John TenEyck
11-30-2020, 3:37 PM
Recently Derek Cohen graciously shared his Dremel tool based carbide tooth- bandsaw blade sharpener. The key to his process is the use of diamond cutting wheels and, as he said, they are cheap. I bought 10 of them with two arbors for $10 at Amazon:
https://www.amazon.com/gp/product/B0791HB7VR/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
I built my unit around a HF Dremel knockoff. I mounted it to a plywood fixture that rides along my bandsaw fence by drilling a 2-1/8" hole in a small bracket that screws to the fixture.
https://lh3.googleusercontent.com/pw/ACtC-3cqOTpkADYlG3Ma5DWQBxVHg-7c99xAt_VpiTzTnMgDej2M-PHKwzNagSUfcZWGo0ITtqBF3LVjgg6VkMdmpRTcSaucST-YdHCuLwZgG8SDbAmBvVcmsSPpR2gt4U9elimqHLTzLIw_gVyfE EwrNnlV5Q=w1006-h566-no?authuser=0
The angle of the mounting bracket was determined by the angle of the back face of the tooth, which was around 22 deg from horizontal on the Lennox Woodmaster CT 1.3 tpi blade I wanted to sharpen. You can use the tool without an indexing feature, as Derek does, and as I did to to see how it worked. If you sit or kneel so you can look at the blade from the side it's pretty easy to index it to the same position relative to the cutting wheel. I also found you don't need a stop; just two light kisses was all that was needed to sharpen the tooth uniformly. I'd guess I took off 0.002 - 0.003". The cut quality was very good, maybe not quite factory good, but more than acceptable. Moreover, I could feel how much easier it was to feed stock through the blade than before I sharpened it.
https://lh3.googleusercontent.com/pw/ACtC-3eQiPGebZVkatu7ouX8kVCeLUxS2ObMp0Ey-Wx4SGcSaN0KIhqULICP5XkDxVg99_IbCT60F9IupJKmw4F1HzG 3s7sgti2QE9p1AguNHt73m_xaep0rpPfy2F8tOs2g5J7vxqIcB 7aN26IOEGr9kkalzg=w1006-h566-no?authuser=0
Since I was on a roll I thought I'd see about adding an indexing feature. I though about how to add something to the sharpening sled itself but realized it wouldn't be easy since it has to slide fore and aft as each tooth is sharpened. So I created a separate fixture to hold the indexer, which is nothing more than another piece of plywood with a runner to fit into the miter slot. A small strap hinge with the end cut off serves as the indexer and is screwed to a spacer on the plywood to bring it up to the correct height so the diamond wheel meets the tooth at the correct elevation.
https://lh3.googleusercontent.com/pw/ACtC-3eH7zu6pikdl_mUx-GAvc12-hQRGdD_K5G88k7e9t-NUpH0wkwL6da06pRUFpGyN76oZV-XnrTNJ-o-4i_DAitGK6h_gaThYI64JaQvQyjua3imIRYzdPRhLEG8bi5yt3 WMugmhfPNgy1h1Um1zqlv0vQ=w1006-h566-no?authuser=0
You pull the blade upwards to index from one tooth to the next.
https://lh3.googleusercontent.com/pw/ACtC-3ePqBzfHBVJEEpfpRDh2EuwOMGSErPNW8WncPmJ4WVehRl2Boe RtlN4YyPU0uEoSBNiEtpC6gZcpp_Z9KcPpNkgDSB3xbCRJ1mJT eVB9n6yrHHURZNbdlplpXDzKfJXawk3foSoRMNZhOTEmvlf_wK ctg=w1006-h566-no?authuser=0
And then pull the blade downward until the indexer seats in the gullet of the tooth.
https://lh3.googleusercontent.com/pw/ACtC-3eHrR0ezJ8BQOy3nHXwsIWJMVQ_SpAaUoJiZyccUztJdOSAeXR jsG_O1ZiPJ9mGEJJR5Lu7VhTXJCIXLusQjNe0Jyn5e_Tb2t5Ls YJAtRR-vgGUmQbyHgmzxN9xTrV30yM_flQ3qqUAAdtEWysLwE7LiA=w10 06-h566-no?authuser=0
Then push the Dremel sled forward to sharpen the tooth.
https://lh3.googleusercontent.com/pw/ACtC-3eIMp-uiRPxX_IdASdm-d9UpGBJw9Ku7Iwz24Fh2XaVluGSRZZs02XC24s4F1vsij-qszUf_n_ZQ3srsiMi2cdJDrDsggtuVjQmZu-Pf0eCJpTFRcYierZHL1xKVHrWdI6td0mt12NaoaYFRVR1Of7xX w=w1006-h566-no?authuser=0
Pull the Dremel sled back, raise the blade until the next tooth engages and repeat. With the indexer sharpening is definitely faster. The only thing to be careful about is for the two teeth at the weld where the spacing might not be consistent with the rest of the band.
John
https://www.amazon.com/gp/product/B0791HB7VR/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
I built my unit around a HF Dremel knockoff. I mounted it to a plywood fixture that rides along my bandsaw fence by drilling a 2-1/8" hole in a small bracket that screws to the fixture.
https://lh3.googleusercontent.com/pw/ACtC-3cqOTpkADYlG3Ma5DWQBxVHg-7c99xAt_VpiTzTnMgDej2M-PHKwzNagSUfcZWGo0ITtqBF3LVjgg6VkMdmpRTcSaucST-YdHCuLwZgG8SDbAmBvVcmsSPpR2gt4U9elimqHLTzLIw_gVyfE EwrNnlV5Q=w1006-h566-no?authuser=0
The angle of the mounting bracket was determined by the angle of the back face of the tooth, which was around 22 deg from horizontal on the Lennox Woodmaster CT 1.3 tpi blade I wanted to sharpen. You can use the tool without an indexing feature, as Derek does, and as I did to to see how it worked. If you sit or kneel so you can look at the blade from the side it's pretty easy to index it to the same position relative to the cutting wheel. I also found you don't need a stop; just two light kisses was all that was needed to sharpen the tooth uniformly. I'd guess I took off 0.002 - 0.003". The cut quality was very good, maybe not quite factory good, but more than acceptable. Moreover, I could feel how much easier it was to feed stock through the blade than before I sharpened it.
https://lh3.googleusercontent.com/pw/ACtC-3eQiPGebZVkatu7ouX8kVCeLUxS2ObMp0Ey-Wx4SGcSaN0KIhqULICP5XkDxVg99_IbCT60F9IupJKmw4F1HzG 3s7sgti2QE9p1AguNHt73m_xaep0rpPfy2F8tOs2g5J7vxqIcB 7aN26IOEGr9kkalzg=w1006-h566-no?authuser=0
Since I was on a roll I thought I'd see about adding an indexing feature. I though about how to add something to the sharpening sled itself but realized it wouldn't be easy since it has to slide fore and aft as each tooth is sharpened. So I created a separate fixture to hold the indexer, which is nothing more than another piece of plywood with a runner to fit into the miter slot. A small strap hinge with the end cut off serves as the indexer and is screwed to a spacer on the plywood to bring it up to the correct height so the diamond wheel meets the tooth at the correct elevation.
https://lh3.googleusercontent.com/pw/ACtC-3eH7zu6pikdl_mUx-GAvc12-hQRGdD_K5G88k7e9t-NUpH0wkwL6da06pRUFpGyN76oZV-XnrTNJ-o-4i_DAitGK6h_gaThYI64JaQvQyjua3imIRYzdPRhLEG8bi5yt3 WMugmhfPNgy1h1Um1zqlv0vQ=w1006-h566-no?authuser=0
You pull the blade upwards to index from one tooth to the next.
https://lh3.googleusercontent.com/pw/ACtC-3ePqBzfHBVJEEpfpRDh2EuwOMGSErPNW8WncPmJ4WVehRl2Boe RtlN4YyPU0uEoSBNiEtpC6gZcpp_Z9KcPpNkgDSB3xbCRJ1mJT eVB9n6yrHHURZNbdlplpXDzKfJXawk3foSoRMNZhOTEmvlf_wK ctg=w1006-h566-no?authuser=0
And then pull the blade downward until the indexer seats in the gullet of the tooth.
https://lh3.googleusercontent.com/pw/ACtC-3eHrR0ezJ8BQOy3nHXwsIWJMVQ_SpAaUoJiZyccUztJdOSAeXR jsG_O1ZiPJ9mGEJJR5Lu7VhTXJCIXLusQjNe0Jyn5e_Tb2t5Ls YJAtRR-vgGUmQbyHgmzxN9xTrV30yM_flQ3qqUAAdtEWysLwE7LiA=w10 06-h566-no?authuser=0
Then push the Dremel sled forward to sharpen the tooth.
https://lh3.googleusercontent.com/pw/ACtC-3eIMp-uiRPxX_IdASdm-d9UpGBJw9Ku7Iwz24Fh2XaVluGSRZZs02XC24s4F1vsij-qszUf_n_ZQ3srsiMi2cdJDrDsggtuVjQmZu-Pf0eCJpTFRcYierZHL1xKVHrWdI6td0mt12NaoaYFRVR1Of7xX w=w1006-h566-no?authuser=0
Pull the Dremel sled back, raise the blade until the next tooth engages and repeat. With the indexer sharpening is definitely faster. The only thing to be careful about is for the two teeth at the weld where the spacing might not be consistent with the rest of the band.
John