Vacuum Chuck on a Blanchard?

[Tunash]

I work for a small machine shop that specializes in precision grinding. We have several rotary grinders (Blanchards), double disc grinders, and one large surface grinder.

Our owner has recently expressed interest in vacuum chucks for the non-ferrous materials we grind, and tasked me with doing some research. For full disclosure, I am not a machinist, I am the maintenance department, lol.

The surface grinder is pretty straight forward, but the rotary grinder seems a bit more complicated. I was looking at Magnalock's catalog and they have what looks like a pretty nice vacuum chuck that can be installed on a rotary grinder, but I want to understand how.

I was wondering if anyone here had experience with a vacuum chuck on a rotary grinder, and how it was installed. Is it something that requires removing the magnetic chuck and retrofitting the vacuum chuck onto the table? Or could it just be mounted directly onto the magnetic chuck?

If it could be mounted directly to the magnetic chuck, that would be ideal. But I start getting confused when it comes to the rotary union on the bottom side of the vacuum chuck. The only thing I can think is that you would need to drill a hole in the center of the magnetic chuck and run the hose out the conduit with the wires for the brushes. But that doesn't seem right to me.

I am contacting Magnalock with similar questions, but thought I would post this here since you guys have been a big help to me in the past.

 

[CarbideBob]

In general vacuum chucks do not have enough "oomph" for a Blanchard. The pressures to for the part to exit the machine much higher than normal surface grinding.
Before thinking about drilling through the center of a Blanchard chuck you may want to look inside at the brush holder.
I do lots of non or low magnetic parts on a such a grinder.
It is done by "ring and keepers", same a blocking on a regular SG but easier. The wheel is tilted just a tad so that all the grind force is one direction towards the ring.
The nice cross hatch.... not good.
One problem with any vacuum chuck used on different parts is that every hole not sealed by the part or mask has to be turned off.
Second is that there is always leaks and a Blanchard is a wet machine so one has to handle water in the vacuum system.

At one point I so wanted this to work. 100 or more parts on the chuck. If I could just eliminate all that keepers and tapping them and the parts in with a brass rod.
Since not grinding full 1/2 chuck in we piped it from the top.
This experiment did not work out well for me.
I have seen it work in big production volumes and the right part. This more in the semiconductor world.
Bob

 

[DDoug]

Maybe on a Campbell Vertical grinder ?

 

[Tunash]

Thanks for the advice. I was also worried about a vacuum chuck having enough holding power on a Blanchard. And drilling a hole through the chuck couldn't be a good idea, I just couldn't wrap my brain around another way to do it. I think I'm gonna try and talk the boss out of this idea. Currently we just block in aluminum and brass.

When we grind stainless(and the customer is ok with it) I tack weld sacrificial steel blocks to the pieces using stainless wire and a special shielding gas. I honestly don't know why or how they decided to use weld blocks, that's just the way they have been doing it for the three years I have been with the company. Again, I am a maintenance guy, not a machinist.

Thanks again.

 

[EmGo]

drilling a hole through the chuck couldn't be a good idea, I just couldn't wrap my brain around another way to do it.

If you don't bring the wheel all the way to center, than you can bring the pipe upwards instead of down. That's what C-Bob was describing, but didn't sound like that worked very well either.

 

[cash]

In general vacuum chucks do not have enough "oomph" for a Blanchard. The pressures to for the part to exit the machine much higher than normal surface grinding.
Before thinking about drilling through the center of a Blanchard chuck you may want to look inside at the brush holder.
I do lots of non or low magnetic parts on a such a grinder.
It is done by "ring and keepers", same a blocking on a regular SG but easier. The wheel is tilted just a tad so that all the grind force is one direction towards the ring.
The nice cross hatch.... not good.
One problem with any vacuum chuck used on different parts is that every hole not sealed by the part or mask has to be turned off.
Second is that there is always leaks and a Blanchard is a wet machine so one has to handle water in the vacuum system.

At one point I so wanted this to work. 100 or more parts on the chuck. If I could just eliminate all that keepers and tapping them and the parts in with a brass rod.
Since not grinding full 1/2 chuck in we piped it from the top.
This experiment did not work out well for me.
I have seen it work in big production volumes and the right part. This more in the semiconductor world.
Bob

I do believe Magnalock has done this in the past. I had some discussions with him on this. there are modifications that need to be done to the chuck and carriage, nothing crazy.

Just use caution with dealing with these guys.