CNC Router/Mill

[Protronie]

Originally Posted by Hachiban VIII

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.

Anyone with a checkbook can order a ready made tool, or order a kit from the back of a magazine...

But be honest... when you look at your home made tools doing the same job if not better than the ready made... don't it give you a sense of pride knowing in was made by your own hands in the USA

Great job team!

-p

[aztech75]

FORGET HAAS!!!!!

You want a Fanuc Robodrill

You can get the robodrill mate for realy cheap. it dose all the things a regular robodrill dose, it just dosent have options that you don't need!!!!

[Pat Major]

The Patriot is a machine we have been considering; price, size and versatility attract us to this machine. http://www.shoptask.com/

[R.C.]

Ok, I like this post, a lot of info. We basically bought a lc series 3024. So we are in the process of setting up. Does the CNC using MasterCam, get drawings from Solidworks and start cutting or am I missing a really important step of how CNC machines work?

[Cory]

Originally Posted by rc_cola1323

Ok, I like this post, a lot of info. We basically bought a lc series 3024. So we are in the process of setting up. Does the CNC using MasterCam, get drawings from Solidworks and start cutting or am I missing a really important step of how CNC machines work?

Yes, but indirectly. the machine doesn't know how to do anything by itself. Nor does MasterCAM. You have to use MasterCAM or your CAM program of choice to choose how to machine features, with what tools, at what speeds and feeds/depth of cuts/etc, and then MasterCAM translates that into code which the machine understands (G-Code).

You need to have a strong knowledge of your CAM program, and a good knowledge of G-code as well. The CAM output is rarely perfect, and as such, your G-code will need to be hand tweaked accordingly.

It is not a simple process. I would recommend finding a local community college that teaches CNC classes and take some of them. There's a lot to learn, and a lot of ways to ruin your part, your machine, or both.

[waialua359]

MasterCAM offers a great educational rate.
We just ordered a couple licenses/keys for our router and mill at much less than the listed price.
I was also told that SolidWorks will also be offering software in the 2009 KOP by a rep. Cant confirm this, just what a rep in California told me last week.

[R.C.]

That would be so awesome, solidworks in the kit of parts. First just gets better and better

[comphappy]

You are talking cnc and tooling and our school is talking about what they are going to do without the teachers they laid off, its a shame.

[Lowfategg]

Hey question, its not quite CNC related, but I rather not start another thread.

I found a Bridgeport "M head" (round ram) milling machine for cheap. Does anyone know how well this mill will suite a FRC team? What should I look for before I buy it? Does anyone know of a good cheap source for DRO that would fit this mill?

And since its a CNC thread, how much is it to convert a Bridgeport to CNC?

Thanks.

[EricH]

Originally Posted by Lowfategg

Hey question, its not quite CNC related, but I rather not start another thread.

I found a Bridgeport "M head" (round ram) milling machine for cheap. Does anyone know how well this mill will suite a FRC team? What should I look for before I buy it? Does anyone know of a good cheap source for DRO that would fit this mill?

And since its a CNC thread, how much is it to convert a Bridgeport to CNC?

Thanks.

Well, I know that some teams have made key portions of robots on a similar machine. Some questions to ask are:
-What tools come with it? (Tools will be the most important part of the machine. Include collets.)
-Maintenance/cleaning
-Does it work? If not, why not?

If the answers are satisfactory, then go ahead.

Oh, one other thing: What size is it? (table travel, spindle travel)

[Lowfategg]

Originally Posted by EricH

Well, I know that some teams have made key portions of robots on a similar machine. Some questions to ask are:
-What tools come with it? (Tools will be the most important part of the machine. Include collets.)
-Maintenance/cleaning
-Does it work? If not, why not?

If the answers are satisfactory, then go ahead.

Oh, one other thing: What size is it? (table travel, spindle travel)

It has some tooling, collets and such.

Looks pretty clean, I still have to go inspect it myself, thats why I asked what should I look for.

Yes it works, and it has a 1 phase VFD as well.

I believe its a 9x32" (42"?), knee is probably 16", and around 3 1/2" of spindle travel.

[Cory]

The M head is really old. It does not accept R-8 collets, which are standard for almost all manual milling machines. It's maximum collet capacity is 0.5" without ordering special tooling. It also has a very weak motor (only 0.5 hp).

Have you seen the mill personally? It's likely been used very hard, due to it's age.

Some things to look for:

Rust. If there's any kind of heavy rust or pitting on the table or ways, avoid it like the plague.

Inspect the table. Is it in good condition? Have people drilled a million holes into it and cut slots through it? Is it flat? (You can check this with a dial indicator, assuming the head is square to the table)

Inspect the ways. They should look like this . This is clearly a very old machine, so they will likely not look nearly as nice as the machine in the picture. You can still check them to see if they're highly worn/pitted/etc.

Run the table to the limits of it's travel in all directions. It should move smoothly and freely throughout it's travel. If it gets drastically harder to move in certain spots, it has major problems.

Check the backlash. All manual mills will have backlash, but you want as little as possible. Our Bridgeport clone has about 0.005". I'd be afraid of anything with a lot more than that. The backlash should also always be a consistent amount. If it varies from movement to movement, the leadscrew and/or half nut are probably shot, which would be a major pain for you to repair.

If it's under power, turn it on, listen to it run. If it's making funny noises, the spindle bearings and/or motor are probably bad.

Ultimately I think it comes down to you either know what you're looking for and can evaluate a machine for it's worth, or you can't. It's very difficult to tell what condition a machine tool is in just by it's outward appearance. Often times previous owners will slap a coat of fresh paint on to cover rust or make a badly worn machine look new. Or they'll sand down the ways to remove rust, pitting, etc. Other machines will have been well cared for and just look old, but perform much better than the cleaner looking machine.

If the cost is substantial, and you don't really feel confident you can spot a lemon from a gem, I'd see if you could find a machinist to go with you and look at it, or avoid it entirely. If it's really cheap and you have the means to transport it, there's not much risk involved, even if it turns out to be a beater.

-Cory

P.S. I came across these articles awhile ago, and thought they were helpful. One is for mills one is for lathes, but the lathe article is relevant to buying any kind of used machinery lathe mill

[edit] I have read good things about this DRO system on some machining forums. If you're handy with electronics, I've also read good things about this DIY solution

[Lowfategg]

Thank you very much!

That pretty much answered everything, but two questions. Will the .5" taper be a major problem and will the 1/2 hp motor have problems making good cuts through the types of metals we will be cutting?

Its either this, finding another mill, or buying a cheap new china made bench top drill/mill. I am thinking that buying a cheaper new one is way worse then finding an older larger knee mill.

Oh by the way, if it is in good shape how much would you pay for it?

[artdutra04]

Originally Posted by Lowfategg

And since its a CNC thread, how much is it to convert a Bridgeport to CNC?

I don't mean to sound like a downer, but I've never heard of a flawless manual-to-CNC conversion of a milling machine. Unless you do CNC-conversions for a living, the vast majority (of even technically inclined people) will struggle and spend thousands and thousands of dollars, struggle for months and months (which might stretch to years...), and often end up with something that often needs a lot of "maintenance" to barely keep running.

Honestly, you'd be much better off buying quality tooling, vise(s), a rotary table, and DROs and leaving it as a manual machine. Quality tooling can be expensive, but don't waste money: don't buy the cheapest tooling and don't buy the most expensive tooling. Somewhere in the middle is generally good. As for vises, a good vise, like Kurt, can run you about $700 (but you can also buy cheaper ones in the $200-$400 range if you don't plan on doing any real heavy duty stuff), and a good rotary table can also be a bit expensive. A dual-axis DRO is generally about $1500-$2000. You don't need three-axis DROs, since the weight of the table often keeps the backlash on the Z-axis to a minimum, and tolerances of +/- 0.005 are easy to keep.

With quality DROs and a good machinist, you can easily machine gearbox plates with tight tolerances on a manual milling machine that work flawlessly on a FRC robot.

[Lowfategg]

Originally Posted by artdutra04

I don't mean to sound like a downer, but I've never heard of a flawless manual-to-CNC conversion of a milling machine. Unless you do CNC-conversions for a living, the vast majority (of even technically inclined people) will struggle and spend thousands and thousands of dollars, struggle for months and months (which might stretch to years...), and often end up with something that often needs a lot of "maintenance" to barely keep running.

Honestly, you'd be much better off buying quality tooling, vise(s), a rotary table, and DROs and leaving it as a manual machine. Quality tooling can be expensive, but don't waste money: don't buy the cheapest tooling and don't buy the most expensive tooling. Somewhere in the middle is generally good. As for vises, a good vise, like Kurt, can run you about $700 (but you can also buy cheaper ones in the $200-$400 range if you don't plan on doing any real heavy duty stuff), and a good rotary table can also be a bit expensive. A dual-axis DRO is generally about $1500-$2000. You don't need three-axis DROs, since the weight of the table often keeps the backlash on the Z-axis to a minimum, and tolerances of +/- 0.005 are easy to keep.

With quality DROs and a good machinist, you can easily machine gearbox plates with tight tolerances on a manual milling machine that work flawlessly on a FRC robot.

Thanks, I sort of expected that. Maybe after we are done with it I can do it for a fun project.