Excalibur Speed Adjustment Part

[kmmcrafts]

Before I stopped scrolling two years ago my Excalibur speed started acting up. I toyed around some with it and fount the mounting nut to mount the dial ( pot switch ) was loose so I blew some air around it and then tightened up the nut which seemed to make it work. Haven’t used the saw much since other than just a quick cut of something that my laser didn’t cut all the way through. Other day while trying to cut out the candle holder ( post in the bragging section ) the saw was mostly stuck on the lowest speed but if I wiggled the dial around I could saw one handed and hold the switch it would work. Was hopeful that it wasn’t the circuit board but once I found holding the switch and it made changes I was certain it was just the switch.
 

I never looked to closely at this switch and always thought it was a part of the circuit board and was only sold as a controller and board together. This morning I looked on Seyco for the parts and found they do sell just the switch with wire pigtail. Figured before I order any parts I’d take it apart and inspect it. Plus I wasn’t about to pay $55+ shipping for a $5 switch that I can solder to my pigtail plug. Upon inspection I found that there are three wire pins on the switch but only two wires connected. On the plug end there are three pins and wires so is one missing? Also found that on the black wire at the switch is really loose and only has one or two strands of wire even soldered which is making me think this is my problem and maybe no parts needed. I’m really curious what the red wire is doing since it’s not connected to anything on the switch end but is connected on the plug end. Maybe this could be a problem? I’m going to take this to my son to have him solder it for me as he is way better at soldering than I am and try it. I’m going to see if I can see how many wires are on the Seyco parts in the pictures. I read somewhere about some of the China made saws had only two wires where the replacement had three but it worked fine anyway so maybe I don’t need that red wire. I’m far from understanding any electrical stuff like this but maybe someone knows why there are some two wire switches and some are three? 

 

[kmmcrafts]

Well duh! Looking at the wires on the other end of the plug that goes to the circuit board just now and I see there is only two wires there so I assume the red wire isn’t even connected to anything. And looking more closely at the pigtail on the switch end I see it looks like the red wire is cut right flush with the sheathing. Assuming they bought the pigtail premade and it came with three wires but they only needed two.

[JTTHECLOCKMAN]

Without seeing a wiring diagram that looks like a pot with 2 variable resistors. More complex circuitry will use both resistors to control signals or speeds to be more exact. That probably is a pot that is universal and they use what they need which is one set of resistors to control resistance in circuit. Having a wire with only a few strands is bad in that that wire can heat up because now more resistance is put on that wire causing heat. Heat is an enemy in the electrical field as it is in many other fields. The vibration of the saw could have been causing increase and decrese in Resistance which is added to the pot and cause surges and decreases. I bet that was your problem.  

[kmmcrafts]

In the automotive repair sector they “ claim “  you should not solder connections because of vibration as solder doesn’t flex and over time the solder will get very small hairline cracks and as you say cause heat and stress on electrical systems. These days with onboard computer systems in cars makes for a really bad situation with soldered connections. 
 

If you watch videos or have one of these style saws many of them that plastic piece where the switches are mounted really shakes on some of these saws. Can’t be good for these soldered connections on the switches.

There are a lot of people out there that repair / restore car dash lights and gauges because the solder on the circuit board of the dash gets hairline cracks and cause issues. My son had to resolder his digital dash cluster on his 1984 Nissan 300ZX because of hairline cracks in the solder of the circuit board. Looked fine with the naked eye but under magnifying glass could see tiny cracks. Really only had to heat up and slightly melt the solder. 
 

Anyway this makes me wonder about all the other Excalibur type saws that I see where people are having speed surging issues etc. and need to replace the $55 switch. Some have also had to replace the circuit board as well, probably fried it from poor connection and got hot from the switch. lol  If you have speed surging issues you should stop running it and if you’re able to solder maybe resolder these connections on the switch. Might save you from spending a lot money. 

[Jim McDonald]

In a former part time job, I worked in a shop repairing sensors for underground mining equipment. (Lots of vibrations on that stuff)

We used solder with 2% or so silver and never had connection issues. Our problem was dirty power resulting in surges and spikes in 440V lines.

Edited February 5 by Jim McDonald

[JTTHECLOCKMAN]

1 hour ago, Jim McDonald said:

In a former part time job, I worked in a shop repairing sensors for underground mining equipment. (Lots of vibrations on that stuff)

We used solder with 2% or so silver and never had connection issues. Our problem was dirty power resulting in surges and spikes in 440V lines.

Dirty power surges is what causes problems with people using standard generators to run electronic equipment on power failures. It will destroy boards. Today so much of our appliances are elctronic controlled as well as cars as Kevin mentioned. Things like vibration as well as surges and even undervoltage when power companys cut back on power distribution in extreme heat situations can really take life out of electronic equipment. Many items have what is called zener diodes built in along with other components that can absorb voltage differences but you pay for better equipment like this. I am sure the electronic field has changed so much today from what it use to be. As I said heat is a huge enemy in the electric field. Even when using too small of extension chords when powering tools. Try to keep as short as possible and the use of chords is preferred to be not used if possible.  

[rash_powder]

If you can measure the RESISTANCE between the two wires, you will find the high value and low value.  Head over to digikey and you should be able to find an adequate replacement that will fit.  There may even be part numbers somewhere on it that you can use to find the replacement.  

All that said, you have what is called a potentiometer; it varies resistance from one set of pins to the other, with the middle being common.  Think the balance adjust on your stereo.  Using only two of the pins makes it function like a rheostat, which is just a fancy adjustable resistor.  Think like the volume control on your stereo.  Pots are far more common.  

Try blowing it out with air or contact cleaner first.  It may just be the internals got a bit dirty.  A common failure is 'dead' spots on the insides; that cannot be fixed.  

[kmmcrafts]

4 hours ago, rash_powder said:

If you can measure the RESISTANCE between the two wires, you will find the high value and low value.  Head over to digikey and you should be able to find an adequate replacement that will fit.  There may even be part numbers somewhere on it that you can use to find the replacement.  

All that said, you have what is called a potentiometer; it varies resistance from one set of pins to the other, with the middle being common.  Think the balance adjust on your stereo.  Using only two of the pins makes it function like a rheostat, which is just a fancy adjustable resistor.  Think like the volume control on your stereo.  Pots are far more common.  

Try blowing it out with air or contact cleaner first.  It may just be the internals got a bit dirty.  A common failure is 'dead' spots on the insides; that cannot be fixed.  

The switch I believe is fine.. the issue is the solder came apart on one of the wires that connects to the switch.. IF I wiggle the wire around the speed control seems to work.. I don't have a solder iron but my son does so I'm just going to have him solder the wire back on.. It currently only has one strand of wire connecting it.. and Yes.. I've replaced these switches before on one of the older Hawk scroll saws I have. Back then the part was $3 but now I see they're nearly $10 by the time I pay shipping.. Still beats buying the part from Seyco at $55 plus shipping.. But anyway.. will try to solder first and if it still has issues then I'll buy a new switch. For those that can't solder you can buy them with wires already soldered on and could probably use a crimp on style butt connectors to connect it to your existing plug.. They seem to be around the same price with the wires as they are without.. I'll just solder the switch but thought that might be an option for those that can't solder. 

[JTTHECLOCKMAN]

2 hours ago, kmmcrafts said:

The switch I believe is fine.. the issue is the solder came apart on one of the wires that connects to the switch.. IF I wiggle the wire around the speed control seems to work.. I don't have a solder iron but my son does so I'm just going to have him solder the wire back on.. It currently only has one strand of wire connecting it.. and Yes.. I've replaced these switches before on one of the older Hawk scroll saws I have. Back then the part was $3 but now I see they're nearly $10 by the time I pay shipping.. Still beats buying the part from Seyco at $55 plus shipping.. But anyway.. will try to solder first and if it still has issues then I'll buy a new switch. For those that can't solder you can buy them with wires already soldered on and could probably use a crimp on style butt connectors to connect it to your existing plug.. They seem to be around the same price with the wires as they are without.. I'll just solder the switch but thought that might be an option for those that can't solder. 

Just a point of interest you want to use elctronic solder as opposed to standard pipe solders. Electronic solder has flux built in and also melts at a lower temp so it does not harm electronic components. It is also a more flexible solder. Cleanliness is key. Clean surfaces helps for better adhesions. 

[kmmcrafts]

Just to follow up, we soldered the wire on better and I just put it back together and it works like it should now. This had been an ongoing problem over the last few years with this saw running jumping speeds around now and then. If you have this with your saw and you can solder you might try resolder the wires before buying parts.

[rjweb]

Good advice Kevin, RJ