DT-1 feedback

[Excelmachine]

Hi:
The place where I work at is thinking about getting a DT-1. I know these machines have been out for about a year now. So does any one have one that might be able to say how they like them? We are looking at possibly getting one with the high speed machining and probe option with extended memory. Anything else that might come in handy?
Thanks.

[Ydna]

I don't have one personally but I can say we've been toying with the idea of getting one for a while, to mainly help with some of our 4th axis work...looking for the right time to expand the shop right now. We have a lot of lathe parts that need little secondary operations done to them, which we currently do on a VF-2, but I'd just love to break up the workload and have the VF perform beefier tasks.

IMHO the high speed machining option is a must. Though I dislike how it's more expensive than it used to be. If we end up getting one of the DTs, we'll probably go full boar and get thru-spindle coolant with it so we can use the drilling and tapping (err threadmilling) abilities to their fullest. We've been outsourcing deep hole drilling which I have no problem doing if only I had a machine with TSC.

The general consensus seems to be that the 15,000-RPM spindle isn't very well suited for steel side-load machining so that's probably to be avoided as much as possible (though drilling is another story).

[Excelmachine]

Thanks for the feedback. We ended up ordering a VF1 with the 15k spindle and probe package. Should be here in the 3rd week of Jan.

[ToyMaker94566]

My DT-1 finally arrived just before Christmas. My service tech has been here all week setting up all the gadgets since the machine arrived with virtually no options. I got just about everything except for the TCS since I'm mostly machining plastics and don't really use speeds above 8k. But I did add the coolant filtration system, plastic is impossible to keep from plugging the coolant drains on the Haas. Even thou you already picked up a machine, I'll give more feedback once she's up and running.

[Donkey Hotey]

Originally Posted by Excelmachine Thanks for the feedback. We ended up ordering a VF1 with the 15k spindle and probe package. Should be here in the 3rd week of Jan.

I'm curious why you guys ordered the VF-1 instead of the VF-2? Same exact footprint with 10" more table and travel for not much more money. Also curious why you didn't go for the SS model. If you were considering a DT-1, the VF-2SS seems like the logical, alternate choice (high speed toolchanges, fast rapids and spindle speeds).

[ToyMaker94566]

Originally Posted by Donkey Hotey I'm curious why you guys ordered the VF-1 instead of the VF-2? Same exact footprint with 10" more table and travel for not much more money. Also curious why you didn't go for the SS model. If you were considering a DT-1, the VF-2SS seems like the logical, alternate choice (high speed toolchanges, fast rapids and spindle speeds).

I actually sold my VF2SS to buy the DT-1. I will miss the table travel for sure but since I was mainly cutting tiny plastic parts, I never needed a 30hp spindle. As far as speed, the DT is twice as fast as my SS, the DT is smokin! One more point on the DT, the DT is a 30 taper as apposed to my SS which was a 40 taper.

This is the smallest part I ever made on my 30hp VF2SS.

Each hole is .003 of an inch in diameter.

[Ydna]

That's an impressive part! Do you get the level of positioning precision you require for things like that?

Myself I wonder the practical performance difference that might come with the coarser-pitch ballscrews that are used with Haas' SS machines (including the DT1, and the SMM's to a lesser extent or so I'm told). The other day I was trying to think of using a "standard pitch" machine like a VM-2 running with a spindle speeder for making some precise dumb little surfaced workpieces we have to produce sometimes. Theoretically better accuracy is appealing from an theoretical standpoint if nothing else...

[ToyMaker94566]

Originally Posted by Ydna That's an impressive part! Do you get the level of positioning precision you require for things like that? Myself I wonder the practical performance difference that might come with the coarser-pitch ballscrews that are used with Haas' SS machines (including the DT1, and the SMM's to a lesser extent or so I'm told). The other day I was trying to think of using a "standard pitch" machine like a VM-2 running with a spindle speeder for making some precise dumb little surfaced workpieces we have to produce sometimes. Theoretically better accuracy is appealing from an theoretical standpoint if nothing else...

Are the ball screws more coarse or are the drive motors simply faster? I suppose the readout scale makes a difference as well... My VF3 and 4 use a 40 amp breaker where both the SS and DT use a 100 amp breaker. In either case, positional tolerance is superb for my applications. To be honest, the only weak link is in the positional tolerance in my 4th axis. I literally have to program for what appears to be a backlash. But I have learned to overcome the issue. When you are drilling intersecting holes that are only .002 thousands in diameter, out of position by .0005 is a mismatch of 25%. I find the Haas machines quite repeatable once they’re warmed up.

BTW, are you a Toy Story 3 fan by any chance?

[Ydna]

LOL...I'm angered Pixar had the nerve to steal my moniker

I'm not sure of the hardware used on the new DT1 but my guess would be that they use both a higher speed servomotor plus a coarse pitch ballscrew too. I only assume that since Haas SS machines use max 3000-RPM servos and rapid at their 1400-IPM, quite a bit shy of the max rapid of the DT. If somebody definitively knows I'd love to hear!
FWIW I don't have a problem with the positional accuracy but I find myself pondering the situation of 3d surfacing @ 90,000 RPM whilst trying to keep 0.002 feed per tooth.

Question - are you using a rotary indexer that has a brake? The 5C closer rotaries don't (errr mine doesn't) but the "platter" rotaries do. We rarely do anything that has a tight rotary tolerance so I've never noticed. But I wonder if the brake clamp/unclamp changes the angular position by a teeny amount.

Interesting stuff...

[MKproto]

The 210HS table is alot faster and has much better positional tolereance, than the gear or harmonic drive tables. But the smaller you are and the closer on center, the less the error compound. The old horizontal I worked on had enough back lash that 9" out from the table center on the 4th you could be .002-.003" out just on a flat cut, adding th 5th in exsaserbated the problem, so we programmed it with backlash moves + 2 to 3 degrees, then - back in. We also added and incremental xyzab shift in each positional operation that could be independently shifted to hold high tru positional tolerances.

[Excelmachine]

Originally Posted by Donkey Hotey I'm curious why you guys ordered the VF-1 instead of the VF-2? Same exact footprint with 10" more table and travel for not much more money. Also curious why you didn't go for the SS model. If you were considering a DT-1, the VF-2SS seems like the logical, alternate choice (high speed toolchanges, fast rapids and spindle speeds).

Well, basically it all came down to overall price and features. We have a Haas HRT-210 which will work on the VF1 but wouldn't have worked on the DT-1. We mainly use the HRT-210 on our VF-3 but now we can use it on the VF-1 if needed, yes, I know it will be tight. I have been using a very well used/abused Excel PMC-10T24 for 6 years now that we bought used. I've been asking for a new machine for the last 2 years and this year we had some money left over at the end of the year. So they said we have this much money for the machining department so plan on getting as much as you can with that budget. A VF-2SS would have been nice and would have been over the allowed budget. If I had asked for that instead, I would have been shot down for another year and I didn't want to wait that long. All we do is prototyping, no production at all. So I am pretty sure the VF-1 will fulfill our needs.

[Donkey Hotey]

I was mostly curious about why you picked a VF-1 over a VF-2. It's a $4K difference but you get 50% more table/travel for that small price jump. In fact, I've always wondered why they bother keeping the VF-1 in the lineup at all.

With the presetter AND the HRT210 on the table, things will get really tight in 20" of X-travel.