# Drill press won't shut off - bad micro switch ?



## David Morrow (Sep 17, 2017)

I'll preface this by saying that most electrical stuff, other than a very basic switch, is Greek to me.

I recently bought a nice little Jet precision drill press. When I plug it in, the motor starts running but won't turn off with the variable speed control even when put into the Off position as the manual says it should.

The power switching is a bit more complicated than your average setup. It has a variable speed control, a light, and a micro-switch. According to the limited description available in the manual, when the speed control knob is turned ON, " a detented click will have been heard as the motor stand-by switch is actuated." That doesn't happen. I can push on the micro switch button and the motor stops but it's not practical to hold it for any more than a few seconds. 

Also, there is a phrase in the manual that says "Quill actuation lever... It's operation is for lowering and raising the quill and actuating the spindle motor as the quill is lowered.. This is accomplished by mechanically linking the quill actuation lever with control panel micro switch operation."

So, my questions are : 
- are there any obvious solutions such as just replacing the micro switch. 
- Or, will it require testing the switch, variable speed control, or the various resistors and capacitors ? 
- Maybe a switch hidden inside at the quill to trigger the micro switch ?


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## Ulma Doctor (Sep 17, 2017)

Hi David,
it appears that somebody may have installed the incorrect control switch for your drill press.
the old owner may not have had a single pole single throw switch.(SPST)
i'm not sure what you guys in vancouver have for hardware stores but, you may have luck at an electrical supply house too
of course there is ebay and the like too
a 15 amp 125v SPST Toggle Switch is what you will need
if you have trouble getting one i have a few extras, i could send one if you need it 

the SPST switch is an off or on switch similar to a light switch but more compact and usually will have a small metal toggle. they are industrial quality in most instances.


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## David Morrow (Sep 17, 2017)

From what I can tell from the manual, the switches are all factory original.

Thanks very much for the offer on the switch. I was thinking of doing something like that. My little Sherline lathe and mills all have an On/Off switch and separate speed  control and that works just fine. It might be best to just un-complicate things by replacing the micro switch with the SPST switch as you suggest.

Edit : I had a few old toggle switches so I tried one and it works just fine. I'll get a new / better quality switch from my local electronics shop.


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## Linghunt (Sep 18, 2017)

So the old Switch was bad?  Glad you got it fixed, but still interesting. 

I have not seen an automatic motor ON switch with Quill position.   I could see this an a *"feature"* that would speed the process for drilling lots of holes in different parts, and having the motor off when you are adding a new part. 
*
What is the product number of that press for a copy of manual?*

A ON/OFF switch and possibly another switch to activate the quill position feature.  A covered foot pedal switch for that type operation might be a solution if someone is looking to do that. 

Disconnecting the wires on the switch and a simple Resistance check for switches in general,  You don't need a fancy meter.  

I got a fancy Fluke with lots of bells and whistles, but still like my old Simpson analog meter.     

Some cheap ones on ebay, might be junk for low cost,  Saw one on Allied for $300 + ,  That's way to much.


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## David Morrow (Sep 18, 2017)

The drill press is Model No. JPD-11HS ( but more often found online as a JDP-11HS for some reason ), Stock No. 354011

This is the only electrical diagram in the manual :


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## Linghunt (Sep 18, 2017)

Thanks, I see the drill now.   The schematic is lame, but it does match the same quality of using different wire colors on the same lug.  The green runs on to the motor I figured.

Not sure I believe the .0002" TIR on spindle with a chuck. Really?  

*Can you remove the chuck?* Add a collet holder,  Maybe an ER-8 , smallest I got is ER-16.  

No clue about the 8 or other options.  Maybe the chuck is way to go.

I like the tool, I would gut the wiring thou if it was me.

-----------------From Practical Machinist post 2007----------------------
* High speed precision drill press
* 12,000 RPM direct drive motor
* Infinitely variable spindle speeds
* Spindle stops automatically when retracted
* Extremely accurate .0002" T.I.R. spindle
* Precision ground work surface
* Worm gear height adjustment
* Drill chuck and key included

Stock Number: 354011
Model: JDP-11HS
Swing (in): 11
Drilling Capacity (in): 3/16
Chuck Size (in): 1/8
Spindle Travel (in): 1-5/8
Spindle Distance to Base (in): 7
Table Size (in): 6-1/2 x 6-1/2
Spindle Taper: JT-D
Column Diameter (in): 1-3/4
Number of Spindle Speeds: Variable
Range of Spindle Speeds (RPM): 800 - 12,000
Overall Height (in): 21
Base Size (in): 8-1/2 x 12-1/2
Motor: 100 W, 1 Ph 115V
Net Weight (lbs): 54


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## David Morrow (Sep 18, 2017)

Yes, I was thinking about adding a collet holder but I can likely live with the slight inaccuracy for building wooden clocks. I just wanted something small, sturdy, and easier to deal with while sitting at the bench rather than my big Craftsman bench drill press.

If the electronics will work properly with the new on/off switch, I don't see a point in gutting the electronics. At that point, what I don't see ( electronically ), I don't care about. Well, not until the next failure, if one occurs. Knocking on wood.


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## whitmore (Sep 18, 2017)

David Morrow said:


> I'll preface this by saying that most electrical stuff, other than a very basic switch, is Greek to me.
> 
> I recently bought a nice little Jet precision drill press. When I plug it in, the motor starts running but won't turn off with the variable speed control even when put into the Off position as the manual says it should.


It's probably NOT a problem with the microswitch; that kind of switch mechanism is often used
for cam-operated switching, and a LONG life is expected.    More likely, your speed control is a triac
type (similar to a light dimmer) and the semiconductor part has failed short circuit (i.e. full speed ahead).

In a way, that's good (the microswitch is a more expensive part than most triacs), but it takes
someone with some electronics knowhow to diagnose and repair, and the diagram... makes NO SENSE.
It shows motor-power DC current going through a switch that's not rated for over 14V of DC.


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## Linghunt (Sep 18, 2017)

whitmore said:


> .....and the diagram... makes NO SENSE.
> It shows motor-power DC current going through a switch that's not rated for over 14V of DC.



Current load of switch is issue, first thing I noticed besides missing so much info is the light powered off of the DC line to neutral.  Tells me the design not so good and suspect everything else.  The build doesn't look like it was done by skilled person either.  Note the melted insulation on the red wires,  the blobby solder on the PCB and parts hanging off the bottom side. someone was messing with it of manufacturer did it, who knows.  

The boys on Ebay and Amazon selling the manual tells me folks desperate and willing to pay.  All red flags to me. Hopefully the manual has a good parts list.

Trying to figure this type of mess out is doable, but still a mess.   I like the gut-mode


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## David Morrow (Sep 18, 2017)

I got a good quality toggle switch and now it works just fine. 

The variable speed control works just fine too ( it always did other than not shutting the motor completely off .)

I paid $15 for a PDF manual which I thought was ok. They probably aren't getting rich given that there don't appear to be too many of these drills out there. 

And the eBay guy that I bought the drill press from refunded $60 for my inconvenience and repair costs which I thought was quite fair. That brings my cost down to $375 which also got me 5 boxes x 50 micro sized drill bits and a bit of Locline.


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## Ulma Doctor (Sep 18, 2017)

congrats!


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