Manufacturing Keyway in a Counter Bore

Dear Sirs:
I was overwhelmed by the response for my previous questionaires. I
hope this issue is going to be another challenging one and going to be
time critical.
I must thank you in advance in this regard.
CHALLENGE: Cutting a keyway of 12F8x100mm long in a counter bore of
Motor Coupling of a Speed Reducer.
We are looking for a High-Productivity tool or system to carry out
Keyway slotting in c/bore of dia 42mm (this bore is having a recess
for 10mm followed by a thru hole dia of 36mm) . At present, this
feature is manufactured in a conventional Slotting machine with DRO
for depth control. This is a EN24 material heat treated to 80kg/sq mm.
PVD coated HSS slotting insert is used for this operation. However the
cutter wears off quickly and tool dragged in the keyway width-wise
causing excess symmetry values (specification: 0.05mm max.). Also,
this is a nasty process consuming a lot of time.
I have come across a key cutter called "eltool"
formatting link
can mounted on a VMC or HMC or Lathe. This tool seems to a promising
one. But I don't have first-hand experience or from my neighbours.
Does anyone have experience with this tool? if so please suggest me if
I can go for this tool.
Also please clarify whether the tolerances can be met or not.
Excepting your answers.
N. Ayyavu
Reply to
natarajan ayyavu
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We bitch about the jobs going overseas and now we are expected to provide free training?
Reply to
Ron Thompson
Hi Thompson
Happy new year for you and your family. There is nothing to be angried at. I am sure you are in are in bad temper. Take Coke and rest peacefully.
For your information, I am going to buy your product if found suitable for us - Of course not for free - OK?!!
STILL expecting answers atleast from others.
With warm regards
Reply to
natarajan ayyavu
Part of the problem is that this is a newsgroup composed mostly of recreational metalworkers, not professionals. Note the start of the newsgroup name "rec.crafts.metalworking".
Thus you really *aren't* going to buy the product (whatever it turns out to be) from most of us. There are a few professional machinists in the newsgroup, and a very few who run companies which sell products to the metalworking trade.
And note that even if we were selling product, you would be buying *one* item (or perhaps a few) -- which hardly makes up for the manufacturing jobs which have migrated out of the US over the past years. Your dimensions suggest that this is not being made for the US market, for whatever value that may have.
This migration is viewed with mixed emotions, because while we deplore the loss of jobs, we are quite happy to buy the machines being surplused from production for our home shops.
I can't really offer the answers, but I have a comment or two to make here -- depending on whether or not I have understood properly what you have said.
What is this? I keep thinking of PCD (Poly Crystalline Diamond), and if EN24 is a steel (which I suspect -- though it sounds more like a European designation rather than one familiar to us in the US (most of the members of the newsgroup, though not all of them.) If it *is* a variant of diamond, it really should not be used in steels, as the erosion rate is quite high -- the carbon in the diamond is absorbed into the steel, producing harder steel, and less diamond.
A blind keyway? I agree that it is nasty.
If it is a seriously hardened steel (I'm not used to the metric terminology for the hardness designation, so I'm not sure), then I would suggest a EDM machine of some sort or other (Electric Discharge Machining). It is slow, but it handles complex shapes with blind bottoms quite well.
I have no experience with it. Looking at the images on the front, I suspect that they might well make the task easier -- as long as you can accept a keyway which either ramps at the end, or which has a semi-circular end, depending on which version you use. I think that the expectation is that you would feed on through for a keyway the whole length of the hub, which I think is not what you were describing.
I'm sure that they can -- but whether they can be met with a process which allows economic manufacture I can't say.
Good Luck, DoN.
Reply to
DoN. Nichols
To the kind attention of Mr. Ron Thompson and Mr. Don Nichols
: ) 2004
Fine. Your answers are eye-openers for me. I understand the human feeling behind this issue. Thank you for expressing them honestly.
Everyday morning I anxiously open newsgroup and found only surprises like these. I am thinking of withdrawing from google newsgroup. Sorry for kindling your feelings. But let me explain to you that we are not grabbing your bread - nor we wish.
In the meantime, I have contacted the tool manufacturers (eltool, national machines) and they are cooperative. We shall buy as soon as technical and commercial terms are understood.
With best regards Nicholson Thompson Ayyavu
Reply to
natarajan ayyavu

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