Temperature control

[Slick]

I'm trying to plead my case in regards to the affects of varied temperature to CNC mills as well as inspection equipment. I'm machining precision molds in a room that fluxuates anywhere from 58-75 degrees (that's a guess, who knows how cold it gets at night). Anyhow's, I was wondering if anyone had any links to articles that would help me explain the damage this can do to a machine (My word isn't good enough!!!)

[Thad]

quote:

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Anyhow's, I was wondering if anyone had any links to articles that would help me explain the damage this can do to a machine

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Damage? I'm not sure what you mean by damage. If you're referring to the temperature causing variation in the size of the parts your machining? Google "gage blocks" and you'll surely find something about 68 degrees.

 

Are you trying to convince them into air conditioning the shop? Good luck!

 

Thad

[robk]

+1 Thad

Not sure if the machines will suffer any damage (my guess would be no), but it will make all the difference in how the machine performs. You need consistent temperature to make consistent parts. If you can't get a temperature controlled room, maybe you need to work with temperature compensation charts.

[Storkman]

We will run a part, take it to QC (a constant 68° in there). Let it get to room temperature, then adjust the machine to compensate. Although we don't deal with this much. We usually have a large enough tolerance band to work with.

[Noel]

about 10 years ago we all stopped working overtime on those hot summer days. It wasn't long after that we got air in the shop. Black mail is a wonderful thing.

 

 

Noel

[Slick]

Thanks for the input so far. I suppose I didn't word it so correctly, you're right accuracy is the main issue, that and the fact that if I'm getting surface rust on my table top, toolholders, and gage blocks from just sitting in a room, just imagine what this could possibly be doing to insides of the machine.

[Thad]

I'm not too sure what to think about keeping the machines in a temperature controlled environment. While you can be sure that an air conditioned shop won't reach 100 degrees, will the temperature be controlled enough to be able to keep your tolerances? In our shop, we have 4 Fadals side by side. There is enough room between them to walk between them, but not much more. It's always a little warmer in the machining area because of the machines running. While the thermostat says it's 68 degrees, a temp reading at the machine, where the actual work is being done, may say it's 5-7 degrees warmer (wild guess). Is that enough to make or break your tolerance? How many degrees does it take to change the part size by a tenth? I've never worked in a shop that demanded those kind of tolerances. To be quite honest, I can't fathom holding 2 tenths on a machine. But then again, I mainly run Fadals.

 

As far as your rust issue, I would guess that everything in the machine that matters already has, and continues to get, a constant light coat of oil.

 

Thad

[MetalMarvels]

The exact temperature is not the real problem. The real problem is maintaining a steady-state temperature at the machine in order to hold a tolerance. On a +/- 0.0002 part, a couple of degrees of temperature swing will cause you to make scrap. I can hold +/- 0.0005 with my Fadal all day long - but ONLY if the room temp is fairly constant (+/- a degree F). Start moving the room temp more than that and I will be chasing the part size the whole time. Of course I don't have Cool Power on the spindle, or glass scales, so temperature has a fairly dramatic affect on my machine (a 10 degree F change can move my Z by up to 0.0015) - it will affect a compensated machine less - but it will still affect it.