Lane and Bodley 400hp Corliss

[steam guy willy]

i think the difference between the cutters is ..one has strait cut teeth and the other has angled cut teeth ? Willy.


...initially was set on using a woodruff cutter but after some stern advice ended up using a Tee slot cutter which worked really nicely...


So, I have a silly question. What's the difference between the T-slot cutter and the Woodruff cutter that made the big difference. They seem rather similar to me, which probably means I'm missing the finer points of both.

Thanks,
Kim
[/quote]

[sco]

...initially was set on using a woodruff cutter but after some stern advice ended up using a Tee slot cutter which worked really nicely...

So, I have a silly question. What's the difference between the T-slot cutter and the Woodruff cutter that made the big difference. They seem rather similar to me, which probably means I'm missing the finer points of both.

Thanks,
Kim

Yes this was a learning exercise for me also Kim - a Woodruff cutter will only cut radially whereas a Tee slot cutter will cut radially and axially as there are two  sets of teeth - one angled to cut radially and cut on the top face and the other set angled to cut radially and on the bottom face.  The Woodruff cutter would probably have done the job but if I'd needed to slightly widen the groove would be more likely to 'push off' rather than cut cleanly than the Tee slot cutter.

Simon.

[Kim]

Thanks Simon and Willy for the replies!

Makes sense when you know the secret!

Kim

[sco]

Final operation in the dividing head setup was to machine a circular register using an end mill and rotating the dividing head.  I wanted to machine the register in this setup to guarantee it was co-axial to the wear plate grooves - the register can then be used to locate the frame axis for machining the diameter that locates the cylinder block - that's the plan anyway!

Ramon also recommended machining a reference edge along the frame axis again to aid alignment for future machining ops so I added that along the bottom - it shouldn't be visible but can be filled and painted at the end if necessary.

After triple checking the drawings to make sure I hadn't missed anything I finally removed the frame from the dividing head setup - seems like it's been in there for weeks!

Simon.

[paul gough]

Hi Simon, Looks like this component became something of a 'thinking machinists' puzzle, if not a headache. Regards, Paul Gough.

[sco]

Hi Paul,

Not been a headache so far but definitely a challenge mainly due to machine size limitations.

Simon.

[Ramon Wilson]

An excellent and well deserved result Simon 

It's always a good moment when you break that set up down with everything gone to plan. Well done indeed.

Keep that good work up - Ramon

[sco]

Thanks Ramon.  Next op on the frame was the cylinder head mounting detail, I rotated the mill head 90degrees and used a large angle plate to locate the frame.  The quill was centred on the previously machined register and then the boring head used to machine the internal diameter for the head cover which I made a very light press fit. 

Then it was just a case of drilling the fastener holes - I found rotating the mill head messed with my head a bit so required maximum concentration to reproduce the hole pattern correctly - I spotted through the head cover first with felt pen to show up any obvious mistakes before they happened :-)

Holes all came out in the right place but I am going to need some kind of back spot facing cutter to clean up the bolt face.

Simon.

[Ramon Wilson]

Another nice result Simon and glad your holes are in the right place - I found four of mine well displaced this morning 

Making a reverse spot-facer is easy enough but that left hand hole (as you look at the pic) might prove a tad difficult given the distance from the face it will have to start - if so maybe you could relieve that using a ball nose end mill to give the S-F a start.

Ramon

[sco]

Ramon,

You mean the ball ended mill axis would be vertical in that picture?  Makes sense but isn't that going to leave a witness that won't be present for the other holes?  I was thinking I was going to have to grind away that whole face to create a smooth profile that gave a similar clearance for all the holes.

Simon.

[Ramon Wilson]

Hi Simon -

Yes that would leave an individual witness but if, as you suggest, you grind that area away to give even access to all holes for the Spot facer then the problem's solved 

Reclaimed my misplaced holes - good old JB Weld to the rescue

Ramon

PS When you make your cutter don't forget to cut the teeth the other way  (for normal rotation direction that is)

[sco]

Ramon - glad you got your holes sorted and thanks for the reminder about the tooth direction as wouldn't have thought of that!

Simon.

[Jasonb]

does look like there is a bit more metal on teh left hand side of the photo so you could file/grind a bit away so you don't get groove.

Spot facer can be filed up from a bit of silver steel quite easily. I ran in reverse then they can be used as normal spot facers the right way up.

[sco]

Jason - good tip on the spot facer but my mill doesn't have the ability to run in reverse.

Simon.

[Ramon Wilson]

Yes good tip Jason  I can do that now but pre VFD was same as Simon

Simon - you may not be able to get a grub screw in if the wall thickness isn't up to it. All those I've made so far just have a free floating pin through a hole. It can just be held with a dab of thick grease, tiny piece of blue tack, sellotape, what have you. The rotational speed is well down so never had a problem with fly out. Last one made just had a 'screw driver' slot across the bottom locating on the cross pin.

FWIW I rarely temper mine but always quench in oil as opposed to water on hardening.

Yes, fixed the holes now lost a 3mm slip 

Ramon