On Tuesday, October 9, 2012 3:36:38 PM UTC+1, Steve Kelly wrote:
> Thanks to Ian and Dean for the initial cleaning of the 3 in 1, to Dean
> amongst other things for the grinder
> and to Ian amongst other things for getting the keys cut.
> Update so far:
> The machine has not been maintained or used correctly. The apron and
> saddle ways were packed with grease! and the shanks of indexable lathe
> cutters have been re-ground to form cutting tools! or should I say a
> rubbing tools. Hacksaw blades used as shims.
> Maintenance is crucial, daily oiling is necessary and oiling and cleaning
> when in use. if it isn't done you end up where we are now which is
> dismantling the machine rebuilding and re-lubricating.
> There is a fault with the crossways table which results in it getting
> stuck when traversed too far. This is caused by the tapered crossways Gib
> which is adjusted by means of a screw head pushing on a slot in the gib
> which moves it backwards and forwards. The slot has rounded off not
> allowing the screw to contact and move the gib. I'll re-cut the slot which
> should prevent this happening but for the time being be careful when
> traversing the crossways table. There are some parts missing to the
> crossways screw which may be impacting on this.
> The crossways were packed with grease! Someone has gone to a great deal
> of trouble to do this and there must have been a specific reason , anybody
> provide any information on this would be helpful. I am not concerned with
> pointing the finger at anyone, I just want to know if there was an
> operational difficulty encountered with the machine which the grease was
> used to sorted out perhaps?
> I have had the crossways table off twice (thanks Phil) and gave it a
> good clean, removed all the grease and re-lubricated with the correct type
> of oil. I have similarly re lubed the bed ways. There is about 80% less
> friction in the ways now and movement is as smooth as silk.
> I have made a new lock for the tailstock, its fine for the time being
> but will replace with a longer lasting mild steel one when I get the
> correct stock.
> The idea behind the lathe is to cut the stock rather than rub it to death.
> I feel I need to emphasise this point given the condition of the cutters I
> have seen in the hackspace, if your cutter is inappropriate for whatever
> reason it will rub, at best producing a crumbling chip rather than cutting
> some nice swarf, ( cast iron is contrary to this).
> Using hacksaw blades as shims is a bit hit and miss if you are not
> prepared to, or cannot grind your cutter down to the correct size (height).
> The cutting edge has to central to the axis of rotation, it can be ever so
> slightly high but that is the margin. So if anyone is using indexable
> carbide tipped cutters with hacksaw blade shims, how are you going to grind
> your cutter down to the correct height? You can't!
> At the side of the lathe there are the shanks of several indexable cutters
> without the carbide tips that have been ground down as cutters themselves.
> I doubt very much that the shanks are high speed cobalt 42 steel or tool
> steel for that matter.
> Indexable cutters with carbide tips may not be appropriate for light
> lathes either, too much chatter due vibration, so do not expect a fine
> finish with them. Brazed carbide should be fine but presents height
> problems when sharpening.
> So in my opinion, presently we are limited to 12mm shank HSS which will
> need to be ground to the correct profile etc.
> Last thing I did on Monday when I was in was grind down an appropriate
> HSS knife cutter profile.
> I intend doing some cuts to further test the current set up. I'll let you
> know how I get on.