Table saw motor upgrade questions

[John Schroeder]

I've been an avid Sawmill Creek reader, but this is my first post. I am having some issues with my table saw motor and am looking to upgrade. After a lot of research I have a few questions about the best way to go.

First off a bit of background. The saw is a 1950's era Delta Homecraft 34-500 with an 8" blade. It was my grandfather's saw and I can't bear to part with it. I know it would likely be a wash to upgrade to a used Unisaw or 66 but that's not in the cards. That said, it's a good quality cast iron saw, decent sized table, wings and extension, and a nice stand, and both he, my dad, and I have done a lot of quality work on it. It's properly aligned and with an aftermarket fence, Forrest blade, and Incra mitre it can make precise cuts.

The saw really means a lot to me, so thanks in advance for any help you can give me on how to get the most out of it. In addition to the technical questions, I'd also really appreciate any opinions on the absolute best option: plenty of power, minimal vibration, and rock solid reliability.

My immediate issue is the motor (specs below). It is 1HP Dayton, not the original motor but dates to the 70s. Unfortunately it is not always adequate for some of the ripping I do on occasion, even with a high quality ripping blade and slow feed. Recently the motor has also started to show signs of bearing problems (gravelly sound and increased vibration) and although I'll likely keep it and rebuild it this is a good excuse to upgrade and improve the saw. Since it isn't the original I don't have any problem swapping it out and would like a little more power.

Specs on the existing Dayton:

Model: Dayton 6K148B (last letter is a guess as it's scratched)
1 HP
1 Phase
SF: 1.25
5/8" shaft
1725 RPM
XG56M Frame
5" cast iron aftermarket pulley
115/230v
Not TEFC


Okay, on to the "what's the best motor" questions.

Things I know I need/want:

- TEFC
- High quality brand like Leeson/Baldor (same ownership?) or would consider one from grizzly
- 240v capable (really don't want to run it at 120)
- I also assume i'm restricted to a 56 frame with approximately the same weight (about 40 pounds +/-)

Questions:

HP: with a single pulley and a contractor's saw I wouldn't think it makes sense to go beyond 2 HP. Does that make sense?

RPM: I located the original manual on the internet and it specifies motor pulleys for both a 1725 (5") and a 3450 (2.5") RPM motor. It there an advantage to going with one over the other? Does a 1725 produce less vibration, or more because of the larger pulley? With the larger pulley does the increased surface area give it a better grip and less likely to slip/easier to transfer more power to the blade?

Type of service: Farm duty/General Purpose/Woodworking. This is a head scratcher. The farm duty seems ideal, but somehow it's cheaper than the GP motors. This makes me wonder what the difference is, and although I've trolled every post/thread I could find I haven't gotten a conclusive answer. Should I care? It's over a $100 difference in price. Also, Leeson has a line of "woodworking" motors. Anyone have any idea what the difference is there?

Service Factor: most of what I've seen is 1.0 versus the existing 1.25. Should I care if I'm jumping to a 2HP motor?

Shaft size: the 2HP motors seems to have a 7/8 inch shaft. I don't mind buying another $20 cast iron pulley, so is a bigger shaft size better? ie less vibration and more stability?


Thanks in advance for any contributions to the above questions.



FYI, I'm currently considering a Baldor general purpose, Leeson 2 hp 1725rpm 56hz Frame TEFC (Farm Duty) 230 volts # 110090, or a 1.5 HP Leeson TEFC 3450 RPM 5/8 In. Shaft 115/230 Volt #110109.

I realize that brand might be a religious question for some and these are likely all good motors, but I'd still appreciate any thoughts. Thanks!

[Jerome Hanby]

Not sure how much room you have, but that 8 inch size caught my eye. About the largest dado stack you can get is 8 inches. If you have the room, you could dedicate this machine to dadoes and go hunting that Unisaw for general use...

[John Schroeder]

Yup, ultimately my plan is to jump to a european slider and dedicate the Delta Homecraft to a dado setup as you suggest. That way it will still have a useful role and a home in my shop. The manual lists a smaller 6" dado (up to 13/16 wide) as an option, but I'm not sure if this is due to size or power. On a cursory inspection an 8" dado does appear to fit. Right now I've got a huge router table and cut my tenons on that, but you've nailed my long term plan.

My wife is pregnant with our second daughter and we're planing to move to a bigger house in the next year or two. :D I'm lobbying hard for a bigger shop space, so hopefully i'll have the room for a dedicated dado setup. Right now it would be a bit tight so I'm in the market for a replacement motor.

[Rod Sheridan]

John, if I were you I'd replace the bearings in the existing motor.

You have a 1.25 service factor on a 1 HP motor which means it can run to 1.25HP.

I Had a 1.25HP saw and it worked fine ripping 8/4 hardwood.

If you do want to replace the motor, find a used 3450RPM 1 1/2 to 2 HP motor and change your pulley to 1/2 the size it is now.

Regards, Rod.

[John Schroeder]

Thanks for posting Rod. Why do you recommend 3450 versus 1725 RPM?

[Tom Slupek]

A 2 hp motor has more torque so you might affect the trunions of the saw if it wasn't designed for larger motor. There is a reason why most of the contractor and hybrid saws come with only 1-1/2 hp motors, the trunions are not strong enough and could possibly flex.

[Rod Sheridan]

Thanks for posting Rod. Why do you recommend 3450 versus 1725 RPM?

The motor will weigh about 10% less, and may be less desirable to many people, hence cheaper.

Your design takes a 1725 RPM motor and through the pulley ratio raises the saw arbour speed to around 4,000 RPM.

Regards, Rod.

[John Schroeder]

Thanks, hadn't thought of that. I know most contractor saws max out at 1.5HP, didn't consider the trunion issue. Sounds like I should look at 1.5HP rather than 2HP.