I'm going to be deliberately insulting:
1750 RPM bench grinders have been sold to gullible woodoworkers for several years now. They are hawked as the cure for over-heating cutting tools while grinding their edges. As grinders they work OK but not as efficiently as the "regular" speed grinders running at 3450 RPM. My complaint with these low speed grinders is they are sold to as a solution to a problem they do not solve.
The reason for the success of the newer slower speed grinders (1800 Vs 3600 RPM) is ignorance and pandering. The object of this wasteful purchase is ostensibly to prevent the overheating of edged tools when grinding them. The result is when purchased the problem recurrs as the original factory dress on the grinding wheel dulls.
Dispelling the ignorance:
The reason the tools overheat while being ground is friction. When the grinding wheel is clean and the abrasive grains in its surface are sharp, they cut cool and efficiently. Any edged tool dulls in use and that's as true with the abrasive grains in a grinding wheel as it is with a lathe tool or a plane iron. When the abrasive grains become dull from use they tend to rub not cut and ever-increasing force on the tool against the grinding wheel is necessary to sharpen it it. Thus a carbon steel tool overheats, turns blue and its temper is lost. A tool will overheat as readily on a 1800 RPM grinder as it will on a 3600 RPM grinder.
Solving the problem:
Learn to dress your grinding wheels. Dressing a grinding wheel "sharpens" it by knocking the dull grains out of the bond to expose fresh sharp grains. Incidentally dressing a grinding wheel removes the roughness, grooving, loading, and makes them round.
Make/buy a diamond wheel dresser on a hand shank so you can dress your grinding wheels. A suitable diamond dresser would be a small cluster diamond such as found in the the MSC catalog and the import tool catalogs for less than $40.
A suitable shank could be made from a piece of 7/8" round bar 12" long by drilling a 7/16" hole in the end 1" deep and cross drilling and tapping for a set screw. This is a life time tool when used in the home shop for the weekly grinding wheel tune up. Your grandchildren will pass it almost unscathed to their grandchildren and they will use it to dress their grinding wheels into the 22nd Century.
Exposing the pandering: when a perceived need is fulfilled by selling something useless by flattering the mark willingness to believe plausible nonsense, that is pandering: magnet therepy, herbal remedies for impotence, beauty products, and slow speed grinders are all in the same class of pandering.
When new, the slow speed grinders work great and why not? The wheels are fresh and sharp and they agressively cut while the work stays cool. You are pleased with the money spent for the problem is solved - until the wheels grow dull and then you're burning the edges again. Then you have to buy another grinder, don't you? Why not? Thats how you solved the first problem.
Nope. There's good reason why grinding wheels turn as fast as they do. That's the optimum speed established almost a hundred years ago for vitreous bonded aluminum oxide grinding wheels in professional shops. You'll never find a slow speed (half speed, actually) grinder in a professional sharpening shop. They're not productive.
Times haven't changed much since 1912. The abrasives and the bond and the process controls for making grinding wheels are much more refined today but the interaction of the grain with the steel edge is still the same 5000 to 5000 surface feet per minute is the optimum speed for aluminum oxide against hardened carbon or high speed steel.
You are looking for 5000 to 5500 peripheral feet per minute (FPM) for aluminum oxide against carbon and high speed steel. FPM = wheel diameter in feet times pi times the grinder RPM. Let's dissect this a little. A 6" wheel is just about perfect for a 3450 RPM grinder at 5419 FPM. 7" is a little fast but very usable. When a 7" wheel wears, it passes through the 6" optimum diameter. An 8" wheel is too large for a 3450 RPM grinder (getting up to the unsafe zone) and on a 1750 grinder is too slow. A 10" wheel is almost unsafe on a 3450 RPM grinder but a bit on the low side for 1750. 12" wheel is likely to burst on a 3450 RPM grinder but the peripheral speed is amlost perfect for 1750.
A grinding wheel wears away in normal use. Ideally, the grinder would have some means of varying the wheel RPM to mantain a constant peripheral speed. A variable or step pulley, a DC motor and variable speed control, a VFD and three phese motor are all suitable drives for those whose budgets or curiosity allow such exploration. There are in fact everal variable speed grinders now on the market but in the very cheap or the very expensive price brackets. A three phase Baldor #500 face wheel grinder equipped with a 3/4 HP VFD would seem to be the most plausible option but if purchased new would be quite expensive.
However single speed grinders have been around for generations and they work very well as is.
Exhortation:
The reason you may want to buy or make a slow wheel grinder is because of deliberately perpetuated ignorance and possibly because the other guys are getting them. Well, you're smarter now. Are you going to make/buy what you don't need and will work properly for a short time? Or are you going to learn dress your grinding wheels and solve the overheating problem forever?
No, you HAVE to use a diamond dresser to make a clean smooth round sharp grinding wheel for the precision grinding of fine edged tools. There are no low cost options. Trust me. The wheel dress obtained by use of Norbide sticks, star dressers, the abrasive stick are all a distant second best to the silky cool cut of a sharp well dressed wheel dressed not too smooth with a diamond dresser.