View Full Version : Control Switch for Enco Lathe

10-09-2002, 12:24 PM
I am wondering/wishing if someone can tell me of a source for the control switch that turns the lathe on (forward and reverse) for the Enco lathes. Mine got oil on the switch (bad design naturally) and made the plastic soft and it eventually broke. Enco says they are on back order and can’t give me a delivery date plus the switch is $120.
Is there a way to install a temporary switch or maybe do away with the Chinese version and go with an American switch with a little modification?
The Chinese switch does not have any #’s to cross-reference and the manual does not list any either.
I have searched the archives but did not find a solution to a simple problem.
I know, I know, that’s what I get for buying a cheap Asian lathe.
Thanks for any help.


10-09-2002, 05:23 PM

Does your lathe have an electrical schematic in the manual? If it does, and you have means to scan it and email it to me, than I'm sure I can find you a replacement you can buy locally.


10-09-2002, 05:37 PM
I do have an electrical schematic for the lathe but I do not think it will be of much use. I do not have the scanner hooked up at the moment but I will hook it up tonight and send it along with a digital pic of the switch. I do have some (not much or so I have been told) electrical experience and I have not come across a switch of this design before. It is actually 4 switches (with one set of contacts each) that lock together and only three of them are used in the switching sequence. One is not used at all. The looks like it is about the 500th copy and you can barely make out the print.
I am redesigning the box that the switch is housed in to possibly remedy this from happening again.
Thanks for replying.

10-09-2002, 05:41 PM
How about forgetting that switch and replacing it with a regular drum switch? You may have to mount it elsewhere, but you can get a good-quality switch that won't break.

I expect if you go into an electrical supply store and ask for a "reversing drum switch for a x horsepower motor" (whatever x is), they'll be able to help you out.

MSC, Grainger, McMaster-Carr, etc. must sell them, too.

10-09-2002, 11:10 PM
You may have the solution to my control switch problem. I have sent NSDesign pics of the switch and schematics but they may not be enough info for him to go on. If not then I will remove the control switch from the lathe and take it with me to Oklahoma City and see what I can dig up. I just hate the thought of going to electric houses and telling them what the switch fits.
I will also try the Internet sources you suggested.
Thanks for your reply.

10-09-2002, 11:43 PM
If you can't find what you need please holler. I'm sure with all of us we can come up with something that will work for you.

10-10-2002, 03:20 AM
A really good drum switch should not cost more than $60-80 beans.

10-10-2002, 09:00 AM
You are probably right.
I just want the $60 - 80$ beans to stay on this side of the ocean this time.
The Enco lathe is my first lathe and it has been a good teacher but I would have preferred an American teacher.
I have learned more on this board than any of the other boards I read (and I read most of them)and you guys never fail to at least try to help someone when in need - for that I thank you all.

10-10-2002, 11:39 AM
You don't mention the model of the Enco lathe that you have. If it is a 12 x 36, 110-2075 model you can get the switch which is shown in their parts list as a Hz5B-10/2D009 from Harborfreight. The same switch is probably also obtainable from Grizzly, or one of the other vendors of this or similar lathes.

One thing I like about the ubiquitous 12 X 36 gearhead lathes is that they are available from a number of vendors. Since these lathes are all very similar if not identical as far as the parts for them go, you can readily get replacement parts from several sources. Imagine if you were trying to get a part for a lathe that is 40 years old and the manufacturer was no longer in business.

<font face="Verdana, Arial" size="2">Originally posted by Gator:
I am wondering/wishing if someone can tell me of a source for the control switch that turns the lathe on (forward and reverse) for the Enco lathes. Mine got oil on the switch (bad design naturally) and made the plastic soft and it eventually broke. Enco says they are on back order and can’t give me a delivery date plus the switch is $120.
Is there a way to install a temporary switch or maybe do away with the Chinese version and go with an American switch with a little modification?
The Chinese switch does not have any #’s to cross-reference and the manual does not list any either.
I have searched the archives but did not find a solution to a simple problem.
I know, I know, that’s what I get for buying a cheap Asian lathe.
Thanks for any help.


10-10-2002, 12:30 PM
As Delmar would say, "I'm with you fellers".

Drum switches are wonderful contraptions, love them. Simplicity itself.

Learned something the other day.

Wired up a drum switch to my Hendey, need reverse once in a while, and the mag starter was a little cranky. Might be because it's 50 years old, didn't like it anyway.

That old 5hp GE 3ph motor on the Hendey has lots of inertia, when trying to reverse without letting motor stop it kicks the converter the other direction, lathe motor keeps turning the same direction.

My converter motor is a bit small, just a cast off 2hp I got out of the scrap, had a busted off shaft. But it starts up machines fine with a grunt and growl, and if I burn it up, what the heck.

They always say to build a converter with a motor bigger than the largest motor that you are going to run, and an old big heavy one is the best. I think I know why now.

Got a 15hp sitting in corner, sometime I might get it wired up as a converter. It should be able to reverse that 5hp at speed.

Drum switches are good.

10-10-2002, 04:06 PM
Yes it is the 12x36 that you mentioned except my lathe was assembled on a Friday evening at 4:45 PM - China time.
My schematics listed the switch as Hz5B-10/2D009 also and I have searched the Net for this switch and am going to start emailing some of the suppliers. If I cannot replace the original switch with one like it for a reasonable price then I think the guys have put me on the right track about replacing it with a drum switch that can be replaced or repaired locally. Haven't found anything I like yet.
I did not know if all of the Enco Lathes used the same control switch but I thought that I may not be the only one that has experienced this problem. I did look at the Harbor Freight 12x36 lathe and several others before buying the Enco model. I looked for new and used lathes for about 5 months before I finally ordered the Enco. I would love to have a used American Machine but I absolutely could not find a decent machine within 150 miles that would fit into my 28’x30’ garage. (I’ve got other things in there too – too many things.)
I have epoxied the switch and made a new housing to hobble by for now but I know it will not last long and will be replaced as soon as I find one. The longer I sit here and type the more I am leaning toward the drum switch.
Thanks again guys.


10-10-2002, 07:31 PM
Hi Larry,

I will post a copy of this reply on HSM board as well...

Hold on with that drum switch idea, I don't believe that you need one. A drum switch is used to control a motor directly, by switching the wires as required for direction control. They are expensive because they have so many contacts that HAVE TO CARRY ALL THE LOAD of the motor. From your photos, it seems that in the control box there is a contactor(s) that does the real load wire swapping. The switch that pooped on you merely controls those contactors. Unfortunately, from the pieces of the diagram that you sent I can't be sure of the situation. The bad news is that I don't think I can discern the manufacturer for a direct replacement. (maybe the other guy's suggestions about Grizzly etc. would pan out.) The good news is that if my ascessment above is correct then any industrial selector switch will work for you.You can go to any good supply house (even graingers) that carries Square D, GE controls, or the like. You need a three position maintained selector switch operator. You also need the appropriate contact blocks for the back. They will have the right combination of normally open or closed contact blocks to build your switch. Bring the old contacts with you. If you do this, you will need to make an adapter to couple the switch to your control lever. HSM to the rescue - I'm sure you can make what is needed.

If you send me a photo of the whole control panel and wiring diagram I can confirm what I suggested above.



10-10-2002, 11:29 PM
Thanks for replying and doing your homework and will post this on the board well.
I talked to an electrician/x-machinist about the switch problem this evening.
I could not take the switch back apart to show him the overall situation we are trying to solve because I had epoxied the swith back together and installed in back into the bracket.
There is one thing that is puzzling me about this switch setup - I have checked voltage to the switch with and without the lathe running and my voltmeter says zero voltage. Checked on all scales plus I checked for DC voltage as well. I also checked for a ground on all four wires going to the switch with the lathe plugged in but reset kicked out to prevent any shocking surprises. No continuity at all. I have the lathe running and I think you are right about not using a drum switch since I checked for voltage.
I am going to make a few electric suppliers since I have not found any cross reference to the numbers on the net. I don't think it will be a problem designing a coupling to another type of switch.
I can't take a pic of the whole motor control box since the lathe is anchored to the concrete floor and against the wall. I have made custom leveling feet for the lathe but have not had time to install them. (Big mistake putting a lathe against the wall and anchoring it to the floor.) Do you have an answer to the voltage not being able to be tested to the switch? The electrician says that they should not be continuity controlled.
Maybe I am just getting tired and losing focus......
It will be Monday before I can make it into OKC (about 75 miles one way) to look for a switch but that will give me time to study the switch a little more.
Thanks again Alan.


10-11-2002, 08:44 PM
Did you check the voltage to ground?

10-14-2002, 11:22 AM
Sorry for not answering earlier - server down over the weekend.
Yes, I did check voltage to ground. That was one of the things that had me baffled. I can not slide the lathe away from the wall at the present time.
Just got your email and I will take pics of the schematic and send to you.



10-14-2002, 08:49 PM
That is odd. Please let me know if I can help.

10-15-2002, 07:32 PM
Gents all I know of your control problems is what I read here. But if you are not measuring a voltage to ground, you may have a control transformer (lo Voltage) controling your relays (contactors). If so maybe neither leg is grounded and no voltage would be normal. This would also simplify replacing the switches- use low ampere , lo vaoltage switches that duplicate the represent present switching arrangement. Handfull of relays, diodes, and conventional switches can duplicate most complicated switches. As I warned you, I don't have a clue as to what your problem is, exceptingyou have a interesting one http://bbs.homeshopmachinist.net//smile.gif

10-15-2002, 08:55 PM
DocSteve has written about what I believe to be the case - an ungrounded control transformer, reversing contactors and a pilot duty selector switch built up of normally open and closed contact blocks. Gator is going to send me photos of the complete schematics so I can confrim this situation and give him an exact parts list for replacement.

10-15-2002, 11:22 PM
You may be onto something here on the control transformer. I have sent NSDesign a couple of pics of schematic and a link to the original manual for him to look at since my photography skills could use some improvement. I may not have an alternative to moving the lathe away from the wall to check into the controls if we can't find a replacement switch.
This is the link if anyone would like to look at the "Harbor Freight" copy of the manual (same manual I received with my lathe). Takes a while to download (if you have a slow connection like mine) to page 7 & 8 to look at the electrical schematics.
Thanks guys.


10-15-2002, 11:26 PM
Sorry...... forgot the link.


10-17-2002, 08:13 PM

Thanks for the link to harbor freight, I was able to look at your schematics and determine exactly what’s going on. Your lathe uses an ungrounded control transformer to drive contactors that control the motor. The control voltage at the selector switch is 29 volts AC. There will be no voltage at your switch under some conditions. Specifically, you have to have the power on, the e stop pulled out (reset), and the apron switch in the middle (off) position. When you press the “power start” button, it will pull in the main contactor and you should measure 29 volts AC between 5 and 7 or 5 and 13. Since the control transformer is ungrounded you will not see any voltage between these terminals and ground.

As far as your switch is concerned, my previous post is correct. You need a 3 position, maintained selector switch. The switch will be available with contact blocks that can be added on the back. These blocks are either normally open or closed. Because each manufacturer makes the activation cams differently, I can’t tell you exactly what combination you need, but any good supply house guy can. Here’s what to tell him: three position maintained, three contact blocks, each block is closed in only one position and open in the other two. The truth table looks like this: Left - X00, Center - 0X0, Right - 00X. (An example is Grainger part number 7A164, but that is $45. I think you can do much better.) Even if this all sounds like gobbledygook, don’t worry, the supply house guy knows what I mean. Remember you will need to cobble up an adapter for the switch mechanism.

When you get your new switch home here’s how to wire it: use your meter on continuity to check each block. The block that is closed in the center position gets wire# 4 and the #5 wire that comes from the cable. Daisy chain #5 jumpers from that terminal with the #5 from the cable, to each of the other two blocks. Put # 7 on the block that has continuity in the left position. Put wire # 13 on the block that has continuity in the right position. This wiring should be very similar to what’s on the existing switch, the blocks just may be in different locations. I might have the rotation directions wrong since they weren’t labeled on the drawing. Please be careful. If it is wrong, just swap 7 and 13. If you have questions please ask, if you want I can email my phone number to you.

Good Luck,

10-17-2002, 11:27 PM
It's probably too late, but let me know the Enco model # of the lathe. If it is the more expensive of the 2 12x36 machines that they offer, I can probably get it for you. I am a Birmingham dealer, but I think the switch is the same. Please sent me a picture of the part you need, I will do my best to help you. My email is mnadeja@bellatlantic.net.

10-21-2002, 10:18 PM
Sorry guys for not replying earlier.
Out of pocket over the weekend.
I got a headache looking at the wiring schematic and trying to figure out how you read all of this out of this drawing.
It would have taken me a couple of years to figure this out. I am amazed. I am still running the lathe with the original switch but it does not start every time when the control lever is engaged and I have not gotten to an electrical supply to get the switch you described. Your instructions are very easy to understand and follow.
Thank you very much for your help and time.

I am sending a pic of the switch and would appreciate any help or suggestions.


10-22-2002, 12:01 PM
Gator: I suggest you try mnadeja and his switch. Might even buy (I would) and try to save time.
I printed out page 7 of the manual. If you find line PE and color it (I used green) where it connects to the motor and TC (The Control voltage Transformer) you will have dividedthe drawing into two parts, the high voltage (220 volt)on the left side and low voltage (Right) sides.

You have a measly three relays . the windings (coils) of the relays are the little rectangles marked KM1, KM2, KM3.

KM1 turns the power to the motor on or off. WHen KM1 is energized, the contacts change positon and the second lite on your control panel "lights".

nothing will happen (motor won't spin) until Km2 OR Km3 are energized. If they should both be energized at once, fuses pop at you power panel on the wall. maybe ruin a relay. This is not likely but is possible should switch SA (which is the one you have troubles with, I suspect) have a set of "welded" contacts (VERY unlikely).

KM2 is forward, KM3 is reverse (or vice versa ifyou want to quibble http://bbs.homeshopmachinist.net//smile.gif.

Use care when reading the schematic. The labels on the high voltage side show KM2 and KM3 contacts kind of funny (strange). And they show them mechanicaly intelocked which i dont think they are (would be smart if they were, but it would cost more and result in a special relay).

Anyway, how many combinations can three relays have? especilally when KM1 must be on no matter what the others do? I think (and would not do unless switch SA is not accpetable) you could get away with three cheap toggle switches, double pole double throw, from Radio Shack (cost less than 5 dollars) and be safe. The design trick is to use Switch (SW) Km1 to supply power to relay Km1(coils) and to SWKM2. SWKM2 in its off positions would suppply power to SWKM3. SWKM2 in its "ON" position would supply power to KM2(Coil) (Which would make the motor spin (run) one way. Of course SWKM3 would have no voltage, so it won't energize KM3(coil). this WOULD allow KM3 to instantly reverse the motor (not good) if BOth KM2 And KM3 were on at the sme time. But you have simular risk if you switch from FWD to rev with out stopping. If the motor has a centrifical start switch, the motor won't reverse direction until it stops or at least slows way down.

NSDesign has a good handle on things, and his brain surely beats mine. But experiencecounts for a little also. Let me know if I can help or not. Be glad to send a phone number, but I think you men need no help at his time