(this is a long winded post and I make no excuses for it, as long as it helps
)
Chris,
It was too hot for me today to do anything on the house or garage, I don't like the heat,
So I decided to go into the cool basement and play with the shaper instead. I did a bit of fiddling, tidying up some dials and adjusting the belts.
To give it a whirl to see what it could do after some adjustments I decided to give it a real tough job by cleaning up the rusty-est bit of metal I had to hand. This is cold rolled steel. I had some similar recently that I could not drill or mill. It just broke tools.
It was suggest by some members on here that ageing this sort of material by leaving it to rust forms a real tough skin which is not only hard but also abrasive to tooling.
I would not want nor suggest that you put a milling cutter anywhere near it. Too expensive to destroy in one pass....
But lathe tools on the other hand are cheap, and HSS is easily re-ground to form a new edge when it dulls.
I machined all the surfaces here with no re-sharpening, heck I didn't even touch the bit up for this job from the last time I used it.
Well it don't come any rustier than this piece I'm about to demonstrate.....btw, I long ago asked Helen to keep an eye out for any bits of metal on her travels when walking the dog. She's dragged home bits and bobs inc this one which is from a bar over six feet long....!! I've no idea how she managed it cos it sure was heavy...
Here I have adjusted the shaper to a high speed , gear No4, and short stroke. Best to keep the stroke as short as you can to use all the power in that distance. If you doubled the length of the stroke you would only have half the power whilst cutting. Worse if you more than doubled it. I'm using a lathe tungsten tip here.
Cutting depth 50 thou/1.3mm table transverse 10thou per stroke.
A video to give another aspect to what I'm trying to describe. Cutting depth 50 thou/1.3mm table transverse 10thou per stroke.
Here you can see I have turned the work 90 degrees and at the same time lengthened the stroke. This saves cutting time as the table has less distance to travel. However, because of the longer stroke I needed to use the next lower gear, No3. I've changed to a HSS toolbit.
Now turned the plate on its side
First pass halfway across. Cutting depth 50 thou/1.3mm table transverse 10thou per stroke.
First pass all the way across
2nd pass, Cutting depth 50 thou/1.3mm table transverse 10thou per stroke.
Final pass, setting changed to Cutting depth 5 thou transverse 5 thou per stroke.
As you can probably tell, my machine is only small and has a 1/3rd HP single phase motor. I was mostly using 3rd speed of four and it barely cut 50thou/1.3mm depth. Mind you I think that's impressive as it is. I could have used 2nd speed to give more power but it would have taken longer.
But, please bear this in mind, even at 1/3rd power it broke the vice tonight and I had to carry out a small repair job on the milling machine before I could carry on. On the vice there is a little clamping plate below that holds the moveable jaw down. The srew that fixes it sheared under the pull of the cutting forces. I had to mill it out and re-tap the vice in order to fix it. (and I didn't have a jam, this was just normal cutting forces)
I say all this as I hear talk of fitting 1HP motors to shapers....that's 3 times the power that I have.
Now just imagine if you get a jam, my motors stalls, 1HP could tear the machines inner workings to bits........just a thought I think you should consider.
It great thinking if you can give it more power to plough through the cutting process, but bear in mind that the machine is also feeling the pressure and just may not like it.
This applies to any machine, shaper mill, lathe etc. I have seen many mini lathes fitted with huge motors...I wonder how long they last....
