What's new
What's new

Looking for used machine : What to go for and what to avoid?

cj133

Aluminum
Joined
May 8, 2014
Location
New Jersey USA
Hi all,

We're finally looking for a real VMC. We need something decently sized with a CAT40 or preferably a CAT50 spindle. Most of our work is larger stuff and steel / stainless. Some aluminum, but not a whole lot.

I'm using Fusion360 for CAM.


What are some machines we should keep a look out for and what should we run from?


A local place has a 2008 SHARP machine for sale with a CAT40 spindle. I think it's a model SV-6030.
 
I'm surprised no one has responded yet. Usually means I asked the wrong things.

From what I've seen on here the Sharp machines seem to be considered good machines? As do the Milltronics?


Right now, my biggest fear is I don't want to end up with another machine that's as limiting as our Prototraks are. They accept a limited amount of gcode, even though they are based on Fanuc 6. Seems like a real Fanuc controller would allow me to do so much more.
 
This has been covered several times, on second hand machines, one of the key things is product support - tech. If you know how to fix it thats not a issue, but other wise, is there a local tech that can fix it and are parts both available now and also for the foreseeable next few years - your planned life of the machine.

FYI im with you on the protrac limitations, really don't get why they are still stuck that far in the dark-ages of computing. Was looking at there 2nd op little machine and the quirks of the control instantly convinced me hell no way am i financing something with less software capabilities than my Linux CNC'ed bridgeport.
 
Define "larger".

There is a huge difference between 40 and 50 taper.

If you actually need a 50 taper for the work you do, a 40 taper machine will be a constant source of frustration and regret right up until you watch it getting dragged out your door.

If you've been working with toy machines up til now, then you likely don't have a solid grasp of what a 40 taper is capable of on a real machine.
 
This has been covered several times, on second hand machines, one of the key things is product support - tech. If you know how to fix it thats not a issue, but other wise, is there a local tech that can fix it and are parts both available now and also for the foreseeable next few years - your planned life of the machine.

FYI im with you on the protrac limitations, really don't get why they are still stuck that far in the dark-ages of computing. Was looking at there 2nd op little machine and the quirks of the control instantly convinced me hell no way am i financing something with less software capabilities than my Linux CNC'ed bridgeport.


As far as repairs, I think we can handle most of them.
My biggest concern I think, is getting a control that has the most post processor support. I seems like Fanuc is where its at when it comes to that, but at the same time floppy disks are a pain........


Define "larger".

There is a huge difference between 40 and 50 taper.

If you actually need a 50 taper for the work you do, a 40 taper machine will be a constant source of frustration and regret right up until you watch it getting dragged out your door.

If you've been working with toy machines up til now, then you likely don't have a solid grasp of what a 40 taper is capable of on a real machine.


I'm sorry, I keep forgetting how big this forum is. I'm used to smaller places where there's a good chance everyone has seen every post.

Our current machine, is a South Western FHM7, which apparently was a machine actually made by some company called King Richard.
It's a tiny 7.5HP machine with a 40 taper spindle, but I've been told by a few the machine isn't near big enough for the spindle. I get the impression it doesn't even qualify for the "toy" category.


We often need to mill mild steel plates that are 3" thick using a 1" x 4" endmill. If a good 40 taper machine can do this with light passes that would get the job done. Our current machine, even trying to take a 2" axial cut and only 0.005" radial will cause chatter. The problem being, I want a nice finish pass and doing stepped passes stinks.

What I would like, is to be able to mill 3" deep and take a pretty heavy cut using a corn cob, I'm assuming that's something we would want a 50 taper for?


Is there a general rule on how big of a tool you should use with a good 40 taper machine?
 
As far as repairs, I think we can handle most of them.
My biggest concern I think, is getting a control that has the most post processor support. I seems like Fanuc is where its at when it comes to that, but at the same time floppy disks are a pain........





I'm sorry, I keep forgetting how big this forum is. I'm used to smaller places where there's a good chance everyone has seen every post.

Our current machine, is a South Western FHM7, which apparently was a machine actually made by some company called King Richard.
It's a tiny 7.5HP machine with a 40 taper spindle, but I've been told by a few the machine isn't near big enough for the spindle. I get the impression it doesn't even qualify for the "toy" category.


We often need to mill mild steel plates that are 3" thick using a 1" x 4" endmill. If a good 40 taper machine can do this with light passes that would get the job done. Our current machine, even trying to take a 2" axial cut and only 0.005" radial will cause chatter. The problem being, I want a nice finish pass and doing stepped passes stinks.

What I would like, is to be able to mill 3" deep and take a pretty heavy cut using a corn cob, I'm assuming that's something we would want a 50 taper for?


Is there a general rule on how big of a tool you should use with a good 40 taper machine?

For solid tools, especially carbide, 1" is really pushing the limits of 40 taper. You can get away with it with HSM style (high DOC, low stepover) paths with ultra short gauge length holders, but 40 taper is more suited to the up to 5/8" range if you want to find the limits of the tool rather than the limits of the spindle.

Profiling 3" steel plate is absolutely 50 taper territory if you want any kind of efficiency.
 
I would not be too concerned with Post support for cam with any of the more common machines - controls. Don't forget that fanucs can be a bit different from one to the next depending on the OEM's configuration.

If your able to maintain a cnc your self learning a bit about posts and how to edit them is well within your capabilities, its not hard and there's a lot online in the correct forums. You really don't kinda edit or write them, more just a copy and paste compile.

By the sounds of what your after cut wise, your outside the 40 taper range IMHO. yes some of the larger 40 taper machines will do it, but its kinda the limits, if you want that all day everyday then 50 taper will be comfortable all day everyday, especially if your into harder than mild steel range. If you want to do this kinda stuff and make serious chip volumes, your into 50 taper in a gantry type setup too. trust me then you can make 3" deep cuts with ease.

Just price the difference including power supply and tooling costs, lots of people find it far cheaper to run passes than they do larger cutters. On a tight machine passes will still leave a good finish. Your talking a massive jump here machine wise compared to the toy you have been using though don't mean that nastily, its on a par with going from a mill drill to a 40 taper VMC, jumping from what you have to a 50 taper VMC.
 
I would not be too concerned with Post support for cam with any of the more common machines - controls. Don't forget that fanucs can be a bit different from one to the next depending on the OEM's configuration.

If your able to maintain a cnc your self learning a bit about posts and how to edit them is well within your capabilities, its not hard and there's a lot online in the correct forums. You really don't kinda edit or write them, more just a copy and paste compile.

By the sounds of what your after cut wise, your outside the 40 taper range IMHO. yes some of the larger 40 taper machines will do it, but its kinda the limits, if you want that all day everyday then 50 taper will be comfortable all day everyday, especially if your into harder than mild steel range. If you want to do this kinda stuff and make serious chip volumes, your into 50 taper in a gantry type setup too. trust me then you can make 3" deep cuts with ease.

Just price the difference including power supply and tooling costs, lots of people find it far cheaper to run passes than they do larger cutters. On a tight machine passes will still leave a good finish. Your talking a massive jump here machine wise compared to the toy you have been using though don't mean that nastily, its on a par with going from a mill drill to a 40 taper VMC, jumping from what you have to a 50 taper VMC.



You can say anything nasty you want about our current machine.
I'm listening to it chatter away as we speak........


It's getting the work done............but very very slow and it's ruining my tools.
 
You can say anything nasty you want about our current machine.
I'm listening to it chatter away as we speak........


It's getting the work done............but very very slow and it's ruining my tools.

Have you had the spindle taper checked recently? Done a pull stud torque test? (Can't remember the official name for it).

Does your machine have bellville washers that are worn/broken?
Maybe all your machine needs is a bit of maintenance.

What is your budget? If you can find an Okuma Genos M560 used for a good price then snag it up.

Also, did I miss the current size of your work? All I saw was 3" cut.

The poster above who said 1" heavy cutting is 50taper territory is spot on.
 
Have you had the spindle taper checked recently? Done a pull stud torque test? (Can't remember the official name for it).

Does your machine have bellville washers that are worn/broken?
Maybe all your machine needs is a bit of maintenance.

What is your budget? If you can find an Okuma Genos M560 used for a good price then snag it up.

Also, did I miss the current size of your work? All I saw was 3" cut.

The poster above who said 1" heavy cutting is 50taper territory is spot on.

I'm sure the current machine needs some help, and we'll give it some. I don't think there's any intention of getting rid of it.

An example of some of our jobs is we often have to clean up hot rolled steel plates. Off the top of my head, I believe they're 18" x 12" x 3". We mill the ends and face the top and bottom. It's a long, slow process on the current machine.

Currently milling 1.5" diameter holes into 4" x 4" x 18" 316SS blocks. After that, hollowing out 7"x7"x2" chunks of ASTM A572-50.

We do some aluminum,and some small parts, but mostly steel and stainless steel from larger stock.

Waiting to hear back regarding budget. My guess, $60-80K for used.
 
I'm sure the current machine needs some help, and we'll give it some. I don't think there's any intention of getting rid of it.

An example of some of our jobs is we often have to clean up hot rolled steel plates. Off the top of my head, I believe they're 18" x 12" x 3". We mill the ends and face the top and bottom. It's a long, slow process on the current machine.

Currently milling 1.5" diameter holes into 4" x 4" x 18" 316SS blocks. After that, hollowing out 7"x7"x2" chunks of ASTM A572-50.

We do some aluminum,and some small parts, but mostly steel and stainless steel from larger stock.

Waiting to hear back regarding budget. My guess, $60-80K for used.

That's quite a budget for used, and if that's the actual budget, a brand new Okuma M560 is only $100k give or take right now. I believe they are running a special right now until the end of August.
 
That's quite a budget for used, and if that's the actual budget, a brand new Okuma M560 is only $100k give or take right now. I believe they are running a special right now until the end of August.


How does Okuma compare to HAAS?

We were considering a HAAS VF-6/50 as a possibility. If it gets approved, of course.
 
For the work you described, I would encourage you to look for a used high-quality Japanese 50 taper VMC with box ways. You want stiffness and a robust spindle for what sounds like heavy cutting over max precision.

Do some searching, if you find some likely candidates you can get opinions here for which seems the better deal.
 
How does Okuma compare to HAAS?

We were considering a HAAS VF-6/50 as a possibility. If it gets approved, of course.

Not much comparison, the Okuma is a much better machine. I would not chose any Haas for the type of cutting you describe. But I also wouldn't suggest a M560 for this application, I think you need a 50 taper.
 
For the work you described, I would encourage you to look for a used high-quality Japanese 50 taper VMC with box ways. You want stiffness and a robust spindle for what sounds like heavy cutting over max precision.

Do some searching, if you find some likely candidates you can get opinions here for which seems the better deal.

Box ways are not the deal breaker some make them out to be, that impression is really a legacy of the early generations of linear guide machines (or plain cheap machines) that use ball guides. Modern roller guide machines are just as capable of heavy cuts as box way machines.

Another aspect of the spindle that's counterintuitive - for heavy milling with carbide insert tools, you really don't want a gearbox. The backlash in the geartrain creates torque "bounce" under load that is hard on carbide. It has been my experience that the life of carbide inserts when roughing of steel is significantly better with a direct driven, or best of all integrated motor spindle. You'll lose torque for big tools, but if you can live without 6"+ facemills and huge boring heads and massive taps etc, it's a worthwhile tradeoff IMO.
 
Thank you for responding.

This may be a stupid question but, it seems like a lot of machines don't list what taper they have?

For example, there's a used SNK FSP-80V local to us. It looks like a large machine, but no mention of what spindle it has, not even on SNK's website. I just noticed the same thing with Okuma, none of them mention what taper they have.

I was concerned about HAAS not being rigid enough, especially since they seem to use both 40 and 50 taper in the same machines.
 
Hi Gregor,
I think you raise some fair points, especially on the spindle. The reason I suggested box ways over roller is the damping, and my guess that an older 50 taper might be more likely to come with box over roller. But a good candidate machine shouldn't be dismissed just due to ways construction.
 








 
Back
Top