zosotd
Aluminum
- Joined
- Sep 19, 2006
- Location
- louisville ,ky
What tricks do you guys use not to put scratches on a nice ground finish when removing from the magnet?
Thanks!
Thanks!
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Best way not to scratch the bottom side of my part when removing from surface grinder
- Thread starter zosotd
- Start date
- Replies 13
- Views 4,642
Spyderedge
Titanium
- Joined
- Aug 28, 2013
- Location
- NY
You must be grinding soft parts.
Stone the chuck every time you set a part down, wipe clean with a paper towel, then wipe with your palm to check for grit (your palm is very sensitive), and do the same to your part. Slide the part onto the chuck to insure no grit is between the two surfaces, after grinding directly lift to remove making sure not to bang the wheel with your residual magnetism lets go. Got gods sake turn your wheel off first.
When sliding your part onto the chuck it is possible to scratch the work if there is any grit you missed. But would you rather have a scratch or an inaccurate part?
Stone the chuck every time you set a part down, wipe clean with a paper towel, then wipe with your palm to check for grit (your palm is very sensitive), and do the same to your part. Slide the part onto the chuck to insure no grit is between the two surfaces, after grinding directly lift to remove making sure not to bang the wheel with your residual magnetism lets go. Got gods sake turn your wheel off first.
When sliding your part onto the chuck it is possible to scratch the work if there is any grit you missed. But would you rather have a scratch or an inaccurate part?
MCritchley
Stainless
- Joined
- Mar 22, 2007
- Location
- Brooklyn WI
Sometimes I use a c clamp on the part to lift it off. I use a squeegee to clean off around the part before I move it.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
Back in the day when IBM cards were still in use I wold set a fancy part on a card wait a bit for the mag to most be less then fold the card on the grind side and slide the part with the card that direction (to the right). Geuss good to get in the habit to clean the chuck well and slide to the grind side where there is less grit.
Yes as MC said a C clamp and a lift or a pry-up would do well.
Now with the reversing switch I can time my release to just go straight off.
Yes as MC said a C clamp and a lift or a pry-up would do well.
Now with the reversing switch I can time my release to just go straight off.
projectnut
Stainless
- Joined
- Mar 4, 2006
- Location
- Wisconsin
As mentioned I've also tried a piece of paper under the part and had success. In my case it was something I read in an older book on the subject, so I thought I'd give it a try. It doesn't seem to have an influence on the dimensions or quality of the grind, but it is a sloppy mess to dispose of it you're wet grinding. The topic "Grinding Technique" farther down on the page discusses the method.
The key is to make sure the chuck and part are clean before placing it on the chuck. Then be sure not to drag it across the chuck and grit when removing it. A few times I've even used the plastic putty knives from the hardware store. You can slip the edge under the part without damaging it.
Most of the time the parts I grind are large enough I can that get a good grip on them and just tilt them to break the residual magnetism or surface tension of the coolant.
The key is to make sure the chuck and part are clean before placing it on the chuck. Then be sure not to drag it across the chuck and grit when removing it. A few times I've even used the plastic putty knives from the hardware store. You can slip the edge under the part without damaging it.
Most of the time the parts I grind are large enough I can that get a good grip on them and just tilt them to break the residual magnetism or surface tension of the coolant.
Zahnrad Kopf
Diamond
- Joined
- Apr 5, 2010
- Location
- Tropic of Milwaukee
+1 on both. I use a KantTwist for the brass jaw faces for this. And this is one of the big reasons I kept my e-mag chuck - for the demag cycle. In the last few years, I have taken more to using the variable setting at 100% or whatever is called for and then simply winding it down to zero when I want to remove the part. Works the treat!
Bradracer18
Aluminum
- Joined
- Feb 9, 2012
- Location
- central, USA
You can get scratches on a 60Rc part too, for the guy who mentioned soft materials! It does happen to me quite often when I'm in a hurry and drag the part off the magnet(sometimes the only way it will come off, and if I don't care about a scratch or two). I learned something here though, I'll try the kant-twist clamps for some parts!
I'm sure I'll get burned here on this, but you can also use the nozzle of your air hose(if its a rubber tip), and push it under the part. It will "pop" the part loose. I do not do this on my small grinder that has a sticker directly on it to not use air blast. I do however do it on the bigger (12x24) grinders, which also are equipped with a demag cycle. It also helps I've found if you have time to run the demag cycle more than once, just quickly switch it on then back off.
I'm sure I'll get burned here on this, but you can also use the nozzle of your air hose(if its a rubber tip), and push it under the part. It will "pop" the part loose. I do not do this on my small grinder that has a sticker directly on it to not use air blast. I do however do it on the bigger (12x24) grinders, which also are equipped with a demag cycle. It also helps I've found if you have time to run the demag cycle more than once, just quickly switch it on then back off.
cash
Titanium
- Joined
- Aug 8, 2007
- Location
- Greendale,WI
On thin parts, blow under them with an air gun.
Larger parts, lifting magnet or c-clamp.
Larger parts, lifting magnet or c-clamp.
Spyderedge
Titanium
- Joined
- Aug 28, 2013
- Location
- NY
*Ahem*
Your mag chuck, with a burr will not scratch a part unless it is soft. You muse be grinding your 60 HRC parts with grit left still on the chuck. Your cleanliness is to blame
Bradracer18
Aluminum
- Joined
- Feb 9, 2012
- Location
- central, USA
I'm not sure what you are referring to grit, if it means there is grit on the magnet when I place the part on it, I can assure you there is NOT. I grind to the tenths (.0005 very commonly) and I can assure you no one does that and has grit or anything on the magnet from before putting the part on. There is at times grit on the magnet, however I try to squirt it off around the part with the coolant. Places you cant reach (like say a hole that goes through the part and holds grit from the current grind) will absolutely leave a scratch! I can't say all of the parts are 60Rc, but many vary from 52-55, and very commonly from 58-60Rc. So yes, they are pretty hard.
Cash, while I know you are very experienced, you can use the blow gun on larger parts. By larger I'm talking parts you can still lift somewhat easily. You have to work it around to blow in the right spot but usually it will at least get it sliding. Just some info if you ever ran into that problem. The kant twist is something I'm going to have to start using!
Cash, while I know you are very experienced, you can use the blow gun on larger parts. By larger I'm talking parts you can still lift somewhat easily. You have to work it around to blow in the right spot but usually it will at least get it sliding. Just some info if you ever ran into that problem. The kant twist is something I'm going to have to start using!
Spyderedge
Titanium
- Joined
- Aug 28, 2013
- Location
- NY
You should have the forethought to see once you start grinding, gunk gets everywhere. Coats everything, including the area around the part. Why would you slide it over the grit after grinding?
Coolant probably doesn't have the ability to blast off metal remnants and bits of abrasive trapped between the Chuck and edge if part. And how fine of a filter are you using to filter your coolant?
Coolant probably doesn't have the ability to blast off metal remnants and bits of abrasive trapped between the Chuck and edge if part. And how fine of a filter are you using to filter your coolant?
Bradracer18
Aluminum
- Joined
- Feb 9, 2012
- Location
- central, USA
Obviously. Like I said if you read, I don't care about some scratches. On some very flat parts it can be tough to get them off the magnet without some movement. If a scratch or two is ok, I'll go ahead and slide it off and then just quickly sandpaper (on a flat block) the scratched surface and move on in a much quicker fashion.
Our filtration system is a paper roll type filter. I'm not sure what the micron level is...I'm assuming they are somewhat standard in the big white rolls, but I'm not sure.
Our filtration system is a paper roll type filter. I'm not sure what the micron level is...I'm assuming they are somewhat standard in the big white rolls, but I'm not sure.
