[tlowe]

Hi Guy's.
I make engine parts for my small business and currently use a Step head Bridgeport with a Anilam 1000 DRO. The machine does everything I want but it is a slow process doing bolt patterns and such.
Much effort was done to make good jigging to speed up machining.

So I decided to get a 3 Axis CNC. Shopping around and studying, I decided to buy a USA assembled product to aid in future service. My budget was small, but my eyes got big seeing some of the prices on machines.
Settled on a 1999 Milltronics VKM4, it is a knee mill design and uses a Z slide to move the head assy and still can use the quill. CAT40 tooling. The controller is a Centurian 6. It is being shipped to me as this is written. Hope it travels well.

Will be picking your brains in the near future for tips and answers as there will be plenty of questions..


First question. I understand a CAD/CAM program is needed if I want to design parts. Is BOBCAD a good choice? I see it also comes with a postprocessor.

[moldcore]

Welcome aboard. I’ve never used it but BobCAD should be just fine for what you’re doing. Make sure it has a Centurion post included. I understand they will come down on the price considerably if you haggle with them. Feel free to ask about anything. Only dumb answers are frowned upon here.

[ZZZZ]

Welcome. What kind of automotive parts do you want to make?
Many 2 1/2d parts cam be programmed right in the control.

[tlowe]

Attachment 229914
I make parts for Chevy inline 6 cyl engines. Valve covers, side covers, intakes are among some of the parts. They are cast here in Iowa and I do the machining.
Attachment 229912

[sportybob]

Hi Tlowe, You will find the Milltronics control easy to operate and progame. ( Although the SLS manual leaves alot to be disired) The control has TONS of features that will help. one that you may be interested in is the direct import of DXF files. if you alraedy have a cad program you can export the tool path you want and import directly into the control during a conversational program. milling and drilling.
It is helpful to make drawings in layers and export just the layer you want to work with. ie all 3/8 holes in one layer, all 1/2 holes in another layer, top of part to be milled in another etc.

here is a link to the DXF file import http://milltronics.net/wp-content/th...mages/4491.pdf This link shows the 7200 control but this featues has been in all controls since software version ~ X.169
here is link to some other usefull "how to's" Milltronics: CNC Controls

Dont' have a cad program try this Delta Cad - World's easiest CAD program, CAD software it does about 95% of what Autocad does for ( free trial) or about $40 for the full version. I have used it for years.

Another tip: Any where you enter a numer you can use fractions or +,- *, and / on that line. ( 2*3+2-4*.5+5/8=2.625) No more " where did I put that ####'n calculator".

definition of a dumb question, The one you don't ask.
definition of a really dumb question, It's Friday, it's 5:00, hey Bob, are ya thirsty?


Welcome to the Miltro club.

Sportybob

[tlowe]

We got it to the shop! It traveled well going over 1 thousand miles enclosed in a trailer. The plastic was blown badly on the bad of the F450 from the dock site. Hope to fire it up this weekend.
This pic is when we pulled the truck out from under it. Was glad there was no Fred Flintstone moment .
Came with a nice assortment of tooling. Questioning what some of it is.
Attachment 230574 What is this?

[tlowe]

Here is is mostly cleaned up. Had all the kids out helping, they were not impressed by having to use a ladder to reach it all. Hope to wire it in this weekend.

What is this?
Attachment 230702
Attachment 230700

[vertcnc]

It looks like a stop to position parts on the same position repeatedly. The base gets mounted to the table and the end of the rod is positioned to touch the parts. So you can setup a second part in the same position as the first.

[tlowe]

Thanks, that makes total sense.

Ok, here we go with the machine questions.

It is a 3 phase machine and uses a VFD to control spindle speed. Called Milltronics today and discussed powering it with single phase. Wired the 240 to L1 and L3. Powered the unit up. All goes well.
I have homed it and did some drill programs. Table and z axis work great.

Next , how to turn on the spindle? This has a Cent 6 control. I don't see where to program the spindle speed. HELP!

[vertcnc]

Not sure on cent. Control but M3 is normally CW rotation and M4 is CCW. If there is somewhere to type in gcode then type Something like S1000 M3. Which would be CW. at 1000rpm

[tlowe]

Here are pics of the control .
Tried getting/ messing around to get the spindle running to no avail. I am sure it is a operator issue. Are there safeties in place that disable the spindle? I have a tool in, the spindle turns easily by hand, air pressure. It looks to be a standard 5 HP type motor and the speed is varied by the VFD. There are no errors.
When programming the drilling mode in MDI, I can setup anything in Drilling on the left side of screen, but do not see how to change the spindle settings on the right side of screen. There are buttons below for CW/CCW rotation. It does recognize if the Speed knob is turned, that knob is just a % of the programmed speed.
Attachment 230818Attachment 230820Attachment 230824

[sportybob]

Hi Tlowe, when you made you program if you did a "drill start" it will ask you to ender a spindle speed and direction. also if you do a MISC line you can enter a spindle speed directly. the format is Srpm Mx.. ie: s1000m3 would run the spindle CW at 1000rpm. (M3 =CW, M4=CCW) when it is running you can stop or change directions with the butons on the front panel.

Did you get the machine manuals with the machine? one manual with the electrical / mechanicals and another with the programming / operations. inside one of the manuals is a "parameter disk"
If you dont have one , MAKE ONE! insert a disk into the floppy drive, select programs, files, save. arrow down to where it says "parameters" and select. then save. If you have a problem and need to reload the parameters, with a disk it is 15sec, with out it is a long process of entering them in by hand.

sportybob

[Brian L]

F5 "MDI", then type in M3S1000, hit enter, then cycle start. When you first turn the machine on your speed commanded will be "0000" as you can see on the display. To turn the spindle on manually using the buttons, you have to first do the MDI process I detailed, then you can use the CW, Stop and CCW buttons to control the spindle manually. If you want to change speeds, you do it in MDI. Oh.... If you are in back gear, i.e. low range, you'll have to call a slower speed, I think 600 is tops in back gear. Better check that first, lever is on the right side of the head, up high.

[ZZZZ]

This is Milltronics SLS (Skill Level Select) control. As others have pointed out, you have to give it a spindle speed and a direction. You can do that in a Tool Change event or a Misc event in a conversational program, directly in a M and G code program, or in MDI (Manual Data Input). In MDI, choose the F9 - Misc option at the bottom of the list, enter the speed and direction, press enter to store the command, then Cycle Start to execute it.

Also, do yourself a favor and go to F10-Util, F10-Parms, F9-Ctrl and make sure you are in Skill Level 2. Skill Level 1 is really for 'brain dead' operators and it limits many of the programming and operating options available to you.

You have a good machine to learn CNC on, you will enjoy it.

[tlowe]

Thanks guy's! Went out tonight and did exactly that. MDI F9 key s1000 and saved. Cycle start and then the CW button. Zoom went the spindle, smooth as silk. Makes my old Bridgeport sound like a corn grinder.
ZZZZ, I also put it into level 2 as you said. Played with some of the programs. Very impressed.

SportyBOB,
I do have the electrical/ mechanical manual and a poor early CENT manual. It also has a setup disc. I did copy the disc onto my computer for safe keeping.

Went to backup the system and found out the floppy drive had been replaced physically but they did not get the right one to match the cable. Will need to get that corrected.

Also called Milltronics today, Troy was great. He emailed me a newer PDF Centurion 7 manual. It is very clear on how to set things up and will make it easier for me to learn. 450 pages.

I cant wait to get this running on one of my projects.

What type of motor does this use to drive the spindle? It is so quite and can be varied in RPM in a huge range with the knob on the console. From 10%-175% of selected RPM.

[sportybob]

Hi Tlowe, On the floppy drive, they did not get the wrong drive. your cable is missing an adaptor for the end of the cable. here is a pic of one type, just the 1st pic I ran across. 5.25 inch to 3.5 inch Cable Adapter ( seems expensive to me.) Once apon a time, there were 5.25" floppies, Then came 3.5" floppies, when you bought a new 3.5" floppy drive, It came with an adaptor to convert the 5.25" cable end to the 3.5" connector. When they quit supplying the adaptor with the drives, they changed the cable to have the 3.5" connector.
You can also get a new cable like 30 inch 34 Pin 3 5in IDC Floppy 2 Drive Ribbon Cable CablesOnline FF 330 | eBay you will need to cut off the end of the cable with the "5 twisted wires) and use just the section with the "straight thru" connections.
PM me if you need or want more info on the cables or ???

The motor is a 3 phase 5HP driven by a VFD ( variable frequency drive) That is what makes it "programmable"

Troy in Miltronics service, IS extreamly helpful and knowlagable.

Sportybob

[tlowe]

Ok, getting a cable from a old computer to hookup the drive.

Got to play with it this weekend. Read up a bunch from the SLS Centurion 7 manual that Troy sent over. Started her up and made my first program. It took a few tries to get things ironed out. But got a program made to machine the bolt pattern into my valve covers. Simple I know, but a welcome thing for my arms having to crank that old Bridgeport. I was just giddy.

Cleaned out the coolant sump, NASTY! Ran 3 fills of hot soapy water through it too. Much nicer now.

What should I use for coolant? I cut mainly aluminum and some steel. Also cast iron but use no coolant for that. Like to use a water based coolant. I know this machine is going to lay it on the floor and would like the coolant to evaporate from the floor. Which ones do not have bad effects on me or cause rust issues?

This machine ROCKS!

[Brian L]

I had fun cleaning years of sludge out of the bottom of my machine too. As for coolant, I didn't want to use flood, it's way too messy with an open machine, you pretty much have to live with floor dry on the floor all the time and then you track that everywhere. So instead I read up on MQL systems, minimum quantity lubrication is what that stands for, there are a bunch of commercial units out there, Unist, Acculube, Trico, and Fogbuster to name a few. I liked the simple design of the Fogbuster so I did some research and made my own home made version and put it together. I've been using it for a year plus now and it works pretty darn well. I've tried a couple different water soluble oils and have been using Trim Sol lately at about 5% mix and get no rust and minimum stickiness of the residue. Not sure if I can attach a pdf file, I created one describing how to make the unit and where to get all of the parts. I'll see if I can attach, if not, email me at blamb11 at cox dot net and I'll send you a copy.

[tlowe]

Brian,
That sounds like a good alternative for me. On the Bridgeport, I would just lube the area before machining or apply as needed. With this machine, I plan on walking away to get the next part.

Why are you using a water soluble oil?

[Brian L]

I'm using Trim Sol now, available from a lot of places, here is the web page for Enco:

Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies

I had started out with a product from Oak Industries, used to be called Valcool, it worked, but smells pretty strongly and did dry up pretty sticky on the machine and parts if you didn't get it wiped off completely. The Trim product smells better, seems to need less in the water mix, and doesn't dry up and get near as sticky. On aluminum parts it stays kind of oily if you don't get it all off and I can still wipe it off days later.

I just realized you asked why, not what.... well, the straight vegetable oil products that Unist and Acculube sell are like $60-$90 a gallon, and you use them straight, not mixed with water. I would probably use a gallon every 3 or 4 weeks... and while that isn't a real deal breaker, the Trim I use now is $25 a gallon (or less if you wait for a 30% off sale which is what I do with my way oil and coolants) and one gallon of it will make me something like 15-20 gallons of mixture. That will most likely last me closer to a year or more, so simple economics, whatever is cheaper and works, is what I tend to use.