[CadRhino]

So keep the speed high and lower the feed (IPM) so it cuts more in less distance, right?

That does seem to help reduce the size of vertical lines but they are still there. They look much better, though.
Thanks,
Natan

try to lower acceleration in your control if that helps...
those marks don't looking resonance issue by tool or machine...

if your surface will be smoother then you save the extra time to finish by hand..
so a little extra time on machining might return you...

[victorofga]

it is not simply reduce the feed...
and theres no guarantee that it solve it perfectly..

as your control try to accelerate if it is too fast, I mean the acceleration then it try to change in shorter segments the speed..
imagine you going with your car... and you can take a 5 deg ramp or a 25 deg ramp
the lower is smoother
same way when you try to break suddenly with your car it wont be smooth..

you can see it better when you try to set some extreme high the accel
and your machine will ""jerk""

so lowering to the other end, it smooth out..

theres no exact value for.. and for most work not necessary.. it just an option, ...

on the end your cnc need to work , that's why you have cnc..

[CadRhino]

I would love to start using my mill as a lathe but since I am using the tts system (and atc) I think the best I could do is to put a 1/2" diameter into a 1/2" tool holder.
If I didn't have the atc and PDB I could put a r8 chuck in the spindle. Do you know if any alternates ways?
Thanks

To me, it would be a lot easier (and faster) to get a good finish on parts like that with a lathe, either CNC or manual. If a dull matte finish, rather than bright, is acceptable than you might try tumbling the mill-machined parts.

Mike

On edit: Using the Tormach as a lathe, as others here have shown, might also be a good solution.

[CadRhino]

Ok I got my parts better by tweaking feeds speeds an using 3-flute cutters.

Now I want to soften them a tad.

I picked up a harbor freight 18 pound vibratory, green pyramids and some fine 24 grit walnut.

I want to run these parts in walnut only for a day or two.
Should I run them dry or as a little soap and water to the walnut?

I could at some point add a little jewlers rouge too.

What do folks use.

Thanks
Nathan

Pyramids are quick. Walnut and corn in a simple tumbler do pretty well for me when smoothing over 6061 and 7075. They will not remove scallops, but surface marks tend to drop off quite well. Yes it does take 1-2 days, but I don't have to worry about dimensional changes when I leave my parts in and forget about them- thankfully. They do not remove burrs and you better plug any holes that you have tapped or plan on tapping!

[SCzEngrgGroup]

Walnut shells are only used dry. Wet they would turn into mush. The pyramids MUST be used wet, with a little non-sudsing soap. I use about a capful of SimpleGreen, with just enough water to keep everything wet.

Regards,
Ray L.

[CadRhino]

Thanks for the insight Ray. Mush would be bad.

Have you ever used any kind of (dry) jewlers ruge or polish with walnut or do you just use plane walnut?

Thanks
Nathan

Walnut shells are only used dry. Wet they would turn into mush. The pyramids MUST be used wet, with a little non-sudsing soap. I use about a capful of SimpleGreen, with just enough water to keep everything wet.

Regards,
Ray L.

[SCzEngrgGroup]

Yes, various abrasives, often rouge, are commonly used with walnut shells. The shells themselves won't do a whole lot. Keep in mind, walnut shells will only do a final high-gloss polish on already very smooth parts - they will not remove any measurable amount of material, so any scratches, burrs, etc. will not be removed, only polished. This will normally be the third (or more) step in the deburring/polishing process. Even then, they can take days to get the job done. If you're really after a mirror polish, you're almost certainly going to need an intermediate step between the pyramids and the walnuts, maybe two, usually using ceramic rods or balls, dry, with some fine abrasive.

For the pyramids, unless you're doing just a few parts at a time, you'll also need a flow-through drip-watering system, to keep the media from loading up with the fine gray paste that is produced by removing material. Without this, after about an hour, the media will simply stop working, and your parts will be covered with a gray residue that can be hard to remove if allowed to dry.

When I went through this about 5 years ago, I finally concluded the whole process was too slow, too messy, and too non-deterministic, and ended up contracting the finishing out to a metal polishing shop. It wasn't terribly expensive, and it took none of my time. They used rubber abrasive wheels to do the roughing, then hand finishing, and gave me a better result overall.

Regards,
Ray L.

[CadRhino]

Thanks for the insight ray

Yes, various abrasives, often rouge, are commonly used with walnut shells. The shells themselves won't do a whole lot. Keep in mind, walnut shells will only do a final high-gloss polish on already very smooth parts - they will not remove any measurable amount of material, so any scratches, burrs, etc. will not be removed, only polished. This will normally be the third (or more) step in the deburring/polishing process. Even then, they can take days to get the job done. If you're really after a mirror polish, you're almost certainly going to need an intermediate step between the pyramids and the walnuts, maybe two, usually using ceramic rods or balls, dry, with some fine abrasive.

For the pyramids, unless you're doing just a few parts at a time, you'll also need a flow-through drip-watering system, to keep the media from loading up with the fine gray paste that is produced by removing material. Without this, after about an hour, the media will simply stop working, and your parts will be covered with a gray residue that can be hard to remove if allowed to dry.

When I went through this about 5 years ago, I finally concluded the whole process was too slow, too messy, and too non-deterministic, and ended up contracting the finishing out to a metal polishing shop. It wasn't terribly expensive, and it took none of my time. They used rubber abrasive wheels to do the roughing, then hand finishing, and gave me a better result overall.

Regards,
Ray L.

[MichaelHenry]

I would love to start using my mill as a lathe but since I am using the tts system (and atc) I think the best I could do is to put a 1/2" diameter into a 1/2" tool holder.
If I didn't have the atc and PDB I could put a r8 chuck in the spindle. Do you know if any alternates ways?
Thanks

You can still put an R8 chuck in the spindle, it will just be more hassle. That is more hassle than I want to put up with so the Slant Bed Lathe is probably in my future.

Mike

[CadRhino]

Really?
I thought I would have to take the whole PDB out to be able to chuck up a standard r8

You can still put an R8 chuck in the spindle, it will just be more hassle. That is more hassle than I want to put up with so the Slant Bed Lathe is probably in my future.

Mike

[MichaelHenry]

I thought it was doable, but that's not a confirmation and I'm not near my mill to check. Can you use wrenches to loosen the drawbar enough to remove the master collet and reverse the process for your non-TTS tooling?

Mike

[philbur]

1) Main cutting (on vertical sides) is a Tormach 1/4" HSS E.M. in an ER20 collet at 5100 RPM and 12 IPM.

That looks like a pretty long reach for a 1/4" cutter, try a 1/2" or better still a 3/4" carbide.

Phil

[Beezle]

I didn't review all of the suggestions above, but here are my thoughts.

1. Carbide cutters, always. I like Niagara's high end mills and always happy with results I get with Lakeshore Carbide's tools. The Niagaras are fairly expensive. Labelled on McMaster as "High-Performance Carbide End Mills for Aluminum." Huge difference vs. HSS.

2. Flutes. Always two. Though I have several 3 and 4 flute mills I tend to use for whatever else. Someone at Tormach suggested two flute mills for the best finish and that's what works best for me. Feed wise, I tend to take GWizard's advice, sometimes tweaked.

3. Coolant. I use a Fogbuster. I think it makes a difference vs. dry.

4. Tumbling. I do not go the same route I see other people use. I use rotary (barrel) tumblers.. For media, I use ceramic stuff sold by McMaster:

McMaster-Carr

Tumbler wise, I prefer tumblers made by Lortone, meant for rock tumbling. Their rubber drums are easier to open and close and have never leaked in 15 years of my using them.

I use water and a wee bit of surfactant (soap) and get very nice results on 6061 and 7075.

[CadRhino]

Let me know what you find out, Mike. I would love to try it on my machine.

I thought it was doable, but that's not a confirmation and I'm not near my mill to check. Can you use wrenches to loosen the drawbar enough to remove the master collet and reverse the process for your non-TTS tooling?

Mike

[CadRhino]

Hi Beezle

Thanks for the input.
Here is where I am at.
I tried a 3-flue 1/4" Carbide Aluma-Power EM I bought from Tormach and it had a better finish but one tooth chipped of after the second run (It just broke, never hit anything so I won't be buying another one of those).
So far the best luck I have been having is running Lake Shore Carbide 1/4" carbide 2-flute EM at 4000 RPM and 5 IPM in .005 (or less) steps. It takes a long time but the finish is much better.
I will try a 3/8" Lake Shore 2-flute to see if that is more rigid.
I have some walnut media and will try it. I don't want a sand-blasted look so I won't be using pyramids so I may end up hand buffing.
I am running KoolMist 77 coolant.
How do you like your fog buster? I was looking at those but a machinist I spoke with steared me away from it because he said it got fog into the air that one could breath and it left a light 'film' of coolant all over their shop.
Thanks,
Nathan

I didn't review all of the suggestions above, but here are my thoughts.

1. Carbide cutters, always. I like Niagara's high end mills and always happy with results I get with Lakeshore Carbide's tools. The Niagaras are fairly expensive. Labelled on McMaster as "High-Performance Carbide End Mills for Aluminum." Huge difference vs. HSS.

2. Flutes. Always two. Though I have several 3 and 4 flute mills I tend to use for whatever else. Someone at Tormach suggested two flute mills for the best finish and that's what works best for me. Feed wise, I tend to take GWizard's advice, sometimes tweaked.

3. Coolant. I use a Fogbuster. I think it makes a difference vs. dry.

4. Tumbling. I do not go the same route I see other people use. I use rotary (barrel) tumblers.. For media, I use ceramic stuff sold by McMaster:

McMaster-Carr

Tumbler wise, I prefer tumblers made by Lortone, meant for rock tumbling. Their rubber drums are easier to open and close and have never leaked in 15 years of my using them.

I use water and a wee bit of surfactant (soap) and get very nice results on 6061 and 7075.

[wtopace]

Hi Beezle

Thanks for the input.
Here is where I am at.
I tried a 3-flue 1/4" Carbide Aluma-Power EM I bought from Tormach and it had a better finish but one tooth chipped of after the second run (It just broke, never hit anything so I won't be buying another one of those).
So far the best luck I have been having is running Lake Shore Carbide 1/4" carbide 2-flute EM at 4000 RPM and 5 IPM in .005 (or less) steps. It takes a long time but the finish is much better.
I will try a 3/8" Lake Shore 2-flute to see if that is more rigid.
I have some walnut media and will try it. I don't want a sand-blasted look so I won't be using pyramids so I may end up hand buffing.
I am running KoolMist 77 coolant.
How do you like your fog buster? I was looking at those but a machinist I spoke with steared me away from it because he said it got fog into the air that one could breath and it left a light 'film' of coolant all over their shop.
Thanks,
Nathan

The FogBuster is named fog "buster" because it does not produce any fog, but instead puts relatively large droplets of coolant directly into to the air, whereas fog is created when the coolant atomizes into the air.

[CadRhino]

Oh, the fog buster wasn't protrayed to me that way. I will look into it more. I getting trouble with my coolant getting all over and the shear surface area of exposed coolant is either evaporating or misting to the extent that it is bothering my lungs a bit. I thought koolmist 77 was suppose to be benine but it isn't. Maybe that is why it crazes polycarbonate.
Do you know of any coolants that are less 'toxic' than even koolmist? I saw that Swift tools has a mist/fog system that they claim is the most non-toxic but it still must have anti-rust chemicals in it.
Best
Nathan

The FogBuster is named fog "buster" because it does not produce any fog, but instead puts relatively large droplets of coolant directly into to the air, whereas fog is created when the coolant atomizes into the air.

[Beezle]

I do not see anything build up from the Fogbuster other than the objects it is pointed at. Certainly nothing in the shop air. Even after running it all day.

I happen to have humidity gauges in my shop for other reasons and they show no sign of increased humidity after using the Fogbuster.

Hi Beezle

Thanks for the input.
Here is where I am at.
I tried a 3-flue 1/4" Carbide Aluma-Power EM I bought from Tormach and it had a better finish but one tooth chipped of after the second run (It just broke, never hit anything so I won't be buying another one of those).
So far the best luck I have been having is running Lake Shore Carbide 1/4" carbide 2-flute EM at 4000 RPM and 5 IPM in .005 (or less) steps. It takes a long time but the finish is much better.
I will try a 3/8" Lake Shore 2-flute to see if that is more rigid.
I have some walnut media and will try it. I don't want a sand-blasted look so I won't be using pyramids so I may end up hand buffing.
I am running KoolMist 77 coolant.
How do you like your fog buster? I was looking at those but a machinist I spoke with steared me away from it because he said it got fog into the air that one could breath and it left a light 'film' of coolant all over their shop.
Thanks,
Nathan

[CadRhino]

Here are some photos of a bracket part I am running with the Lake Shore Carbide 1/4" 2-Flute at 4000 rpm and 5 IPM and .003 DOC and Conventional milling.
It is pretty good except you see the first cuts have some weird cut lines (very hard to see) and the rest is pretty good.
This part took 45 min. to cut. Does that seem excessive for such a small part?
I like the finish but need to get the times down more.
Best,
Nathan

[bhurts]

I don't use a tormach. I still would think that part should take maybe 5 minutes or so worst case.

Ben