Cross Cutting Ply on the Shopsmith

[John Morris]

Yesterday son and I made some Pull Out Shelving for mama, see proceeding link. And while cutting down the panel for the shelves, we had to do some cross cutting of ply on my Shopsmith. I was pleasantly, actually, very very happy, to see the quality of cut that was produced on the smith with the blade I used. Also this cut was made without a zero clearance insert, I just had on the factory insert, and the quality was perfect, I was very impressed.

I don't remember getting this good a cut even on my 12" 5hp Grizz cabinet saw using an 80 tooth Amana Blue melamine blade. I am not sure what happened here, but really, I was not expecting such a great cut, so there are several factors in play here. And I'll list them.

 

• Quality of ply, the ply we are using is excellent, prefinished maple ply Made in the USA. Just great stuff. So the finish is binding the maple veneer which may be preventing tear out.
• Shopsmith 60 tooth 10" blade
• The variable speed on my smith, I had it set at "R" or 3500 RPM, (not sure if that is arbor speed or tooth speed)

 

Given that, I am sure the factors created a concert for a perfect cut, I'll have to test the cut on some less desirable ply, and see if that makes a difference. But boy was I happy. Again, no zero clearance insert here.

 

Something really cool about the smith, is the variable speed, so I could have done some test cuts, and played with the speed a little to get the best cut, but in this case the first cut was perfect. I just used the Shopsmith speed chart, they did not list ply in the chart, so I chose the setting for softwood thinking ply is equivalent possibly to soft wood.

 

My Shopsmith keeps giving me surprises like this frequently, just when I think I have pushed the limits of the smith, something like this happens, and it just makes me feel better about giving up my dedicated machinery as I had, and the smith in its place.

I am not advocating the idea that the smith can take the place of dedicated machinery, I don't wholly agree with that, machinery made for a specific use is going to be much better and more efficient, typically, but for those who are considering a Shopsmith in order to save space, or you moved to more confined quarters, or just to add one to your arsenal of machinery, the cut quality on ply, may not have to be a concern during your deliberations. That being said, for my use, and my tight quarters (car in garage at night) I could not imagine another machine in my shop, or needing another machine, I have had this machine for two years now, while I needed to adjust my brain around it, and the sequence of work, yes there was an adjustment period, and a honeymoon period, and a disappointment period that was due mainly to my own ignorance on how the machine works, and its capabilities. But at this time after using it for two years, and learning its operations, I am happy. And it keeps surprising me, pleasantly.

 

Image below is the top side of the cut

 

 

Image below is the underside of the cut

 

 

I used this Shopsmith 1 1/4" arbor 60 tooth cross cut blade. The blade below is from their website, but I used this exact same one.

 

[Smallpatch]

John I find the quality of the wood being cut will make my saw look good or bad?

[Fred W. Hargis Jr]

I love it when someone is happy with their tool(s). Often folks don't like something they have because it's not popular on the 'net. That cut is very nice, how much trouble was it managing the sheet of ply on the saw table?

[kmealy]

The variable speed on my smith, I had it set at "R" or 3500 RPM, (not sure if that is arbor speed or tooth speed)

 

 

Umm, RPM would be for both (Revolutions per minute).   Tooth speed could also be measured in FPM (feet per minute) or feet per second.  The larger the diameter, the higher FPM per same RPM

 

(circumference = pi * diameter)

so at 3500 RPM,  

FPM = 10/12 * pi * 3500

       = 6193 

Edited April 26, 2020 by kmealy

[Artie]

2 hours ago, kmealy said:

The variable speed on my smith, I had it set at "R" or 3500 RPM, (not sure if that is arbor speed or tooth speed)

 

 

Umm, RPM would be for both (Revolutions per minute).   Tooth speed could also be measured in FPM (feet per minute) or feet per second.  The larger the diameter, the higher FPM per same RPM

 

(circumference = pi * diameter)

so at 3500 RPM,  

FPM = 10/12 * pi * 3500

       = 6193 

They TOLD me there would be no math during the quarantine.

[Artie]

John, I’m trying to think of how to ask this without anyone thinking I’m trying to be a wise guy (which is pretty much normal for me lol). With plywood is any cut a crosscut or rip? Plywood is glued in plies perpendicular to the preceding ply? I know you want to use a blade designed for melamine/plywood for best cut according to what I’ve read. I always thought that you just cut plywood with a plywood blade, or in the Shopsmith case maybe their combination blade? 

[John Morris]

37 minutes ago, Artie said:

John, I’m trying to think of how to ask this without anyone thinking I’m trying to be a wise guy (which is pretty much normal for me lol). With plywood is any cut a crosscut or rip? Plywood is glued in plies perpendicular to the preceding ply? I know you want to use a blade designed for melamine/plywood for best cut according to what I’ve read. I always thought that you just cut plywood with a plywood blade, or in the Shopsmith case maybe their combination blade? 

Artie, great question! actually you touched on something that folks may not even think about when orienting your ply for cutting, the internal layers, however the internal layers of ply have little if any consideration when cutting your ply. 

 

More importantly you want to consider veneer (top layer) grain direction. Typically the veneer longrain is running the length of a sheet of ply, so the grain is in the same direction as the typical 8' length. So if you are cutting a sheet of ply from one end to the other end, the entire 8' length, that would be a rip because you are cutting with the grain, or parallel with the grain.

Typically sheet ply runs in the 48" width, so if you are cutting the ply across the width, that would be a cross cut, and that is because the grain is running perpendicular to the width of the ply. So cutting across the grain, is a cross cut, cutting with the grain, is a rip.

 

As far as their combination blade, I have used it on ply before and I had considerable tear out during a cross cut, this is the first time I used the 60 tooth blade by Shopsmith and it was perfect as you can see. So if I were you, if you care about tear out, then you may want to use the 60 tooth blade.

[John Morris]

2 hours ago, kmealy said:

The variable speed on my smith, I had it set at "R" or 3500 RPM, (not sure if that is arbor speed or tooth speed)

 

 

Umm, RPM would be for both (Revolutions per minute).   Tooth speed could also be measured in FPM (feet per minute) or feet per second.  The larger the diameter, the higher FPM per same RPM

 

(circumference = pi * diameter)

so at 3500 RPM,  

FPM = 10/12 * pi * 3500

       = 6193 

Thank Keith!

[John Morris]

3 hours ago, Fred W. Hargis Jr said:

I love it when someone is happy with their tool(s). Often folks don't like something they have because it's not popular on the 'net. That cut is very nice, how much trouble was it managing the sheet of ply on the saw table?

Happy yes Fred, relieved too! I had some apprehension when going into the whole Smith thing, I really did. But the more I use it, the more relieved I am.

Handling big sheets is a pain. I can't just swing up a full sheet like I used to with my cabinet saw and outfeed table. In this case, I cut down the sheet to a manageable size with my Skil saw and straight edge, then got it up on the Shopsmith. The Shopsmith can handle a full size sheet, but the setup would not be worth it in my opinion, I can have the full sheet cut in half in 3 minutes, much less the time it would take to set up the tables for a full size sheet.

 

[Larry Buskirk]

3 minutes ago, John Morris said:

Happy yes Fred, relieved too! I had some apprehension when going into the whole Smith thing, I really did. But the more I use it, the more relieved I am.

Handling big sheets is a pain. I can't just swing up a full sheet like I used to with my cabinet saw and outfeed table. In this case, I cut down the sheet to a manageable size with my Skil saw and straight edge, then got it up on the Shopsmith. The Shopsmith can handle a full size sheet, but the setup would not be worth it in my opinion, I can have the full sheet cut in half in 3 minutes, much less the time it would take to set up the tables for a full size sheet.

 

Same way I do it on my old "Tilty's" John. 

Never liked doing full sheets on any table saw.

Edited April 26, 2020 by Larry Buskirk

[John Morris]

5 hours ago, Smallpatch said:

John I find the quality of the wood being cut will make my saw look good or bad?

Precisely Jess, as I mentioned in my original ramblings, the fact that I am cutting a Made in the USA pre-finished sheet of ply, probably has much to do with the cut quality. So I am going to cut a crappy piece of ply I have on hand and come back here and report to you guys my results.

That being said, I had also mentioned that I do have some what of a baseline for my brag, on my 12" 5hp Grizz with an 80 tooth Amana Blue blade, I did not get these same results, there was tear out, cutting this exact type and brand of plywood. So there is some comparison.

[Larry Buskirk]

Blades do make a difference. 

I've actually gotten nicer cuts from some cheap blades, why? (Insert IDK emoji here)

[John Morris]

1 minute ago, Larry Buskirk said:

(Insert IDK emoji here)

Dang, I need to fix that.

But ya, my high dollar Amana blade I used on the exact same ply when I had my Grizz, had tearout, this Shopsmith blade, did a really nice job.

[Larry Buskirk]

I've got an old Craftsman 10" Kromedge blade I found "Curb Shopping" that makes really nice cuts. 

It has to date from the 1950's or 60's. 

[Artie]

1 hour ago, John Morris said:

Artie, great question! actually you touched on something that folks may not even think about when orienting your ply for cutting, the internal layers, however the internal layers of ply have little if any consideration when cutting your ply. 

 

More importantly you want to consider veneer (top layer) grain direction. Typically the veneer longrain is running the length of a sheet of ply, so the grain is in the same direction as the typical 8' length. So if you are cutting a sheet of ply from one end to the other end, the entire 8' length, that would be a rip because you are cutting with the grain, or parallel with the grain.

Typically sheet ply runs in the 48" width, so if you are cutting the ply across the width, that would be a cross cut, and that is because the grain is running perpendicular to the width of the ply. So cutting across the grain, is a cross cut, cutting with the grain, is a rip.

 

As far as their combination blade, I have used it on ply before and I had considerable tear out during a cross cut, this is the first time I used the 60 tooth blade by Shopsmith and it was perfect as you can see. So if I were you, if you care about tear out, then you may want to use the 60 tooth blade.

See, I knew if I could phrase my question correctly I could get me an answer, and learn something  Thanks.

[JimM]

11 hours ago, Larry Buskirk said:

I've got an old Craftsman 10" Kromedge blade I found "Curb Shopping" that makes really nice cuts. 

It has to date from the 1950's or 60's. 

I have one of those too - it's labeled "planer" blade, probably mid 70s vintage.  Not sure exactly what that means.  I wrote that on it with a sharpie.  Hopefully, when I have to send it out for sharpening, it's done correctly.

Jim

[Cal]

That is sure a fine cut.  From the pic of the saw blade, it has a 1 1/4" arbor.  Can you pick up a new blade locally, or is SS or online your only source?

[John Morris]

7 minutes ago, Cal said:

That is sure a fine cut.  From the pic of the saw blade, it has a 1 1/4" arbor.  Can you pick up a new blade locally, or is SS or online your only source?

For me Cal, I need to order from Shopsmith.

But, there are adapters that you can purchase to install a normal sawblade if one wants to use their favorite blades from other vendors.

[Gunny]

Like to you John I am not much for wrestling a full sheet of plywood. I will cut it down on sawhorses outside then bring in for cutting more manageable pieces.  But I do have sawhorses always ready. Mine stay outside and are heavier than most.  So they stay put when wrestling the plywood.

 

Plans for new shop in Ukraine call for 2000 SQ feet of shop. Finally everything under one roof.

 

 

[Gene Howe]

4 hours ago, John Morris said:

For me Cal, I need to order from Shopsmith.

But, there are adapters that you can purchase to install a normal sawblade if one wants to use their favorite blades from other vendors.

I've always used the "adapters" or arbors, as Shopsmith calls them. Don't know why, though. Many blade manufacturers will sell blades to fit the Smith without the arbor.