New (to me) VMC

[forhire]

I've been working on converting my fixtures to the new mill. I needed to mount a 10" scroll chuck used to index castings. I've long wanted a keyed center similar to what I'd use on the rotary table. I started by drilling and boring the plug and then milled to fit the 5/8" table slots. I then decided to make a 12mm-1.75 T-nut. I have lots of nuts but nothing metric. The metric t-nut allows me to use the same wrench for everything on the setup. No reason to mix imperial and metric when possible.

[forhire]

After locating the chuck on the table with a casting it became very clear the chuck wrench was going to be a problem. After some thought I decided to use a 5" ratchet extension. This allows me to use a normal ratchet and gave lots of clearance. Started by removing the detent ball bearing and and rough shaped on the bench grinder. I then welded up the detent well and finished shaping on the belt sander. Quick and dirty chuck wrench.

[forhire]

Finally found some time to finish mounting the chuck. The t-slot width is such that I can't used the existing holes like I did on the Lagun. I was thinking I'd just use clamp straps but ran into clearance issues. So, I then drilled it, figuring I'd just bolt it down, but ran into more clearance issues. So I did it right and counter sunk everything. I'm loving my CAM software. I never used it much with the Lagun because it's memory was so limited. I finally have the post processor dialed in perfect, it make clean code. I few minutes in cad then a few more in cam is all it takes. It even calculates the feeds and speeds based on the material, although I must admit I'm not ready to entirely trust it. Some things are best tweaked by hand.

Now I need to pull some Ethernet so I can use my FTP server. The "sneaker net" using the USB dongle is driving me nuts as I have to reboot every time I remove/replace the drive. Maybe I can find a way to unload and reload the drivers without a reboot... but DOS is so limited in that aspect.

[el bob]

Tonight was the third time I looked at your scroll chuck index parts. I cant say why, but tonigt is the first time I actually understand it! Third time's the charm.

Good luck with the Ethernet run, sounds like you are getting close!

[forhire]

I've been in thread milling hell all day! After several false starts I finally wrapped my head around the G12/G13 method Bridgeport uses. Darn G2/G3 doesn't do helical interpolation the way I expected. Argh! It also doesn't support cutter comp! Running old junk will be my demise.

That said I can produce a 3/4-14 NPT in two lines of code... which is really cool... once I figured it out. The linear move with a radius call out stumped me for hours. The tool change takes longer than cutting the thread.

G01 R0.2660 I0. J0. A0. F40.
G13 A360. Z-0.8036

Anyone really familiar with this method? This is the snip-it from the manual:

G0(G1)R__I__J__A__Z__ (F__) ;Move to Helix Start Point
G12(G13)A__Z__F__ ;Do Helix

G1 is the G-Code for XYZ Linear Interpolation (Feed);
G12 is the G-Code for Helical Interpolation in a Clockwise Direction (CW);
G13 is the G-Code for Helical Interpolation in a CounterClockwise Direction (CCW);
A__ is Polar Angular Motion defined in terms of the total number of degrees of
helical travel (for G12 & G13 only). This is an “unsigned” incremental value;
Z__ is the absolute depth of travel;
F__ is the Feedrate;
R__ is the Arc Radius; and
I__, J__ are the X & Y distances (respectively).

I think I'll need to get some gages to check the parts coming off the machine. This is a low/no pressure application so provided it's close it will work. I've been working to port this program over and there are so many syntax differences it's making me crazy. The control on the Lagun (Centroid CNC4) allows me to omit a lot of stuff like arc end points on full circles and decimal points on whole values. The Bridgeport is much more strict.

[forhire]

Tonight was the third time I looked at your scroll chuck index parts. I cant say why, but tonight is the first time I actually understand it! Third time's the charm.

Good luck with the Ethernet run, sounds like you are getting close!

The chuck was originally for my rotary table. The center plug was designed to locate it concentric. Several years ago I welded an tang onto the #2 jaw that indexes the casting in a position that allows me to drill/tap for some pipe fittings. The center plug isn't really necessary but it certainly speeds up the squaring up of the #2 jaw. I've thought about doing this forever and decided I'd setup the new machine right.

I started hanging conduit this morning. I have about 30 feet yet to hang before I can pull cable.

What fascinates about your metal working abilities is how much you know about computers and software too. The stuff you talk about is way over my head, but what little I do get out of it is interesting.

Glad it's interesting. I learn new things every day.

[forhire]

Finally making chips!

9 minutes and 49 seconds! Not bad considering that includes the two new thread milling operations. I just re-wrote what I had to and pushed up the ipm in light on the higher speed spindle. I still need to optimize it a bunch. My goal today was to get it running, no excuses. On the old Lagun this operation took 38 minutes and I still had to tap the 3/4 and 3/8 bungs by hand.

I'm so happy. I can finally thread mill. No more tap ratchet. Yeah!

[flightrisk]

Is there a reason you are thread milling rather than tapping in the MC?

[forhire]

Is there a reason you are thread milling rather than tapping in the MC?

No reason specifically other than I already had the thread mills.

Rigid tapping can be expensive to tool up, especially for NPT. I'd have to get a CAT40 rigid tap holder, collet, and spiral tap, none of which are cheap. For this part I'd need two setups. Thread milling was way cheaper. It also doesn't use as much HP and is likely faster. I was very happy with the finish. I do a lot of rigid tapping on my Mori but I generally don't tap anything larger than 1/2". I have a nice straight shank head from the lathe that will likely see some action on the mill eventually. I think being able to mill threads on thin parts will be real nice. Just like the lathe, you can cut threads you'd never dream of tapping.

[killdozerd11]

Glad to see it working

[forhire]

Nice videos Tackit. Here's my video of the process.

I had to make a mount for the camera which didn't take long. Old junk mag base, an arm from another smaller mag base. Some misc. bolts and some silicon bronze. Quick and dirty using junk scrounged around the shop. Worked great except the plexi on the cnc is cloudy. I've been reading on the aquarium forums how to refurbish old plexi to make it crystal clean again. I might start with a spot in front of the camera.

I snapped a photo of the 3/4 NPT thread mill. Basically you drop into the hole and go around once and exit. Much faster than the single profile thread mill.

[Rog02]

I've been reading on the aquarium forums how to refurbish old plexi to make it crystal clean again. I might start with a spot in front of the camera.

Try some FLITZ polish for starters. I have quick cleaned aircraft wind screens with it and had good results. For more severe damage there are several product lines that offer products and methods ( i use Meguiers just because they were kind enough to come and give a demo at one of the helicopter owners gatherings). I guess you might want to check out one of the headlight cleaning kits that all the auto parts places sell these days as well.

TIP! Never use ammonia cleaners on plexi or lexan.

Nice job on the VMC. Looks like a productive piece of equipment.

[forhire]

Nice job on the VMC. Looks like a productive piece of equipment.

Thanks for the polishing advise. I need to order something and try it.

I finished hanging the EMT conduit and pulling the cat5 today. Went pretty smooth aside from the pesky RTL8139 chipset requires PNP to be enabled in the bios even though it is DOS. I suspect it has something to do with the fact it's a PCI chipset on an ISA SBC. All said the packet driver works and it didn't break anything.

I used mTCP http://www.brutman.com/mTCP/ which has a basic FTP client and some other tools. I also used the NTP client so I can synchronize the clock with my NTP server on bootup. Nifty. Here's a screen shot of the FTP working.

[forhire]

Decided to play around a little today. Chucked a piece of 6" aluminum scrap and designed something random in CAD. After that I spent most of the day messing with the CAM software and the machine. I found an extra long 4 flute 0.5" ball mill in my tool box. Not ideal, but it was all I had. I decided to give it a go. I wanted to see if I could produce clean code and just get some run time on the machine. Despite some poor finish due to chatter caused improper tooling and/or improper feeds, it was very successful. I was able to use the FTP transfer several times to load the programs. The finish paths were larger than the 256k memory in the control so I was able to DNC them off the hard drive. Easy as pie. Overall I feel much more comfortable on the machine and in using the CAM software. I've never done any 3D milling, my old Lagun was simply too limited. I'm really enjoying the new machine. Not sure I'm sold on the ball endmill idea. I think I'll program it up for proper tools and only use the ball mill for the corners. Lot more to learn.

[el bob]

Very cool! Very cool on multiple levels!

[forhire]

Very cool! Very cool on multiple levels!

Thanks.

I spent yesterday working with MecSoft support to get the post routines in AlibreCam sorted out for the thread milling operations. The G12/G13 use absolute values and it required some changes to the post processor and the model. After a few failed attempts I now can program the thread mill directly from CAM. I also sorted the tapping routine that wasn't generating the correct feed. All I have to do now is get a CAT40 holder for my rigid tap holder and I'll be in business tapping.

Tonight I finished up the Dave Strider turntables for my daughter by cutting down some old vinyl to 10". I honestly felt bad cutting the Def Leppard Pyromania album but she picked it up for 50 cents so I got over it. It was scratched anyway. Double sided tape to the rescue. Here's a few photos. Enjoy.

[ZTFab]

I honestly felt bad cutting the Def Leppard Pyromania album...

Blasphemy!!!

[forhire]

Mounting the rotary table on the VMC presented a few challenges. First I had to raise it at least a half inch so the castings can rotate when mounted. I had a 1" riser I made for another mill long ago... so I decided to modify it. Even with the riser I had to remove the handle to clear the table. Because the riser was keyed for 90 degrees to the table I started by milling a new slot down the middle. I The whipped out some ears to bolt it down from some scrap. The part was designed around the scrap. I then welded the ears on and gave the part a quick kiss with the flycutter to make sure it was flat. It didn't take long to mod and it was faster than making it from scratch. I can still use it on the other mill if required.

[killdozerd11]

Running a fly cutter in an enclosure ...That's a wonderful thing

Spacer looks great are you going to motorize the rotary table ?

[forhire]

Spacer looks great are you going to motorize the rotary table ?

Motorized would be sweet. These are castings and they always vary just enough that indexing off a feature is more reliable than counting degrees. It would take some ingenuity to automate it. Given time I may think of how to do it. For now I'll rotate, press the button, rotate, and repeat. The biggest advantage is I only have to fixture the part once to drill and tap. Previously, I've been drilling them all and then tapping them all. I'm trying to cut down on operations. Here's the thread that shows the indexing fixtures: http://weldingweb.com/vbb/showthread.php...r-rotary-table

[killdozerd11]

Never seen that thread...Very ingenious

[forhire]

I've been using the VMC quite a bit. I had to remove the rotary table and setup for another quick job. When I put the rotary table on the machine I had a friend help me. It was tricky as you have to clear the front cabinet and extend about a foot to the table. We put a board there and slid it on. It is now very clear why the Y axis covers were damaged. Removing it was out of the question. It weighs over 200 lbs at least... so I moved my gantry over to the mill and used it. All I had to do was make an extension cord. I even had a the parts on hand. As a result I've been gather the supply to put a crane at the mill. I think it will be something similar to this one over my lathe.
http://weldingweb.com/vbb/showthread.php...hanging-chucks

So I have a couple old chain falls but what I really wanted was an electric hoist. I like the Coffing hoist I use at the band saw. And the manual chainfall on the lathe is work. So as normal I was searching CL for 3 phase deals and stumbled across a guy in with a Yale for $75. No number so I emailed. No response for a week or more. Yesterday, he calls. It's old but works... and he'd throw in the trolley. SOLD! Today I picked it up. 1 ton hoist, 1 ton trolley, and all the cable. I couldn't even buy an import trolley for that price. It will have an easy life at the mill... nothing is ever more than a few hundred lbs.

Tonight I hooked it up. Works great. I was a little worried about the rope actuator but it works so slick. It even reverses at the top and bottom of the chain. It will work perfect. It only has 8' of chain so I may have to swap it out but I have some hoist chain someplace... I even found the manual online.

[Rog02]

$75???????????? Randy "YOU SUCK!"

What a deal!

Can't wait to see the jib boom you build for it.

[killdozerd11]

I agree with Rog

[forhire]

$75???????????? Randy "YOU SUCK!" What a deal! Can't wait to see the jib boom you build for it.

I agree with Rog

Thanks guys. I don't need a very long run on this crane. I found a 46" drop of W6x15 that I had planned to use but the trolley maxed out at 5" wide. No big deal I just took about 5/8" off each side. Nothing like hand written g-code for a quick job like this. This beam is major overkill for the application but I'm using what I had. Here's a couple photos if interested.