[toneV8]

Fixittt: thanks for describe the process. Instead gold or silver can it be used to cast aluminium parts with small wall thickness 0.8-1mm.

[Monte]

my guess is that with all the corrosion ect. The contacts were so intermintant that it was causing resistance or something. With a probe you do not use a pull up resistor. It is wired straight to the printer (LPT) port. Unlike limit or home switches.

Great thread! Just cruised it, lots of work on the mill that looks like it's paid off.

Why don't you use a pullup resistor with a probe? Seems like it's the same as a limit or home switch. Can you point me to more info on that? I asked this question a couple different forums and the only reply I've gotten back so far says that a pullup resistor is used with a probe.

Monte

[Fixittt]

Monte,
Sorry it took so long to reply. Life has a way of interfering.
The probe was sent to me. It didnt work when I received it. I had to tear it apart and clean the contacts.

The probe is not wired in as a limit or home switch. It is wired into pin 15. So no pull up resistor is needed. For what I do the probe is a great value. Its nothing more then a digitizing probe but the ends were made so that it sits upright and has a small table top fo the tip of the tool to press on. Its the same inside.

[Fixittt]

More work has been done to the machine. My flex couplers, simple and effective as they were, well I was wearing out the delrin inserts in under a month. So I removed them. I went back to the ridgid coupler design. I installed thrust bearings between the couplers and the stepper motor shaft as the steppers had end play.

Also I picked up a small lcd panel from the flea market. Its a 12 volt power vtga unit that only supports 640x480. So playing with it. I was able to power the lcd from the mach3 pc`s power supply. My video card supports dual monitors so I still have my 17 in CRT monitor connected but set the resolution to 640x480 on the second monitor. I then proceeded to edit a screen set for mach taking out alot of the functions I never use. And I made the buttons a bit bigger to offset the size of the small screen. The lcd viewing area is 4.5 inches by 5.5 inches.
The machine was moved tot he corner of the bench to help with the wax chips that were covering the design computers keyboards and monitors. I have a small fan that blows the wax chips into the corner then use a shop vac to clean it up

Here are some pics.

[Dick Le.]

What are you using for 4 axis toolpath software?
Thanks for a great post with lots of info on the build !
regards,
Dick

[Fixittt]

i cut wax models for the jewelry industry, I use artcam for modeling and toolpath.

If I had to do it all over again, I would not have bought this machine...............

[Fixittt]

I have been working slowly to get a older minitech minimill up and running. I hae to say these machines are BUILT!!!!!!!!!
While I am saving my pennies for a 4 axis driver I was able to get my hands on a manual rotary indexer. My thoughts were to have the machine machine one side of the wax then manually rotate it 180 and do the backside. Well, I thought more and more about it and I didnt like that idea. So, here is what I came up with.

[rsa]

We had a MaxNC 15 CL in storage gathering dust at work after they bought a FADAL a few years back, so I offered the manager in the production area $100 for the MaxNC, and got myself a new toy. The computer that ran it had gotten lost (probably just as well), and the electronics were like something from Gilligan's Island. So I picked up a 3-axis board from "mechatronics" on ebay for another ~$65 and downloaded the free Linux EMC2 to run it. And it worked!

And I really like the EMC2 AXIS GUI because it shows you the toolpath ahead of time, and also while it is running, so that you can zoom in and/or spin the whole thing around in space to look at it from any angle, as if it were a solid model in Solidworks. So if anyone wants to go that route, and has any question on it, I could run out to the garage and try to remember whatever it was that made it work.

So far I've just engraved a few signs in wood and plastic with it, using another free download called DeskEngrave. This is actually pretty nice program, with about as many fonts as Windows has. And I figured out that I could engrave the back of a piece of clear plastic and read through the plastic from the front by editing the post with a couple of search and replace alls to switch all of the +y and -y's with each other. (Maybe that is an old trick that everyone knows about except me, but it was neat to see how you could mirror text like that.)

But the construction of the machine is flimsy in ways that range from obvious to ingenious, and basically any part of it that isn't changed for something better would become the new weakest link. So I'm trying to avoid going down that path and just use it for engraving or maybe circuit boards. The only other thing I did to the machine was to make an alternative spindle out of a Bosch Colt laminate trimmer mounted on a bracket. Usually I just turn this down to 16k rpm so it isn't as loud.

So basically I'm just playing around with this to become a little more familiar with CNC programming with some projects made for their entertainment value as much as anything else. For example, drilling a bunch of jagged holes through a piece of sheetmetal, arranged to spell someone's name on their very own cheese grater would make a really nice Christmas present for some of my friends! (My wife says this is silly, but you should see some of the things our friends have given us!) But I'm also hoping to find the time to make it into a small platform, for an EDM sinker, and experiment with that, since those cutting forces are not like actually milling steel.

Roy