What's the easiest way to make a 1-3/4" hole?
Posted: Mon Oct 14, 2019 8:40 am
I thought that I had finally accumulated enough tools to make most any woodworking cut with relative ease and precision. But yesterday, I ran across a seemingly trivial task that would seem to say otherwise. I simply want to make a Shopsmith way-tube sized hole in a piece of pine 2x6. A 1-3/4" diameter hole, to be specific.
Plan A: No problem -- I'll just grab a Forstner bit. Nope -- my set jumps from 1-5/8" up to 2".
Ok, Plan B. Get out my tool-of-death adjustable circle cutter (and the Shopsmith speed reducer, so that I can spin it at 100 RPM and not actually lose any valuable body parts). Uh-oh, it only adjusts down to a 1-7/8" diameter.
Plan C: Well crap, let's see if I can find my old hole-saw set, and cut from both sides. Ten minutes later, I finally found them. But no 1-3/4" saw in the set.
Plan D: Desperate times call for desperate measures. I have a cool old adjustable auger bit that came in a 10ER goody box. Sure 'nuff, it turned out that I can set it for 1-3/4". Next clean the sawdust off of my biggest antique brace, and give it a try. Wow -- that takes a lot of torque -- good thing the brace has a ratcheting mechanism. But with the workpiece held in my bench vise, the brace is up too high for me to add much down-force, and the screw pilot stripped out the wood after drilling maybe 1/4" inch deep. I could have rigged up some sort of lower-down workholding means, but the auger-bit cut was going to be more ragged than I wanted anyway.
Plan E: Just how much does a 1-3/4" Forstner bit cost, anyway? It turns out that the local Woodcraft has some for about $20. But that's an hour drive, round trip. Time to get creative.
Plan F: Drill a 1-5/8" hole with a Forstner bit. Then use my overarm pin router to open it up to 1-3/4". That's not too hard -- just use a 1/2" guide pin with a 3/4" router bit, to open up the topside of the hole. Then flip the workpiece over and use a flush-trim bit to extend the larger bore all the way through. Not too bad, but I could probably make the trip to Woodcraft in the time it takes to do all that. And then I'd have the right tool for the job the next time I need it.
Plan G: Use the Shopsmith in lathe mode to make a pattern with a 1-3/4" bore. Then use a router and a pattern bit to transfer the bore to the workpiece. Nah, that's even more work Plan F.
Half-baked plans: I also considered pattern sanding on the Shopsmith, but it didn't seem practical on a relatively small ID like that. And buying a Shaper Origin is not in the cards for this project! It also dawned on me that an adjustable boring bar mounted to the Shopsmith spindle should be able to open up nice clean custom-sized holes in a stationary workpiece. But although such boring bars are common for metalworking, I've never seen one for woodworking lathes -- much less a Shopsmith.
So guys, I'm out of ideas. Any others from the Shopsmith brain trust?
Plan A: No problem -- I'll just grab a Forstner bit. Nope -- my set jumps from 1-5/8" up to 2".
Ok, Plan B. Get out my tool-of-death adjustable circle cutter (and the Shopsmith speed reducer, so that I can spin it at 100 RPM and not actually lose any valuable body parts). Uh-oh, it only adjusts down to a 1-7/8" diameter.
Plan C: Well crap, let's see if I can find my old hole-saw set, and cut from both sides. Ten minutes later, I finally found them. But no 1-3/4" saw in the set.
Plan D: Desperate times call for desperate measures. I have a cool old adjustable auger bit that came in a 10ER goody box. Sure 'nuff, it turned out that I can set it for 1-3/4". Next clean the sawdust off of my biggest antique brace, and give it a try. Wow -- that takes a lot of torque -- good thing the brace has a ratcheting mechanism. But with the workpiece held in my bench vise, the brace is up too high for me to add much down-force, and the screw pilot stripped out the wood after drilling maybe 1/4" inch deep. I could have rigged up some sort of lower-down workholding means, but the auger-bit cut was going to be more ragged than I wanted anyway.
Plan E: Just how much does a 1-3/4" Forstner bit cost, anyway? It turns out that the local Woodcraft has some for about $20. But that's an hour drive, round trip. Time to get creative.
Plan F: Drill a 1-5/8" hole with a Forstner bit. Then use my overarm pin router to open it up to 1-3/4". That's not too hard -- just use a 1/2" guide pin with a 3/4" router bit, to open up the topside of the hole. Then flip the workpiece over and use a flush-trim bit to extend the larger bore all the way through. Not too bad, but I could probably make the trip to Woodcraft in the time it takes to do all that. And then I'd have the right tool for the job the next time I need it.
Plan G: Use the Shopsmith in lathe mode to make a pattern with a 1-3/4" bore. Then use a router and a pattern bit to transfer the bore to the workpiece. Nah, that's even more work Plan F.
Half-baked plans: I also considered pattern sanding on the Shopsmith, but it didn't seem practical on a relatively small ID like that. And buying a Shaper Origin is not in the cards for this project! It also dawned on me that an adjustable boring bar mounted to the Shopsmith spindle should be able to open up nice clean custom-sized holes in a stationary workpiece. But although such boring bars are common for metalworking, I've never seen one for woodworking lathes -- much less a Shopsmith.
So guys, I'm out of ideas. Any others from the Shopsmith brain trust?
) so that the pilot had something to grip all way thru.