Building your own grinder: cheap and easy
I got the idea for this grinder when I was working on a 7 day set that needed regrinding. I did the first one by hand, but it was a lot of work because of all the damage. the thought of doing 6 more like that was not appealing so I went looking for something better that would not break the bank.
I finally came up with an electrical sander costing all of 30 dollars, and easy to make.
This is one of those e-z sharp appliances that you can find in many hardware stores. These things are advertised as wet grinders, but they are worthless, and often not even trued. I've tried using the as wet grinder for de-pitting a wedge, and they suck. But luckily, you can turn them into something useful.
the first step is to remove the water resevoir. This is not necessary if there is plenty of room between the stone and the sides / bottom of the reservoir, but even then it is more convenient.
As you can see, this is a high precision job, meticulously executed with a hacksaw and a pair of pliers ;)
http://msmvps.com/cfs-file.ashx/__ke...ep_5F00_01.JPG
The next step is to coat the stone with double sided tape. don't worry too much about any hairline gaps theat might be left they won't make any difference.
http://msmvps.com/cfs-file.ashx/__ke...ep_5F00_02.JPG
When that is done, you remove the coating of the tape, and fix a strip of rubber over the tape. The strip is the same width as the stone.
The purpose of this ruber is to make sure that the sandpaper is cushioned, and that any minor bumps in the stone do not cause scratches when grinding. The stone on this thing is bumpy and uneven (after all, it was cheap) so this is really needed.
http://msmvps.com/cfs-file.ashx/__ke...ep_5F00_03.JPG
On top of that you put tape. Go at least twice or thrice around the rubber band with 1 continuous piece of tape. This is to make sure the rubber stays on, and to provide a flat and stable surface to fix the sandpaper to.
http://msmvps.com/cfs-file.ashx/__ke...ep_5F00_04.JPG
Now it is time to fix the sandpaper. you can do that by putting small patches of double sided tape on top of the black tape. Use only small patches so that it is easy to replace the sandpaper. And if the tape becomes rumpled after a while, it too can easily be replaced.
http://msmvps.com/cfs-file.ashx/__ke...ep_5F00_05.JPG
And on that double sided tape you can mount the sandpaper. whether you need 1 or 2 strips depends on the length of paper that you have, but be sure that there is a bit of an overlap, and make sure that the overlap is in the right direction.
http://msmvps.com/cfs-file.ashx/__ke...ep_5F00_06.JPG
And voila: here you have a very cheap grinder that will do a reasonable job. I restored that entire 7 day set with it, and you can see the results here:
http://straightrazorpalace.com/galle...7-day-set.html
It died pretty much immediatly when that set was done. The gearbox was made of plastic cogwheels, and I had accidentally run the motor into its thermal protection a couple of times.
The grinder should only be used in 20 - 30 minute intervals, and then given an hour at least to cool off. It will depend on the way the grinder is built, but for 30$ or les, you cannot expect much. It had thermal protection, but after I used it for an hour+ and the protection kicked in for the first time, it lost a significant amount of torque. I suspect I shorted out a good number of coils.
Also, it pays to use good sandpaper. Don't use wet / dry because it clogs up faster if used dry then plain dry paper. I found aluminium oxide paper to be excellent. silicon carbide might be better still, but I haven't tried it yet.
This is by no means an equal alternative to a Bader or KMG belt grinder. Grinding pitting damage from a wedge will take some time. But at least the amount of time will be reasonable, and you won't get a tennis elbow in the process.
