Re: Horizontal Sawing
Posted: Tue Nov 01, 2016 4:05 pm
Jmolten,
If my Greenie was the best tool I had for the job, I would do it in a heartbeat without thinking twice. I know everyone else has said that they wouldn't. I don't believe anything is inherently safe or unsafe. There is a continuum of risk. You identify the risk, assess the likelihood of occurrence and severity of possible consequences, mitigate it as appropriate, and make your own decision to proceed or not.
It looks like you attached a picture, but I can't see it, so please keep that in mind. I would do it in horizontal normal Shopsmith table saw mode to better handle the weight instead of doing it in vertical Shopsmith drill press mode. Plus that way you don't have weight of the beam trying to close the kerf as you continue the cut. I would use infeed and outfeed supports (a second Shopsmith off Craigslist is invaluable). I would clamp a long straight piece of wood (at least 4' long) to the table fence and use that as a fence to provide more support in guiding the beam. This mitigates shorter irregularities in the beam dimensions. Depending on the size/weight of the beam, I would use a featherboard or another fence on the other side (not a 4' long piece, just a regular fence the length of the table). I would run the whole length of the beam through with the blade all the way below the table to ensure that irregularities in the beam don't catch or bind between the two fences, or the fence and featherboard. I would not use carbide saw blades if I had other options available - they are too expensive to risk chipping a hard but brittle carbide sawtooth on a nail. I would use old fashioned traditional blades and prepare to sharpen them as necessary. Even an amateur quickie sharpening job will reap huge dividends. If carbide blades are all I had, I would use them and be prepared to go buy more if needed. I would wear eye protection and my 3M respirator. I would make a cutting pass on a beam and then (assuming the blade doesn't go high enough to cut all the way through, would flip the beam end over end and make a second cutting pass from the other side. Flipping end over end keeps the same face of the beam against your 4' long fence to line up cut #1 and cut #2 in case you didn't set the fence so that the cut is perfectly in the middle of the beam. If two cuts at max blade height doesn't get you all the way through, I would use a circular saw to finish it off if I have a circular saw with a large enough blade to do so. If not, I would use a hand saw or bow saw to cut the last half inch or whatever is left. Statistically, there won't be a nail left in that last little bit. If there is, oh well - I might end up buying a new circular saw blade or bow saw blade. I would prefer to use two people, one guiding on each end of the beam, but I have done it alone with good infeed and outfeed support. I would use dust collection (shop vac, dust collector, chip separator, whatever you have) to help keep sawdust from clogging the kerf, especially if the cuts are not through cuts. I would choose a blade with fewer teeth and larger gullets between the teeth to clear the sawdust out of the kerf if I had multiple blades to choose from.
What are the risks? If the beams are as large and heavy as I am thinking they are, I don't believe there is a risk of kickback. If things get sideways and the blade binds, or if internal stresses cause the blade to bind, it will probably simply stall the sawblade (remember the Gilmer clutch in Greenies). I would have some precut wood wedges on hand to help keep the kerf open as I proceed along the length of the kerf if I'm worried about internal stresses binding the blade. I believe you can accomplish the task at hand with the tools you have on hand.
All that being said, I believe the table saw function is the Shopsmith weakpoint so I maintain a separate table saw that I would use. But if my Greenie was all that was available, I would do it in a heartbeat.
For everyone else who would assess these risks and choose not to do it, please notice I am not telling Jmolten to do it or not. I am simply telling him what I perceive to be the risks, what I would do, and how and why I would do it. We are all big boys and each make our own choices. Improvise, adapt, and overcome.
Semper Fidelis,
Culprit
If my Greenie was the best tool I had for the job, I would do it in a heartbeat without thinking twice. I know everyone else has said that they wouldn't. I don't believe anything is inherently safe or unsafe. There is a continuum of risk. You identify the risk, assess the likelihood of occurrence and severity of possible consequences, mitigate it as appropriate, and make your own decision to proceed or not.
It looks like you attached a picture, but I can't see it, so please keep that in mind. I would do it in horizontal normal Shopsmith table saw mode to better handle the weight instead of doing it in vertical Shopsmith drill press mode. Plus that way you don't have weight of the beam trying to close the kerf as you continue the cut. I would use infeed and outfeed supports (a second Shopsmith off Craigslist is invaluable). I would clamp a long straight piece of wood (at least 4' long) to the table fence and use that as a fence to provide more support in guiding the beam. This mitigates shorter irregularities in the beam dimensions. Depending on the size/weight of the beam, I would use a featherboard or another fence on the other side (not a 4' long piece, just a regular fence the length of the table). I would run the whole length of the beam through with the blade all the way below the table to ensure that irregularities in the beam don't catch or bind between the two fences, or the fence and featherboard. I would not use carbide saw blades if I had other options available - they are too expensive to risk chipping a hard but brittle carbide sawtooth on a nail. I would use old fashioned traditional blades and prepare to sharpen them as necessary. Even an amateur quickie sharpening job will reap huge dividends. If carbide blades are all I had, I would use them and be prepared to go buy more if needed. I would wear eye protection and my 3M respirator. I would make a cutting pass on a beam and then (assuming the blade doesn't go high enough to cut all the way through, would flip the beam end over end and make a second cutting pass from the other side. Flipping end over end keeps the same face of the beam against your 4' long fence to line up cut #1 and cut #2 in case you didn't set the fence so that the cut is perfectly in the middle of the beam. If two cuts at max blade height doesn't get you all the way through, I would use a circular saw to finish it off if I have a circular saw with a large enough blade to do so. If not, I would use a hand saw or bow saw to cut the last half inch or whatever is left. Statistically, there won't be a nail left in that last little bit. If there is, oh well - I might end up buying a new circular saw blade or bow saw blade. I would prefer to use two people, one guiding on each end of the beam, but I have done it alone with good infeed and outfeed support. I would use dust collection (shop vac, dust collector, chip separator, whatever you have) to help keep sawdust from clogging the kerf, especially if the cuts are not through cuts. I would choose a blade with fewer teeth and larger gullets between the teeth to clear the sawdust out of the kerf if I had multiple blades to choose from.
What are the risks? If the beams are as large and heavy as I am thinking they are, I don't believe there is a risk of kickback. If things get sideways and the blade binds, or if internal stresses cause the blade to bind, it will probably simply stall the sawblade (remember the Gilmer clutch in Greenies). I would have some precut wood wedges on hand to help keep the kerf open as I proceed along the length of the kerf if I'm worried about internal stresses binding the blade. I believe you can accomplish the task at hand with the tools you have on hand.
All that being said, I believe the table saw function is the Shopsmith weakpoint so I maintain a separate table saw that I would use. But if my Greenie was all that was available, I would do it in a heartbeat.
For everyone else who would assess these risks and choose not to do it, please notice I am not telling Jmolten to do it or not. I am simply telling him what I perceive to be the risks, what I would do, and how and why I would do it. We are all big boys and each make our own choices. Improvise, adapt, and overcome.
Semper Fidelis,
Culprit
He sez next house, a central vac system, with a floor sweep opening in the kitchen floor like some wood shops have. 