A good basic bench grinder. But "basic" is the operative phrase here.
Written: Apr 19 '04
|
Product Rating:
|
|
|
Pros: Reliable performance at a reasonable price.
Cons: Finish and quality control could be improved if the one I got is any indication.
The Bottom Line: In terms of feature set and quality of finish, there is nothing unusual in this item. But the Craftsman name is still worth something.
|
|
|
| rumpel2's Full Review: Craftsman 6 in. Bench Grinder, 36 and 60 Grit Whee... |
I've been thinking about adding a bench grinder to my workshop for some time. When Sears offered the Craftsman 6" model (in Canada, Model No. 152.287160) at a price reduction of nearly 50%, I decided to grab it.
It's a good basic grinder. The bells and whistles available on some of the more expensive 6" models would have been nice to have (e.g., work light; angled groove in the right tool rest for sharpening drill bits; reservoir for cooling water, and a shaft brake on the top-end model), but they would have doubled or tripled my outlay. That wasn't in the cards.
But it wasn't perfect. It was one of those products that make some say that the Craftsman name is sometimes somewhat over-rated.
The specs:
Grinding wheels: 6" x 3/4", with a 1/2" nylon bushing for the arbor. The supplied grits are 36 and 60, in gray aluminum oxide (AlO).
The motor: 1/5HP continuous duty, 1/2HP max developed; 2.8A, 3450rpm (no-load); sealed bearings (no maintenance required); three-wire electrical plug.
Other features: adjustable U-shaped tool rests on both wheels, adjustable spark arrestors; wheels fully enclosed except for a 90-degree sector for grinding the workpiece; Lexan eye shields; recessed illuminated power switch (not lockable); rubber feet; 2-year warranty.
My observations:
Some assembly was required out of the box, e.g. attachment of the tool rests, spark arrestors, and eye shields. A small spanner (12mm and 10mm hex) is needed, and is supplied. Instructions for assembly and operation are reasonably clear, with good attention paid to safety of operation.
The supplied grinding wheels are 36- and 60-grit gray aluminum oxide (AlO), which have a hard bond and grind hot. They are a good general-use selection, but one woodworking expert has remarked that these wheels might be better used as paving stones in your garden if you are using the grinder for regrinding edged woodworking tools like chisels and plane blades. Woodworkers seem to have a strong preference for a wheel with a softer, more open bond, which will wear faster but run cooler. You are less likely to overheat the tool and draw the temper from it. (Once you do that, the tool is useless unless you can either grind off the de-tempered steel (without overheating it again!) or re-temper the tool. It's easier, and far less time-consuming, to buy a new tool.) The favoured wheels for grinding edged woodworking tools seem to be the softer white AlO wheels made by Norton in 80- or 100-grit.
The supplied 36-grit wheel needed a bit of truing -- radial runout was about 1mm. The 60-grit wheel was OK for radial runout, but had more than 2mm lateral runout. The result was noticeable vibration. In addition, that much lateral runout is likely to be problematic for drill sharpener guides that use the side of the wheel if not corrected. A wheel dresser (a required accessory for any bench grinder owner) will serve to remove radial runout, but I'm not sure that it is possible to correct lateral runout safely.
However, the rubber feet did serve to minimize the amount of vibration transferred to the workbench. The combination of the cast-iron base and the rubber feet served well to ensure that the grinder did not move unexpectedly. The base does provide for a mounting pad to allow the grinder to be bolted to a workbench (mounting hardware not supplied).
The tool rests are aluminum (or pot metal?) castings. They are fairly sturdy and nicely finished, but I wonder about their strength. And some say that abrasive particles can embed themselves in an aluminum tool rest, possibly leading to scratching of a workpiece. Those comments indicate that steel tool rests do not have this problem. In any event, I doubt that the nice finish on the tool rests will last long with all that abrasive grit and grindings flying around.
Enough of the tool rest extends around the sides of the wheel to provide support for odd-shaped workpieces -- but there isn't enough tool rest at the side of the wheel to tempt you to grind against the side of the wheel, which would be a no-no. A good compromise.
The wheel guards are formed sheet metal and are reasonably sturdy, and surround more than 3/4 of the wheel on both sides of it. The spark arresters are adjustable so that they can be kept within 1/16" of the wheel to prevent sparks carried right around the wheel from being thrown back onto the workpiece or into your eyes. Those spark arresters will also keep more of a wheel within the guard if a wheel breaks in use. Pieces of the wheel thrown at the grinder operator can be extremely dangerous. (That's never happened to me, but those who have experienced it describe it as a terrifying experience -- akin to an explosion.)
As in the illustration of this product, the power switch is illuminated but non-locking. (I suspect that the product description for this category is wrong.) The recess that the switch is set in means that it's not likely to get turned on by accident.
The lack of an axle brake meant that it takes more than a minute for the grinder to spin down, which can be a nuisance and a potential hazard. But there is enough rotating mass there that it is wiser to leave it alone than jam something into a wheel to stop it.
On a trial run, I noted that both wheels were throwing lines of oil droplets. Investigation revealed that it was coming off the flanges that secure the grinding wheels to the arbor shaft. That oil had probably been applied for rust prevention -- but even so, I found rust on the flanges and on one arbor shaft under the wheel bushing. Craftsman may need to look into the storage environment, or find a better rust preventative. I wiped off the excess with a cloth saturated with WD-40 so as not to have thrown oil marking a workpiece or other stuff in the area.
Bench grinders have enough power to be quite dangerous in the wrong set of circumstances. A little care will make sure those circumstances don't arise. Some safety tips:
*Treat a bench grinder with as much caution as you would a junkyard dog. It has much the same temperament.
* Always wear safety glasses.
* Grinder wheels spin fast and have lots of traction. They will wrap loose clothing or hair around a wheel with extreme suddenness. Never wear loose clothing or allow long hair anywhere near the spinning wheel.
* Inspect your grinding wheels regularly. And tap the wheels with a fingernail or a small screwdriver handle. If it goes "ting", it's probably OK. If it doesn't, be suspicious. Very suspicious. (This test is much more reliable when the wheel is dismounted and held at its center.) If a wheel is cracked or damaged, remove it from the grinder immediately. (You do NOT want to forget that it's damaged, and spin it up. It may explode. You can always run the grinder with only one wheel in place if you have to -- but make sure that the guards are in place for the missing wheel so the spinning arbor doesn't snag something.)
* Stand to one side when you start your grinder. If the wheel is going to break apart, it'll probably do so as it starts up.
* Always wear safety glasses.
* Always use the heavy paper/cardboard labels under the flanges when mounting a wheel. They're essential for distributing the pressure under the flange. Without them, the pressure under the flange may crack the wheel.
* Never exceed the rpm limit that's printed on the label on the side of the wheel.
* Never drop the grinding wheel or over-tighten the retaining nut. You could crack the wheel and set up a dangerous situation.
* Never grind on the side of your wheel. Pressure applied to the side of a spinning wheel can easily break it.
* Position the tool rest as close to the wheel as possible. You do NOT want to suck anything into the gap between the tool rest and the wheel!
* Dress the wheel if it's clogged, out of round or glazed. Wear a dust mask in addition to your eye protection when you do that. It would be a good idea to wear a dust mask whenever using the grinder.
* Wear gloves only when you're dressing a wheel, for protection against flying grit. But remember that gloves make it more likely for your hands to fumble the workpiece, and they won't save you if you jam a finger against a spinning wheel. Keep your hands at least 10 in. away from the grinder at all times.
* Always wear safety glasses.
* Unplug the tool when you're finished (especially if you're performing maintenance on the grinder) and keep young kids out of the shop when you're not there.
Recommended:
Yes
|
|
|
|
Epinions.com ID:
rumpel2
|
|
Member: Rob M.
Location: Vancouver, BC, Canada
Reviews written: 8
Trusted by: 1 member
About Me:
Eclectic public servant into choral music, computers and DIY.
|
|
|
- Add to My Yahoo!: 
- Add to Google Homepage: 
© 1999-2009 Shopping.com, Inc.