Re: CNC Router/Mill
 

Just having CNC equipment won't do you any good either.

You need an experienced operator who knows how to do setups and programming.

I started using a CNC mill about 4 years ago. I've been using one regularly for the last year or so. I've taken 5 classes, and I still barely know what I'm doing compared to a real machinist. I know experienced machinists who could take a drawing and do the setup/programming/cutting in 1/3 the time it would take me. Without a strong background in cnc programming, you're going to be wasting a lot of time making scrap, or nothing at all.

Re: CNC Router/Mill
 

That is why I am think a manual one is the best then try to get more advance parts made by either a sponsor or another team.

Re: CNC Router/Mill
 

If you have a manual milling machine, a rotary table, and digital readouts for all three X, Y, and Z axis', you can pretty much make anything you'd ever need in FRC. You may not get all the fancy lightening pockets that is possible with CNC, but you can still achieve tight tolerances and have fully functional parts.

Re: CNC Router/Mill
 

And you can still make most of those pockets, it'll just not be automatic.

Re: CNC Router/Mill
 

Team 116 bought one of the Industrial Hobbies mills last year. We bought the CNC upgrade kit this year, and are currently in the process of installing it. The mill is an absolute beast, and wonderful to work with. It is twice as heavy as the Rong-Fu RF-30 or RF-31 mills (or all the Rong-Fu clones that are out there from Grizzly, Enco, HF and others), and much sturdier. The square column is very stiff, and I could not find any measurable flex under heavy machining loads. The stiffer design helps with better surface finishes than we can typically get on the smaller mill-drill machine we have without a lot of extra work. Unlike the smaller mills (which can use 120-volt single phase), you will need 220-volt, 3-phase service for the I.H. mill. The 30" table travel envelope is larger than any other machines of a comparable size, and that has already proven to be useful. The I.H. mill uses standard R-8 tooling, so if you have already been collecting tooling for any of the typical mill-drill machines, it will transfer right over. Otherwise, you should plan to easily spent as much for tooling as you will for the mill. Having the head tilt option is one thing that we have not yet had the opportunity to take advantage of so far, but I have a few plans...

My only regret is that we waited for as long as we did to get the I.H. mill - I wish we had bitten the bullet and purchased it it at least five years earlier.

-dave

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Re: CNC Router/Mill
 

Or to put it another way, just because it's CNC doesn't mean it is better.

You can make absolutely outstanding parts with a manual mill, and you can turn out scrap with a CNC machine. And scrap is even more likely from a cheap CNC machine.

You can also learn more about machining from a manual mill.

There is no such thing as a cheap milling machine. Either you pay up front for good quality, or you pay after the fact in poor quality, frustrating setup & operation, and wear/damage.

If you have $40k for a nice Haas, go for it, you won't be disappointed. But if that gets cut to $10k (or $4k), go for a nice manual mill, used. There are used tool dealers all over who can help you find what you need and can afford.

Don

Re: CNC Router/Mill
 

Indeed, another thing people don't always realize is CNCs don't always make perfect parts the first time. Be sure to measure them after to verify all dimensions (especially bearing bores, as cutters can be undersize).

Re: CNC Router/Mill
 

We did the same thing last year. We used the CNC upgrade kit to retrofit a mill from Industrial Hobbies. Its a great mill and I would recommend it to anyone.

But I would NOT, under any circumstances, ever, recommend that anyone try and upgrade the mill themselves. Both the mechanical and electrical challenges we faced were extremely daunting, and we lost much of the accuracy the tool would have had had we left it in its original condition.

My father and an electrical technician (who mentors our team) spent all summer wiring the speed controllers and getting it running. Along the way we fried many components and broke a lot of stuff - not because we were incompetent, but because there was very little documentation on the process.

Add to that the fact that Industrial Hobbies changed hands and most of the technical assistance was temporarily lost :mad:

If you do chose to buy an Industrial Hobbies machine, buy one that is already built for CNC.

Re: CNC Router/Mill
 

Wow, thanks for the user feedback on the Industrial Hobbies machines guys! It sounds like the IH mills are a solid and accurate manual machine and are a much better buy for the money than any of the similar Enco, Grizzly, or even Rong-Fu machines. I get the feeling the jury is still out on the CNC retrofit though and wonder if the IH mill isn’t best left as a manual mill and not try to make it something it isn’t.

If you guys had it to do over again would you still go for the CNC retrofit or not? With the CNC retrofit installed is it still possible to use the mill manually or does the CNC retrofit kit pretty much remove all manual functionality?

Also, how was the “fit and finish” of the manual machine out of the crate? A lot of the import machines seem to suffer in this area. Was it pretty much ready to run out of the crate or was a total disassembly and cleaning to remove excess packing grease, etc. required? Were the ways straight and properly adjusted or did it require hours of frustrating adjustments to make the machine smooth and accurate? How about the tram?

Thanks again for the info guys!

Re: CNC Router/Mill
 

It wasn't that the CNC was bad it was that it was VERY difficult to install, and there was almost no instructions or info on how to do it. We would definitely go with the CNC again - we just wouldn't install it ourselves... (IH gives you the choice to buy it assembled or DIY)

The CNC retrofit replaces the big handles with itty-bitty ones that make manual milling very difficult. I worried that total CNC control would be difficult, but once I got used to it, it was supper easy. There's really no need for manual control with a computer hooked up :)

The IH mills are just cheap Chinese mills. They use ACME screws and are not ultra precision. Retrofitting the mill requires replacing the ACME screws with precision ball-screws, which are super accurate. This process is VERY difficult, but when done right it will transform the tool into a high quality machine.

Out of the box everything was smooth and nice. But of course, we had to take it apart to install the new screws - which required re-adjusting it...

Re: CNC Router/Mill
 

After hearing about manual mill CNC conversions, I'm curious... has anyone in Chief Delphi community built their own from parts/scratch?

We have a router table (6'x12') at work we built from scratch, but it isn't sturdy enough to handle metal cutting, just plastics and woods.

Hachiban VII: Do you have any pictures/videos of you guys installing the ball screws into that mill? I'm guessing you had to take the ways off of it and all... I guess you used an engine hoist or something? That's a ton of work to get your backlash down... :ahh:

Also, it sounds like some people just want a CNC mill to cut shapes, speedholes, etc. out that go all the way through. This past summer (so, the 2008 season being the first one we've used it in) we got one of the PlasmaCam machines out of the back of a Popular Science. It took us a while to get it all up and running, but now that it is... it makes nice parts REALLY fast (for example, it cut out all the brackets for our shooter in about 2 minutes).

We use a Hypertherm Powermax 1000 8.4kW hand torch with our plasma cutting table. The biggest stuff we've cut with it so far was 1/2" aluminum plate, which it cut at about 30 inches/minute. The only two things you have to worry about are 1) You have to wear a welding shield because of how brilliant the energy beam is 2) You need REALLY good ventilation. For us, we open the garage door and put a big Snap-On squirrel cage fan in the shop.

Pair that with a pipe bender, an all-in-one bench top break/shear/roll, a box of U-bolts, and your usual assortment of hand tools... you woudln't believe how much you can make and how fast you can make it. (The whole top of our robot (everything but the frame) was prototyped using these tools alone) :yikes:

If you want to know anything else just let me know... I could go on and on and on... :rolleyes:

-q

Re: CNC Router/Mill
 

No pics, but there used to be some on the IH website detailing the process.

As you said, we used an engine hoist to remove the ways. But that wasn't very hard for us. The hardest part was getting all the balls and greese and stuff packed in the bearings. We also had to drill and tap some holes in the mill to bolt stuff on - that's really hard to do with a hand drill :eek:

Come to think of it our team spends more time building tools than making robots :) We also built our own pipe bender from primitive equipment donated to us by a blacksmith.

Re: CNC Router/Mill
 

You seem to have had a much more difficult time with the CNC upgrade installation on the I.H. mill than we have been having. The manual is certainly not the most complete document that I have ever used. However, if you study it carefully (more on this in a moment), you can figure out most of the installation process. Where there were any questions, the folks at I.H. were very helpful and always seemed happy to talk with us on the phone and walk through any steps that were problematic. We were doing the installation right in the middle of the I.H. transition to new ownership, which I would have normally expected to cause a lot of problems. But they were still very responsive and able to get us all the answers we needed.

In our case, the ball screw installation was an operation that required some attention to detail, but it was nothing outrageous. With a little care and planning, one person was able to assemble each ball screw and install it in about an hour.

To do the CNC installation, you do have to completely disassemble the machine. And I do mean completely disassemble it - everything comes apart. You have to strip it down to the base castings. Most of the individual parts can be handled by one person. But you will definitely want at least two people to drop the Z-axis tower and move the X-Y table. A small hoist would be very helpful here if you have one, and is recommended. But if you don't have one handy, these parts can be persuaded to move where you want them to if you are very careful and don't try to rush the job (we used two "old guys" on the team, who managed to move the parts without spraining anything :) ). One lesson learned - as you disassemble the machine, take pictures of each step and each part you remove. These will be invaluable resources later as you put everything back together and are trying to remember exactly where those little copper shims went...

The only item that was an issue for us was that when you disassemble the I.H. mill for the CNC installation, you need to send the Z-axis carrier plate and clevis back to I.H. for some machining. We didn't read the manual as carefully as we thought the first time through (which was completely our fault) and did not realize this until we were half way through the CNC installation. We had to pause the installation process for several weeks while the parts were sent in and modified by I.H. Had we been paying attention up front, we could have avoided this delay in the installation.

I am not sure that I would volunteer to do it this way again - as noted, you can purchase the CNC upgrade pre-installed by I.H. and that may be the way to go for a lot of people. Our installation did take a while an required a lot of effort that might otherwise have gone into machining parts. But there is one irrefutable benefit that came from doing the installation ourselves - we now know that machine inside and out, and any problems that crop up are much, much easier to diagnose and repair than they would be otherwise.

-dave

Re: CNC Router/Mill
 

One of our engineers bought a like-new Tormach mill that has been good. He blew a stepper controller almost immediately, but he believes it was just defective. I believe Tormach's are pretty cheap as far as CNC's go, and the quality seems pretty well, but we've only been using it for a year.

They have packages, and I think ours is the "Complete PCNC Package," it cost $15,654.35.

Re: CNC Router/Mill
 

What did you do about wiring the speed contolers? The mechanical stuff was easy compared to the electrical wiring :rolleyes:

The motor they sent us was also not up to the task of raising the Z-axis (it drew crazy current). We had to buy a different motor on ebay and install it.

I looked at the new IH website. The manual looks a LOT better then the one we used. Perhaps the DIY has gotten easier.