Right and left mounts. Only use the one with the left-hand threat, sell the other so out of your shop.
That wheel should be OK. I like white and pink if the pink id from radiac.
Open wheel is the space between the grits. I don’t know how open that blue wheel is. with 100% concentration there is no space and so with no space the wheel run hotter,
vfd ..be sure to not run wheels faster than the speed on the blotter, ring test all wheels at mounting, mark all wheels with a mount up arrow on the blotterr.
Grinding a Magnetic chuck (Old grinder hands please make comment if I have missed something here, or if you find fault...Buck)
So very often a new grinder hand will choose first off to grind the chuck. This is a bad plan because grinding a chuck is for the seasoned guy/gal and some grinding time /experience should come first. Best to practice grinding a large part so to realize how heat can build and cause a burn not often common to grinding small parts.
To begin it is not a bad idea to check under a chuck, rust can build up with being unnoticed and the chuck may have been ground with some rust under it. Some suggest to grind the set pad but I only do that if the machine has been re scraped or if finding the pad not flat. A grinder having poor way straightness due to bed wear or ball or roller racks wore out may be made worse by grinding the pad. Do figure 8 hone the set pad, and check it to be flat.
Still, rust can induce stressing a table so grinding the set pad can be a good/Ok idea. I most often evenly figure 8 hone the set pad with a big fine oil stone, and do the same to the bottom of the chuck. Scraping the chuck is also a viable possibility but I have never done that. Grinding the bottom of the chuck is often done and needed if the bottom is out of flat. The Norton 6” or 8" stone is Ok for this task. I small stone bevel all the set pad edges that are under the chuck and stone bevel edges of the chuck. With the chuck and the set pad absolutely clean I use heavy lubrication oil under the chuck. 30 weight lubrication oil is OK and way oil is also good, Yes, not automotive crankcase oil. With the chuck in position I set the clamp downs so they hit the innermost area of the chucks set hold downs so they angle a little down and touch near the inside of the notch. I tighten with a standard wrench with a one hands medium pull. Care taken to see the chuck sets where one can long travel and cross-travel a wheel to be able to grind the entire chuck and off the back and off the front so the correct wheel width must be chosen. Walker chucks suggest 20- or 30-foot pounds and that seems fine likely I tighten to about that (20 is plenty).
The magnetic chuck may be the largest thing a grinder hand might grind a so very important concern and consideration is due. Very often a new grinder hand or a new to grinding person will think grinding the chuck true is the first thing needed. This is a task for the seasoned grinder hand or at least one who has studied the proper method. Using the wrong wheel and rushing the job can ruin a chuck. A grinding burn can put stresses in the chuck that may cause years of problems. The act of grinding may seem easy at first when only a small portion of the chuck is being ground. When more or all of the chuck is being ground heat may build faster than expected. The grinding may seem to be going well with not noticing that heat generated has made the center portion swell and so when the job is done and the chuck cooled the chuck center may actually be low even when no burn or problem is noticed.
The wheel choice should be an open wheel with having lower concentration (open). The grit larger and the hardness letter to the medium or softer range. I like a 46 h to 46 k wheel and that is likely the finest (smallest) grit and hardest wheel one should use. Many like a 36-grit wheel so getting a lower surface finish but less chance of a burn. I prefer a white aluminum oxide wheel as they seem to run cooler on mild steel as most magnet chucks are made of. Wet grinding is best even if a hand spray bottle is the only coolant source. Frequent testing the chuck for the slightest heat. The chuck can swell even when no heat is felt. When the whole chuck is being ground greater over travel at each end (going off) can be employed to aid keeping it cool. To cross feed only on the grind side and a no-feed on the climb side can also aid cooling if needed.
When grinding and after a full chuck pass over the chuck should be allowed to cool and then with watching sparks often one can see the spark pattern/volume to see the spark- out are even at both sides and front to back. Only sparks at the right and left side indicates the chuck heat swelled and so took more stock off the middle or back side, this suggests that the chuck will not be true to flat. Many say the magnet should be on and this is true for the last .001 /.002. Prior to the finishing the chuck will run cooler with the magnet off due to not trying to retain or catch material from the coolant. Still grinding the whole job with the magnet on is fine and that way you won’t forget to turn it on..
Good to check your set pad to be flat with using a straight edge and run a hone over it.
If you grind the set pad run an abrasive paper over all the edges the hone the edges and then hone the top. The chuck sides and all edges should be flat honed and all corners and edges hone beveled and bug free.
Be sure to take off the back rail.
* Again, wet grind even if you use a hand spray bottle.
* Good to buy a large plate of steel ¾ x 6” x 12” and make this your practice grind. You can use it for a checking plate so a practice with a purpose.
1. Set the chuck on the set pad in a position that will allow grinding the back rail and centered to the set pad. Best to place the chuck where you can get the wheel off the chuck at the far side and off on the close side to be clear off the chuck. it is common to indicate a chuck side to make it square to the machine. Strike pencil marks Criss cross on the chuck.
2. Dress a name brand wheel of perhaps 46 H to K /or 36 h to k. Tighten wheel as tight you can with one hand on the wrench and one on the wheel / Then set the wrench end on a block and make a little tighter.
3. Balancing may not be needed for 7” wheel but 8” and up I recommend balancing, balancing is a plus for the 7”.
4. Bring the dressed and not running wheel to hand feel the chuck at close to you at the far right and note that down feed number. Then bring the wheel down at the far away chuck center to rub and note that number. Rub very easy or you will need to re dress the wheel.
5. raise up and come back down to .005 above the highest number and travel the parked wheel across the chuck to see that it misses touching the entire chuck.
6. fire up the spindle at let run for 5 minutes if a bearing spindle /20 minuet if a plane bearing spindle.
7. crank or auto feed long travel for 5 minutes to warm up the bed.
8. With long traveling across right and left down feed .0005 till you get first spark at the close to you edge.
9. long travel and incremental cross ¼ to 1/3 the wheel width per pass with spraying coolant on the chuck.
10. cross and long travel all the way to clear the chuck at the far side with cross feeds off the chuck.
11. cross feed back to the chuck front and with .0002 down feed grind chuck again.
12. continue until all pencil Xs are gone.
Pull down .00005 and take a spark out, or two.
After top grinding the chuck hone bevel and de burr edges so there are no sharp edges, replace the back rail with first cleaning the screw holes and selecting high grade screws that are as long as possible with not bottoming out. Tighten the center most screw first the outer ones, tighten with a light feel of one or two fingers at about 2" on the wrench. Dish the back of the wheel so only the edge will grind the back rail. Bring the parked wheel to just feel the back rail and to feel your scale setting on the chuck. cross away and cross back to be .005 away from the back rail. fire up and with long traveling carefully come to touch the back rail and tickle grind to clean up. An over lip back rail is best. That is one that is 1/16 higher than the chuck with a lip that protrudes toward the operator position. *Much care here because it is not uncommon for a new grinder hand to accidently down feed and put a divot in the chuck when grinding a back rail. Another bump rail is handy at the go side of the chuck (left edge).
Yes, an experienced grinder hand might take greater down feeds depending on the wheel and machine but for the new to grinding guy don't recommend doing that.