Post by deb193redux on Jan 29, 2013 14:42:49 GMT -5
Yes, on 6" trim saws, a thicker blade can permit making "slabettes" of about 1" cut depth similar to the logic of a 7" tile saw. IMO, it takes a bit more patience because 6" trim saw RPM is typically 1750, while tiles saws spin at 3400 RPM or higher. I am very impatient so this matters to me. When I had a Rock Rascal and a 7" tile saw both within reach, I often turned to the tile saw for quick slabetts and trim cuts, and then turned back to the grinding wheel on the Rock Rascal. Of course, the Rock Rascal saw did throw less spray. If I was not in my basement with the tile saw in a laundry tub, I might have been forced to learn some patience.
As for the 1-wheel vs 2-wheels and a polish pad, more is generally better, but you cannot beat the bang for a buck of the rock Rascal - especially if you are tumble finishing.
What you get with the extra wheel and the pad is the ability to reduce your tumble time with the 2nd wheel, and/or to more delicately shape material that would undercut in the 120g initial vibe cycle. But, no guarantee it will not undercut some on the 2nd wheel.
With the polish pad you do get touch up ability, and also the ability to polish small flats w/o rounding edges.
The market might determine things. If you had refined your use-case a few weeks sooner, you could have jumped on the RockRascal that was recently offered here. I think you might take the next RockRascal or Lx-6 type you see at a reasonable used price, letting the luck of the draw decide. Why wait overlong to save a few dollars?
Some statement such as "runs good" or "quiet bearings" would be desirable. There is always a risk with used equipment. I would not worry about paint job or appearance, because these machines spend their lives under mud and gunk. It is a messy hobby. Also, if the wheel(s) are stated in good condition, that is a plus, but often new wheels are a matter of course. Some used units may have the older SiC wheels anyway, and diamond is a good upgrade. Replacement 80-100g and 180-220g ish nickle-braised 6" x 1" diamond wheels are available for about $40-$55 each.
I ran 100g (rather than 120g) on my Rock Rascal because of that impatience thing. Now on my Lortone 6-wheel unit I use 80g and 180g for the two grinding wheels.
The one configuration you have not mentioned is 1 wheel and 1 expando drum. If you had a 100g wheel and a 220g belt on the drum you would be pretty well set. You could also at a later time get a few finer-grit belts to sand and polish if a particular project comes up.
You will also find that small units hold their used value fairly well. They are not too bad to ship, so you have reasonable chances of recouping a lot of what you pay if you resell. Selling the unit w/o wheels/drums/belts or motor, and moving such things onto your new equipment makes sense too. Unless they are close to replacement, why not keep the abrasives you know. Also the buyer does not have to try to figure the used value of the abrasives, just the hardware. Motors are expensive to ship.
I think you have done a good amount of homework. Maybe take a plunge. You might later realize that some other configuration would have been a little more suited. You may get a piece of used equipment that needs a flange, or wheel, or (gasp) bearings replaced, but this is not too likely, and these things are doable.
One last note, combo units are economical. Shared motor and footprint and all that. But I never liked the saw spinning the whole time I was grinding. You spend more time on the grinder and the spinning saw bothered me. Don;t know why it bothered me more than other wheels spinning, but it did. If you got a Model-T Rock rascal (trim saw only) you could change the pulley to spin the blade faster. You could get a 2-wheel arbor of various design: direct drive, belt drive, attached pans, free standing pans, overhead drip (best) or bubble-spritzer ... etc. It would not cost that much more and the increase in flexibility would be large.
Good luck.
As for the 1-wheel vs 2-wheels and a polish pad, more is generally better, but you cannot beat the bang for a buck of the rock Rascal - especially if you are tumble finishing.
What you get with the extra wheel and the pad is the ability to reduce your tumble time with the 2nd wheel, and/or to more delicately shape material that would undercut in the 120g initial vibe cycle. But, no guarantee it will not undercut some on the 2nd wheel.
With the polish pad you do get touch up ability, and also the ability to polish small flats w/o rounding edges.
The market might determine things. If you had refined your use-case a few weeks sooner, you could have jumped on the RockRascal that was recently offered here. I think you might take the next RockRascal or Lx-6 type you see at a reasonable used price, letting the luck of the draw decide. Why wait overlong to save a few dollars?
Some statement such as "runs good" or "quiet bearings" would be desirable. There is always a risk with used equipment. I would not worry about paint job or appearance, because these machines spend their lives under mud and gunk. It is a messy hobby. Also, if the wheel(s) are stated in good condition, that is a plus, but often new wheels are a matter of course. Some used units may have the older SiC wheels anyway, and diamond is a good upgrade. Replacement 80-100g and 180-220g ish nickle-braised 6" x 1" diamond wheels are available for about $40-$55 each.
I ran 100g (rather than 120g) on my Rock Rascal because of that impatience thing. Now on my Lortone 6-wheel unit I use 80g and 180g for the two grinding wheels.
The one configuration you have not mentioned is 1 wheel and 1 expando drum. If you had a 100g wheel and a 220g belt on the drum you would be pretty well set. You could also at a later time get a few finer-grit belts to sand and polish if a particular project comes up.
You will also find that small units hold their used value fairly well. They are not too bad to ship, so you have reasonable chances of recouping a lot of what you pay if you resell. Selling the unit w/o wheels/drums/belts or motor, and moving such things onto your new equipment makes sense too. Unless they are close to replacement, why not keep the abrasives you know. Also the buyer does not have to try to figure the used value of the abrasives, just the hardware. Motors are expensive to ship.
I think you have done a good amount of homework. Maybe take a plunge. You might later realize that some other configuration would have been a little more suited. You may get a piece of used equipment that needs a flange, or wheel, or (gasp) bearings replaced, but this is not too likely, and these things are doable.
One last note, combo units are economical. Shared motor and footprint and all that. But I never liked the saw spinning the whole time I was grinding. You spend more time on the grinder and the spinning saw bothered me. Don;t know why it bothered me more than other wheels spinning, but it did. If you got a Model-T Rock rascal (trim saw only) you could change the pulley to spin the blade faster. You could get a 2-wheel arbor of various design: direct drive, belt drive, attached pans, free standing pans, overhead drip (best) or bubble-spritzer ... etc. It would not cost that much more and the increase in flexibility would be large.
Good luck.