like to thank everyone for their advice.  As it turns out I was able to get a brand new reversing drum switch(squareD) very, very cheap.  I installed it between the magnetic starter and the motor.  It may be overkill, however, the magnetic starter provides an element of safety via the contactor and the overload protection.  Plus the drum switch is very convenient, especially because of its location.

   Cheers

   David

2. 
   booch | Mar 26, 2003 03:21pm | #12

   Yes that certainly would work for wood work ;-).

   The switching of non running loads would protect the dinky contacts in the DPDT switch.

   Contacts are a funny thing. There are 3 types commonly refered to.

   Definite purpose contacts (in a contactor) are minimal bits of metal sized for a specific application based on inrush of a motor as well as the number of operations the OEM expects it to have to perform. Airconditioner circuits are the prime consumer of those.

   IEC contacts are application rated as well. They are a bit larger in mass but again these are rated for a motor's inrush but IEC style give us the ability to select based on how many and what type of operation you plan to use. For example AC1 rating is for resistive loads, AC3 is for inductive loads turned on/off less than 3 times per hour*, and AC5 is jogging Duty. Each contactor runs a "life" that can be found by looking at the curves published. The curves take into account the load, type & intensity of use. These are the most popular and the most economical as you can specify what your needs are.

   NEMA rated contacts are for Us general users. These are horsepower rated adn built with heavy contacts that meet all applications from jogging duty to resistive loads. Frankly most of us don't want to think about the type of application we are using we just want safety and reliability. In industry you don't make money by spending 2 hours deciding what to do. Yes the NENA starters are more money but they work in all applications. The Drum switch falls into that realm of NEMA devices. Big massive contacts and abuse / neglect resistant

   Now the DPDT switch you described is in the realm of definite purpose devices. Some are HP rated but I've sold enough of the bat handle switches to see some smoky failures from mis-application. Your suggestion is a good one and safe IF it isn't used as an inline reversing switch. There are no arc chutes and not enough mass in the contacts to keep them from melting severely if the reversing was a SOP.

   * I couldn't find the reference source on the # of operations for each AC rating. As catalogs keep getting larger details keep being left out. If anyone cares I can find a source.Jack of all trades and master of none - you got a problem with that?

3. 
   TKanzler | Mar 25, 2003 06:30pm | #6

   A lot of tool motors just use a DPDT toggle switch, which acts to reverse the start winding connections.  That's how you reverse the motor rotation when you do it in the j-box, after all.  The switch doesn't necessarily have to be motor rated, however, since it doesn't make/break the connection while energized.  Even if you switched it with the motor running, the start winding is out of the loop, unless it has a run capacitor in addition to the start capacitor, in which case the start winding stays in the loop all the time.  That's how they were able to use such a small and inexpensive switch.  Delta used to use a drum switch on their small 1/2" shapers (Homecraft, no longer in production, with a newer version shown in the link below without the drum switch), but, as Booch mentioned above, the drum switch was also the start/stop switch, and therefore had to be motor rated.  Some of Delta's HD shapers, which are now 3 hp, used a DPDT toggle switch on the motor j-box, with a separate manual or magnetic starter on the outside.  They may still do that, I don't know.

   Here's a couple of links to past ebay auctions that have photos of the small DPDT toggle switch I'm referring to.  Look at the junction box in motor close-ups.

   http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2515415630&category=11810

   http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2311973086&category=632

   Be seeing you...