Why Shopsmith uses a 1 1/4” bore in their blades

[RFGuy]

I was just saying I didn't consider it definitive & case closed by any means. You guys are far too trusting.

[DLB]

My guess of Sales and Marketing as a reason was not meant as criticism. If they also offered a 1" arbor I'd buy that too. Nor was I disagreeing with Scott's conclusions. I'm suggesting that the reasons that apply today may not be the same as the reasons that applied ~70 years ago. For sure, today, 5/8" has emerged as the U.S. market leader in 10" table saw arbors, some call it standard. And Shopsmith offers, as optional equipment, a safe 5/8" saw arbor compatible with blade guards etc. I take the word "uses" in the thread title as present day, present company. If I buy a rip blade today from Shopsmith it has a 1-1/4" bore. Their plywood blade has a 5/8" bore. The reason isn't safety, or they'd be the same. In my experience it isn't performance. I'm glad that Shopsmith continues the 1-1/4" line, it ensures continued availability of quality blades that fit the several arbors I already have at mid-range prices. If they started offering 5/8" as standard equipment, I think that supply would disappear quickly. I would guess that I'm in the majority of frequent users of the Mark table saw in that I have arbors in both sizes and have the freedom to choose whatever blades I want.

A quick check of Forrest blades reveals that their popular 10" table saw blades are available in nine arbor sizes. They consider 5/8" standard and most optional sizes, including 1-1/4" are $15 higher.

- David

[RFGuy]

My guess of Sales and Marketing as a reason was not meant as criticism.

Mine wasn't so much a criticism as merely stating the reality of doing business in the world. As an engineer with several patents that I earned and having worked with many sales, marketing and executives coworkers, I can tell you that the reason for doing something in business isn't always because there is a patent that could be perceived associated with it. There are many different reasons that companies file for patents. Some naively assume that the existence of a patent means one came up with a better mousetrap and staked their claim to protect the IP. Just saying this isn't always the case and this particular patent may not tell the whole story of the business strategy for why this company chose to initiate a bore size at 1-1/4" and maintain that requirement for many years.

[edma194]

Sometimes there's only one reason for a design feature on a machine, but at least as often there are multiple reasons with no clear priority order to them. When the initial decision was made, for whatever reason(s), the current market for 10" circular saw blades and 5/8" arbor holes being the most common could not have been known with certainty, so at the time any choice could have been second guessed. We do see how the matter turned out though, and Shopsmith offers 5/8" arbors so customers are not locked into use of Shopsmith blades requiring a larger arbor. I don't think we need one specific reason for this arbor size, it came to be out of the reasons known at the time, and was continued non-exclusively over time. So we have a choice and that's better for all of us whatever the underlying reasons may be.

That said, I don't find anything wrong with Scott's conclusions, but I've noticed this odd thing about history, it keeps changing. It's not as fixed as we might believe, and there's new history made every day.

[JPG]

'New' history is never made after the fact. Interpretations of why history occurred do however change with more accurate understanding. Key word is accurate. Anything else is speculation.

[dusty]

If one wants or perceives a need for a saw blade with a 1 1/4" bore, where can I satisfy that need?

[DLB]

If one wants or perceives a need for a saw blade with a 1 1/4" bore, where can I satisfy that need?

Shopsmith has three choices that I know of and Forrest offers, I'd guess, more than twenty. That covers what I consider mid-range and high-end.

- David

[Erik]

Dusty,

I have three non-Shopsmith 1 1/4" blades: two from Forrest (Woodworker II and Plywood) and one from Ridge Carbide (TS200 super rip). All three blades make glass-smooth cuts (the three workhorses are in the middle of the storage rack). I clean them at the end of each project and after a good scrubbing all three blades are as sharp as when I took them out of their packaging 5 years ago. I can highly recommend both companies and these blades in particular.

One other thing. When using the table saw I've gravitated towards using the lower end of the recommended sawing speed. That seems to give me more torque so I rarely bog down even when working with 2" hickory (it's really hard!) or 2" cherry (it's prone to burning). Most cuts yield a glue-ready joint.

Finally, I borrowed jsburgers idea for storing saw blades with arbors (viewtopic.php?p=258776#p258776). It worked so well for saw blades that I almost immediately built one for sanding discs (both regular and conical). One thing I really like about the Mark V is that arbor system makes it so easy you can always have the right blade or grit for the job. I think that is an under appreciated jewel of the Shopsmith ... although you probably don't need seven blades like I have!

-Erik

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[JPG]

Interesting miter joints!

[RFGuy]

One other thing. When using the table saw I've gravitated towards using the lower end of the recommended sawing speed. That seems to give me more torque so I rarely bog down even when working with 2" hickory (it's really hard!) or 2" cherry (it's prone to burning). Most cuts yield a glue-ready joint.

Erik,

Thanks! That is something I will have to try. Sometimes I have trouble with 8/4 cherry, even with a super sharp Forrest Woodworker II blade. Usually double checking & adjusting belt tension fixes it, but I will try lowering the sawblade speed a bit and see if that is better. Really appreciate this feedback.