Joined: 2:49 PM - Oct 01, 2014

1:03 PM - Jun 12, 2018 #31

Dude, all machines break. Even our HAAS VF2 shit itself recently. It destroyed its spindle all on its own. Long story short however, HAAS covered the repairs under warranty despite it being out of warranty by over a year.
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Joined: 12:28 PM - Apr 15, 2003

3:16 PM - Jun 12, 2018 #32

Hmmm.. when it comes to CNC, anything I buy now has servos. The occasional brownout we get here has made that feature (the machine knowing where it was when it cut out) worth its cost many times over. 

Im just dealing with lasers on that, but I would kill for my printers (like the $30K flatbed) to know where they cut out at when connectivity was lost) to have the same abilities. IF I was running any machining centers instead of farming that stuff out, I would be all over it at just 2K more. I think over a year or 2, it would pay for itself. 

Although, entry prices and budgets are very real to me as well. Im looking at a 9K label printer right now. A freaking inkjet label machine... that can spit them out at 8 a second. It will be super helpful, and drop some costs, but thats a heavy investment. 
__
Designer / maker of Jeep gauges and assorted automotive bits and baubles.
TeamADW.com
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Joined: 2:02 PM - Jul 10, 2016

7:47 AM - Jun 19, 2018 #33

One of the things I have always liked about Doc's accounts of his machine refit/repair fits, is that he has never objected to upgrading something well beyond what the manufacturer considered worthwhile.  I find that admirable.

If the Tormach mill perhaps isn't as good as you consider worthwhile, wait.  You haven't seen yet what Doc's probably going to do to it.

I mean, its speed etc will probably never be up to the Haas, but a lot of those flaws you mentioned are fixable.

My relatively pathetic mini-mill came with a LOT of flaws, and I found ways to fix many of them.  Like, a real spindle motor instead of a router, and feedback channels from encoders on the ends of the screws, and filling the broad fiberglass tubes of the frame with epoxy putty, and reinforcing the gantry, and adding a tooltip sensor for setting the z-axis, etc.  I turned it into a much better machine than it was, although I know it'll never be in the same class as real machine tools.  But anyway, the point is that now the results of running it make me happy, and they didn't really when the mini-mill was new.

Doc is starting with something a lot more awesome than I did, and he's got the chops and the machinery already that he doesn't need to limit himself to the relatively minor kind of mods I made.  So don't assume that it's going to remain inadequate, in his hands.  At least, not inadequate to his needs.
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Joined: 11:31 PM - Oct 06, 2014

1:13 PM - Jun 19, 2018 #34

Snowtroll wrote: As a fat guy, I must say that there's no question. If not cheesecake, what else is the meaning of life?
Why, bacon, of course!!
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Joined: 12:00 AM - Jan 01, 1970

9:33 AM - Jun 28, 2018 #35

The CNCCookbook site recently had an article about mods and upgrades for the Tormach machines- stuff like improved coolant nozzles, an inexpensive "wine rack" style tool changer, a lever-actuated drawbar, bigger coolant reservoirs, and so on.

One of the bits, in context with part of the discussion in this thread, is from a fellow that systematically worked to improve his machines' surface finishes, eventually producing finishes almost identical to his Mori-Seiki.

It took some time and analysis, but he eventually chased it down to basically the same issue I was having with my Jet- namely, the pulleys and motor cooling fan needed to be balanced.

The resulting improvement cut his finish time in half, and the pics show very clean and smooth finished parts.

Some of the other mods are kind of a fun read as well.

Doc.
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Joined: 12:00 AM - Jan 01, 1970

9:30 AM - Aug 10, 2018 #36

Just a bit of an update: I was doing Friday's comic, and checking YouTube for something interesting to listen to. (Like this live version of Karnivool's We Are. 😁)

And one of the "also recommended" videos that popped up (I can't imagine why 😆 ) was this guy's issues with his Tormach.

Now, he's not the first guy I've run across that has had problems with one, but he is one of relatively few that said the company was basically rude and dismissive to him. Kinda wondering if anyone else has seen the same thing.

Hasn't really turned me off, though, I still plan to get one, although I'm still kinda waiting for them to release pricing on the "MX" series. ('Course, I also tend to wonder about this guy wanting to mill a solid 6" round, 4" thick block of steel on what's really just a glorified desktop mill, and I'd be curious as to what the actual problem with the apparently common backlash issues is.)

And you know the worst part about all this... There's a guy, here in the State, only about 250 miles away, with a HAAS VF-3, plugged in and hot, for $12,000. 😋

But, there's just a couple minor issues: One, it's a 1993 machine with a lot of hours, and a VF-3 is the size of a frikkin' bus. Okay, not really, but compared to, say, a Tormach 770, it's huge. Considering I'm going to have to do some serious jockeying just to fit the weeny little 770 in here, the only way I could jam a VF-3 in here is if I permanently occupied an entire car bay in the garage, which at the moment means I'd have to stack all the other machines. 😁

Doc.
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Joined: 2:02 PM - Jul 10, 2016

6:42 PM - Sep 10, 2018 #37

Thanx for posting the link to the page of Tormach mods on the CNCcookbook site.  I've been reviewing the designs of homemade toolchangers in particular. 

I've been properly run off by commercial tool changers that cost more than my mini-mill cost new, but I want a tool changer so I've been considering trying to build my own.  The thing I came up with, having the intent to use my current end mills, was  way simpler than anything I saw anybody building, so I wanted to explain the design and see if anybody here knows a good reason why this wouldn't be expected to work.

I was thinking of making a very simple tool rack, milled out of brass or bronze. I am limited in materials my little hobby mill can work with; steel is quite possible, but it's definitely a strain for my reinforced-but-still-wimpy gantry. I mostly make wooden things.  As far as I can see a simple changer for end mills that can all use the same collet potentially requires no moving parts.  And since a bunch of my end mills all have a 1/4 inch shaft, they all can use the same collet.

So I envision a simple block with a row of sockets precisely shaped to exactly fit my end mills leaving the shafts vertical, with a hole at the bottom of each (and possibly air from the vac system) to blow dust and chips out. I can't have crap in these sockets because the fit has to stay exact.  Bolted to that block, another block from which a flange goes over all the holes.  The flange would need to be about 1/4 inch thick, which is narrower than the length of shaft below the collet nut and above any greater-width portions of each end mill. 

Cut into the flange, a set of slots positioned so one slot goes directly over each socket. For the bottom 1/8 inch these slots exactly fit the exterior of the collet nut, and the top 1/8 inch has 45-degree relief on the top so that the top opening is 1/4 inch wider than the collet nut.  The idea there is that although there's a step to make the collet nut reasonably aligned before sticking it into the slot, it probably isn't exactly aligned. Thrusting it down from above (given that the XY position is correct) ought to be enough to turn the shaft slightly leaving it aligned.

One would use it by placing the spindle in a position where a small laser sensor is blocked except when the collet nut is aligned, turning the spindle slowly until the laser is unblocked, moving the spindle to put the shaft of the end mill in the slot where that tool belongs, then thrusting down in the Z axis to stick the tool into the socket and simultaneously catch the collet nut in the slot.  Release the collet by turning the spindle against the wrench, raise the spindle vertically leaving the tool in the socket (possibly with the assist of vacuum and/or a rare-earth magnet from below) then move to the socket containing the end mill you want and reverse the procedure. 

It's (reasonably) simple and has no moving parts, uses existing end mills, collets, and collet nuts, and just plain bolts onto one edge of the mill's working area.  The limitation is that all the mills have to have shafts that fit in the same collet and you can't use it with differently-shaped end mills than the ones it was made for.  These aren't much of a hardship for my setup, but definitely are a capability the "pro" changers have and this doesn't.

Does anybody see a good reason why this won't work, or should I just go ahead and build it and find out? 
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Joined: 8:17 PM - Sep 14, 2018

8:53 PM - Sep 14, 2018 #38

Lord [Redacted] wrote:
8:11 PM - Jun 08, 2018
Snowtroll wrote: As a fat guy, I must say that there's no question. If not cheesecake, what else is the meaning of life?
Bacon.

And sometimes cheese.   Way TOO MUCH cheese.
Bacon cheesecake?

Where did all this drool come from?

On another note, Doc, did you look into the backlash issue that many buyers of Tormach have complained about? It seems to stem from the use of a GiB in the ways, like a Bridgeport, rather than the typical linear rail setup used in most industrial CNC machines.
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Joined: 12:00 AM - Jan 01, 1970

9:49 PM - Sep 14, 2018 #39

I have yet to find anyone that can tell me, definitively, what the issue is. Most references I've been able to chase down just say something like "crappy screws" (IE, ballscrews) or "crappy bearings" (IE, where the screws attach to the table) or "a poor fit" (presumably the table ways to the saddle ways, etc.)

A few write ups describe having fixed it, and of course complaining about having to fix it and how long it took, etc., but almost no one (that I've run across, anyway) has done a full, detailed write-up of exactly what they found, how they determined it, and what they did to fix it.

I would be very interested in reading such a thing, if anyone knows of one.

But in any case, it can't simply be the fact it's a gibbed way- machines have been using those even in high accuracy situations for a hundred years. It could be a badly fitted gibbed way, or an incorrectly machined gibbed way, but just the fact that it IS, isn't going to cause backlash.

Doc.
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Joined: 8:17 PM - Sep 14, 2018

10:25 PM - Sep 14, 2018 #40

I think  Nerdly on youtube got into it, as they had bought a machine, and then returned it, as it wouldnt hold tolerances (i think he mentioned something like as bad as 7 or 8 thou off) You might want to go watch what he has to say about it.

Consideering that the harware at least is chinese made, a badly made/fitted gib is almost certainly a possibility, but then, Tormach is also using steppers, so theres also the possiblity that its missing steps is also a possiblity. The announced new MX series that uses servos and has a BT30 spindle is a step in the right direction, but at that level of cost, it makes more sense to just make the Jump to a new or used Haas Mini mill/enclosed toolroom mill, which is what im planning on doing, after looking at a tormach in person and being disapointed in the price vs performance of the machine, and then having the purchase of a VMX30 from my employer when they upgraded, fall through. That wierd straight shank setup they use with the tool changer in particular out me off, not particularly cheap, no positive retention, possible z issues, and single source availability..
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