Getting Started - A Pathway into CNC Milling

[GregGleason]

Thanks Andrew for the info. How "turnkey" is the TAIG system, as in what else would I need to get?

[Tkamsker]

Hi,
ok thats funny because a part of the use of cnc is also doing mold. See picture attached thats what i do.
so i think any cad will do the job rhino also ok. I think your job can be done (depending if you have time constrains ) by any 3d software i do/did use cut3d, deskproto 5 pro because of the lathe i bought now bobcad but this may be an overkill for your tasks.
Have a look at the machine (i use the kit for doing pcb´s and have a toolchanger in it) USOVO.de - Proxxon MF70 CNC 2008 MF70CNC2008
so 800 Euros not that bad. But for my molds i use an Heiz 400T look at the machine aroud 2400 Euros. Sufficient for alu and all sorts of wood and plastic. 3D CNC Fräse 400er Serie -. When your mold should be done i alu i think the heiz is fine. I now have to build something in steel so i did buy an local turning lathe with an miller head. Here the ictures http://www.klippfeld.at/frame_de/dre...aschine=K-10B# so i think
it makes sense when you mill on your own ,..
but which machine and software combination is hard to say. i recommend an list what is important for you ,.. and weight it in verry important till nice to have then make the machines compareable in an kind of excel and then decide. Thats the way i did it by the heiz and the klippfeld. ,.. i see i cant post pictures i will do that in my area cu thomas

[awerby]

Thanks Andrew for the info. How "turnkey" is the TAIG system, as in what else would I need to get?

But you do need to provide it with a computer that has a parallel port and is capable of running Mach3. That means a 1.5ghz+ CPU, and about 1gb of RAM. Laptops generally won't work, and onboard graphics cards can cause problems. Aside from that, you get everything you need to get started along with the mill - it comes with a control box, cables, collets, a vise, even a couple of endmills.

All you need to do to assemble it is to fit the column onto the base and screw it in so it's perpendicular to the mill table, thread on the motormounts, and mount the motors with the little nylon tubes in the coupler holes (this provides a motion transfer that won't bind up or break off due to minor misalignment). Mount the spindle motor onto the vertical aluminum bar that comes up off the Z axis, using the 2 screws provided. Hook up the cables, install the supplied Mach3 software and the XML file that loads the right values for the mill, and you're ready to go. You'll need some lubrication oil (I like Vactra #2 Way Oil) and some safety glasses, then you're good to go.

Of course every project you launch into will probably require some special tooling. For that fin mold, for instance, you'd need some hold-downs or a fixturing plate, and probably some ball-end cutters. A chip brush is handy too...

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[Delw]

Let me answer the question of what I want to make.

Attached is a fin mold (which I made in Rhino, self-taught, after learning AutoCAD, self-taught), hopefully to be milled from 6061 some day.

This is a special fin profile that I engineered for a hobby rocket that I am in the process of making. The molds will be for a carbon fiber layup, with high-temperature epoxy at the edges to mitigate frictional atmospheric heating. These fins are supposed to perform well in the transonic region, and with the right motor maybe get to about Mach 1.4 at motor burnout. (BTW: there are some guys who get their rockets to fly at Mach 3+, so this isn't that big of a deal).

There are lot of custom items like this that exist theoretically, but you just cannot go out and buy them.

If I get a quote of $550 or so to mill these, I begin to think, why not get my own CNC milling station?

So, like a few RC flyers, the CNC hobby augments aspects of their hobby. I'm learning to get from where I am to get to the point where I have the finished product in my hand. All while managing job and home responsibilities. I hope this makes sense.

Anyway, I'm a Texan by birth and heritage. I don't intend to quit.

Greg

Oh man the rc racers are the worse for tolorance on there molds,I have made race plane molds. you rocket guys are just as bad LMAO.
the problem with most of these guys is they dont know what tolorance is or why its needed, in most of your applications I think you all over tolorance things. plus or minus .005 will be more than adiquet for what your doing.

A cheap mill like the taig? that was mentioned above should work fine.

with hand layed carbon fiber you will have more of a weigh distribution error to worry about than a worrying about one fin being off a few thousanths for directory pupose's ( hope you under stand that cause I worded it wrong).

for the mold you show and using a cheap machine its best to get ground alum plat or mic 6, however I have found that mic 6 doesnt polish as well as 6061. this will cause the resin to stick to the mold more, Yes even with a good releasing agent.
the reason I say buy ground plate is because cheap machines wont hold a dead nuts flat tolorance with a face mill and your mating surfaces will be off.
its very important that you have very flat stock, hand lap it and shim it if required.


As far as taig the one guy above said it was made in america, Good to know, Dont buy a chinese POS no mater what the cost

[Tkamsker]

Hi,
i now had a closer look to the taig seems to be ok.
Important no china made and you have local support of someone who can assit you if youre new to cnc ,..

I think you will need also some kind of handcontrol it seems to me that the machine is plain cnc with no handweels ,.
So there will be for convenience the need of handwheel i think but thats my private flafour
And i think you will need in the beginning a number of extra millers.
I learned it the hard way (because one of my pieces had an 45mm depth step in it so i had to get to extra swiss aluminium capable millers ,

because everytime my cooling went of the miller brake verry soon.
And this is boring if we talk about milling times of 12 Hours of an side of the mold,..

and about control software i dont know how "good" you about computers ,..
(i do that for more than 20 years ) if you have some it experience look at EMC2 control. Some millers got broken because of Mach3 and WIN-NC PC which i used in the beginning. They work ok for days and then (you know windows ,.. ) the do something odd but really nothing was changed i tried 5 different pc´s win200, xp and 2 different controlers.
So Windows is not an real time system so expect from time to time some odd to happen or ,..
happy milling
thomas

[GregGleason]

Oh man the rc racers are the worse for tolorance on there molds,I have made race plane molds. you rocket guys are just as bad LMAO.
the problem with most of these guys is they dont know what tolorance is or why its needed, in most of your applications I think you all over tolorance things. plus or minus .005 will be more than adiquet for what your doing.

A cheap mill like the taig? that was mentioned above should work fine.

with hand layed carbon fiber you will have more of a weigh distribution error to worry about than a worrying about one fin being off a few thousanths for directory pupose's ( hope you under stand that cause I worded it wrong).

for the mold you show and using a cheap machine its best to get ground alum plat or mic 6, however I have found that mic 6 doesnt polish as well as 6061. this will cause the resin to stick to the mold more, Yes even with a good releasing agent.
the reason I say buy ground plate is because cheap machines wont hold a dead nuts flat tolorance with a face mill and your mating surfaces will be off.
its very important that you have very flat stock, hand lap it and shim it if required.


As far as taig the one guy above said it was made in america, Good to know, Dont buy a chinese POS no mater what the cost

Ha! As you know rockets fly way faster than the planes the RC guys fly. But I believe you are right about the tolerances being at +/- 0.005 are close enough. The more important thing is that the fin is symmetrical with respect to the sides. If they are off, it's not such a big at slower speeds. More of an issue when they are getting to about Mach 0.8 or so. They can induce a lot of unwanted torque, and cause bad things to happen.

I intend to use 6061 for the mold.

Greg

[GregGleason]

But you do need to provide it with a computer that has a parallel port and is capable of running Mach3. That means a 1.5ghz+ CPU, and about 1gb of RAM. Laptops generally won't work, and onboard graphics cards can cause problems. Aside from that, you get everything you need to get started along with the mill - it comes with a control box, cables, collets, a vise, even a couple of endmills.

All you need to do to assemble it is to fit the column onto the base and screw it in so it's perpendicular to the mill table, thread on the motormounts, and mount the motors with the little nylon tubes in the coupler holes (this provides a motion transfer that won't bind up or break off due to minor misalignment). Mount the spindle motor onto the vertical aluminum bar that comes up off the Z axis, using the 2 screws provided. Hook up the cables, install the supplied Mach3 software and the XML file that loads the right values for the mill, and you're ready to go. You'll need some lubrication oil (I like Vactra #2 Way Oil) and some safety glasses, then you're good to go.

Of course every project you launch into will probably require some special tooling. For that fin mold, for instance, you'd need some hold-downs or a fixturing plate, and probably some ball-end cutters. A chip brush is handy too...

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

Thank you Andrew. That is very helpful information. Does this TAIG machine require much in the way of maintenance?

Greg

[awerby]

Thank you Andrew. That is very helpful information. Does this TAIG machine require much in the way of maintenance?

[Not really. You need to keep it lubed (I like those Zoom-Spout oilers with the long plastic tubes that can reach the slides and screws under the machine). And every so often you need to adjust the bronze nuts if you're concerned about minimizing backlash. If you're machining wood, you need to flush out the screws and slides once in a while, since the wood dust will combine with the oil to make a doughy paste which can gum up the works. But if you're cutting aluminum, just keep it oiled, keep the chips from accumulating, and you should be fine.

If you get a new one, it's advisable to run in the spindle gradually, giving it a few hours running slow, then another couple at medium speed, before running it at top speed for a while to break in the bearings. But once it's accustomed to running, it will keep going and going...]

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software