Is UMC-750 that bad?

Redonion · Nov 18, 2019

I can get a slightly used 2019 model UMC-750 for a really good price and I don't know any one who owns one so I searched the web on UMC's and I am a bit puzzled

If I am correct Haas uses HRT-450 rotary for their B-Axis;

Haas also modified the original air actuated rotary brake boosters onb the B-Axis with a hydraulic power brakes, it seems like they even offered a retrofit kits for this upgrade;

https://www.haascnc.com/service/tro...aulic-power-brake---retrofit-kit---ad0440.pdf

A fellow user stated the accuracy of the machine as follows;

X Pos, ±0.0002” Rep. ±0.0001"
Y Pos, ±0.0002” Rep. ±0.0001"
Z Pos, ±0.0002” Rep. ±0.0001"
B Pos, ±15 arc-sec Re. 10 arc-sec
C Pos, ±15 arc-sec Rep. 10 arc-sec

Source

UMC-750 Applications Troubleshooting Guide

When Drilling From B90 C0 to B90 C180 The Holes Don't Line Up:

On a UMC-750, when using a drill from two sides of a part you can get up to 0.002 inch (0.051 mm) error per side.

This can add up to a total of 0.004 inch (0.102 mm) mismatch between the two drilled holes.

Use a probe to get separate offsets for the B90 C0 and B90 C180 side. This can reduce this mismatch error.

^ Are these "Accuracy Errors" and "Surface Finish Problems" worst case scenarios or common numbers for UMC-750? Since Haas tweaks-improves their machines, is there a change that 2019 model UMC-750 might be better?

Or are these error are caused by low resolution rotary scales and lack of scales on linear axes??

Strategies for solving UMC surface finish problems

Make sure the tooling is correct for the application. Gage length should be as short as possible. Use milling chucks or shrink-fit holders. If that's not possible use ER collets. Avoid Weldon shank holders. Endmill runout needs to be under 0.0005â€�. Balance all tools that turn 10,000rpm or more to grade G2.5 or better

Can I really improve accuracy, finish quality by tweaking the code and using milling chucks or shrink-fit holders and tweaking the code?

----

Further more they redesigned their rotaries with Cycloidal Rotary Drives on UMC-500 and UMC-1000 and I guess they are going to refresh UMC-750 soon.

	UMC-500	UMC-750	UMC-1000
B-Axis / Max Torque	1854 ft-lbf	400 ft-lbf	2240 ft-lbf
B-Axis / Brake Torque	900 ft-lbf	1800 ft-lbf	2000 ft-lbf
C-Axis / Max Torque	1854 ft-lbf	300 ft-lbf	1854 ft-lbf
C-Axis / Brake Torque	900 ft-lbf	500 ft-lbf	900 ft-lbf

UMC-750's cutting and rapid speeds are really far apart compared to other Haas machines [1200ipm vs 650ipm] UMC-750 moves like SS [1400ipm] and cuts as fast as regular VF [650 ipm].

Weirdly, UMC-750 and UMC-750SS's Feedrates are identically same on the Haas's website, I guess they might did an error on the website.

Any comment will be vastly appreciated.

My other alternative is a equivalently used and specd 3+2 DMG MORI CMX 50 U which costs %20 more, offer bigger table but smaller work envelop and comes with linear scales.

Mike1974 · Nov 18, 2019

I ran a UMC750 for a few years, you might have quoted me on the hole specs being out by up to .002" from opposite sides.

That is true, BUT easy to fix by probing a known feature / hole when rotating to other side of part. I didn't get to full 5 axis on it, but full 4th axis and speeds and finish were acceptable for us. Not silky smooth, but visually fine (was cosmetic, no Ra value needed).

I don't think you are right on the DMG having a bigger table... but maybe? Didn't see numbers for table size, just travel. I think the UMC table is 20" across the flats, they advertise a 27" swing ion the C axis, plus UMC750 is 40+1 tools, and DMG is 30(+1?)..

edit: I posted this before, but on the UMC750 table you can get 2 Kurt D688 (not sure of equivalent new part number) on the table and still do full 360deg rotation...

cameraman · Nov 18, 2019

Redonion said:
I can get a slightly used 2019 model UMC-750 for a really good price and I don't know any one who owns one so I searched the web on UMC's and I am a bit puzzled

If I am correct Haas uses HRT-450 rotary for their B-Axis;

View attachment 270357

Haas also modified the original air actuated rotary brake boosters onb the B-Axis with a hydraulic power brakes, it seems like they even offered a retrofit kits for this upgrade;

https://www.haascnc.com/service/tro...aulic-power-brake---retrofit-kit---ad0440.pdf

A fellow user stated the accuracy of the machine as follows;

UMC-750 Applications Troubleshooting Guide

^ Are these "Accuracy Errors" and "Surface Finish Problems" worst case scenarios or common numbers for UMC-750? Since Haas tweaks-improves their machines, is there a change that 2019 model UMC-750 might be better?

Or are these error are caused by low resolution rotary scales and lack of scales on linear axes??

Strategies for solving UMC surface finish problems

Can I really improve accuracy, finish quality by tweaking the code and using milling chucks or shrink-fit holders and tweaking the code?

----

Further more they redesigned their rotaries with Cycloidal Rotary Drives on UMC-500 and UMC-1000 and I guess they are going to refresh UMC-750 soon.

UMC-500 UMC-750 UMC-1000
B-Axis / Max Torque 1854 ft-lbf 400 ft-lbf 2240 ft-lbf
B-Axis / Brake Torque 900 ft-lbf 1800 ft-lbf 2000 ft-lbf
C-Axis / Max Torque 1854 ft-lbf 300 ft-lbf 1854 ft-lbf
C-Axis / Brake Torque 900 ft-lbf 500 ft-lbf 900 ft-lbf

UMC-750's cutting and rapid speeds are really far apart compared to other Haas machines [1200ipm vs 650ipm] UMC-750 moves like SS [1400ipm] and cuts as fast as regular VF [650 ipm].

Weirdly, UMC-750 and UMC-750SS's Feedrates are identically same on the Haas's website, I guess they might did an error on the website.

Any comment will be vastly appreciated.

My other alternative is a equivalently used and specd 3+2 DMG MORI CMX 50 U which costs %20 more, offer bigger table but smaller work envelop and comes with linear scales.

@redonion I think you laid that all out really well !

My local DMG Mori sales 'Peeps" are really good at what they do, actually almost better than anything else that DMG Mori currently offers in terms of "Excellence".

Usually part of a good sale's person's job is to appraise and temper the "prospect" of "Realistic expectations".

BUT on the other hand that "device" is also used to naturally upsell the client on something else (especially if they suspect they have more $ to burn).

Sometimes sales people will steer clients/ prospects AWAY from a particular product line because it's a bit of a disaster and causes more harm than good all round.

The pre-cursors to the CMX for being a 3+2 dumbed down version of the original DMU 50 (2nd gen) was real disaster. Mainly as lot of components and building of machines took place in CHINA. There was no equivalency component wise between the 5 axis universal "eco line" and the DMU 50 2nd gen.

^^^ Has anything changed since then with the newer CMX 5 axis universal 3+2 offering ? Does anyone / anybody know ?

________________________________________________________________________

@redonion for some applications a HAAS UMC 500 or even a 750 could be an excellent fit BUT entirely depends on what you are trying to do and application and production needs are as well as other equipment you might own as part of your "process" (set apart from job shop work). [Sim 5 axis -ish ].

Doosan have rolled out a couple of nice universals (not sure if that's in your budget or not ?). New.

____________________________________________________________

The cycloidal drives are more for taking a hammering and easy replacement not so much for improved accuracy other than being more torque resistant in-cut.

D Nelson · Nov 18, 2019

I think the new machines have scales in the rotarys now. We have a 1000 coming be here December 3rd
We will see how it looks shortly after
Don

Sent from my iPhone using Tapatalk Pro

cameraman · Nov 18, 2019

D Nelson said:
I think the new machines have scales in the rotarys now. We have a 1000 coming be here December 3rd
We will see how it looks shortly after
Don

Sent from my iPhone using Tapatalk Pro

The CMX 1100V 3 axis vertical was and seems a really good re-design and cure for a lot of older problems.

Locally "Peeps" that have plumped for that are very happy with them so far.

I'm not sure if the CMX U series CMX U 50 and CMX U 70 got the same redesign "treatment" from Mori Seiki (original) in Japan ?

The designer of the Dura verticals was the guy that reworked things to derive the CMX 1100V … (at least that is what published / claimed.).

Seems the CMX and DMU 50 2nd gen and 3rd would be less dependent on the quality of their foundation + installation than a HAAS UMC 750

+ better thermal compensation for cmx U (spindle wise at least) ~ theoretically for what's on paper.

+ mineral casting.

_________ Original problems they had were bearing related (If memory serves me right ?) ____________

@redonion

taken from CMX U series brochure...

"current CMX U Positioning accuracy To ISO 10791 – 4 for X / Y / Z-axes (indirect / direct distance measurement system)
mm in

0.016mm / 0.006 mm | 0.0006 / 0.0002"
0.016mm / 0.006 mm | 0.0006 / 0.0002"

."

^^^ Added units some of that is volumetric accuracy vs. linear positional accuracy.

"To ISO 10791 – 4 for B- and C-axes (direct distance measurement system) arcseconds 16' 16' … "

^^^ I hope they mean direct angular measurements ?

Need to dig up the 10791 - 4 definitions but IF memory serves me right that 16 arc seconds with scales is a normal distribution curve (more or less) for +/- 8 arc seconds of uncertainty of positioning.

Bear in mind distance off the table relative to the bearing centers + rigidity / deflection under weight + compound errors on two axes B and C. But at least the scales should keep things somewhat in check.

The HAAS new cycloidal drives I thought were +/- 20 arc second

Mike1974 · Nov 19, 2019

I find it strange that the DMG has no end support on the trunnion. When Haas first came out with that design everyone screamed they were idiots. I wonder what the DMG is doing (or is thinking?) different that this no support isn't an issue... or maybe it is?

cameraman · Nov 19, 2019

Mike1974 said:
I find it strange that the DMG has no end support on the trunnion. When Haas first came out with that design everyone screamed they were idiots. I wonder what the DMG is doing (or is thinking?) different that this no support isn't an issue... or maybe it is?

That's a really excellent point.

When you have a "floating" bearing on the end of a knuckle style table*, that bearing is set to an assembly and part of the casting at the furthest extremity of the machine and usually where the "bed" casting such that it is very thin compared to the body casting of the "Bridge". So in the case of the HAAS UMC 750 and 500 etc. it's geometric alignment is very dependent on the quality of the installation and it's foundation. That was an initial problem with the MAZAK VCU 400 and 500 5 ax. I think the UMC 500 has a proportionately more rigid "Bed casting".

~ Whereas with the floating knuckle (no end support) it's alignment is 100% to the main bearing (B axis) that is set into the body of the machine (the monoblock) and is not affected by a mis-match / movement of machine and foundation. I believe the DMU 50 3rd gen is very substantially cantilevered, however I'm not sure that the CMX is cantilevered to such a degree + thickness of castings etc.

MAZAK have a few 5 axis machines that do have an end support on the far end of a driven table that is close to the operator's door. For example Variaxis J 600 (5ax) and has a cut-out that allows the operator to get much closer to the table so you don't have to lean into the machine with heavy fixtures etc. so the end support bearing is not obstructive to the operator.

In the case of HAAS UMC end support, they need that as the machine is not substantially cantilevered (i.e. behind the front wall of the bridge) - this end bearing also means the table can receive a real pounding + help dampen any vibrations from an overly long unsupported table.

It is true other MTBs like Doosan (Korea) and various Taiwanese builders like Feeler and Litz build universals with an end bearing support.

I don't know if HAAS were the first one's to come up with that ?

______________________________________________________________________________________________________________

* There is a substantial engineering challenge for very rigid machines to have a large ring bearing in a very solid mount and a distant second "floating bearing" at a distance (mechanically connected to each other by a rigid assembly), and to make them "agree " with each other without one interfering with the other. I think the partial give and flexibility of the HAAS UMC 750 helps that all to "gel" better.

Redonion · Nov 19, 2019

Mike1974 said:
That is true, BUT easy to fix by probing a known feature / hole when rotating to other side of part. I didn't get to full 5 axis on it, but full 4th axis and speeds and finish were acceptable for us. Not silky smooth, but visually fine (was cosmetic, no Ra value needed).

Thank you, I was planning to do something similar to what you were doing but I was not sure that it will fix the errors.

Do you have any opinion why these errors occur on parts when you move them from C0 to C180 @B90?

Is it because machine do not have linear scales and just drill a hole perpendicular to the floor just on the wrong location? OR is it because of the low resolution rotary scales or C axis brake which can bows or flexes the platter?

Dwell Marks During 5-Axis Machining:

On a UMC-750, the face of the platter can bow or flex up to 0.001 inch (0.025 mm) when the C Axis brake is engaged or released.

When doing simultaneous 5 axes machining, it is recommended to release the B and C axes brake ( M11, M13 ) before engaging the tool in the part.

Then engage the B and C axes brake ( M10, M12 ) when the simultaneous 5 axes machining has finished

Redonion · Nov 19, 2019

D Nelson said:
I think the new machines have scales in the rotarys now. We have a 1000 coming be here December 3rd
We will see how it looks shortly after
Don

This also puzzles me, when you try to configure a UMC-750 on Haas's website, it states that machine has rotary scales as standart;

Source

View attachment 270431

High-Res

UMC-500 and UMC-1000 might have a different approach to their B axis and they might come with better rotary scales but UMC-750 is running HRT450 for it's B axis and they HRT450's manual states that they come with rotary scales as well.

Maybe early UMC-750s was lacking rotary scales but I guess UMC-750 have rotary scales now.

Redonion · Nov 19, 2019

Mike1974 said:
I find it strange that the DMG has no end support on the trunnion. When Haas first came out with that design everyone screamed they were idiots. I wonder what the DMG is doing (or is thinking?) different that this no support isn't an issue... or maybe it is?

DMG's B axis seems much beefier compared to UMC-750's

View attachment 270418

High-Res

But DMG U50's rated table weight is much lower compared to UMC-750

	UMC-750	HRT-450	CMX U50	CMX U70
Max Table Load	300kg	386kg[Supported]	200kg	350kg
Table Diameter	ø500mm	NA	ø630x500mm	ø800x620mm
Max Torque

[td]
542 Nm
[/td]
[td]
542 Nm
[/td]
[td]
NA
[/td]
[td]
NA
[/td]

[tr]
[td]Brake Torque [/td]
[td]
2440 Nm
[/td]
[td]
1830 Nm
[/td]
[td]
NA
[/td]
[td]
NA
[/td]
[/tr]
[tr]
[td]Backlash [/td]
[td]
NA
[/td]
[td]
30 arc-sec
[/td]
[td]
NA
[/td]
[td]
NA
[/td]
[/tr]

BTW, I am planning to use this machine in a heat controlled room. Nothing fancy, just an air conditioner unit in a isolated room. I can also get a coolant chiller.

Will it improve accuracy and fix errors to an extend?

Mike1974 · Nov 19, 2019

cameraman said:
That's a really excellent point.

When you have a "floating" bearing on the end of a knuckle style table*, that bearing is set to an assembly and part of the casting at the furthest extremity of the machine and usually where the "bed" casting such that it is very thin compared to the body casting of the "Bridge". So in the case of the HAAS UMC 750 and 500 etc. it's geometric alignment is very dependent on the quality of the installation and it's foundation. That was an initial problem with the MAZAK VCU 400 and 500 5 ax. I think the UMC 500 has a proportionately more rigid "Bed casting".

~ Whereas with the floating knuckle (no end support) it's alignment is 100% to the main bearing (B axis) that is set into the body of the machine (the monoblock) and is not affected by a mis-match / movement of machine and foundation. I believe the DMU 50 3rd gen is very substantially cantilevered, however I'm not sure that the CMX is cantilevered to such a degree + thickness of castings etc.

MAZAK have a few 5 axis machines that do have an end support on the far end of a driven table that is close to the operator's door. For example Variaxis J 600 (5ax) and has a cut-out that allows the operator to get much closer to the table so you don't have to lean into the machine with heavy fixtures etc. so the end support bearing is not obstructive to the operator.

In the case of HAAS UMC end support, they need that as the machine is not substantially cantilevered (i.e. behind the front wall of the bridge) - this end bearing also means the table can receive a real pounding + help dampen any vibrations from an overly long unsupported table.

It is true other MTBs like Doosan (Korea) and various Taiwanese builders like Feeler and Litz build universals with an end bearing support.

I don't know if HAAS were the first one's to come up with that ?

______________________________________________________________________________________________________________

* There is a substantial engineering challenge for very rigid machines to have a large ring bearing in a very solid mount and a distant second "floating bearing" at a distance (mechanically connected to each other by a rigid assembly), and to make them "agree " with each other without one interfering with the other. I think the partial give and flexibility of the HAAS UMC 750 helps that all to "gel" better.

I can't swear to model number, other than it being a variaxis, but actually their trunnion is 90 deg from a Haas. So you actually have a large bearing on each side of the trunnion. Now, this was 2-3 years ago so not sure if there have been updates to that design or not.

Not the machine I am talking about, but the correct trunnion orientation.

cameraman · Nov 19, 2019

Mike1974 said:
I can't swear to model number, other than it being a variaxis, but actually their trunnion is 90 deg from a Haas. So you actually have a large bearing on each side of the trunnion. Now, this was 2-3 years ago so not sure if there have been updates to that design or not.

Not the machine I am talking about, but the correct trunnion orientation. View attachment 270432

That's right MAZAK have a larger number of machines that have trunions that are driven from one side and have a very substantial bearing assembly on the other side... That's kinda the same for a lot of machine that are not dual driven trunions "Tandem drive", like Hermle, DMG Mori DMU 60; I have trouble untangling which MAZAK models are dual driven or one sided. Matsuura MX 520 is side to side trunnion driven from one side, but the whole trunnion assembly moves in x with a ram style Y and Z over it.

Ergonomically the side to side trunnion like you have pictured here is sooooo much easier (especially if you have knackered your back) to get close to the table with straight back , you don't have to lean into the machine, but they are more "Spendy" for sure.

Mike1974 · Nov 19, 2019

cameraman said:
That's right MAZAK have a larger number of machines that have trunions that are driven from one side and have a very substantial bearing assembly on the other side... That's kinda the same for a lot of machine that are not dual driven trunions "Tandem drive", like Hermle, DMG Mori DMU 60; I have trouble untangling which MAZAK models are dual driven or one sided. Matsuura MX 520 is side to side trunnion driven from one side, but the whole trunnion assembly moves in x with a ram style Y and Z over it.

Ergonomically the side to side trunnion like you have pictured here is sooooo much easier (especially if you have knackered your back) to get close to the table with straight back , you don't have to lean into the machine, but they are more "Spendy" for sure.

Yes I can certainly attest to that! The cutout in the door/front for the variaxis is so simple, but pure genius from a setup and operate perspective. Definitely a back breaker on the Haas having to lean into the machine to load vises and fixtures.

cameraman · Nov 19, 2019

Redonion said:
DMG's B axis seems much beefier compared to UMC-750's

View attachment 270418

High-Res

But DMG U50's rated table weight is much lower compared to UMC-750

UMC-750
HRT-450
CMX U50
CMX U70
Max Table Load
300kg
386kg[Supported]
200kg
350kg
Table Diameter
ø500mm
NA
ø630x500mm
ø800x620mm
Max Torque

[td]
542 Nm
[/td]
[td]
542 Nm
[/td]
[td]
NA
[/td]
[td]
NA
[/td]

[tr]
[td]Brake Torque [/td]
[td]
2440 Nm
[/td]
[td]
1830 Nm
[/td]
[td]
NA
[/td]
[td]
NA
[/td]
[/tr]
[tr]
[td]Backlash [/td]
[td]
NA
[/td]
[td]
30 arc-sec
[/td]
[td]
NA
[/td]
[td]
NA
[/td]
[/tr]

BTW, I am planning to use this machine in a heat controlled room. Nothing fancy, just an air conditioner unit in a isolated room. I can also get a coolant chiller.

Will it improve accuracy and fix errors to an extend?

@redonion sorry couldn't make your attachment work / open ?

As far as I know there is no spindle chiller option for the HAAS machines but I believe there are "Peeps" here on PM forum that have a 3rd party 'hack" for that.

In general spindle growth (in Z) is a big deal. Really depends on your application and what kind of parts you are manufacturing.
However some machines do and try to make pretty reasonable thermal compensations using temperature sensors and the control , they have that mapped out (Mazak do that), Hermle C250 (no spindle chiller) but Heidenhain control tries to compensate.

Personally if you have a spindle running many hours a day then heat build up is significant and has to removed somehow...

It IS possible to thermally map the begeeezus out of a machine and process (without extensive thermal compensation, scales and chillers) but usually that is only successful if you are making only one part the same way day in day out and you are able to control climate adequately.

Also really depends how much hands on work you do at the machine gauging and comping versus letting the machine get on with it and leave unattended. I think thermal compensation is most important for unattended automation type situations or super long cycle-times like mold work + high tolerances.

The thing that's interesting with the DMG MORI machines with scales is that they have temperature sensors in the scales, so that means that the thermal expansion of the scales themselves is taken into account.

Some of the HAAS machines you can't have linear scales for 3d contour work but only for prismatic parts like on the HAAS VM(5).

___________________________________________________________

@redonion how extensive is your AC + insulation is like a couple of four ton units or something that hangs out a window, I am assuming industrial space-ish / building that you can maintain to +/- 4 degrees C ?

_________________

The DMU 50 3rd gen has much more extensive thermal compensation strategies built into it i.e. cooling of the bearings, ball screws and parts of the castings as it's a much faster than it's second gen predecessor and generates more heat at key points. I am assuming the CMX U is a much slower machine and does not have so much heat build up at these key points more like a DMU 50 2nd gen.

cameraman · Nov 19, 2019

@redonion I believe you can still buy the DMU 50 2nd gen... New.

I don't know what they run for these days...

Not as beefy or fast as the 3rd gen but some folks here on Pm forum get on quite well with them.

cameraman · Nov 19, 2019

Redonion said:
DMG's B axis seems much beefier compared to UMC-750's

View attachment 270418

High-Res

But DMG U50's rated table weight is much lower compared to UMC-750

UMC-750
HRT-450
CMX U50
CMX U70
Max Table Load
300kg
386kg[Supported]
200kg
350kg
Table Diameter
ø500mm
NA
ø630x500mm
ø800x620mm
Max Torque

[td]
542 Nm
[/td]
[td]
542 Nm
[/td]
[td]
NA
[/td]
[td]
NA
[/td]

[tr]
[td]Brake Torque [/td]
[td]
2440 Nm
[/td]
[td]
1830 Nm
[/td]
[td]
NA
[/td]
[td]
NA
[/td]
[/tr]
[tr]
[td]Backlash [/td]
[td]
NA
[/td]
[td]
30 arc-sec
[/td]
[td]
NA
[/td]
[td]
NA
[/td]
[/tr]

BTW, I am planning to use this machine in a heat controlled room. Nothing fancy, just an air conditioner unit in a isolated room. I can also get a coolant chiller.

Will it improve accuracy and fix errors to an extend?

As to the point you are making here regrading 'Weight" on the table...

Would you not compare the CMX U 70 with the HAAS 750 not the CMX U 50 ? (perhaps) more apples to apples-ish ? ish ?

I think also it's what the manufacturer would set such weight limits at is somewhat arbitrary. [Do you really have 400lb of fixtures + parts ? ] .Seems the HAAS UMC 750 has been very very popular as large work can be handled pretty well especially if you are probing and comping and being fairly hands on with things like mike1974 is saying. I think HAAS understand their "home" market pretty well there .

@redonion ~ Not sure what the price and second hand market is for the machines you are looking for. The HAAS UMC 500 is $114K to $160K ish depending on options new .

Not sure on weight (stock + fixtures), envelope and tolerances shapes/ geometries and materials of parts you need to crank out ?

Redonion · Nov 19, 2019

cameraman said:
As to the point you are making here regrading 'Weight" on the table...

Would you not compare the CMX U 70 with the HAAS 750 not the CMX U 50 ? (perhaps) more apples to apples-ish ? ish ?

I think also it's what the manufacturer would set such weight limits at is somewhat arbitrary. [Do you really have 400lb of fixtures + parts ? ] .Seems the HAAS UMC 750 has been very very popular as large work can be handled pretty well especially if you are probing and comping and being fairly hands on with things like mike1974 is saying. I think HAAS understand their "home" market pretty well there .

@redonion ~ Not sure what the price and second hand market is for the machines you are looking for. The HAAS UMC 500 is $114K to $160K ish depending on options new .

Not sure on weight (stock + fixtures), envelope and tolerances shapes/ geometries and materials of parts you need to crank out ?

Thank you for your detailed responses.

Would you prefer brand new UMC-500 over brand-new UMC-750 [similarly specd]?

After UMC-1000 and UMC-500's release, UMC-750 seems like a 7 years old beta test for UMC machines.

cameraman · Nov 20, 2019

Redonion said:
Thank you for your detailed responses.

Would you prefer brand new UMC-500 over brand-new UMC-750 [similarly specd]?

After UMC-1000 and UMC-500's release, UMC-750 seems like a 7 years old beta test for UMC machines.

Personally (if those were my only choices) yeah definitely a new UMC 500 over a new UMC 750.

Maybe HAAS have something up their sleeve for the future replacement for the UMC 750. ? (just around the corner ?)

The UMC 500 frame has been redesigned so it is proportionately more rigid in spite of it's lesser mass than the HAAS UMC 750.

It does have rotary scales (not to a super high accuracy, but at least they are there ).

possibility of HSK (if you want or are into that). I think there is a BBT (dual contact option).

I think the usual "Jiggery pokery" having to implement artful geometric compensations* of one sort or another should be lessened with the UMC 500. + cycloidal gearing and drive mechanism on the B axis should be a lot more "Bomb proof" / crash proof.

Despite whatever current "Moans" that people might have about HAAS, depending on where you are DMG Mori seem to have some ways to go to be more comprehensive on the 'Support" front.

_____________________________________________________________________________________________

* Some folks have described the problems of trying to iron out the alignment issues of the UMC 750 as "Paradoxical" as the machine uses a lot of shims for the main masses + general alignment of the knuckle-trunnion [knunnion ?]

____________________________________________________________

Redonion said:
UMC-750 seems like a 7 years old beta test for UMC machines

^^^ That's kinda funny, that's kind of a DMG thing to say ;-) Given how many years DMG (wing) have been building 5 axis universals as compared to HAAS. Indeed from field experience they (HAAS) have changed the design of the UMC line so it's less hassle for HAAS and less hassle for the customer + other improvements. Kinda funny how HAAS does have it's own way of doing things and unique /odd / subtle hacks and non-obvious solutions built in. + constant improvement to all lines in their own way. The HAAS UMC 750 has been a tremendous success/ big seller for them. There are certain types of parts that are well suited to that machine and the UMC 1000 (if you need that envelope) is effectively a 5 axis 40 x 20 mill (that's very impressive) + fairly affordable giant pallet cell (if that's your "thing". ~ As I said before HAAS really understands their "Home" market as sperate from what a 5 axis machine is meant to be / do. ).

So "On paper" the CMX U looks good... mineral casting , good choice of controls , thermal stability and linear and rotary scales (to higher accuracy than the UMC 500) etc. etc. but not sure where and how they are built + sourcing components from ? + support also being a big issue (depending on what territory you are in ) .

Redonion · Nov 20, 2019

cameraman said:
Personally (if those were my only choices) yeah definitely a new UMC 500 over a new UMC 750.

Maybe HAAS have something up their sleeve for the future replacement for the UMC 750. ? (just around the corner ?)

The UMC 500 frame has been redesigned so it is proportionately more rigid in spite of it's lesser mass than the HAAS UMC 750.

It does have rotary scales (not to a super high accuracy, but at least they are there ).

possibility of HSK (if you want or are into that). I think there is a BBT (dual contact option).

I think the usual "Jiggery pokery" having to implement artful geometric compensations* of one sort or another should be lessened with the UMC 500. + cycloidal gearing and drive mechanism on the B axis should be a lot more "Bomb proof" / crash proof.

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* Some folks have described the problems of trying to iron out the alignment issues of the UMC 750 as "Paradoxical" as the machine uses a lot of shims for the main masses + general alignment of the knuckle-trunnion [knunnion ?]

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^^^ That's kinda funny, that's kind of a DMG thing to say ;-) Given how many years DMG (wing) have been building 5 axis universals as compared to HAAS. Indeed from field experience they (HAAS) have changed the design of the UMC line so it's less hassle for HAAS and less hassle for the customer + other improvements. Kinda funny how HAAS does have it's own way of doing things and unique /odd / subtle hacks and non-obvious solutions built in. + constant improvement to all lines in their own way. The HAAS UMC 750 has been a tremendous success/ big seller for HAAS. There are certain types of parts that are well suited to that machine and the UMC 1000 (if you need that envelope) is effectively a 5 axis 40 x 20 mill (that's very impressive) + fairly affordable giant pallet cell (if that's you "thing". ~ As I said before HAAS really understands their "Home" market as sperate from what a 5 axis machine is meant to be / do.

So "On paper" the CMX U looks good... mineral casting , good choice of controls , thermal stability and linear and rotary scales (to higher accuracy than the UMC 500) etc. etc. but not sure where and how they are built + sourcing components from ? + support also being a big issue (depending on what territory you are in ) .

I really thank you guys, buying your first machine is a really stressed situation.

When you try to configure an UMC-750 on haascnc.com, under "Product Options" it denotes that UMC-750 has rotary scales as standard but I am not sure these units on par with UMC-500/1000's scales.

I also suspect that UMC-750 or 800 is around the corner

I also learned that C axis brake is still pneumatic and HAAS upgraded the B axis brake with a hydraulic one on UMC-750.

A side note; All UMC-750's comes TSC-Ready

.

Further more, UMC-750 and UMC-750SS has same rapid/cut feedrates [1200ipm/650ipm].

cameraman said:
@redonion how extensive is your AC + insulation is like a couple of four ton units or something that hangs out a window, I am assuming industrial space-ish / building that you can maintain to +/- 4 degrees C ?

Would your suggest me to cool the machine with AC If I can get +/- 4 degrees C's?

Mike1974 · Nov 20, 2019

@Redonion- I just noticed you were / are in FL, what area? I am near Tampa so it's possible I might be able to help in person if you are still looking at the Haas UMC750..

It appears you have still not said what mats and tolerances you are looking at doing? That will probably make a bigger difference than price. If your parts are +/-.005, the Haas will certainly do that and better, however, if you need perfect seamless blends on multiple machining ops (3-4-5 sides) you will be stuck probing everything (IMHO), or living with hitting tolerance limits...

Feel free to PM me if you are in the area and we will talk. I did meet a member here a couple years back and met him on a Saturday at his shop to discuss some things, so I can and will follow up if you are close enough. :cheers:

edit: +/- 4 deg Celsius is ALOT... We kept our shop, with the UMC, to about +/-2-3 Fahrenheit (and humidity controlled as well), and cmm room was at +/-2 (or something close to that)

	UMC-750	HRT-450	CMX U50	CMX U70
Max Table Load	300kg	386kg[Supported]	200kg	350kg
Table Diameter	ø500mm	NA	ø630x500mm	ø800x620mm
Max Torque

Is UMC-750 that bad?

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