Member postings for Y C Lui

I have problem in getting good finish when side milling with my Emco FB2 mill. I recently did a cutting test under different settings and found that the relatively poor finish occurs only if the cutting is done along the Y axis. The gibs of the table have already been readjusted so loose gibs should not be the cause. The only reason I can think of is the poorer rigidity of the head which is expected to flex / oscillate more along the X axis. Would like to hear you guy's opinions

Details :

machine : Emco FB2 bench mill, weight about 300 lbs
workpiece material : 6061 aluminium
tool : Carbide end mill 10 mm diameter, run out measured next to the collet face = 0.01 mm TIR
spindle speed : 2000 rpm
feed speed : 65mm / min power feed ( along the X axis ) , about 80 mm / min manual feed ( along the Y axis )
depth of cut : 0.1 mm ( finishing )
length of cut : 9 mm
conventional cut
all axes with no motions including the quill locked
cutting fluid used ( Rocol )
set up shown in picture 2
surface finish comparison shown in picture 3.

Typical finish of side milling along the Y axis :

https://www.hobby-machinist.com/attachments/p1060758-jpg.391089/

Test cut set up ( milling along the X axis ):

https://www.hobby-machinist.com/attachments/img_6365-jpg.391335/

Test cut results :

https://www.hobby-machinist.com/attachments/3_28-jpg.391342/

Edited By Y C Lui on 09/01/2022 05:18:19

Thanks, Nigel. May I know more about the shimming that you have done ? what material is the shim made of ? how big should it be ? will it affect the rigidity significantly ?

Regarding the magnitude of the tilt, I indicate a square on the table and found that there is a offset of 0.03 over a vertical distance of 100 mm. How much did you see in your FB2 ?

I recently found that my EMCO FB2 has the vertical slide tilted backward and head tilted forward slightly. May I know if how it can be fixed ? the machine does not allow any adjustment of the tilt along the Y direction but just X.

I have owned an EMCO Compact 8 lathe for almost 20 years and just recently I found that extensive cracks have developed in the lead screw mounts of the cross slide table and that of the compound. Has any Compact 8 owner experienced the same thing ?

Anyway, these two parts will need be replaced. I understand that the EMCO division making hobby machines is already out of business but is there any chance that some suppliers may still be carrying these parts ? Any information that will help to bring my compact 8 back to live again will be very much appreciated.