Author Topic: CraigsList Delta Milwaukee Toolroom Surface Grinder - $375 (Somerset, NJ) image  (Read 4519 times)

chips and more

Yeah Bondo, what would I do without it. I tried lead one time. Notice I said one time. I could not make it stay put on a vertical surface to safe my life!

woodchucker

so still trying to get flood coolant and drainage running. in the process.


Got a question, if I decided to drive the table by a cylinder, can I use pnuematic, or is it too fast and hard to adjust the speed. Or am I better with a closed loop hydraulic system. I assume the valve to control direction makes them both similar.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

Terrywerm

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I would tend to think that a hydraulic system would provide a more consistent rate of travel. Air, being compressible, would most likely move the table by fits and starts rather than at a smooth and steady rate. Air can be made to do it somewhat smoothly, but requires a double acting cylinder, which you would need for bi-directional travel anyway. The trick is to fully pressurize the one side of the cylinder, then bleed air out of the other end at a controlled rate. That would get rid of most of the jerky movement. Compressed air would be noisy, too, even with mufflers on the exhaust ports.


 :coffee2:
Terry

Making chips with old machines!

woodchucker

thank you good points, I was also thinking about the compressability, but you added some more light to that.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

woodchucker

what do you think about these 2 choices. Seems like all the hyrdaulic pumps are $$$$$.. so these seem reasonable. But 12v, would prefer 120v but that's out of reach right now. Maybe I can run off a car battery, and a charger to the car battery. I don't think I would get the amps using a transformer and a bridge rectifier.


https://www.ebay.com/itm/WILLIAMS-HYDRAULIC-POWER-UNIT/164242606856?hash=item263d9f4b08:g:gi4AAOSwtGRe5ADI


https://www.ebay.com/itm/Yale-Pump-HPI-8530463-ELECTRIC-HYDRAULIC-FORKLIFT-PUMP/283913697239?hash=item421a9337d7:g:anoAAOSwjdReycYT


Too much pressure? I really don't think I need a lot of psi.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

Terrywerm

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Those sound good, but the 12 VDC units are meant for intermittent use for short periods, like a minute or two at most, and they heat up pretty fast. You could probably get by with a cheap 1.5 or 2 GPM pump from Northern or someplace like that and probably drive it with a 1/2 HP motor. You wouldn't need high pressures, you could run it at 500 PSI and have plenty. 1.5 or 2 GPM would be more than you would need but you don't want to go too small either. To figure out what you will need, we need to know a few details.
* Table stroke
* Cylinder diameter and stroke, including rod diameter - The stroke should be nearly as long as the table stroke, but you don't want the table stops stopping the cylinder - the results could be UGLY.
* Fastest travel speed you would want on the table in inches per minute or feet per minute, either one is fine.
* Pressure you want on the system.
Once we have all of those, it isn't too hard to figure out what size pump and motor you would need as well as directional valve, tank, and needle valves.


Truth be told, unless you plan on doing a LOT of grinding, it probably won't be worth setting up the hydraulic drive. If you set it up with shuttle valves and everything so that it operates automatically, it will get expensive real fast. I don't know right off hand where you would find the shuttle valves either.  One place where you can often find deals on hydraulic components is  http://www.surpluscenter.com  but what they have on hand changes quite a bit, so you might not find the same thing twice.

ON EDIT:  Had to come back in and correct a couple of errors - fingers are both too fast and too fat!

 :coffee2:
« Last Edit: June 16, 2020, 10:14:27 PM by Terrywerm »
Terry

Making chips with old machines!

woodchucker

yea, that's why I originally thought the pneumatic system might work... less $$.


I was planning on putting a valve in the middle and having the stops flip the valve back and forth.


A shuttle valve seems more like an automated way of doing that?
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

Terrywerm

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I misspoke when I called it a shuttle valve, the correct term is sequencing valve. It automatically changes the direction when the pressure exceeds a certain point, which would occur when the table hits a stop, set by you at the end of the desired stroke. A sequencing valve would be required at each end.


 :coffee2:
Terry

Making chips with old machines!