Aluminum

Aluminium is remarkable for its ability to resist corrosion and its light weight. richards

A few days ago, I broke a ball mill because aluminum heated up and glued itself to it. This is no longer a problem with coolant. I am running the same program as before, this all runs in a puddle of coolant, runs great and no more problems.

i

Or, perhaps the old mill was not quite as sharp as the new one. Aluminum will mold itself to the edge of a dull end mill.

Paul

Stir welding

And of course you have splashed coolant on all 4 walls and the ceiling..right?

Gunner

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

Not really, it is pretty well contained. I will make a little enclosure soon and could run at higher speed.

i

No, it was definitely good.

i

But its not splashing the walls now, is it?

As I previously mentioned..its doable without massive guarding and splash shields and so forth.

But you didnt believe me...chuckle

When the big machining centers fire up..they are pumping literally gallons of coolant per minute..and that indeed will spray everywhere. But for our kinds of home work....little coolant goes a very long way.

Gunner

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

Not at all. 99% driips down into the sump, 1% ends within a foot of the mill.

It is not bad with a tiny stream. It would be MUCH worse if I let the full flow go out of the orifice.

They spray coolant at 200 PSI. I sold a pump like that once, scary stuff. It is actually very effective.

i

It a sharp earbide em will experience chip welding also. DAMHIKT. Got too greedy on the feed one time. (Cutting dry)

Wes

While Im not the smartest fellah..there are a few things I know something about. A few things..shrug.

Thats why there is a valve on there. Like the accelerator pedal in your car.. you can push it too much. You open it up only enough for the task.

I installed 24 of them on OmniTurn lathes last year in one shop. Deep hold drilling without any pecks sure saves time. But mine are pressured up to 340 psi. And yes..it is very effective.

And yes..they need full enclosures.

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

Carbide is actually a bit worse than HSS..they are not sharpened as razor sharp as a HSS bit is.

Gunner

"A conservative who doesn't believe? in God simply doesn't pray; a godless liberal wants no one to pray. A conservative who doesn't like guns doesn't buy one; a liberal gun-hater wants to disarm us all. A gay conservative has sex his own way; a gay liberal requires us all to watch and accept his perversion and have it taught to children. A conservative who is offended by a radio show changes the station; an offended liberal wants it banned, prosecuted and persecuted." Bobby XD9

Yup, keeping the workpiece cool helps greatly. Also, cooling the chips reduces welding to the cutter.

Jon

Yes, and lubrication helps even more. This is the way to go if the table permits coolant collection.

Right now I am gluing together a lexan enclosure 24x24 inch, that would keep splashes and chips inside. Then I could increase the speed.

I ordered an encoder for the spindle from US Digital. With that, I would like to accomplish two things:

1) Rigid tapping 2) Setting spindle speed programmatically. My spindle has speed set by INCREASE and DECREASE buttons. Right now they are connected directly to their switches. I would like, instead, EMC to control speed, with buttons serving merely as inputs.

I understand that 1) is definitely doable, but what about 2)? Can I somehow close this control loop and say, I want spindle speed of approximately 2800-2900 RPM by controlling spindle nicrease and increase pneumatic valves?

i

Forget the variable pulley drive, just set it to allow top speed or close to it, and do your speed control from the VFD. Upgrade the VFD to one that supports serial communication and let EMC2 send speed commands to the VFD that way using the normal G-code "S" speed commands. A VFD that supports serial communication likely also supports a load meter output too.

I do not like this at all.

i

It's the closest to the way the commercial mills operate. Most people retrofitting mills and lathes with the often temperamental variable pitch belt drives lock them off at a suitable setting and use the motor VFD for speed control.

If you want to have EMC2 control the variable pitch belt drive you're going to have to custom code a modules to do it, since I doubt anyone has already created one. You'll have to hang it off of the M03/04 commands, since the spindle has to be running to adjust the variable pitch drive.

The basic process will be something like this:

- Start the spindle in the specified direction based on the M03/M04 command.

- Measure the spindle RPM from the spindle encoder.

- If the RPM differs from the current "S" commanded speed by more than the allowable amount, send a pulse on the variable pitch drive (VPD) up/down actuator as appropriate. If the RPM is within tolerance, return from spindle start command.

- Wait a second for the VPD to adjust and stabilize.

- Return to the measure RPM step and check again.

You'll also need to code an "S" command module that will adjust the pulleys if the spindle is running using the same process above, or return an error if the spindle is not running.

If you use VFD motor speed control to control your spindle RPM and leave the VPD pulleys at a fixed setting, you'll need a single module for the "S" command which most likely already exists, to send the VFD and RPM command on a serial connection. This "S" command will work properly, spindle running or not, and requires no iterative adjustments to get the spindle to the correct RPM. Set "S" to 2,000 RPM, then M03, the spindle starts and gets to 2,000 RPM in the VFD's acceleration time and you're good to go.

I will check with EMC guys later. I thought someone did this, this is actually very common. I vagely recall something like that mentioned. If I am correct and EMC supports this, then I would rather use the stock VS drive than adjust VFD frequency.

i

I have an air gear motor that came off a series 1 for changing speed. You need two outputs running air solenoids, one for faster, one for slower. After you get an encoder running, you could talk me out of this item. I've been going to mount it for ten years and haven't got "A Round Tuit"

Karl