[stijnrasta]

I'm interested in how a VMC would perform against an HMC in terms of maintenance: complexity, cost, frequence, etc.

To compare apples with apples both machines would have to perform the same tasks, have the same specs, heavy duty machining (Ti or St).

From my experience VMC's are simpler and require less maintenance. And if they do, it's usually easier and shorter. However, nobody has really done a thorough comparison within our company and I couldn't find much on the internet either.

Any good sources of information ?

Thx, Stan

[yours_prabhat]

Summarized Advantages - HMC vs. VMC

Spindle Utilization

Fewer machines required

Remember 25% vs 85%?

Shorter Throughput Times

Increased shop throughput

Less in process work

Set-up Time Reduction

Efficiency / less downtime

Set-ups internal to machining cycle

Chip Evacuation

Better tool Life

Higher quality finish in parts

Reduced Operator Attendance Time

Reduced direct labor $ COSTS $

Put your labor to better use, like inspection or other equipment.

No doubt the running VMC is easier than HMC but HMC provides lots of scope than VMC , It depends on the use , The part we are machining , and application ,
In the maintenance point of view since The Spindle of HMC apply force towards non gravity (base of axis) so the load on table in XY gravity is higher , But in VMC its vise versa . The MTB has their own designed now to reduce less failures in HMC also .

regards

[underthetire]

HMC's are best for repetitive or long run jobs usually, since set up is more complicated. As far as maintenance is concerned, it's more or less just 1 more axis, full 4th or indexing. Yes, you will have a hydraulic unit to service that you dont on most new VMC's. You must also keep the pallet changing area clean, just like you do on a VMC with a APC. Not all HMC's are created equal though, i've seen some pretty bad low end ones. The other thing to keep in mind, is don't drop part corners off in the machine, turn them to chips. This should be done on VMC's as well, but usually not as critical. A drop on a HMC will usually end up punching a hole in a waycover, or jamming the auger somewhere where it's a PIA to get to.