Odd SawStop Behavior Diagnosed and Solved

[Dave Wright #2]

So far all I've had to post about the SawStop Cabinet Saw is good news. Steve Gass knew, with the saws going out to hundreds of shops, that unusual behavior might turn up in odd shop settings. He has been listening closely to feedback from the field. I identified an odd behavior and was impressed with how quickly and proactively Steve worked to resolve it.

Setting: I work in an unheated garage shop. I often start winter worksessions around or below freezing. Things warm up to a light jacket level pretty quickly with the help of space heaters, the lights, my activity, and the tools.

Normal saw behavior: The blade brake stays active during coast down - the time between when you turn the power off and the blade comes to a complete stop. When running the green LED on the control panel stays on constant. During coast down this LED blinks. Do not touch the blade while the green LED is blinking, because that will release the brake.

How my saw behaved: The first couple times I would run the saw, particularly if run for short periods, the green LED would blink beyond the point when the blade had stopped turning. A person who did not notice that the LED was flashing could easily touch the blade and set off the brake when not needed. Oops! This behavior stopped after the saw had warmed up a bit, and did not interfere with my work. A note to people who use these saws and watch them very closely: it is normal for completion of the LED blinking to not exactly match the precise point of blade stop; the algorithm results in mismatch of up to 1 second.

First attempts at diagnosis: I think that SawStop had run the saws in cold temperatures but had not observed this behavior. They were very interested in figuring it out. At first they suspected faulty parts. Steve offered to have one of the owners visit my shop personally and check out the problem. I declined. A new electronic filter and control box were sent out. I installed them but it didn't correct the behavior. The good news was that my saw had been built to spec.

The solution: Steve Gass thought about the problem some more, and figured that the EMF signals that are monitored to tell when the motor has stopped might be getting confused with power pulses to the resistance heater than keep the brake cartridge at proper operating temperature. He reprogrammed a cartridge to shut down the heater during coast down. The cartridge, tested in my machine yesterday evening, seems to have solved the problem.

Next steps: I will sent my cartridges back to SawStop for reprogramming. That will take care of me. My guess is that future cartridges will go out with this revised program code, and that owners of saws in the field will be given the chance to have their cartridges updated.

I was not surprised that a minor issue came up, and think that SawStop handled it well. Steve Gass says that this is the only unusual behavior that has been reported since the December start of normal production.

Happy New Year to All,

Dave

[Frank Pellow]

That's good service, but you should expect good service.

In the computer software business (my previous career) , we would have called you a "beta test" customer and (in good software companies) would also have given you the "hands on" attention and service that you are getting from Sawtop.

[John Shuk]

Dave,
It is nice to a toolmaker working with you to fix any issues. It is also obvious that Saw-Stop has a good customer in you. It is good that you are taking the time to give feedback to them as well as let us know what they do to solve issues.
Are you concerned about condensation on your motors in starting in a cold shop? I'd hate to see you shorten the life span of your tools. I might be off base here as well an I don't want to hijack the thread to something you didn't intend. It seems to me that the temp change might not be good for the toolss.

[Bart Leetch]

John

I could be wrong & it wouldn't be the first time, but I don't think this is a problem They have been doing this in construction for years. My Dad was in construction as either a Superintendent, Foreman or sawyer for about 30 years & on some jobs the sawyer had an area with a space heater to bring the temperature up to a little over bearable from freezing & it didn't seem to hurt the machines at all. He just kept them clean & kept the surfaces waxed real good. This was before Boeshield & other fancy smancy spray protectants.

Dads shop was also wood heated for about 40 years a stone cold when not in use during the winter. We had 2 diesel space heaters kitty corner from each other in a 20 x 50 foot shop hooked to a thermostat centered on one long wall. Dad would go out in the morning & turn up the thermostat & light the wood stove & come back to the house & eat breakfast & drink his coffee & go back out to a warm shop. The diesel space heaters were not use when he was in the shop just to bring it up to working temperature about 60-65 degrees & the 50 gallon barrel wood stove kept it there. This was in a building with cedar lap siding over craft paper on the studs & no insulation in Vancouver Washington. His tools never rusted & he is still using them today at 82 years of age. Most of his tools are Craftsman made & purchased in the 50's & 60's when Craftsman made good tools & 1 Delta shaper & Foley Bellsaw planer.

[Dave Wright #2]

John,

Condensation would take place if you moved cold tools into a shop that already has warm moisture-laden air. In my case the shop and tools are both cold. As I add heat to the space the humidity goes down so moisture does not condense on the tools. The time I risk condensation is the conditions when dew would normally occur - warm moist air cools as night falls and drops its moisture. I haven't noticed much if any of that in my shop because the enclosed space and concrete slab thermal mass slow the temperature swing.

A bigger concern for me is working in the muggy South Carolina Summer conditions. We get high humidity for extended periods of time. I use TopCote liberally on my raw cast iron surfaces, and have gotten used to living with light discoloration. None of my tools have displayed corrosion that in any way affects their function or long term outlook, but they lose their factory fresh look in the first few months.

Anyone else have experience with unconditioned shops? Maybe it reduces the life of quality tools from 100 years to only 50...or 20. Hmmm.

Regards,

Dave

[Dave Wright #2]

Thanks for the firsthand experience, Bart. I used to run a kerosene heater. Later on I figured that it would be best to stick with electric resistance heating to make sure I wasn't adding combustion products to the mix. All that can happen from an electric space heater is to raise the temperature which lowers the humidity. Dave

[Alan Turner]

Dave,
Thanks for the update and continuing information. Keep it coming as this new guy is of much interest to many. Did you get both the regular and the dado cartridges? How long to change between them, do you think? I frequently don't use a dado set just becuase it takes too long to change between the blades as is, but for a larger dado operation I do take the time.
Alan

[Dave Wright #2]

Alan,

The SawStop only comes with the regular 10" blade cartridge. The 8" dado cartridge is separate, as is the insert that you can cut through for your dado. Changing from the regular to dado cartridge takes about 1 minute, and that includes the time to shuffle parts. It takes me much more than that to figure out and tweak the dado width.

As long as people appreciate my updates I'll keep them coming. SawStop may or may not like everything I have to say. My goal is to convey a balanced and accurate picture of life with the saw. So far I'm happy I got it. Just yesterday I turned my previous saw into Habitat for Humanity. They'll put it to good use. Sorry to see an old friend go though. The last project I cut with it was two bookshelves I just gave to my parents for Christmas.

Regards,

Dave

[Rich Person]

As long as people appreciate my updates I'll keep them coming. SawStop may or may not like everything I have to say. My goal is to convey a balanced and accurate picture of life with the saw.
Oh, yeah. Keep them coming.

Dave,

I can't remember, did you get the 3 or 5 hp machine? Either way, are there any issues with the electrical setup you'd recommend. I'm going to have to have add a circuit for my saw and am wondering if there are any special issues with the power.

Rich

[Dave Wright #2]

Rich,

I got the 3 hp single phase flavor. All it takes is the 3 wires - two 120 legs running opposite phase to make 240 and the ground. The saw is all 240, so there is no need for a 4-wire feed that includes the neutral as well as hot legs and ground.

I ran a dedicated circuit for my saw. At the wall I have a 3 prong twistlock outlet. I run to the saw with the male side of the plug and about 20 feet of good grade 12/3 wire.

Once you get to the saw there are a couple notes worth mentioning. In the box you will find three main connection bars and a ground at the side. These are the same bars that are used for the 3-phase saws as well as the single phase. Ignore the middle bar unless you're doing 3-phase. The connections are really designed for crimp-on loop connectors. The loops are pretty small. I recommend that people open the box and check the situation out, then head to Radio Shack or wherever and get the correct crimp-on connectors. If you don't already have a crimper (part of most multi-function electrician pliers) you probably shouldn't be running 240 power anyway.

That's about it. The saw comes with a good wiring diagram for each saw flavor. Our house runs hot and with decent wire size. The saw is seeing about 242 when not running, and 241 when running but not cutting. Good enough.

Take Care,

Dave

[Paul Glanville]

hello. Appreciate the info on sawtop. I ordered mine today. I have portable bldg just put behind my house I am renting. I have not been able to get electrician to come and put in subpanel - they promised every day for over two weeks and finally told me they don't have time at all to come and do anything!!!!!

I ran extension cord from drier plug with 10 gauge wire - 15 feet to bldg. I have 3 hp 230 V motor and cyclone hooked up. I want to use dust collection when saw is on. So, with circuit from drier which is higher amp than regular 230 volt, should I be able to run both saw and vac system at same time?

The drier has 30 amp breaker - I see the stove has 60 amp breaker. If needed I suppose I could figure out how to tap into that since I almost never use the stove.

Paul

[Mike Cutler]

Paul. Having 2, 3hp motors on the same "extension cable" would be problematic if a single 30 amp breaker is the supply, or even the 60 amp breaker. Not that it wouldn't work. In your situation I would make an extension cord from #8 or #6 and use the stove breaker for the feed. The extension cord could have a "breakout box" with 2 receptacles for your machines. I'd still run the temporary extension cord from the dryer receptacle and put the cyclone and the TS on seperate breakers.

I can't emphasize strong enough that this solution would be only very temporary, From an electrical standpoint it would be OK, but you really are at the outside margin.

In the interest of not hijacking Dave's thread, I would like to thank Dave for the excellent writeups on the Sawstop machine. I've been interested in the Sawstop for a few years now. These reviews have been a big help in sorting out the hype from the reality. Kudo's Dave.

[Chris Padilla]

Keep 'em coming, Dave...perhaps one of these days that cool TS will find its way into my shop! :)

[Charlie Kocourek]

HI Dave,

I will most likely order a new SawStop sometime this summer and I am very interested in other's experience with their saws. From everything I've heard so far it sounds like a quality saw from a (so far anyway) quality company.

Charlie