Help! Why Round Column Mills not fit to convert to CNC?

[szcharle]

I found a round column mill some user tell me it's good, and it have a Six Speed
Gear Head, motor is small, 200W, the head (main axis) can rotate with certain angle.
so i think this is fit me to convert to CNC,(due to i want use cnc mill to cut stainless steel,need a bit strong)
but this mill is round column type, so can i use this mill convert to CNC? and what is the weakness for this type Mill? why? Thank you!

btw: I am at China ,this price only CNY 3700,about USD 460, or EU 370.

[philbur]

The CNC Z axis travel on a round column is limited to the quill travel, max normally 4 to 5". Which in any case is very often sloppy. Manually using the column to raise/lower the head half way through a part loses the x and y co-ordinates, and in any case kinda defeats the object of CNC. However it depends on what you will use it for, some classes of work does not necessarily need a lot of z-axis travel.

Regards
Phil


[QUOTE=szcharle]I found a round column mill some user tell me it's good, and it have a Six Speed
Gear Head, motor is small, 200W, the head (main axis) can rotate with certain angle.
so i think this is fit me to convert to CNC,(due to i want use cnc mill to cut stainless steel,need a bit strong)
but this mill is round column type, so can i use this mill convert to CNC? and what is the weakness for this type Mill? why? Thank you!

btw: I am at China ,this price only CNY 3700,about USD 460, or EU 370.
/QUOTE]

[Bubba]

I guess I was like the bumble bee (which according to science say it can't fly). I have a round column machine that I cnc'd and with planning, can usually do a setup without having to move the column. Yes, it can be a PITA planning it out, but usually can be done depending on the type of work you do. The biggest problem I have with this size machine (for the type work I do) is the lack of rigidity! But then again, it is a hobby and by doing the work more slowly (lower forces), I can get it done.

IF the machine will do what you want it to, then I would say, "Go for it!"

My opinion:})

Bubba

[philbur]

Yes it can fly, but only just.

Phil

I guess I was like the bumble bee (which according to science say it can't fly).

Bubba

[fkaCarel]

/QUOTE Manually using the column to raise/lower the head half way through a part loses the x and y co-ordinates, and in any case kinda defeats the object of CNC./QUOTE

This is an Emco FB-2 clone, you can see the key on the last photo.

Carel

[szcharle]

Hi, philbur and bubba
thanks for your reply, and your advice!
to myself ,i think i was attract by Gear Head,and can rotate the head 90 degree,sometime can act as a Horizon Mill.(also,the price is a big reason
I decide to purchase one, fisrt familiar and then step by step change it to CNC. Thank you!

[yukonho]

Bee's can fly, early studies didn't take into account the vortex created by the down flapping wing that help to create a low pressure area above the wing....

Rond column mill's are typically a little less rigid, but the biggest issue is travel. Using endmill holders (instead of collets) and short length drill bits can help to minimize the difference in tool lengths and make set-up easier.
Colin

[Bubba]

yuknonho,
Thanks for allowing me to fly and my mill to do its thing:})

As for rigidity, I think "most" of the mills in our "hobby class" suffer from this problem especially if you are trying to take big cuts at fast feeds.

As for the travel problem, I get around this by one of two ways:
1. elevate the work piece (vise or aux. table) and change tools in a space with more room
2. use a straight shaft extension ER collet adapter for the "short" tools like a 1/16 end mill that I use for engraving. Yeh, I know more flex, but then again, with experience, I have found with slower feeds I can get around this problem.

Again, it is a HOBBY and I am not getting paid by the hour for my jobs. Also, I still get amazed at watching the tool do its thing and I don't have to twist the handles. AND it is more accurate and faster than I could IF I were twisting the handles. (try to do and arc by hand:})

[Ron111]

Also to stay within the working range od the Z axis (where you don't have to move the head on the column) when planning out my work, I have even gone to the extent of shortening drill bits which may have caused clearance problems forcing repositioning of the head.

Ron

[phantomcow2]

You are in China, maybe you can buy an X3 directly from Sieg? This is a far better choice, and you wont have to constantly deal with how to keep from moving the head.

Using the quill to mill is not the ideal way.

[fkaCarel]

Phantomcow: I pointed out in post #5 that the key, preventing rotation, was visible in the last photo. I also stated that this was an Emco FB2 clone. These things are not comparable to the contraption machine everybody is referring to. The column travel of an FB2 is around 300mm (12").

[Ron111]

fkaCarel,

Interesting, are you saying that with this mill, the Z axis can be relocated with out losing X & Y settings?

Is the keyway adjustable with a gib adjustment or something to prevent any slack.

Give us a little insight.

Ron