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| Author: | charliewood [ Thu May 24, 2007 7:13 am ] |
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Hey guys I have sourced all the parts for my binding jig and have the wood to get that underway as well - which I will be doing pretty soon - but I like to have other projects in the wings, so that when Im done one thing its on to the next thing without too much delay and time spent sourcing parts.. Well one thing I have been looking to build, is my own hopmemade MKIII power sharpening system, or you know....at least an approximation of one - I am using this page as inspiration and guidance https://home.comcast.net/~rexmill/sharpening/MKIII/MKIII.htm l Well I was planning on using an old but good motor I had salvaged from a wurlitzer organ - its the motor that would spin the rotating speaker assembly. Its ratings are 115V .85A 1550rpm (but one of the reasons I thought it would be good for its new purpose it the fact that it still has its variable speed circuit attached, which I though would allow me to dial in the 600-700rpm speed that seems to be preffered for the power sharpening system} I emailed Johnny Kleso at rexmill and asked him a few things about his unit, and told him what I planned to use for mine. He seemed to think that 1/3hp was the minimum amount of force he would want to use on a system like this... Well I know that he is far more inclined than I to know what the heck he is talking about in this respect - but still I couldnt help feel that this might be a bit overkill mabye? I dunno,........... what do you guys think - ??? using the hp conversion equation I figure this motor is about 1/6hp.... but it still feels realy strong - strong enough to put a requisite amount of force for chisels - mabye, but not plane blades though? Id love to hear what you guys thought about the motor dilemna and the project in general. Thanks for any insights in advance. Cheers Charliewood |
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| Author: | charliewood [ Thu May 24, 2007 7:16 am ] |
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to follow the link reconnect the letter "l" to ".html" in your address bar and hit enter.. Thanks Charliewood |
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| Author: | John How [ Thu May 24, 2007 7:31 am ] |
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Well there is not much drag on the thing and the real deal has a pretty small motor in it as well. I was going to build on myself but had a small winfall at the time and bought one from Lee Valley instead. I really like it and am soon going to put a felt pad on an extra platter for a quick buff and polish job. After the initial sharping, that's all you need to get the edge back, that is until you drop it. |
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| Author: | burbank [ Thu May 24, 2007 7:45 am ] |
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Charlie, If it were me, I'd have this conversation with myself."I already have this motor, and it would probably work, but just barely, and I'll probably regret it if I use it." Wish I had a dollar for every time a project turned out that way. As you move away from the center of the spinning disk with a blade being sharpened, the effective drag on the motor increases. So, the effect of the drag on the motor would be at a minimum if you keep the blade near the center, but would increase arithmetically as you move outward. Might be just OK for chisels, but maybe wouldn't cut it (no pun intended) on plane irons. One thing in your favor though is that if you use pulleys to reduce the motor speed instead of the speed control, you'll get an increase in torque from the motor by a factor of about 1550/650 = 2.38. You could just give it a try with your motor, and if it's too weak, changing it out wouldn't be a big deal. With my build volume as a hobbyist, I'd use the scary sharp method for the first steps in sharpening and save myself the trouble of building a power sharpening system, then go to the stones (if I had 'em, which I don't). I just have so little need for aggressive sharpening. Good luck with it, and let us know what happens. Missed you at the West Coast get-together! |
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| Author: | charliewood [ Tue May 29, 2007 4:39 am ] |
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John and burbank - good points!!! burbank I know I really missed out on the West Coast get together I know, I know.. I feel really bad about it seeing as I was one of the people who spearheaded the idea in the first place, but honestly it was financially unfeasible - in that I wouldnt have felt right spending $300 or so on a trip, knowing I could have invested that money into tools I need in order to start my projects, you know? I did invest that cash into tools and now I feel really good about being SOOOOOOOO close to getting started on building... next year I promise I will be at the 2nd annual OLF WC get-together no matter where it is... Hopefully in Cali (or NM) the missus has never been! Anyhow.... Back to the project... the reason I felt the motor could do the job is,.... in the pictures Ive seen of the actual MkIII system Im copying - it seems like it couldnt possibly have a 1/3hp motor in it (could it?) John How mabye you could have a look at the spec sheet or check the side of the motor and see what it is for me? This would be realy helpful if you could. And thanks in advance if you would... Hot Tip: I used to do stonework (lapidary) and I know the local lapidary store/rock and gem shop has tons of self adhesive, silicone carbide grit pads, in a range extending into the several 1000's, as well as leather (and acrylic?) pads for applying different grit pastes and polishing powders and pastes, etc... this is the route Im following to begin with & mabye this will come in handy for people setting up grinding/sharpening systems of thier own so I thought, seeing as these fit on the aluminum backing plate I already have - I figure it would be really easy to setup either grinding or a polishing setup with this motor... no harm done Im curious to see if this will do the job - curious to know what the specs are on the real MkIII motor also.. and as you say no sweat to switch out the motor... Cheers Charliewood |
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| Author: | charliewood [ Tue May 29, 2007 4:48 am ] |
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My apologies, its actually called the MkII - to avoid confusion,,,, I didnt know - oooops Cheers Charliewood |
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| Author: | charliewood [ Tue May 29, 2007 4:55 am ] |
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Again I apologize (or rather wish there was an edit button still!) for yet another post in this thread! I went to Lee Valley and saw in the product description that the motor rating is actually 1/4hp... so there is actually no need to actually look that up for me John - but thanks anyHow.<- bad pun intended So it would seem that this motor is signifigantly underpowered compared to the real MkII's power plant.. perhaps I should order one... Cheers Charliewood |
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