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Side wheeling direction with Harig 612/Lectric-Center?

akjeff

Aluminum
Joined
Nov 17, 2008
Location
AK
A good chance that I'm overthinking this, but would like to run it by some folks with way more experience than I. I'm making a cylinder square, that I'd like to grind after the 3"x6" 8620 cylinder gets carburized( Will do a practice grind before heat treat, to get it close ). Planning to use a Harig Lectric-Center on my 612 grinder. My dilemma is, the spindle on a Harig 612 is spring loaded, which pushes the wheel towards the column( away from the operator ). The Lectric-Center is also spring loaded, but in the opposite direction. So, there's no way to do the side wheel grind of the rim on the "good end" of the cylinder square, with both spindles in their most rigid direction. Any opinions on which one should be the rigid one? Obviously very light cuts will need to be taken. I'd imagine it will still need to be fine tuned with lapping, but I would like to grind it as close as possible first. If it's a wash either way, I'd opt for dressing the side of the wheel facing me, as it will be easier to see what's going on for both dressing and grinding. That would put the grinder in its most rigid direction, and just take super light cuts on the end of the work piece.Thanks for any opinions on this.
 

akjeff

Aluminum
Joined
Nov 17, 2008
Location
AK
Need to get in some practice time with the Lectric-Center, as I just got it, and have never used one before. So, I went ahead and did an initial grind of the cylinder, and it turned out pretty well I think. The diameter change from end to end is under two tenths. This was with a 5SG46G-VSP wheel, and mist coolant. I didn't notice any change in how it behaved traversing away from, or towards me. But I never took more than a two tenths downfeed at a time. Before I try side wheeling the ends, I may wait until I get a different wheel. Mine is a VSP( very porous ), and my understanding is they are not great for side wheeling, and can be rough on diamond dressers??
IMG_1510 copy.jpeg
 

EmGo

Diamond
Joined
Apr 14, 2018
Location
Over the River and Through the Woods
Use a shallow cup wheel, it will work better. (For the side grinding, I mean).

[Also, can you put a little more pressure on the part ? This is like one of those centerless attachments where the part sits on rollers ? It looks like you're getting a little bit of vibration, not chatter yet but it would be if it hummed a little more).
 

akjeff

Aluminum
Joined
Nov 17, 2008
Location
AK
Use a shallow cup wheel, it will work better. (For the side grinding, I mean).

[Also, can you put a little more pressure on the part ? This is like one of those centerless attachments where the part sits on rollers ? It looks like you're getting a little bit of vibration, not chatter yet but it would be if it hummed a little more).
Thanks. I'll see if there's any more adjustment left in the spring pressure. The workpiece is held between dead centers. One end is spring loaded, pressing the work against the fixed end.
 

akjeff

Aluminum
Joined
Nov 17, 2008
Location
AK
Nice job for just starting!
Thanks! Better lucky than good. It was fortunate that the dead centers on the fixture were pretty darn close, and it ground a paralell cylinder. I'm not going to touch it until I have the workpiece hardened( carburized ) and then grind it again with a 60 grit wheel and see if it repeats. If it does, I may try to raise the center on the large end by a half tenth or so. Would also like to try the higher speed pulley on the fixture, and see if it has an effect on the surface finish.
 








 
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