Cool new RS 5 mill

[cadfan]

not bad the new Korean flagship

 

[zero_zero]

That kinda looks like the Arum mill....

 

[cadfan]

That kinda looks like the Arum mill....

but a lot things are evolution constructed and over 250 kg less

 

[CoolHandLuke]

any idea who sells them and where they fall on pricing?

 

[brayks]

Hmm....
I'm not sure- would it be appropriate for me to comment?

 

[smilesatgalleria]

looking likely Arum mill

 

[brayks]

I know a bit about this machine and it is most defiantly NOT an Arum.

Dental Plus released this machine a couple of years ago but apparently were only able to sell a hand-full of units in Korea and other countries during this time.

I've been told that a Korean implant company tried to sell it and a large Japanese electronics and ceramics manufacturer tested it but both gave up do to quality issues. It's unclear if if any of the issues have been addressed in the current model.

It is very difficult for me to compare OUR Arum based Versamill 5X-200 to the Plus Mill RD 5 because I have heard about only a few of these machines and their Technical Specifications are a little light.

I know a Korean spindle company invested in Dental Plus and it likely uses their spindle which are of unknown specifications and history.

Certainly their 1.2Kw spindle (likely only a max power rating as well) is significantly lower power and torque compared to our 3Kw Sycotec spindle. I don't see how this machine (especially with such a low power spindle) could effectively and reliably machine hard metals, especially cobalt-chrome. I'm sure it could do it but slowly, with the spindle operating at the top of its torque/power curve for a long period of time- which is something you really never want to do (read spindle overheating, failures etc.).

The RS5's 145kg machine weight (compare to our cast aluminum-alloy framed 405kg machine) is pretty light to expect to achieve effective metal removal with fast cycle times, long tool life and quality finishes/margins. Of course I'm sure it could do sintered metals.

They have also been seeking distributors in the USA for a couple of years. At one point they did have a Korean distributor in Virginia- not sure if they still do. I'm also not sure of their communication skills relative to the English language. I would venture a guess that support would likely come from Korea (especially after browsing their brochure and website).

Having said all this, I have never actually seen one "in the wild" to actually look it over in detail to make any quantitative analysis. My thoughts are based on Dental Plus' marketing material, discussions with other dental machine manufacturers, software suppliers, web research and personal experiences.

So, just one guy's opinion...out.

 

[Aggrey Abwonza]

Price?


Sent from my iPhone using Tapatalk

 

[CoolHandLuke]

steve your opinion and analysis are perfectly valid and welcome. at least i welcome it.

now that you mention it i can see what you mean when you say the machines spec sheet is a little light.

if i were trying to purchase one of these i think the most i would be willing to value it for, would be in the 20-25k canadian range. i dont think it would be worth the same as a dwx which i already think are a bit high on the scale.

 

[cadfan]

1 kw power is enough i can show you a lot mills with that power" only " !!
5 my plus minus repeatability what more data sheet same on yours Steve but i personnel know not even one direct span mill that can do that ( standard tooling and a few other aspects)
btw 100-200 kg is the lowest range for Bar milling bitches more 150-200 kg they all cost around 50 K
a casted alu frame is top but polymerbeton and additional laser and HSK and so on is better but it although works on the smaller
I dont know the company personel but cool pics and some cool details 4 th fives ax , preform holder one side only , cooling and waste drawer and so on thats all

http://www.cctechnik.com/en/products/fräsmaschinen/organical-desktop-8.html#tab-produkt 180 kg 400 watt

http://www.dental-concept-systems.com/leistung/produktuebersicht/item/fraesmaschine-dc1 170 kg 950 watt

http://www.imes-icore.de/deu/coritec-350i-dentalfraesmaschine.html 180 kg 1 kw

http://www.cctechnik.com/en/products/fräsmaschinen/organical-multi.html#tab-produkt 750 kg 1 kw

http://www.goldquadrat.de/produkte/fraesmaschinen/zfx-inhouse5x/ versus ZFX versus Primacon 250 kg 300 Watt but thats a bit low ZFX castrated it.

and so on

 

[brayks]

The price is USD $70,000~USD $75,000 in Korea. I don't know their price in the USA as I am not aware of any sold here.

 

[CoolHandLuke]

yeesh

 

[brayks]

1 kw power is enough i can show you a lot mills with that power" only " !!
5 my plus minus repeatability what more data sheet same on yours Steve but i personnel know not even one direct span mill that can do that ( standard tooling and a few other aspects)
btw 100-200 kg is the lowest range for Bar milling bitches more 150-200 kg they all cost around 50 K
a casted alu frame is top but polymerbeton and additional laser and HSK and so on is better but it although works on the smaller
I dont know the company personel but cool pics and some cool details 4 th fives ax , preform holder one side only , cooling and waste drawer and so on thats all

http://www.cctechnik.com/en/products/fräsmaschinen/organical-desktop-8.html#tab-produkt 180 kg 400 watt

http://www.dental-concept-systems.com/leistung/produktuebersicht/item/fraesmaschine-dc1 170 kg 950 watt

http://www.imes-icore.de/deu/coritec-350i-dentalfraesmaschine.html 180 kg 1 kw

http://www.cctechnik.com/en/products/fräsmaschinen/organical-multi.html#tab-produkt 750 kg 1 kw

http://www.goldquadrat.de/produkte/fraesmaschinen/zfx-inhouse5x/ versus ZFX versus Primacon 250 kg 300 Watt but thats a bit low ZFX castrated it.

and so on

Hey cadfan,
Good stuff, thanks for the post.

I apologize for the long winded nature of this post, however I think it is good information (not necessarily for you as you seem to have a pretty good grasp on machine technology) but for the some brethren of the forum. I believe it is important that the following issues should be considered when evaluating machines for purchase. Having said that, it's pretty dry stuff and I'm pretty sure most will get bored quickly.

Anyway...

I hear ya. the accuracy numbers, while important don't hold too much weight with me as well. Repeatability is a bigger deal in my mind. However these numbers are typically based on controlled no-load tests. Heck, compare accuracy and/or repeatability tests at 20 deg. C and one at 30 deg. C and the stated 3 or 5 microns go right out the door.

It's what happens when you actually use or push the machine that matters. This where construction characteristics, spindle, fixturing, way system, tooling, machining strategies and machining parameters come into play. All of great importance and should be considered.

Relative to what I consider a bit light on specifications, there is no mention of axes travels, particularly the rotary A and B-axis as well as the feedrates with the rotary feedrates being most important.

Additionally the big part of the equation is the spindle and the spindle drive/controller. Here torque is of great importance. I've seen many a "high power" spindle with anemic torque ratings at RPM's required to machine a given material (given the tooling and required/desired SFM). Many spindles may have a max power rating but the actual power and torque are limited by the spindle drive/controller (a very common way to cut costs)

Beyond that many manufacturers show the MAXIMUM power of a spindle (even though many times with a driver/controller installed that is not capable of delivering that power). What is important is the S1 or continuous duty rating of the spindle (there are many other ratings, but I will spare the commentary) with the driver/controller that is delivered with the machine as well as the way the spindle cools down, especially after driving it high on the power/torque curve as it would be with a 1Kw-ish spindle (defiantly not advisable).

For example our Versmill 5X-200 utilizes a 3Kw Sycotec DC spindle (Max rating) produces a continuous 65Ncm torque in the 10,000 to 30,000 RPM range (typical range for small diameter coated tools cutting metal). This same spindle/driver, under continuous duty (S1) produces 500w to 1.2Kw of power and a continuous 40 Ncm torque. Conversely a higher power Syotec AC spindle drive (rated at 1.8Kw maximum) like the one in the Versamill 4X-100 delivers, in the same RPM range, 800w to 1.8Kw of power and 80Ncm down to 55Ncm MAXIMUM. This same spindle (again in the same RPM range) delivers only 200w to 400w of power and a mere 20Ncm down to 12Ncm torque.

This of course is a specific example and exact numbers vary from spindle/driver manufacturer to spindle/driver manufacture but the above is pretty typical.

Many CNC machine motors simply do not perform well as heat increases, and may take a long time to cool down. Some can cool down only when at rest. These motors often run at temperatures above say 212° F when in the continuous-duty HP range. Other motors are designed to run at that maximum 212° F in the continuous-duty range, and begin to cool down as soon as the load reduces.

This means that even if a portion of a machining cycle requires maximum output, the motor will begin to cool as soon as the demand drops, even as the machine tool continues operating.

Temperature, of course, not only affects the life of the spindle motor, but other machine components such as ball screws and bearings. Additionally, thermal expansion can lead to out-of-tolerance parts with chipped margins and bad fits. So not only is it important for the motor to dissipate heat quickly, but also for the machine tool maker to build in methods for compensating for increased temperatures.

Unfortunately, some of the off-the-shelf motors some dental machine tool builders use have spindles that may appear to have adequate HP ratings, based upon power consumption rather than actual output, and may not meet other important criteria. For example, these generic motors may have higher operating temperatures that can impact the bearings, ball screws and other machine components. They may not cool down after short-term operation until they have stopped, idling the machine tool which means lost production time.

The spindle motor on a CNC machine tool should be designed and built to last the lifetime of the machine, not just for a stated number of hours. If the builder takes a holistic approach to the machine tool design, factors in all of the above considerations, and if routine maintenance is applied, barring any “crashes” or thermal sensor failures, the spindle motor will perform reliably for as long as the machine tool is functional.

I agree, there are mills with 1Kw-ish power ratings. Will they do the job when it comes to machining metals like the very hard CoCr and the more machine-friendly titanium? Well that depends. It depends on, of course the other issues mentioned above and the expectations/requirements of the user in terms of cycle time, finish, tool wear, machine and spindle life, etc. Technically yes as I had stated. I have much experience with this and it is definite that cycle time and spindle life will suffer. Trying to achieve optimum cycle times, tool wear, finish, spindle life, etc. is very difficult.

It is important to know the specifications and capabilities of this very key component of a dental milling machine and work within the parameters for which it is designed.

Spindle run-out is as you mention is also an important factor and for many of the reasons the accuracy metric is somewhat a tough one. I believe the use of an HSK/laser tooling-like system, in the size/format of these dental machines, that do not require exceptionally long tooling, to be a bit overkill.

I have helped implement many HSK, heat-shrink holders with laser measurement for run-out and length control for high-speed machining of large heat treated/hardened molds. The main application is typically cutting ribs that were formally sunken by EDM. These deep machining applications required length-to-diameter ratios greater than six times. Here run-out is of utmost importance and the HKS system is of great benefit (and cost). I believe the HSK tool holding system, while a very fine system to be unnecessary given the costs involved and the shorter length tooling utilized in machining dental restorations- especially since a good spindle/collet given appropriate attention to cleaning should be able to keep run-out in the completely adequate 3-12 micron range.

Relative to machine frame construction, there are many opinions out there (I am of the opinion they are pretty much equal),but needless to say the ability to absorb vibration and dissipate heat to be of extreme importance. As you mention cast-aluminum alloy and epoxy-granite frames are at the top of the heap. Further down the line are aluminum "fabricated" frames. All of these are preferable to the vast majority of the frames (or lack there of) utilized by most popular dental mills.

Cadfan, I'm not quite sure what you may be referring to or suggesting related to the "5 my plus minus repeatability what more data sheet same on yours" but I did not see a repeatability spec for that machine (ours is published as 3microns) only an accuracy spec which, at 5microns is the same as the Versamill's accuracy rating.

If you are suggesting (and I do not think your are- it's just a language/translation issue) that we, as other manufactures tend to do, only provide minimum information.

I believe that our marketing collateral's are pretty darn thorough and supply significantly more information about our mills than can be found by any of our competitors- anywhere. From our website to our brochures, videos, etc. I have worked pretty darn hard to provide substantive detail regarding the specifications, features, functions and benefits of our solution. I wanted to make sure people interested in our products, and machine technology did not have to dig to find what is important, why and what we have to offer.

There is actually a lot more to to say, and I just basically did a "Reader's Digest" on the topics covered, but enough is enough - end of report.

See, I told you it would be long and boring...

Best
Steve

 

[zero_zero]

It's nice to see a few micron accuracy being advertised on these small mills, but when I ask my machinist buddy (who has a few multi ton industrial monsters, with glass scales and all the goodies one could dream of) what's the precision they could hold, I hear: "about 50 microns across the work envelope"....go figure...

 

[Getoothachopper]

Hey cadfan,
Good stuff, thanks for the post.

I apologize for the long winded nature of this post, however I think it is good information (not necessarily for you as you seem to have a pretty good grasp on machine technology) but for the some brethren of the forum. I believe it is important that the following issues should be considered when evaluating machines for purchase. Having said that, it's pretty dry stuff and I'm pretty sure most will get bored quickly.

Anyway...

I hear ya. the accuracy numbers, while important don't hold too much weight with me as well. Repeatability is a bigger deal in my mind. However these numbers are typically based on controlled no-load tests. Heck, compare accuracy and/or repeatability tests at 20 deg. C and one at 30 deg. C and the stated 3 or 5 microns go right out the door.

It's what happens when you actually use or push the machine that matters. This where construction characteristics, spindle, fixturing, way system, tooling, machining strategies and machining parameters come into play. All of great importance and should be considered.

Relative to what I consider a bit light on specifications, there is no mention of axes travels, particularly the rotary A and B-axis as well as the feedrates with the rotary feedrates being most important.

Additionally the big part of the equation is the spindle and the spindle drive/controller. Here torque is of great importance. I've seen many a "high power" spindle with anemic torque ratings at RPM's required to machine a given material (given the tooling and required/desired SFM). Many spindles may have a max power rating but the actual power and torque are limited by the spindle drive/controller (a very common way to cut costs)

Beyond that many manufacturers show the MAXIMUM power of a spindle (even though many times with a driver/controller installed that is not capable of delivering that power). What is important is the S1 or continuous duty rating of the spindle (there are many other ratings, but I will spare the commentary) with the driver/controller that is delivered with the machine as well as the way the spindle cools down, especially after driving it high on the power/torque curve as it would be with a 1Kw-ish spindle (defiantly not advisable).

For example our Versmill 5X-200 utilizes a 3Kw Sycotec DC spindle (Max rating) produces a continuous 65Ncm torque in the 10,000 to 30,000 RPM range (typical range for small diameter coated tools cutting metal). This same spindle/driver, under continuous duty (S1) produces 500w to 1.2Kw of power and a continuous 40 Ncm torque. Conversely a higher power Syotec AC spindle drive (rated at 1.8Kw maximum) like the one in the Versamill 4X-100 delivers, in the same RPM range, 800w to 1.8Kw of power and 80Ncm down to 55Ncm MAXIMUM. This same spindle (again in the same RPM range) delivers only 200w to 400w of power and a mere 20Ncm down to 12Ncm torque.

This of course is a specific example and exact numbers vary from spindle/driver manufacturer to spindle/driver manufacture but the above is pretty typical.

Many CNC machine motors simply do not perform well as heat increases, and may take a long time to cool down. Some can cool down only when at rest. These motors often run at temperatures above say 212° F when in the continuous-duty HP range. Other motors are designed to run at that maximum 212° F in the continuous-duty range, and begin to cool down as soon as the load reduces.

This means that even if a portion of a machining cycle requires maximum output, the motor will begin to cool as soon as the demand drops, even as the machine tool continues operating.

Temperature, of course, not only affects the life of the spindle motor, but other machine components such as ball screws and bearings. Additionally, thermal expansion can lead to out-of-tolerance parts with chipped margins and bad fits. So not only is it important for the motor to dissipate heat quickly, but also for the machine tool maker to build in methods for compensating for increased temperatures.

Unfortunately, some of the off-the-shelf motors some dental machine tool builders use have spindles that may appear to have adequate HP ratings, based upon power consumption rather than actual output, and may not meet other important criteria. For example, these generic motors may have higher operating temperatures that can impact the bearings, ball screws and other machine components. They may not cool down after short-term operation until they have stopped, idling the machine tool which means lost production time.

The spindle motor on a CNC machine tool should be designed and built to last the lifetime of the machine, not just for a stated number of hours. If the builder takes a holistic approach to the machine tool design, factors in all of the above considerations, and if routine maintenance is applied, barring any “crashes” or thermal sensor failures, the spindle motor will perform reliably for as long as the machine tool is functional.

I agree, there are mills with 1Kw-ish power ratings. Will they do the job when it comes to machining metals like the very hard CoCr and the more machine-friendly titanium? Well that depends. It depends on, of course the other issues mentioned above and the expectations/requirements of the user in terms of cycle time, finish, tool wear, machine and spindle life, etc. Technically yes as I had stated. I have much experience with this and it is definite that cycle time and spindle life will suffer. Trying to achieve optimum cycle times, tool wear, finish, spindle life, etc. is very difficult.

It is important to know the specifications and capabilities of this very key component of a dental milling machine and work within the parameters for which it is designed.

Spindle run-out is as you mention is also an important factor and for many of the reasons the accuracy metric is somewhat a tough one. I believe the use of an HSK/laser tooling-like system, in the size/format of these dental machines, that do not require exceptionally long tooling, to be a bit overkill.

I have helped implement many HSK, heat-shrink holders with laser measurement for run-out and length control for high-speed machining of large heat treated/hardened molds. The main application is typically cutting ribs that were formally sunken by EDM. These deep machining applications required length-to-diameter ratios greater than six times. Here run-out is of utmost importance and the HKS system is of great benefit (and cost). I believe the HSK tool holding system, while a very fine system to be unnecessary given the costs involved and the shorter length tooling utilized in machining dental restorations- especially since a good spindle/collet given appropriate attention to cleaning should be able to keep run-out in the completely adequate 3-12 micron range.

Relative to machine frame construction, there are many opinions out there (I am of the opinion they are pretty much equal),but needless to say the ability to absorb vibration and dissipate heat to be of extreme importance. As you mention cast-aluminum alloy and epoxy-granite frames are at the top of the heap. Further down the line are aluminum "fabricated" frames. All of these are preferable to the vast majority of the frames (or lack there of) utilized by most popular dental mills.

Cadfan, I'm not quite sure what you may be referring to or suggesting related to the "5 my plus minus repeatability what more data sheet same on yours" but I did not see a repeatability spec for that machine (ours is published as 3microns) only an accuracy spec which, at 5microns is the same as the Versamill's accuracy rating.

If you are suggesting (and I do not think your are- it's just a language/translation issue) that we, as other manufactures tend to do, only provide minimum information.

I believe that our marketing collateral's are pretty darn thorough and supply significantly more information about our mills than can be found by any of our competitors- anywhere. From our website to our brochures, videos, etc. I have worked pretty darn hard to provide substantive detail regarding the specifications, features, functions and benefits of our solution. I wanted to make sure people interested in our products, and machine technology did not have to dig to find what is important, why and what we have to offer.

There is actually a lot more to to say, and I just basically did a "Reader's Digest" on the topics covered, but enough is enough - end of report.

See, I told you it would be long and boring...

Best
Steve

Could you be more specific !.................................................................Kidding.

 

[cadfan]

It's nice to see a few micron accuracy being advertised on these small mills, but when I ask my machinist buddy (who has a few multi ton industrial monsters, with glass scales and all the goodies one could dream of) what's the precision they could hold, I hear: "about 50 microns across the work envelope"....go figure...

Its to cold in Canada the scales do not work

 

[Aggrey Abwonza]

Anyone with a Sirona used Mxl mill to dispose?


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