Next step, beyond Taig CNC?

[saturnnights]

I have a Taig CNC mill that I really like. I haven't yet run into limitations, but I can "feel" that there will be another new CNC mill in my near future. Anyway, I see a lot of discussion about the Industrial Hobbies mill and the Tormach. Those are about in my price range for an upgrade/step up from my Taig. Some of the things that I wonder about however, are these: The IH mill has a 6-speed gear head. How does this run as far as heating? I have a Harbor Fright mini-mill that I mess around with and it has a 2-speed gear head that gets pretty hot in high gear. My Taig can run all day, non-stop - really! That's what I'd need in my next mill. Secondly, with the Tormach - they say this on their website:

"Designed specifically for short run and prototyping applications, the PCNC 1100 addresses the needs of research, development, education, small business, and home shop machinists."

Okay, does "short run" mean that if I ran it all day, that would be too much?

I should elaborate a bit - I am making (primarily, right now), small molds out of brass and bronze - only a couple of inches (3-4 max) each. But I need to make one, take it out of the vise, clamp up a new piece of brass, start again - many hours at a time. I use small end mills - like 1/16" - 3/32" so I run at a nice, high rpm and only about 10ipm feed (average).

How will each of these machines handle all-day operation?

Thanks,
Mark

[Enraged]

why not use your current machine to build parts for a 2nd custom machine that is built to your exact needs?

[saturnnights]

Originally Posted by Enraged why not use your current machine to build parts for a 2nd custom machine that is built to your exact needs?

Because of the time that I'd waste doing so. Time is money and I believe that I could go bankrupt making my own machine rather than using that time to make and sell my product

Not that it wouldn't be a fun project for retirement....

Mark

[pstockley]

I have a Tormach but I can't give you much real world feedback just yet as it isn't running yet (finishing building a stand). The reason they say it is for short run production (small number of same type of part) is due to the limited speed by production machine standards. I think it should run for extended periods ok. One problem I see for your use of small cutters is that the spindle speed is really a limiting factor for increased production rates. You need 10,000 to 15,000 to efficiently run 16th to 1/4" cutters. You could fit an auxiliary high speed spindle for use on small cutters but this will increase the cost. A geared spindle really is unsuitable for high speed use.

[phil burman]

For your class of work ideally you should have spindle speeds in the range of 4000 to 10,000 rpm. The IH is way short of this and running the gearbox at high rpm all day long is not a good idea anyway. You could of course strap a high speed router/spindle on the side. The Tormach at least hits the bottom end at 4,200 rpm. I think the reference to “short runs etc” in the Tormach website refers the issue of setting up time verses actual machining time. There is no automatic tool changer and the rapids are not particularly fast. I don’t think it has anything to do with durability. For higher rpms on the Tormach you could change out the 3ph motor for a 2 pole and relatively easily install a higher rpm spindle. But I don’t think the spindle would be particularly cheap.

So anyway for you class of work the IH is really a none starter so if you have to pick between the two it is has to be the Tormach.

Regards
Phil

[saturnnights]

Originally Posted by pstockley I have a Tormach but I can't give you much real world feedback just yet as it isn't running yet (finishing building a stand). The reason they say it is for short run production (small number of same type of part) is due to the limited speed by production machine standards. I think it should run for extended periods ok. One problem I see for your use of small cutters is that the spindle speed is really a limiting factor for increased production rates. You need 10,000 to 15,000 to efficiently run 16th to 1/4" cutters. You could fit an auxiliary high speed spindle for use on small cutters but this will increase the cost. A geared spindle really is unsuitable for high speed use.

Hmmm... I run my Taig at 4,200 with my 1/16" cutters, but admittedly, I don't feed very fast. I wonder what other machines I should look at in the same price range/class as the Tormach to get faster spindle speeds?

Mark

[saturnnights]

Originally Posted by phil burman For your class of work ideally you should have spindle speeds in the range of 4000 to 10,000 rpm. The IH is way short of this and running the gearbox at high rpm all day long is not a good idea anyway. You could of course strap a high speed router/spindle on the side. The Tormach at least hits the bottom end at 4,200 rpm. I think the reference to “short runs etc” in the Tormach website refers the issue of setting up time verses actual machining time. There is no automatic tool changer and the rapids are not particularly fast. I don’t think it has anything to do with durability. For higher rpms on the Tormach you could change out the 3ph motor for a 2 pole and relatively easily install a higher rpm spindle. But I don’t think the spindle would be particularly cheap. So anyway for you class of work the IH is really a none starter so if you have to pick between the two it is has to be the Tormach. Regards Phil

If the Tormach hits 4,200, then I think I should look at something else? Any other suggestions? I liked the Tormach's price/quality. I'd like to stay in that same price range with my next mill...

Mark

[pstockley]

I'd want to run a 16th endmill at least at 10,000rpm. The problem you will have is finding a mill with the spindle speeds you really need. At the moment, the Taig may be your best bet. In commercial mills, things start to get real expensive with spindle speeds much above 4500rpm. I guess you could find a used higher spec bridgeport that runs to around 7000rpm and retrofit it with new CNC controls. Not too sure how much they go for.

Just to go back to basics, why do you feel an upgrade in mill is required?

1) increased production rates
2) larger capacity
3) greater accuracy

[acondit]

KDNTool shows a 45K spindle on a CNC retrofitted X2-minimill. You might contact them. They sell CNC retro kits as well as retrofitted machines ($2500 and up).

Alan

[phil burman]

Rumor has it that Tormach is in the process of offering two high speed spindle options. One is a low cost strap on die grinderr type and the other is a more expensive/quality/high power option. Here is what Greg Jackson replied to my query on the subject.
............
I've have to learn to keep quiet in those forums.

The high speed spindle option that will be released in the next few months is a combination of a high quality 20,000 RPM die grinder, an offset mount, and an adaptor to connect the two. We have not manufactured the adaptor yet, I'm waiting to see the production quality of the offset mount (aka: Universal Mounting Arm). The design is shown in one of the attached files. The price will be something around $200 USD for the die grinder and mounting components.

I have not made any official announcement because if I don't like the quality then the whole set of mounting arms will go into the trash and we'll start over with another manufacturer. I ordered a big bunch of them an they're somewhere in the Pacific Ocean right now, on the way to the USA.

This option will only be a 100 Watt spindle. That's plenty of power for some light engraving and prototype circuit board manufacturing.

We have ideas on a 1.5 hp high speed spindle but that's a much bigger project. There will be months of testing and evaluation. It could provide a 9000 RPM spindle but I'm not sure it will work. If it does, it will be a much more expensive option, with balanced components and high tech bearings. That is far in the future.
...............

I have a Tormach in delivery and have bought a 700W router with 10,000 to 30,000 rpm range to use as a strap on. I had a short window of opportunity and it was only USD 60 so I bought it. It will probably be OK for the odd bit of engraving but 8 hours a day 5 days a week is another matter. quality high speed spindles for continous use, which ever way you cut it, don't come cheap. However they will greatly improve your productivity/profitability. In your situation, for the present, Providing you can double your feeds I would look at keeping the Taig and fitting a good quality high speed spindle, this would double your production rate for the absolute minimum cost.

Also remember that the dynamic stiffness of your machine will increase with spindle speed. So finish will also improve noticeably.

Regards
Phil

Originally Posted by saturnnights If the Tormach hits 4,200, then I think I should look at something else? Any other suggestions? I liked the Tormach's price/quality. I'd like to stay in that same price range with my next mill... Mark

[BobWarfield]

If you haven't hit the limitations of the Taig, why not just buy a second one? You're trying to run a business there. It doubles your capacity, provides a back up if one machine goes down, and it will work with all the same tooling and processes you've developed around the first mill.

There is a reason Southwest Airlines is profitable and flies only 1 kind of airplane!

Best,

BW

[JeremyLee]

"Why buy one, when you can get two for twice the price?" - Contact

As Bob said, you get benefits from having two of whatever you depend on. If it's the spindle speed you care about, then you can probably experiment with removing the usual motor and spindle assembly (keep them as backups for the new one) and bolting on something else. The TAIG is nice that way.

Ever consider compressed air tools? I hear they can be surprisingly fast and powerful, and have inherent cooling.

Plus with two, you can use one as the coarse pass, and one as the fine pass, without the trouble of tool changing.