I bought one of little cheap Harbor Freight 1 x 30 belt sanders to use as a knife sharpener. I also bought some high grit belts and a leather strop belt. At first all was well. The motor is pitifully underpowered, but I knew that and it's actually fine as a sharpener, not so much as a grinder. Had fun sharpening every knife I could find. Along the way the strop belt apparently stretched enough to allow it to rub on the frame at the tensioning pulley. That hinders the motor and would wear the belt and frame if the motor were more powerful.
So, how can I shrink the belt? Soak it in water maybe? (I am skeptical of that. I grew up on a farm and I know from careful observation that cows do not shrink when it rains.) Any other Ideas?
Yep, there is an idler pulley at the rear (the third pulley) that is spring loaded. The problem is it has pulled the belt back into contact with the frame. I need to look and see if there is some other adjustment.
The leather on cows is not dry. I put mineral oil on my leather strops and *real* neatsfoot on all leather horse tack but I don't know if that will prevent stretching. I doubt it since it is the nature of leather to stretch. Otherwise cows might be walking around stiff-legged and stiff-necked.
I suspect a tensioner for a cloth-backed sanding belt is much too high for a leather belt. I think leather belts generally use an idler pulley to compensate for the stretch and provide proper tension. Maybe research how the old shops that used leather belts on overhead drive shafts or on machinery.
"stretched enough to allow it to rub on the frame at the tensioning pulley" doesn't give much information. Is the belt moving off side of the pulley? (tracking problem) Photo? Better description?
Some ideas:
Option A, contact RealSharp and get one of their stropping belts. It's not leather but some type of fiber. I've been using one on my knife sharpening machine for several years now and there is no stretch.
Option B, buy a RealSharp knife sharpener. http://www.realsharpllc.com/ You will not be sorry. As discussed previously, it uses three belts and puts the sharpest and most consistent edge on a knife that I have ever experienced. Then repeat this mantra:Never buy anything from Harbor Freight that has moving parts. Life is too short to cheap out on tools.
Option C, forget the leather belt stropping and strop with a flat piece of leather or wood with a little polishing compound rubbed on it. For skew chisels and some other edges I use a piece of 3/4" MDF resawn in two to expose a rougher surface. Stropping by hand is a 10 second operation. This also saves the time of swapping the belts, annoying at best on most belt sanders. (Hint: the RealSharp machine has a spring-loaded quick-change mechanism that allows changing belts in about 5 seconds.)
And no, I'm not a RealSharp dealer or own stock. If someone stole mine I'd buy another tomorrow.
"Option C, forget the leather belt stropping and strop with a flat piece of leather or wood with a little polishing compound rubbed on it. Stropping by hand is a 10 second operation."
I can think of no improvement to this advice and how it is worded.
I will spend some time later trying to decipher that site. It's one where the obvious piece of information is carefully not included.
This little sander has a third wheel out the back that is spring loaded to tension the belt. The problem is that there is very little clearance between the wheel and the frame.
As I recall that Realsharp machine was hundreds of dollars. I don't want to go into the knife sharpening business, I just want to sharpen my own. I have done that and it only took two or three minutes each and they are sharper than they have ever been.
I have some leather to make and manual strop. I also made a disk of MDF I put on the lathe and run it backwards and use the diamond compound out of the Beale Buffing system. That thing is amazing. You can see the metal disappearing.
I am pretty happy with the little cheap sander other than the leather belt. I tried shrinking it, but I also contacted the maker and they are sending me a replacement. Good on them (Tx-sharpening).
I'm old enough to remember when barbers shined up their straight razors with a selection of leather strops that hung off the side of their chair. It wasn't a lengthy process.
These are attached to the side of my butcher block via clips. Linen for honing cleaver and leather for sharpening knives. Ebay has similar for under $12
>>>As I recall that Realsharp machine was hundreds of dollars. I don't want to go into the knife sharpening business, I just want to sharpen my own.
You are correct. I also just sharpen my own knives, those from the kitchen, and for a few friends on occasion. A perfect razor edge on a fillet knife is a joy in itself.
Cost is relative. I can't remember ever being sorry for buying good tools. Before I learned that I was sorry several times for buying cheap tools. It's frustrating and a waste of time to have to make compromises and work around problems that would otherwise not be there.
You could try cutting a long scarf joint out, then re-glue it back however much shorter you want.
Another good option, is to saw out a disk from 1/2" MDF , then screw it onto a faceplate for your lathe. Then you can true it up with your turning tools and charge it with whatever compound you like. Rather than a square edge, I like a long elliptical rounded end that I can polish the inside curve of my bowl gouges with, then everything else is done on the face side. But a word of CAUTION, is to always work from the back, with the edge pointing away from the rotation, or it will snag and take the tool away from you.
Leather drive belts need to have the tension relaxed or removed from pulleys when not in use, else they will permanently stretch over time. They are not as elastic as a rubber based belt. Once leather stretches, fibers change and won't go back.
I soaked the belt in warm water, water about the temperature of a cow at rest, for several hours, and then laid it on a convenient flat surface and let it dry over night. I was counting on whomever the good spirits are that work with glue and paint to assist woodworkers in the night. In the morning, I put the belt back on the machine and it appears to be as good as new. I will save the replacement as a backup.
You are correct. I also have never regretted spending the bucks on excellent tools, but I could not afford The Oregon model 760. The Realsharp is obviously a home built machine, a prototype proof of concept version. I think they bought the switch at Lowe's. If I turn mine around and lay it on it's back, I could add the strip of oak with two grooves. I already have the clamp. I paid $40 plus tax for mine. It's disposable. If it pisses me off it can spend the rest of it's life in the dump, and it takes up very little room on the shelf. I am very pleased with it's cost vs functionality.
Of course, it will take some machining to duplicate their quick change method. Others have done it and I've seen those for sale, but not recently. Maybe the legal department stays busy.
The belt change is "tooless". The Idler pulley is spring loaded. Just squeeze it in ad remove and replace the belt. I leave the side off to accommodate belt changes. There is a little curved "top" cover that I stick back on to keep debris from following the belt and flying into my face and eyes. I loosened the screw on it so it pulls off and slips back on. I don't who changing the belt could be any easier or faster.
There were fifty or a hundred Youtube videos on using this little crumby sharpener to grind and sharpen knives. The motor is so pitifully under powered it's not a grinder, but does well as a sharpener. It's the Sawstop of grinders. You can stop it with a finger and not lose any flesh.
When I put it back on the machine, I had to retract the tensioning wheel fully. For a few seconds I thought the belt was now too short, but it went on and ran in fine.
The Company that sold me the belt cautioned me not to leave it on the machine when not in use. I will be careful about that.
I have also run across synthetic stropping belts. I may get one of those.
