Mini Mill Work Envelope

[moldmker]

This has probably been discussed before but a search didn't reveal much.

A local shop is selling their 2001 Mini Mill. They have 2, one seems to stay busy with a dedicated product line, the other sits empty.

Every time I go over the work envelope #s, the 10" Z travel looks very confining. I currently have a larger VMC.

Are you guys using 6" Kurt vises in these?
How about extended toolholders or drill chucks?
I think the spindle is 7.5 hp, has anyone had any rigidity issues?

One job that I run alot of entails pocketing aluminum blocks with .5" rougher x .62" deep, 4000 RPM, 30 IPM, lots of coolant to clear the chips.
Would this be OK on a Mini Mill?

Thanks,
Bob

[Geof]

...Every time I go over the work envelope #s, the 10" Z travel looks very confining. I currently have a larger VMC.

Are you guys using 6" Kurt vises in these?
How about extended toolholders or drill chucks?
I think the spindle is 7.5 hp, has anyone had any rigidity issues?

One job that I run alot of entails pocketing aluminum blocks with .5" rougher x .62" deep, 4000 RPM, 30 IPM, lots of coolant to clear the chips.
Would this be OK on a Mini Mill?

Thanks,
Bob

Yes the 10" is a bit confining. We use 6" Kurt vises but our parts do not stick up much above the vise. Drill chucks are out, they are too long. Lyndex ER holders are even a bit long and stubby drills are a good idea. Rigidity is okay but the 600 rpm max and 7.5 hp is a bit limiting. It is possible you could run that rough okay on a MiniMill because your speed and feed is conservative.

What a\price is b eing asked for the Mini? If you can get it for $15,000 I think it could be worth it; if they are asking over $20,000 they are breathing thin air.

[Donkey Hotey]

Last year, I seem to remember a debate about the value of a Mini vs other machines. Geof really likes them. I think the gist of the conversation went like this:

If it's going to be your only machine, it's not such a good choice. If it's going to be setup to run one type of parts, it's a great value. It takes up little space and while it might not be the most rigid or fastest machine in your shop, it will free up your other machine while it slugs out your production stuff.

It sounds like you already have one job that you know will fit in the envelope. You can purchase specific cutters for that job and might even invest in a custom tooling plate to hold more parts than a pair of vises. Now you can set up the job, press the green button, then work on something else while it prints money for you. That's a lot of bang for the small bucks and footprint.

[automizer]

I sit in front of a mini mill and super mini mill all day and there great machines.
If you can pack in the part you want to do try putting it in the machine and see how it fits.
they are good at hogging out Alum. but you need to watch the bottom and keep the chips out. I have had coolant run down the handle of the chip scraper on to the floor. The bottom fills up preaty fast if your hogging and there isn't much room so that is my biggest beef with this machine

[billystein]

Hi,
I have the 4" extended z. still has 10 inches but 4" clearance. my problem is that with small cutters I have been forced to buy 4" end mill holders just to reach the top of a vise.
i don't think that a 1/8 em will touch the table with a 4 " holder.


billy

[Geof]

Hi,
I have the 4" extended z. still has 10 inches but 4" clearance...

.... i don't think that a 1/8 em will touch the table with a 4 " holder.


billy

I think that is an advantage; I don't want to touch the table with any end mill.

Seriously though the 4" extension sometimes makes it difficult to go far enough down, but it makes it possible to mount the HRT210 rotary and have rotary fixtures that cover the entire X travel and machine parts sticking 4" out from the A axis.

[mactec54]

Hi Moldmaker
The Zaxes has 14" of travel the 10" is the tool change height so you have 4'' it can go up after a tool change if you need it to clear any thing & the height is fine with Kurt vises if your tool holders are the shortest you can buy then you have plenty of room for most jobs

[Geof]

I seem to remember reading somewhere in Haas literature that using the 4" above Z zero is not recommended because the guides are not fully anchored up there.

[moldmker]

Guys,

Thanks for all the good info.

Geof, your pricing is right in the ballpark of what they're asking. (options: rigid tap, coolant tank, 3.5" fdd)

I'll post the outcome of the deal next week.

Thanks,
moldmker

[mactec54]

Hi Geof
You need to check with Haas Tec support because they told me that it is not known by many because knowbody asks about the extra 4" of Z travel but they told me that the extra 4" was there to use Management also backed this up as well

Those that added the 4'' to the Zaxes don't have as ridge machine by doing this

There is plenty of room if you buy the right tooling 2 photos attched the part is 3.5" above the Kurt Vise the tool/End mill is 3.6" out of the tool holder the first photo the tool is at 4" above the part the second photo is with the Zaxes 8" above the part I would say you would have to have a very large part to be a problem on this machine & then you can mount the part on the table or buy a bigger machine

I also have the same rotory table size as you do & it is not a problem I have even lifted the rotory table up with a 1.250" spacer to swing a bigger diameter with still no problem with tool clearance

[Geof]

....I also have the same rotory table size as you do & it is not a problem I have even lifted the rotory table up with a 1.250" spacer to swing a bigger diameter with still no problem with tool clearance

Show me a picture.

[Geof]

Here is what I posted above;

I seem to remember reading somewhere in Haas literature that using the 4" above Z zero is not recommended because the guides are not fully anchored up there.

Sure looks to me like the Z axis guides are not attached up at the top of the travel. Of course I am getting old and my eyesight may be failing.