Beginner CNC Mill Comparison

[Andy A.]

Originally Posted by Akash Rastogi

Along with the 1100, I was thinking the 4th axis would be the best addition. Anything else you guys would suggest? Possibly a power drawbar as well.

I use the Tormach sourced 4th axis on my 1100. It works, and for what I do it works very well. However, it has some drawbacks.

For one, it takes up a lot of room in an already small work envelope. I'm making really tiny stuff, so that's not an issue for me, but keep in mind that the 1100 has 18" of X travel to start with, and the 4th gobbles up a bunch of that. In most setups it precludes the use of the ATC. It's also relatively slow; in my work it's usually the limiting factor in feeds/speeds. Set up/take down is a bit of a pain, as it weighs a ton and seeps oil, but you may find you have to do it frequently to make room for 'normal' work. You also have to think a bit about backlash- it's driven by a stepper, and a lot of direction reversals will start to accumulate some positioning error if you aren't careful to keep the backlash adjusted.

On the upside, it is a real deal 4th axis for not a huge amount of money, and you can purchase it any time after the mill. If you have a really good case for using it, go for it, but I doubt it'd be a reasonable return for a FIRST team. I bought it with a specific need and, half a year later or so, it's just starting to really pay for its self.

For school/FIRST use, the power drawbar would be a lot more useful. The ATC even more so. More tool holders and/or tooling is even better then either.

If you haven't already, check out Tormachs paper on the 1100's design decisions. I think they make a credible case for the machines size and capabilities, and it's nice to see a company publish this kind of in depth stuff.
http://www.tormach.com/engineering_pcnc1100.html

[scottandme]

The ATC on the Tormach seems like a waste - it's pricey compared to the overall cost of the machine, and FIRST teams generally have enough manpower on hand to hire a "student powered toolchanger". For the Haas it makes a lot more sense. The power draw bar on the Tormach is a necessary addition.

When you're looking, don't forget to consider freight/installation, space for the machine, power and air requirements, and money for tooling.

The Tormach is a 220V single phase 20A line. The Haas (TM-1P) needs a 50A line or a 208V 3 Phase @ 30A. The Haas also needs 4 SCFM @ 100psi, not sure if a drier is recommended or not.

The Tormach 1100, stand, and power draw bar ran us almost exactly 12k with freight (add another 2-3K for vises, tooling, misc). If money matters, I can't see justifying a TM-1P for triple the price, unless you're considering running production on the machine or something like that. The extra HP, spindle, rigidity, etc is nice - but it's not like we're cutting stainless in production where time is money. The table travel is really the biggest plus, but that really only comes into play for machining frame rails, or squeezing more parts on a fixture plate.

[rees2001]

I find myself in a similar position to the OP. I have been given the OK to put in for a new machine. We currently have the Prolight 1000 which is great for my CIM class but not a whole lot more than that. We also have an old Bridgeport with a ProtoTRACK Plus 2 axis mill which was donated to the school and has suited us well for the past 6 years. Unfortunately this past year the Y-reader and scale went bad and I have had a hard time finding someplace to repair it. (I will get it done before build season starts.) This has alerted the school that it is time to upgrade our shop. We do have limited funds to spend so the question I have is would I rather get the Tormach (or other similar machine) with all the bells & whistles or a stripped down HAAS, or something else, maybe a new 3 axis Bridgeport? We are a PLTW school so we have Inventor with EdgeCAM so software isn't the question. I have until the end of the month to put in a requisition. Any more insight would be appreciated.

[sanddrag]

One other selling point that may convince a school to go for the HAAS is the fact that it's fully enclosed and has safety interlocks. It's a much safer machine for a school environment where people are learning.

For whatever you get, make sure you have the power for it.

rees2001, I'd be interested in hearing more about your CIM class. It sounds interesting.

[rees2001]

Originally Posted by sanddrag

rees2001, I'd be interested in hearing more about your CIM class. It sounds interesting.

Straight from the PLTW Website:
Computer Integrated Manufacturing (CIM)
How are things made? What processes go into creating products? Is the process for making a water bottle the same as it is for a musical instrument? How do assembly lines work? How has automation changed the face of manufacturing? While students discover the answers to these questions, they’re learning about the history of manufacturing, robotics and automation, manufacturing processes, computer modeling, manufacturing equipment, and flexible manufacturing systems. This course is designed for 10th, 11th or 12th grade students

From my point of view? Kids get to work with programming VEX, draw in inventor so they can actually make stuff, write G&M code, use CAM software to take a 3-D model and make parts. It's fun to teach.

[Akash Rastogi]

After discussing with the lead teacher, we are now fully considering holding off and purchasing a Haas TM1. Allocating funds to this seems to be the wiser investment.

Again, thanks for the feedback everyone.

[Mr. Mike]

Will this machine be used in a general shop class or will there be a CNC class?

[Akash Rastogi]

Originally Posted by Mr. Mike

Will this machine be used in a general shop class or will there be a CNC class?

This school has a full Robotics Engineering class focused around FIRST. The usage of the machine wil be taught by local college professors and machinists.

[Mr. Mike]

When choosing a machine tool be sure to look at the whole picture.
You have mentors that know the machine whom can set up, operate, and program.
If it is a G code machine like Haas you may also need programming software. These machine are very good for complex shapes or high volumes.
Conversational programmed like Hurco and Trak are programmed at the machine. They do not require an off line programming software but you do give up some control over the tool path.
Most conversational machines also include engraving in their software.
One other advantage Trak machines have is they can also be used as a manual machine.

[sportzkrazzy]

We bought a smithy machine last year, unfortunately it was delivered a couple of months after they said they would have it for us, aka right in the middle of build season. Granted they did give us some free tooling and a slight discount to try to compensate for this but the time was already lost. We had a small bench-top Light Machine that did alot that season but thankfully a couple of our sponsors and another local team (233 thanks Mike D.) chipped some machine time and helped us bust out some of the larger parts we needed.

During the off-season we have used it a lot on a prototype a drive train. Over all its a great machine for the price. It works well with Inventor if you purchase the InventorCAM, which is a major plus for us because that's what we do the majority of our work in. I like the cad to cam software a lot as it lets you set up your fixtures as part of the drawing and you can simulate everything before you actually make the part fairly easily. The program also so has really nice Imachining feature that keeps a constant bit pressure and allows it to be really aggressive with the machining. It has a few quirks in it that you will get used to. It defaults to the machine tool table over the one in InventorCAM so make sure they match. Physically its not bad for the price. Beds a nice size the only problem is that when flooding the part with coolant expect puddling to occur in the drip pan which means you need to add more once the process has started. It runs on Linux and support for the whole system is pretty nice. They pretty much get back to you the same day and the people seem pretty knowledgeable. If you connect it to the web they release updates pretty regularly. All in all I am pretty happy with it for the price minus the shipping issue. Once we worked out some of the quirks like which gcode post processor we needed to use its been a great machine and I think it will be a very valuable addition to our lab for this season. Obliviously this will not compete with some of the higher end machines but for the price its great and produce parts in a repeatable manor with except-able FRC tolerances, we have made a couple of gearboxes side-plates with it and they run pretty smooth. If you order it now Do not expect to use it this season as it wont get it in time. Use the off-season and prototype something that you have been wanting to and get used to the machine and by next build you will have a valuable addition to you lab as well.

With what ever machine you get I recommend getting a quick-change system for your tools. It will save you a lot of time once you get into it. That way you wont have to re-zero you machine on the z with every tool change if done right the tool table will compensate for the bit difference and size.

We have this set up and it works pretty well.
http://www.cncmasters.com/pdf/R8Tool_Pgs_90_91.pdf

If you have anymore questions, want pictures, or are going to be in town feel free to ask or pm me.

[Undertones]

While I can't speak as to the purchasing of the equipment we use (our major sponsor, SAIT, is the owner), I can say that learning CNC machining on high end machines is a ton of fun. Having almost no restrictions on what a team can build in-house is incredible. The higher-end machines and software are beneficial to the students in the long run as well, as the equipment they're familiar working on is essentially what they'd be using in industry, potentially later in life. So, if you have any possible way of affording it, HAAS machines with Solidworks and MasterCam works beautifully and is well worth the investment.

[nighterfighter]

For what it is worth-

1771 used the MicroKinetics mill.

We loved it, the only problems we really encountered was it had a smaller travel axis than we would have liked.

Although we didn't make super detailed parts, it served us well for various projects, both robotics and school projects.