[migrusch]

That sounds to me like a REALLY bad idea! WD-40 has a flash point of only 120F, and breathing the vapor is not good for you. FogBusters can put a LOT of vapor into the air. If it ever ignites, you could be in serious trouble....

Regards,
Ray L.

Wasn't a long term plan. Just easy to source. Plenty of other people doing it too.

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[migrusch]

Actually, I don't think there is very much vapor with my setup. Certainly don't smell much.

Lots of people spray wd40 from the can when machining al without trouble.

All the same I am looking for an alternative, but haven't found anything here in Australia.

Open to suggestions!

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[unexpectedly]

On my manual machines, I use kerosene as cutting oil / "coolant" on Aluminum.

[migrusch]

On my manual machines, I use kerosene as cutting oil / "coolant" on Aluminum.

Can't imagine that has a very high flashpoint.....

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[LeeWay]

Right.
Kerosene, solvent and alcohol have all been spoke about being used here as coolant. That stuff is bad enough being brushed on, but put it in a mister and you might be in for a flash fire. I have personally seen a small carbide end mill turn cherry red in literally a second or two while being flooded with coolant. That is hot enough to flash just about any flammable solution. The mistake I made that caused this? Added one zero to many on the speed setting in the Cam. How easy is that to overlook? It happens too fast to do anything about it.


Your part looks pretty good. Rather than rely on super glue or tape, I would use tabs. Just a few very shallow narrow tabs will hold that part in place with no trouble. Clean up on the tabs is very easy really. You can even polish the edge to mirror like afterward if that is what you are looking to do.

[migrusch]

Like I said, I am looking for an alternative coolant.

Just to be clear on one thing.... the flash point temp is not when the substance suddenly burst int flame. An ignition source is still required. I.e. a spark

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[dick cnc]

Nice to see it up and running if you could let us know the speeds and feeds and the size and of end mill that you used. I am interested because I'm kind of limited on spindle speed and I am planning on pumping it up a little bit. I'm with leeway as far as using any flammable coolants that would be a little worrisome to me. Doesn't take much set it them off could be even a static spark generated by the air movement. Probably turn it into a flamethrower you mentioned that you are going to make some kind of walls or enclosure to keep the chips contained . Why not build a pan and put it under the base of the machine any reason you want to stay away from the water mixed coolants. Possibly flood coolant

[migrusch]

Hi dick. At the moment I only have the spindle on the lower speed pulleys. So rpm is about 3500. 6mm two flute hss cutter. Feeding at 350mm/min with 1mm doc and 2.4mm step over.
Not optimised at all, just first stab at it.

I am planning on having a tray at the bottom of the stand with a pull out draw for swarf. Still need walls to stoo the chips flying about.
Will just be using coreflute as paneling.

Want to stick with the fog buster as it's just less hassle amd mess than flood (I've used both). Realy just need a non flammable coolant that doesn't rust the table.

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[Zenji]

Your G4 / G3 problems happen in real world industry as well, I worked on Mazak in the 90's and if you turned up the feed to much the computer could not keep up with calculating the G3 interpolation.
It resulted in warped radius on the corners, G4 and G3 really gave the cpu a workout on older computers.
And resonance?
It will reappear, i assure you, i sorted out my machine, let it sit for 12 months, fired it up again and it needed retuning - voltage change? a virus maybe?
(rubber motor mounts are how Epson solve it in their printers)

Write down all the settings, voltages, etc for future reference.

[migrusch]

I have eliminated all of the factors you mentioned. I realy don't expect this to return.

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[dick cnc]

Are you happy with it keep us up to date

[migrusch]

I haven't posted for a while.... but a few things have been going on.

I have made a few parts and learnt alot about the software packages. Also built a vibration rumbler (some pics to come) and bought a sand blaster for surface finishing. Just need to renew the chemicals in my anodizing tanks.

A few weeks back I was running a 3hr job and the spindle noise was getting worse and worse. Finally I paused the program and stopped the spindle. The primary drive belt fell right to the ground. See the pic..... utter destruction!

On closer inspection the intermediate shaft had also spun in the bearing (again!)

Time for a redesign. .......



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[migrusch]

So I was never able to run my spindle up on the high gear (10k RPM) the motor just didn't have the grunt for this type of spindle.

So now the plan is to spin the motor 180deg and remove the troublesome intermediate shaft altogether. Now I will run direct, aiming for 6k top speed.

Hopefully rhis works! I have looked into a Chinese vfd spindle. ..... but need a new inverter and just don't trust some of the products out there.

So let's start the cave up....



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[migrusch]

Forgot to mention why the drive belt was torn up.

I had a clasic NASA moment! Mixing imperial and metric.

I am running xl belts because they are easier to get in lots of sizes.
One of the pulleys was recovered from a German machine, whereas the others were all ordered with the belts.

So it turns out that 5.08mm doesn't go into 5.00mm at whatever belt surface speed I had.

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[dick cnc]

That's really good if that's the only thing you have to do is change the spindle drive. Again keep us informed

[migrusch]

Ok. I am back up and running.
Now have a direct belt from the motor to thr spindle giving me 5500rpm.
Also added a second fogbuster.

Attachment 226530

Attachment 226532

Runs much quieter. Also after spending some time adjusting the spindle the cut is much cleaner with no burr.

There is still some vibration in one axis which can be seen in the surface finish.

Also need to add clamps to the fogbuster lines as I had one let go spraying wd everywhere (yes I will find an alternative fluid!)

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[migrusch]

This is supposed to be a phone case...... I had to abort the run about 3/4 through when I realized that one operation was cutting on thevwrong side of the feature. One click to fix in HSM but too late for this chunk of Al.

Need to watch the simulation more closely!

Attachment 226534



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[migrusch]

I also finally sorted out a problem that was really annoying me. When touching off the z axis during manual tool changes it would be off by aprox 1mm and I would have to pause and redo the touch off.

Finally foundva default tool table in linux cnc..... which I don't need with my setup.
Anyway, this had a 1.2mm offset on tool #3.

Cleared the table and now all fixed.

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[migrusch]

This shot is a good before and after. These are the scraps from the center of the phone case above. bottom piece is before.



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[migrusch]

Z