Purchase dilemma - DT-2 +4th Vs VF2ss, and DWO?

Hi all,

We have decided we are buying a likely new Haas machine. Primarily we built one-off parts, fairly small around 4" cubed for now. Our main part has features on all 4 sides vertically, which the top and bottom features are critical in regards to being parallel and concentric. With typical vise or fixture I believe we can still get these within good reason, but we do have a 45* pocket. The rotary would reduce our setups from 5 to 2 or 3.

At the moment, we are mostly considering a DT-1 or -2 with an HRT160, with the rotary helping solve our feature alignment challenges. I see though we can get recent but used VF-2SS machines for about the same price, but the older software and unknown machine histories are always a worry.

New DT-2 with HRT160
Brand new machine with warranty, super quick, rotary helps address feature tolerances. Worried may miss having the 'full' machine.

Used (2015) VF-2SS with Rotary
Used without warranty, but 12k spindle, full power machine, dont see any future desire to upgrade. Lacks NextGen control, which I wouldnt mind having the alerts but no DWO support.

New VF-2SS without rotary
Same benefits of a new machine, but would have to do setups the old fashioned way. Does have potential to add rotary in future if we really hurt without it.

Objectively the DT-2+4th looks to be the best compromise. One cant help but wonder what the VF2SS could offer for the additional dollars in the long term.

With that said, my main confusion with buying an older machine, or a rotary at all, revolves around the whole DWO/TCPC thing and related costs. It appears the rotary can be used without it, but it is very tedious to do so. If the DWO ($5K option) and the rotary calibration tool ($500 option) are strong recommendations, plus the additional vise ($1000), this adds an additional $13k with rotary accounting for current sales discounts to the base price of the machine. Would disqualify the rotary as an option for us.

Aluminum is mostly all we cut. Airgun and chip auger are the only primary options we would add.

Thank you

Your post begs the obvious question. If:

1- You have parts that require critical accuracy AND
2- You've got enough volume in making them to require a chip conveyor...

Why are you too budget restrained to do what you should do and get a 5 axis trunnion?

Having said that, if the parts are index only, tool centerpoint control isn't really necessary. Programming off the centerline of rotation is easy enough (just be anal about rotary alignment and nailing it in your WCS). If you want to be dead-on accurate, probe an individual WCS point for each index. If you are exceptionally anal, in-process probe the workpiece on each index.

If only have the need for indexing and not simultaneous rotary cutting, you can do without DWO/TCPC option and use a macro. I've posted in the Haas section the macro I made and use every day.

However, if you need simultaneous cutting, TCPC is a nice option to have and can make programming and setup easier. Of course you could always program from centerline as well, not needing DWO/TCPC option.


If you're gonna go with the SS or DT machines, perhaps the faster HRC rotary would be a better match.

Before you think about the DT. Are your parts going to change at any point? The DT is fast but you are very limited on tool length stick out, and the gage length from the spindle nose to the table is too much. Our DT1 has a max tool length of 7", and it is 7" on the nuts. If you're longer you will break a tool or break a pocket. The gage length is something like 4" or 5". Basically too long to make working off the table a possibility.

Talk to your HFO and see if they have any demo machines they would be willing to part with. Usually they have all the bells and whistles and have been very well maintained.

gkoenig - I dont think the 5th axis would help us here since all of our work in this case, aside from roughing and corner rounding, revolves around one axis. We need or want the auger because the last thing I want to do is have to shop vac or shovel chips out by hand.
I figured it could be done without DWO as you mention but having to load the part in exactly centered would be a big pain, I guess if we load the stock in OK as first op It would be fine. Then we would just have to clean off the dovetail, making for 3 ops.

thesidetalker - Understood. I believe indexing is fine for now. Ill take a look at your macro - thank you!
I saw the HRC as well, only around $800 more. Was not sure if the additional speed really mattered for us, or if there are other benefits Ive yet to uncover.

AARONT - We do want to make other things, but nothing comes to mind that would require a tool longer than 7". Regarding gage length, if I understood this correctly we would need a riser to hold parts up off the table, or tools around 5" long to reach parts mounted to the table - is that correct?
I have met many times with my local HFO - they have been extremely good to us so far. Their only machines in house are a VF-4SS and UMC.

I do a lot of 4th axis parts on vf4ss and vf2ss and use a HRT210 on both ... I like the vf2ss machines a lot and there easy to work with , meaning you can reach in and get to the parts easy , the vf4ss can be a pain to work with in that you about have to jump inside the machine sometimes to get to the parts. but the only "BIG" upside to the vf4ss is the extra Z above the table ,, with the shorter distance from the top of the 4th axis parts to the tool changer pots I have had it throw chips up past the brushes and get on the tool tapers,,, never had that on the larger vf4ss.

I think the DT mills have even less distance in Z and I do not know if chips would be a problem with them of not but you might ask around about that .

The vf2ss machines are on sale still , I just got a new one a month ago and they have fixed the problems with the next gen control and well it was some relearning on my part after running the older control ,, I really like the new one , The only big change has been to the probing. The new 31 tool capacity and faster tool changer is nice and they even cleaned up the excel and decal so I run the machine at 100% with out jumping around ,, the older machines meaning 2015 and 2016 I run at 50% so they run smoother. The only thing I don`t like about the new machine is they went and changed the sheet metal around the control to some cheap brushed alum were they had nice looking stainless before .. then went and changed the nice chrome handles on the doors to brushed stainless that you cant keep clean.

I don't think I would by a DT or DM unless I had a steady diet of small parts. The VF2SS is one of the most versatile platforms out there. It's not exactly a slouch when it comes to speeds, and I would prefer to have the extra space if I was running a HRT160.

Glad to hear any recent updates are working well, it looks like the used 2015 vf2ss is gone already anyway. Went quick.

I am still debating the dt2 vs vf2ss (new). After a quote, with the rotary, the DT is still cheaper than the VF2 by about 3k. I am leaning towards the VF2SS with the thought that if we really need a rotary, we could always add it as an upgrade path. But if we get the DT and the size/travel/tool length becomes an issue, then we are screwed. The rotary should help us produce better parts for our expected use case. Hmm.

Scheduling an electrician to see if we can simply run a 3phase outlet or if we would have to use a phase converter. This will determine cost of electrical. If we need a phase converter, wed have to spend another grand or two to power the VF2.

In regards to the DT versus VF, the biggest *performance* difference is going to be spindle taper. Running a VF is going to be a much more capable machine when it comes to longer tools and tools with bigger diameter, or pretty much any type of roughing operation. As mentioned there's a strict gauge length restriction (on my 2017 DT it's actually more like 6.3" unless you remove part of the door guide which is where a longer tool will crash) but there's also a 2.0" diameter restriction caused by the toolchange arm.

Generally when I encounter this question, I recommend a general purpose machine to start then in the future you could elect for something more specialized to take up the slack in ways the general-purp has become a bottleneck. But it doesn't apply to everybody since there are tons workpieces that can be made on a BT30 machine without any trouble. So I can't make blanket statements either way (lol)

Don't get me wrong, a DT will outpace a VF any day of the week but their speed advantages come at the cost of power and work envelope. Running a 12krpm VF seems slow in comparison, escpeailly the chip-to-chip time which is muuuuuuch longer than a DT. However, the 12krpm Cat40 spindle can make cuts that are easily 10 times heavier than the comparative cut on a MM, TM, DT, or DM. If the machining bottleneck is going to be the small details, feedrate restricted by surface finish, fragile tool, or fragile workpiece...then a lightweight taper can be very effective and you will be happy. However, if the bottleneck is tool rigidity, spindle power, gauge length or Z-travel, or loading the machine with some heavy hardware...well you gotta get something beefier.

(owner of MM, DT, VF, VFSS, and way too many other Haas machines )

YdnaD makes a point about the DT being faster at tool changes and getting up to speed than the VF2ss . but a lot of that time can be saved with running lots of parts on the table ,,, I do about every thing in big fixtures and can get a lot of parts down to 10 to 30 seconds per part ,, even some pop can size parts I can do under 2 min ,, when you run 48 to 200 parts on the table and only have 5 or 6 tool changes in 45 min you save "VARY" little per part on a DT type machine and make up for it with a 40 taper..

A vertical mill has about 25% cut time on a good job and that means you can try and cut down on the 75% non cut time or waste a ton of time trying to save a little off the 25% cutting time ,,,

I run a large load of parts on the VF4ss and running at 50 percent rapids the job takes 1:42 min and at 100% rapids the job takes 1:39 min ... so even with double the tool change time and double the rapids I only see a 3% change in output ..

I've always programmed 4 ax parts to the center of rotation. The only reason you'd need to have your material exactly on center is if it's a second op or no excess material.
DWO would be nice if you just had money to blow.

Thank you for all of the input. We went a head and purchased a VF-2SS today! With WIPS, auger, air gun, and HSM.
Going to grab one of the new orange vises. Super excited!