need info on a new IH mill

[fabman13]

I work as a machinist running cnc bridgeport knee mills and im trying to set up a small shop at my house to machine small parts. I think im going to go with a ih with fagor 40i an the nt30 spindle. what kind of accuracy/tolorences should i be able to hold with this machine out of the box? i have read that the quill my have some problems with runout an different things. is the quality there with these machines or should i be looking for a bridgeport clone?

thanks Jeremy

[BobWarfield]

Get the gibs tuned up properly and stick a cheap Z-axis DRO on the quill and you should be good to 0.001".

Best,

BW

[bohica]

I recently cut 3 parts and was within an average of .0004 of design spec.

[Shev]

I recently cut 3 parts and was within an average of .0004 of design spec.

On a manual (not cnc) IH mill?

[fabman13]

On a manual (not cnc) IH mill?

yeah thats on a manual mill for now with 3 axis DRO. Anyone know if the z axis is ran off the quill or the head?

[williamsmotower]

Z ballscrew moves the head.

The quill is still manual.

Actually will come in handy I think. Move to a postion, then can use the quill manually for specific operations if needed.

[bohica]

I recently cut 3 parts and was within an average of .0004 of design spec.

Sorry, this was on a CNC version.

[BobWarfield]

Yep, the CNC conversion increases the accuracy quite a lot. I can't really speak to how accurately you could machine with a nice DRO though, as that would also make a difference. I just know 0.001" was straightforward except for the quill, and with a cheap quill DRO that was taken care of.

There's a little bit of non-linearity in the quill. It moves slightly when you lock it, for example. But you can see and compensate for that with the DRO.

Cheers,

BW

[Cruiser]

The reason we lock and forget the quil is that the fitment of the quil to the gear box bore has generous clearance to benefit the warming and expansion of the quil. It is a necessary evil to keep it from binding. With quil extended there isn't enough cylinder contact area to keep it firmly in place and it can wiggle to varying degrees.

[Shev]

I recently cut 3 parts and was within an average of .0004 of design spec.

Sorry, this was on a CNC version.

Thank you for clarifying. 0004 is pretty impressive...

[fabman13]

what is the pros an cons of the nt30 spindle on the IH cnc website it says it will spread the force of milling more throughtout the spindle instead of stressing the bearings in the quill. anyone have any thoughts on this is worth the extra money? r8 tooling an assesories are pretty easy to come by an that means alot when outfitting a machine but if the nt30 with ER colletts is going to be easier on the machine an the accuracy is there is that the way to go?

thanks

[philbur]

I don't understand how it spreads the force and reduces the load on the bearing. All the side and axial forces produced by the tool are taken by the bearings, regardless of spindle configuration.

The only reason to use a 30 spindle on a machine of this size is:

1) If you all ready have a lot of 30 tooling (or cheap access to a load of)
2) You want to build a full grunt ATC.

The advantage of an R8 is you can use the quick change TTS system (or home made equivalent) and still use a full grunt R8 solid tool holder when needed.

Phil

what is the pros an cons of the nt30 spindle on the IH cnc website it says it will spread the force of milling more throughtout the spindle instead of stressing the bearings in the quill. anyone have any thoughts on this is worth the extra money? r8 tooling an assesories are pretty easy to come by an that means alot when outfitting a machine but if the nt30 with ER colletts is going to be easier on the machine an the accuracy is there is that the way to go?

thanks