Performax 16/32 Plus Modification (*PICS*)

[John Weber]

Like most others that have them, I have found a lot of uses for my drum sander. I use it all the time. While I get good use out of my sandpaper and sand with decent efficiency, I occasionally still stall the drum sanding. For those that do not know, this typically means the motor reset kicks in, causing the motor to stop and makes a divot in you work piece. A major pain, especially when it is on or near the last pass.

Some time ago I though I saw a similar modification to the one I made, however I cannot find it to give credit where credit is due. Panel meters are used on most large equipment to monitor the motor and machine operation, so I borrowed the idea.

I started by buying a 20 AC Panel Amp Meter on eBay for $4 + $5 shipping. It’s a used Weston and a high quality unit. There are typically a lot of meters available, and prices are reasonable. The key was the range of 0-20 amps, so I could use the full scale. Digital meters are also available but a fair bit more expensive. The hook up was very straight forward as the meter is full voltage and simply installs on the hot leg side and full current passes through. The box and other parts were more expensive then the meter, but total cost was still very reasonable. The most difficult part was locating the meter box. I ended up mounting it to the extension table forward and below the main switch. I can easily see it, and it’s out of the way.

The motor is rated for 14 nominal amps at 110 volts. At idle it draws about 10 – 11 amps. Typical sanding seems to run around 15 amps, however it will run up to the 20 and over range (I haven’t done a lot of testing yet to see actual draw when the motor reset kicks in. I suspect it is around 19/20 amps for a short run. With a high amp draw it is only a matter of when the motor trips. The cool thing is by adjusting belt speed and depth of cut you can vary the amp draw from just over 10 amps to almost 20 amps. So it should now be very easy to maintain the 15 amp optimal motor draw. The meter appears very accurate as I double checked several readings with my clamp on meter.

Again, I apologize to whoever had the idea originally, or maybe I just dreamed it. So far it seems like a very useful modification. If I did it again I might use a 30 amp meter, as if would be easier to check the upper end, however the 20 amp range is otherwise perfect.

The first picture shows the overall installation and the others different amp readings.

Thanks for looking – John

<img src=http://www.weberwoodworking.com/picss04/amp1.jpg><p>
<img src=http://www.weberwoodworking.com/picss04/amp2.jpg><p>
<img src=http://www.weberwoodworking.com/picss04/amp3.jpg><p>
<img src=http://www.weberwoodworking.com/picss04/amp4.jpg><p>

[Frank Pellow]

Great idea! I don't yet have a drum sander but will file this tip for the future.

[Alan Tolchinsky]

sander yet but this is one thing I would definitely put on it. Alan in Md.

[Tony Zaffuto]

John, can you elaborate a bit on how and where you hooked the meter? By stating you hooked into to the "hot leg side", does that mean you simply wired the meter inline to the black wire going to the motor? (please excuse my electric mental block or lack of understanding)

I have a 16/32 and I experience a high incidence of motor stalling, and even with lessening the depth of cut, the stalling still occurs. The cure, as you stated earlier, is a much slower feed rate, however, I would like to see the amperage draw on the motor.

[Chris Padilla]

Tony,

Yes, ammeters always go in line: black in one side and black out the other side (or white in one side and white out the other). In other words, you have to "break the circuit" and then insert the ammeter in the break so the circuit can work again.


John, nice, simple, cheap little trick! I love those kind! I think one on my DC might be appropriate.... :)

[John Weber]

Tony,

There are a couple different meters available, on a full amperage meter (like the one I used) there are two terminals on the back. You hook the incoming line on one and the outgoing on the other, just like a single pole switch.

The other common AC amp meters require a donut transformer. The hot wire passes through the donut and the amperage is read by the meter. They work just like a clamp on meter.

The local electrical supply house (Kirby Risk) sells full amperage meters for around $30 I believe.

John

[Chris Padilla]

That donut is a chunk of ferrite in the shape of a torroid. Wrap some insulated wire around it, pass a current through the wire, the ferrite picks up the resulting magnetic field which can then couple to another insulated wire wrapped around another section of the torroid. Viola, a coupled line that is isolated (DC-wise)!

In my business of electromagnetic compliance, we use torroids wound as common-mode chokes for filtering noise.

[Michael Perata]

John

Thanks for the tip. I have a 16/32 and the idea of watching the draw to set depth is an excellent idea.

[John Weber]

Yea, what he said...

Thanks Chris, it's all clear as mud now :-)

John

[Michael Perata]

Yea, what he said...

Thanks Chris, it's all clear as mud now :-)

John

Yeah, I asked him what he did for a living and got the same kind of answer. Unfortunately, I understood him. :D

[Dan Stuewe]

Forgive an uneducated question, but does this help by showing you when you're about to stall? (Then you quickly kill power.) Or does it help teach you how to set up your sander?

Never having used one, I'm just wondering how it all works.

Thanks,

[Chris Padilla]

http://www.sawmillcreek.org/showthread.php?threadid=7594

Just in case this thread has whetted anyone's appetite for a drum sander...as it did mine! :) I see my post in there...I guess I got the BS over the sander! :D

[Michael Perata]

Forgive an uneducated question, but does this help by showing you when you're about to stall? (Then you quickly kill power.) Or does it help teach you how to set up your sander?

Never having used one, I'm just wondering how it all works.

Thanks,
Dan

My experience with the 16/32 is if the cut is too deep it will stall and there is nothing to do to stop it. It takes too long to crank the height adjuster, and you can't pull the stock out backwards.

Having the current indicator will give you a reference as to how deep a cut you can make in what kind of stock. Sometimes a 1/64" is too much, sometimes you can go +1/32".

Solution is to let the stock feed through the sander and let the motor cool for 15-20 seconds and pop the overload button back in. Take a 1/2 turn out of the depth and try again. Hopefully you haven't burnt the sanding belt too much.

[John Weber]

Dan,

I haven't played/tested a lot, but so far tests are as expected. Under normal sanding conditions the motor has a base line current draw. When the feed rate is to fast, the cut to deep, or the board to wide the motor can slow and draw more amps. The meter gives instant feedback so sanding can be monitored real time. If the amperage is above what you normally see, or begins to climb you can make an adjustment to the feed rate to get the amp draw back into the normal range. Before the motor reset would kick out without warning or feedback. Now that I have a visual feedback I can respond to different sanding conditions before the motor stops. I just finished the mod, and haven't done a ton of testing, so some of this might be theory, but I think I'm on the right track.

John