CNC decision paralysis - Probably Tormach

I view CNC machines as highly expendable -just like automobiles. Buy them, maintain them and get rid of them when they're worn out. Also, the way I see it there are two kinds of CNC machine... High-end pro stuff -and everything else. The high end pro stuff comes with ATCs; it's just a question of how large of a magazine you want to get. -And you won't find a high-end machine without position sensors and full closed-loop control... I thought about this and researched the market long and hard and looked at pre-canned "intermediate" machines -and I didn't see the value proposition when you stand them up to a pro-line machine.

The machine I have is not high-end. It's capable of a certain class of work and gets the job done with no frills. Putting an ATC on it would offer some convenience but, unless it also had DRO/position sensors, I would still check and adjust the Z after an auto tool change operation...


Ray
 
Putting an ATC on it would offer some convenience but, unless it also had DRO/position sensors, I would still check and adjust the Z after an auto tool change operation...


Ray[/QUOTE]


That’s the beauty of the TTS, If the ATC is set up correctly you shouldn't have to adjust it after a tool change. There are plenty of Tormach owners with the ATC that don't have repeat-ability problems.
 
~Re: CNC decision paralysis - Probably Tormach

So I've dug into this agian, for the N[SUP]th[/SUP] time. I located a reasonably priced Haas TM-1 and Mini Mill. They are both at the top of my budget. But I could swing the machine purchase. However, here's my situation. I live in a low/non-industrial area, so most of these machines are 1500-2000 miles away. So I'd need to add significant freight costs. My garage doors are 7' and ceiling is 8'. So the Z would need to be removed or modified to fit under the door and then reassembled, for many of these machines. Then the ceiling would need a little drywall work to fit the Z height.

I moved my Bridgeport inside a large Penske truck with a lift gate. This mill was 2500 lbs and was at the limit of the lift gate. These machines (at least the TM1) are significantly more than this. So that means the rental of a large fork truck (and the associated delivery and pick-up charges) or I'd need to hire riggers to unload and install the machine.

Then... None of the machines I found came with any tooling. So I'd need to purchase this. None of the machines came with CAM software (nor would I expect them to), so I'd need to purchase this also. So now the machines that fit into my budget, now exceed my budget by a factor of about 2x.

I also looked at older CNC machines for retrofit. I've always liked the Centroid units. These are available in ready-to-install prewired configurations with or without servos. This gets the old CNC machines in line with my budget. But again, Rigging, tooling and CAM software all some into play. So now these $5k obsolete CNC units, are over budget by about 1.2-1.5x.

I definitely see the niche that the PM, Tormach, IH and other machines fill. They may not be as capable, rigid, or fast as their big brothers, but one can get into a well tooled machine, with software, delivery and installation for a relatively small comparative budget.

This may not be all encompassing, as many great deals come along and if one is willing to take more risk, or resides nearer to larger machines, the options open a lot. For me, my situation and my location here's what I found.

For a budget of 0~$5K, a small retrofit is probably in order - lots of work, lots of tinkering
For a budget of $5k~$20K, a PM, Tormach, IH or similar machine may be the best choice
For a budget above $20k, a full size CNC machine options open (depending on a lot of other factors, of course).

Again, this may not fit everyone's situation, but seems to fit mine. I had a lot of PM's with many folks here, all of which were exceedingly friendly and helpful. So thanks to all for assisting my research.
 
09kevin said:
Putting an ATC on it would offer some convenience but, unless it also had DRO/position sensors, I would still check and adjust the Z after an auto tool change operation...


Ray


That’s the beauty of the TTS, If the ATC is set up correctly you shouldn't have to adjust it after a tool change. There are plenty of Tormach owners with the ATC that don't have repeat-ability problems.
Click to expand...

The real issue which applies to not only Z but, X, Y and A too, is that steppers used without position sensors are best effort. If the machine skips a step (or two, or three -or ten) the controller only knows how much it told the motors to turn -but doesn't know if they actually did it or not and therefore, actual position cannot be known.

You can put the odds of not skipping steps in your favor by not taking aggressive cuts and doing mostly hill climbs (which place less resistance against the motors). By not taking aggressive cuts then, you are slowing down the overall process.

On a system with a closed feedback loop, the controller issues instructions based on known positions and once a tool is properly zeroed, there's theoretically no need to re-zero the tool. Even at that, on many of the high-end machines cranking-out really precision parts, I've seen some re-zero the tool and go through a calibration process before doing the final finish passes.

So far, I've had good results by zeroing the tool then, using roughers to do the grunt work. Then I switch to a finish bit and re-zero the tool (X, Y and Z) and complete the finish passes. Also, I don't zero the tool on the part but rather, off a reference point (placed at a known distance from the part) that's coded into the CAM model.


Please don't misinterpret... I'm not saying anything bad about the machine you own as, I'm referring to all machines that aren't really high-end equipment -and that applies to my machine as well. I could put all kinds of fancy bells and whistles on my machine -and have fun and make a project out of it. -But in my opinion, it's tantamount to putting racing slicks on a bicycle.


Ray
 
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Well from a newbie perspective you have the wizards of the forum with some great info and advice. Me personally. I like the pm45 rongFu type platform. Parts and kits for about anything you wish are probably out there. Just a thought. Ray has a few other vids and a rather neat close up interview with his PM 45 mods. Check that out if you want to get close up to a shiny pm45?

When I was looking it was deemed a hobby. Something for my Son and I to do small stuff. So I did not buy the PM45CNC but I go to the site and stare on occasion (lol). I bought a used setup with a lot of extras for 50% of new.

I was also keen on IH. I wanted to show you this link with a comparison chart vs the Tormach http://charteroakautomation.com/our-products/cnc-bed-mill/#competitor_comparison

On either choice I do not think you will not go wrong here. Wish I were you right now! Enjoy the process and all the best on your purchase!
CG
 
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Re: CNC decision paralysis - Probably Tormach - Decision Made!

OK, so Decision made...

I came across a pretty good deal on a used Tormach. It's 5 months old and still under warranty. It came with 40, or so, ER-style tool holders, as well and set screw and other holders. It also came with many of the needed measuring devices, a touch probe and a NIB/unused 4th axis. It also came with 2 of the Glacern CNC vises, which were the exact model I was going to purchase anyway. One is unused. I ended-up paying about 65% of new price. I picked it up on the 3rd and made the slow 450 mile trek, at 55mph. It took 8 men and most of the morning, to get it loaded into my U-haul trailer. Oddly, it only took me and my two daughters 2 hours to get it out and on the shop floor. It's a little grimy, with coolant residue, but in great shape.

After getting it in the shop, my decision to get this machine, over a larger unit was confirmed. Even this small of a machine is fairly overwhelming in my 2-car garage that is already populated with 6 other machine tools. I wanted to say thanks to everyone for their posts and to others for their lengthy PM discussions. All the information was very helpful and was great to reference, during this decision process.

I'm embarrassed to take any photos now, as the shop is in total disarray. But I'll get some posted soon. Here's a quick shot of the machine & parts in the back of the trailer. They were very anxious to get me out of their hair, so Everything was loaded as it was. I'm in the process of cleaning-up everything currently.

[url=http://www.ericchesak.com/Galleries/CNC-/Tormach/i-xMTW53B/A]IMG_20140704_083114_769-M.jpg[/URL]

Everything was well strapped and padded, and made the trip without incident.

So now I have to get the software figured out - my weak point.

Thanks again for everyone's assistance,

Eric
 
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:applause: Yaaaay! A 10 year long decision comes to an end!

Enjoy...


Ray
 
Congratulations, that is a ridiculous deal. If those are the TTS er holders, than you are looking at close to $2k just in tooling :greenwithenvy:
 
Re: CNC decision paralysis - Probably Tormach - Decision Made!

Super deal! Keep us posted! Very happy to hear of your find.
 
Thanks folks. The ER holders are about 1/3 Tormach, and the other 2/3 are TTS compatible from a Canadian company (Darkon). They look to be VERY nice (they actually look nicer than the Tormach units). But I'll have to do some run out tests on the ER20 and ER32 holders.

I forgot to mention that it also came with an unused 3-Jaw chuck for the 4th Axis, and the Tension-compression tapping set, with extra collets. There's also a small box of ER20 collets that I've not sorted through yet.

The seller had a large plexi enclosure on it, but I'll probably make some changes here. He also misplaced some of sheet metal for the chip tray and the software, so I have to work through the details of getting copies of the software. But a few headaches are definitely worth the money saved.

Thanks again...

Eric
 
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