material for a 510 connector.

[zoiDman]

If you don't mind letting the machine run for 4 hours and the Finish and DIMS are good, I don't see a problem.

So what is your Feed Rate in Inches per Minute? And what is your RPM's for that .0625 End Mill?

 

[Lance_Wallen]

I'm working in metrics, I was running about 150mm per minute, RPM... not sure, it's a variable dial on the motor so I don't get to set it exactly, basically I turned it low then turned it up until it started to chatter a little then backed it off until it smoothed out.

With a more rigid end mill (was using a relatively "long" cutter) I could most likely increase the feedrate up to ~250mm per minute and still get good cuts but I honestly don't like how much material its wasting and the fact that I could turn the part down on my lathe in 1/4 the time easily then just mill out the air channels manually, i sorta dropped the idea.

As for letting it run 4 hours, I don't mind but I can't let it run un-attended. it's a very simple machine, it doesn't have protection for the lead screws so I shopvac off the chips every couple of minutes just to keep it clean and keep the tool paths clear (and because I'm OCD and like to watch).

I'm moving to a new house in February and have a proper shop there, I'm going to build a vacuum system into the headstock when I get there. Figure the airflow will actually help cool the bit a little at the same time it cleans up the chips.

 

[zoiDman]

I'm working in metrics, I was running about 150mm per minute, RPM... not sure, it's a variable dial on the motor so I don't get to set it exactly, basically I turned it low then turned it up until it started to chatter a little then backed it off until it smoothed out.

With a more rigid end mill (was using a relatively "long" cutter) I could most likely increase the feedrate up to ~250mm per minute and still get good cuts but I honestly don't like how much material its wasting and the fact that I could turn the part down on my lathe in 1/4 the time easily then just mill out the air channels manually, i sorta dropped the idea.

As for letting it run 4 hours, I don't mind but I can't let it run un-attended. it's a very simple machine, it doesn't have protection for the lead screws so I shopvac off the chips every couple of minutes just to keep it clean and keep the tool paths clear (and because I'm OCD and like to watch).

I'm moving to a new house in February and have a proper shop there, I'm going to build a vacuum system into the headstock when I get there. Figure the airflow will actually help cool the bit a little at the same time it cleans up the chips.

150mm per minute is about 6 Inches per Minute. That sounds Reasonable for RPM over 6,000 or so.


If you want to do it right, you might consider running a Spray Mist instead of a shop Vac.

What ever you do I would get those Ball Screws covered up ASAP. Chips in a Ball Screw is the 1st Sin of Machining.

 

[Lance_Wallen]

yeah, right now I'm mostly cutting wood and babysitting the thing with a shopvac. I don't have a way to deal with any liquids with this machine so any coolant is sorta out. But I won't be doing anything that really needs it. I was also considering a blower system that blows the chips and other debris to the corner of a box and having a shopvac on a timer that would randomly suck up everything that was in that corner

ultimately most of my jobs will run pretty fast and I like watching it or I can be working on something on the other bench while it's running and just pop over to clean up every couple of minutes. If I end up going into some sort of production mode where I have to run a lot of jobs i'll hopefully be making money at it and I'll just buy a big boy CNC with a proper coolant and cleaning system (and a bigger working envelope for nesting parts).

 

[zoiDman]

A Shop Vac for Cutting wood is a Great Set-Up. I have clamped the Vac Hose to the Spindle Head so it follows the cut around. Works well.

Cutting some metals Dry can be done. But your cutters don't last as long. Cutting something like Stainless without out coolant is kinda tough. Unless it is just some Quick-n-Dirty skim cut.

 

[Lance_Wallen]

yeah, I might do some copper, brass, aluminum... I won't be doing steel on this matchine.

 

[zoiDman]

Aluminum is fine to cut dry.

The problem with Copper and Brass is they can be "Gummy". It's not that they are Hard, its that the Chips want to stick to the Flutes of the Cutter when there is no Coolant.

Same with some Plastics.

 

[Lance_Wallen]

yeah, I noticed that a little bit with the brass yesterday. I put some tap lube on top of the part and it stopped.

I'm goign to be doing some delrin stuff in the near future which has me a little worried about melting but I figure delrin is relatively cheap so I'll just trial and error it a little. I think I should be able to cut delrin almost as fast as I cut wood so it shouldn't get too much localized heat build up.

 

[zoiDman]

yeah, I noticed that a little bit with the brass yesterday. I put some tap lube on top of the part and it stopped.

I'm goign to be doing some delrin stuff in the near future which has me a little worried about melting but I figure delrin is relatively cheap so I'll just trial and error it a little. I think I should be able to cut delrin almost as fast as I cut wood so it shouldn't get too much localized heat build up.

Plastic can be Tricky.

Some don't like Oils on them and some will simply turn to Mush with Some Tapping Fluids. Compressed Air or a Cold Gun sometimes is about the Only way to go.

BTW - Be careful when using Tapping Fluids. Some may contain Trichloroethane 1,1,1.

"Trike" is Bad News. It makes the Cancer Causing Chemicals in Analogs look like Mother's Mike. Wear Gloves an Eye Wear when Using Tapping Fluids.

 

[Switched]

yeah, right now I'm mostly cutting wood and babysitting the thing with a shopvac. I don't have a way to deal with any liquids with this machine so any coolant is sorta out. But I won't be doing anything that really needs it. I was also considering a blower system that blows the chips and other debris to the corner of a box and having a shopvac on a timer that would randomly suck up everything that was in that corner

ultimately most of my jobs will run pretty fast and I like watching it or I can be working on something on the other bench while it's running and just pop over to clean up every couple of minutes. If I end up going into some sort of production mode where I have to run a lot of jobs i'll hopefully be making money at it and I'll just buy a big boy CNC with a proper coolant and cleaning system (and a bigger working envelope for nesting parts).

CNC without cooling is just asking for trouble. How long have you been machining?

How many do dads can you fabricate in an hour? There is no way a human can compete with a CNC, that is why they are there = mass production!

 

[Switched]

Aluminum is fine to cut dry.

The problem with Copper and Brass is they can be "Gummy". It's not that they are Hard, its that the Chips want to stick to the Flutes of the Cutter when there is no Coolant.

Same with some Plastics.

... same as aluminium!

 

[Lance_Wallen]

CNC without cooling is just asking for trouble. How long have you been machining?

How many do dads can you fabricate in an hour? There is no way a human can compete with a CNC, that is why they are there = mass production!

It's not that I'm faster than the CNC machine so to speak but that the specific thing I'm making would go faster with me doing it on my lathe and then machining out the slots as opposed to carving the whole thing out of a block of brass.

A CNC lathe would do it even faster I just don't have one. just a function of wrong tool for the job really and my lack of experience didn't let me figure that out before I went into it. Also, regarding CNCing without coolant, given the material it's not that big a deal. You can go faster and deeper with coolant but it's not an option on my set up. I've been talking off and on with the head machinest at the company that makes my mill and getting tips off and on, it's pretty common to do brass, aluminum, copper, other soft metals on this thing without coolant, you just can't run it at the max speed.

 

[zoiDman]

... Also, regarding CNCing without coolant, given the material it's not that big a deal. You can go faster and deeper with coolant but it's not an option on my set up. I've been talking off and on with the head machinest at the company that makes my mill and getting tips off and on, it's pretty common to do brass, aluminum, copper, other soft metals on this thing without coolant, you just can't run it at the max speed.

The First Rule in a Machine Shop is you do the Best with what you have to work with.

If you don’t have Coolant, so be it. You get the job done without it. I have made 1,000’s of Cuts on a Bridgeport without coolant. It’s not that big of a deal.

Coolant does a couple of things for you. The big thing it does is Improve Surface Finish and Extend Tool Life. Yeah, you can cut Stainless without coolant. But you have to cut it So Slow you can’t make money doing it in a Shop Environment. And your cutting tools will dull quickly. Sometimes Very Quickly.

For someone like yourself, cutting slowly may not have such a huge downside. And how many cuts are you making? Tool life isn’t as important when your Drilling 1 Hole to make a part versus drilling 900 Holes per hour.

BTW - Are you using HSS or Carbide End Mills?

 

[Lance_Wallen]

I've got both, HSS for woods and plastics, carbide for metals. most of my HSS have that super long life tin coating crap. I've gotten most of them from McMaster.

 

[zoiDman]

I've got both, HSS for woods and plastics, carbide for metals. most of my HSS have that super long life tin coating crap. I've gotten most of them from McMaster.

The reason I ask is that Carbide can take more Heat / cuts than HSS before they get dull.

But one thing that is nice about HSS though is they will Flex. Carbide doesn’t Flex, they just break.

 

[Lance_Wallen]

well, my brass thread stock will be here tomorrow. I've got a party to go to tomorrow night but if it shows up early enough I'll try to whip up a connector an some drip wells/retainer nuts for it an see if I can dry fit it into the mod case.

 

[Switched]

It's not that I'm faster than the CNC machine so to speak but that the specific thing I'm making would go faster with me doing it on my lathe and then machining out the slots as opposed to carving the whole thing out of a block of brass.

A CNC lathe would do it even faster I just don't have one. just a function of wrong tool for the job really and my lack of experience didn't let me figure that out before I went into it. Also, regarding CNCing without coolant, given the material it's not that big a deal. You can go faster and deeper with coolant but it's not an option on my set up. I've been talking off and on with the head machinest at the company that makes my mill and getting tips off and on, it's pretty common to do brass, aluminum, copper, other soft metals on this thing without coolant, you just can't run it at the max speed.

Ahhh me bad I wasn't sure what you were/are using. I checked out Sherline now I have a better picture

 

[Lance_Wallen]

the sherline is fun, for the price it can't be beat. It's small, well built and functional for a hobbiest.. no one is gonna go deep production on em though.

I mean, long term I might end up making 'alot' of these mods so I'll figure out how to nest as many parts as possible in one job, etc but I have no illusions that I"m using a pro set up

Hey, maybe I'll be able to sell some of them to local tobacco shops and afford a big boy CNC, who knows

 

[zoiDman]

well, my brass thread stock will be here tomorrow. I've got a party to go to tomorrow night but if it shows up early enough I'll try to whip up a connector an some drip wells/retainer nuts for it an see if I can dry fit it into the mod case.

Be sure to take some pictures when you cut it. I’d like to see what it looks like when you’re down.

---

Speaking of End Mill Flex, here is a Good Example. I did this a couple of months ago.

This is what happens when you do a Quick Edit by hand to a C-Bore in the Code and Don’t lift the cutter High Enough between cuts. It did this with a ¾” HHS 2 Flute End Mill in Rapid. I was told it was Kinda Loud and the Opperator just about Crapped in his Pants.

It’s Bad Enough to Lose a Die after 36 Hours of Machining. But it’s a Double Whammy to Lose the Die AND break a $280 Carbide Cutter.

Since the Cutter was HSS, it could Flex enough to Not Break. There was enough HP on the Head to keep the Spindle from Stalling at 300 Inches per Minute.

Notice how I missed the Head of that 3/8” Cap Screw by .020” at the top of the Cutter Trench. Sometimes you get Lucky.

 

[Lance_Wallen]

well crap, apparently I checked the wrong tracking number. They broke my order up into two parts, one part made it today... the part I need with the brass in it isn't showing up until monday. So.. a weekend of possible production time lost ><