small mill for machining steel. Max spend £500 including computer

[Andrew Wilding]

rough machined spindle and housing



pulley key machined



spindle exploded assy

[Andrew Wilding]

I thought I would post an update on the mill progress. I have been a bit busy fitting a kitchen, drawing tractors for my son and somwhere along the way had time to make anther sprog - due soon!

As you can expect progress has not been great on the mill front, however I have the spindle operating and have made some cuts in delrin then steel . The machine performed ok but I am now making improvements. The next few post will bring you up to latest progress

[Andrew Wilding]

These shots show the spindle drive pulley arrangement. Tensioning of the high speed belt is achieved by rotating a block in which the counter shaft is mounted (eccentrically). The low speed (v belt) is tensioned by rotating the pulley assembly.



note that no guards have been added yet but are on the list before the mill is complete.

[Andrew Wilding]

The anti backlsh seemed to work ok but I had an idea how to improve them. I modified the design so that the two nut halves are radially fixed to each other but axially free. this was acheived using 4 off 3mm rods in close fitting holes in both nut halves. The slave nut is threaded with a fine thread and an outer collar threaded on. this is biased with a tprsional spiring to take up any backlash. hopefuly this greasy sketch might help - it was used when I was machining the parts so it is not the clearest:


drilling the holes for the rods in the nut halves

[Andrew Wilding]

machining castelations in the collar


some surgery to the bed to fit the larger diameter nuts in - I love machining cast iron!



X axis nut in position but biasing spring not fitted over collar (lash up wiring shown!)

[BillTodd]

Nice build :)

Bill

[Andrew Wilding]

one more picture showing x axis nut