- Joined
- Dec 19, 2013
- Messages
- 25
After having a good number of years using several different sizes and brands of horizontal surface grinders, I tend to pronounce it as one of the most dangerous tools in your shop. I don't mean to be "mean spirited or trying to scare you from taking on the learning curve but it is without a doubt one of those tools that you will be "surprised by" at some time, some day when you least expect it - and even when you've been exceptionally careful with your setups thinking that this would be your saving grace. The primary reason is that regardless of the brands of wheels you find - you can never quite tell just how "robust" that wheel is by looking at it. If you hold it by sticking something like an 1/8" allen wrench thru the inside and then tapping very lightly on the outer rim area there should be an almost "bell like" sound to a good wheel - you won't be playing "The Sound of Music" with them but this can help to identify wheels that get loaded up with someone using it improperly by maybe not dreswsing it down thoroughly enough to get the grains back to a clean an clear area. There's a tendency sometimes to think about that diamond that you're dressing it with and how much money you paid for it (so you don't tend to use it too much) but you should - the entire purpose of dressing the wheel is to remove those areas where the metal particles are still imbedded in the partical grains of the wheel. Sometimes you will also see a glazing on the grinding surface that is almost like someone polished it... this too is not a good situation because that "glazing" is made up of many of those particles from the previously ground steel but also from the adhesive and grains of the wheel you're looking at. Having that type of surface will seldom ever do what you want in the way you want because it's just an opportunity for generating more heat and with surface grinders in particular, heat is never you friend. Keeping things cool is cool and should be done in whatever means possible - whether that is a flood coolant that will drown your magnetic table (good thing) or even just a spray mist like you would use on your mill to flush particles away from the cutting area. The coolant liquid is doing the same thing in the grinding operation by flushing those surfaces (you wheel and your stock for removal) continuously which is always good. I've often used a light coat of WD-40 that can work sometimes better than other depending on the steel types you're grinding. So just when you get this cooling details firmly planted in your planning and your grinding, you'll start thinking that this isn't so hard.. the grinder's doing all the work and you just have to keep two hands doing two different things in a steady motion and pace and then the provervbial stuff will not only hit the fan but wipe it off the mount you made on the wall to keep things cool in the shop.. the wheel can explode when you least expect it and I'd guarantee you won't be expecting it but when it happens you'll remember it and once your heart rate settles back down you can do some shop cleanup operations and find a better wheel to continue with. There may be no visible proof of anything you did wrong, but the wheels (to me) are the achilles heel in that they age, they get loaded up with such a mix of liquids, particles and grinding "junk" that you can never quite tell when it's likely to be a problem. I've seen people try to flush a wheel in a parts cleaning tank and then use an air hose with about 90+ psi pressure to try to blow thru the conglomerate to clean it - partially helpful on coarser grit wheels but rather doubtful on anything above a 100 grit zone.
Having a reliable and proper functioning digital readout is a definite plus but without it, the grinder can still do an excellent job if you pay very close attention to the scales on both the vertical and Y-Axis travel to gain an understanding of exactly what happens when you move the dial by .001" or by .0001" - you need to know how well the threads and the bed works together after years of use. That too depends on how maintenance might have been handled by previous owners. The part people forget about is that if you break off one very small particles of grit from a wheel and put it in the wrong place, the grinder will feel like you just submerged it in your kids sandbox... all of the ways and channels under the main table are there for a specific purpose in making two fairly heavy pcs of steel slide together as though the top one was floating on air... when it feels that way, it's probably getting oil where it should be and you can become extremely sensitive with your own fingertips about what is clean and what is not. Regrinding the magnet is probably one of the jobs that will improve the accuracy if it's done correctly but will be one of your worst nightmares if it's not. You are relying on the grinder as a final step in a sequence of steps that are all intended to gain accuracy so if the magnet surface is not flat and true with the final grind operation, you will trying to obtain dimensional results that will drive you nuts in the process, but be patient, be particular and be persistent in marking surfaces, dealing in tenths or better for a valid reason and you can be rewarded with one of the best tools in your shop. When you can trust it to do what you ask and get the results without taking 3 days instead of 3 hours, then you'll feel rewarded for all of those extra steps you took to get it right.
As for the grinder being any more dangerous than anything else in the shop, it's probably not but it demands a healthy level of respect for what it can do in a split second.. not just to your nearly prized pc of steel but to your hands, eyes and the rest of your facial features! I've seen people forget to turn the magnet on when their intending to dress the wheel and they get the diamond just every so slightly off-center (to the right) of the wheel and if you do this, I guarantee you will know the value of an anal transducer attached to the power plug! Just pay attention to what you're doing and don't get distracted by your music or your kids or your schedule.... when you get the work done that you wanted to represent your best efforts, then it will be done when you're done with it!!! There are some good books about grinding and I would suggest finding a couple and learn what you can about basic and sound examples of setups that stay in place, don't vibrate while you're passing over them multiple times and this is one case where some of the older books are probably as good or even better than something written last year - by last year everyone was convincing themselves that they had to have a CNC controlled surface grinder.. I'd say NOT true ... learn to be good without it and you may be even better someday but there's a lot to learn about proper techniques and retaining all ten fingers and getting thru those chapters should take the better part of the next 5 to 10 years... don't be discouraged - be the student you need to be to be good with this tool and you'll be glad you did. And above all, don't hide your mistakes - they are golden opportunities to learn more and that's what you will do as you learn more and begin to push your own skill boundaries more and more.
Follow up with some notes in another 6 months or so and let all of us know what has been the more challenging portions of your experiences with the grinder and what are the areas where you've learned more and improved your skills within this timeframe. We can all learn from each other in that way and it will give you a reasonable goal and timeframe to work in to see your own progress. Thanks and work safe.
Chip4Lips -
Having a reliable and proper functioning digital readout is a definite plus but without it, the grinder can still do an excellent job if you pay very close attention to the scales on both the vertical and Y-Axis travel to gain an understanding of exactly what happens when you move the dial by .001" or by .0001" - you need to know how well the threads and the bed works together after years of use. That too depends on how maintenance might have been handled by previous owners. The part people forget about is that if you break off one very small particles of grit from a wheel and put it in the wrong place, the grinder will feel like you just submerged it in your kids sandbox... all of the ways and channels under the main table are there for a specific purpose in making two fairly heavy pcs of steel slide together as though the top one was floating on air... when it feels that way, it's probably getting oil where it should be and you can become extremely sensitive with your own fingertips about what is clean and what is not. Regrinding the magnet is probably one of the jobs that will improve the accuracy if it's done correctly but will be one of your worst nightmares if it's not. You are relying on the grinder as a final step in a sequence of steps that are all intended to gain accuracy so if the magnet surface is not flat and true with the final grind operation, you will trying to obtain dimensional results that will drive you nuts in the process, but be patient, be particular and be persistent in marking surfaces, dealing in tenths or better for a valid reason and you can be rewarded with one of the best tools in your shop. When you can trust it to do what you ask and get the results without taking 3 days instead of 3 hours, then you'll feel rewarded for all of those extra steps you took to get it right.
As for the grinder being any more dangerous than anything else in the shop, it's probably not but it demands a healthy level of respect for what it can do in a split second.. not just to your nearly prized pc of steel but to your hands, eyes and the rest of your facial features! I've seen people forget to turn the magnet on when their intending to dress the wheel and they get the diamond just every so slightly off-center (to the right) of the wheel and if you do this, I guarantee you will know the value of an anal transducer attached to the power plug! Just pay attention to what you're doing and don't get distracted by your music or your kids or your schedule.... when you get the work done that you wanted to represent your best efforts, then it will be done when you're done with it!!! There are some good books about grinding and I would suggest finding a couple and learn what you can about basic and sound examples of setups that stay in place, don't vibrate while you're passing over them multiple times and this is one case where some of the older books are probably as good or even better than something written last year - by last year everyone was convincing themselves that they had to have a CNC controlled surface grinder.. I'd say NOT true ... learn to be good without it and you may be even better someday but there's a lot to learn about proper techniques and retaining all ten fingers and getting thru those chapters should take the better part of the next 5 to 10 years... don't be discouraged - be the student you need to be to be good with this tool and you'll be glad you did. And above all, don't hide your mistakes - they are golden opportunities to learn more and that's what you will do as you learn more and begin to push your own skill boundaries more and more.
Follow up with some notes in another 6 months or so and let all of us know what has been the more challenging portions of your experiences with the grinder and what are the areas where you've learned more and improved your skills within this timeframe. We can all learn from each other in that way and it will give you a reasonable goal and timeframe to work in to see your own progress. Thanks and work safe.
Chip4Lips -
