Hi,
Bit of a newbie question.
I am about to start my first project, the classic Stuart 10V. This is
calling for a number of reamers.
Looking at various ME suppliers, I am confronted by "UK manufactured"/"top
quality" products or significantly cheaper "imported" ones at typically less
than half the price.
Simple question, what is the difference? Are the cheap ones reliably
dimensionally accurate? Which is after all what I am using a reamer for. Or
is it the case that the "best" ones are more durable and more suitable for
long life in a production enviroment? After all for this project I only need
to ream a couple of holes in each size.
Any brands that can be recommended or are best avoided?
Second quick question, I have also seen adjustable reamers. What is the
application of these?
As always, advice would be much appreicated.
Regards
Stuart
Hi Stuart,
For the cast iron you will be reaming, you will not likly need the
more expensive ones. I think you'll probably need streight-flute in
1/8, 5/32, and 9/32" for the 10V. It is not a demanding application,
any HSS ream of proper size should do fine.
That said, one hopes that this is just the start of a lifetime of
enjoyment in machining, and perhaps you'ld like to invest in owning a
fine set of reamers for future use.
I think the important thing is to learn how to properly handle and use
whatever reamers you choose. Run about 1/3 the speed that you would
use to drill. Never run one backwards, I hope you know that. Also
leave the correct amount to take off after rough drilling for the ream
to cut, depending on diameter, say from .003" to .007 would be a
working range for the 10V size holes. Keep them in protective covers
when not in use, avoid nicking them. Sharpening a ream is tricky.
You'll need to get experience before you try it.
Good luck,
Thanks Paul,
I last used a reamer in 1980 when I did my apprenticeship, so I know the
basic do's and don'ts, although it is a bit rusty.
I am rapidly realising that this hobby is getting somewhat expensive with
regard to set-up costs, but as you say once the investment is there, I will
have the kit for life.
I agree with you regarding protection and looking after quality cutting
tools. I did my apprenticeship in the aircraft industry and everything was
supplied new with a waxy protective coating. I must admit I was somewhat
surprised when attending my first ME exhibition last year to see some of the
trade stands selling reamers piled loose in trays, with nothing stopping
them knocking against each other.
Stuart
wrote:
Hi Stuart,
For the cast iron you will be reaming, you will not likly need the
more expensive ones. I think you'll probably need streight-flute in
1/8, 5/32, and 9/32" for the 10V. It is not a demanding application,
any HSS ream of proper size should do fine.
That said, one hopes that this is just the start of a lifetime of
enjoyment in machining, and perhaps you'ld like to invest in owning a
fine set of reamers for future use.
I think the important thing is to learn how to properly handle and use
whatever reamers you choose. Run about 1/3 the speed that you would
use to drill. Never run one backwards, I hope you know that. Also
leave the correct amount to take off after rough drilling for the ream
to cut, depending on diameter, say from .003" to .007 would be a
working range for the 10V size holes. Keep them in protective covers
when not in use, avoid nicking them. Sharpening a ream is tricky.
You'll need to get experience before you try it.
Good luck,
You will need reamers once you get onto more demanding
projects, but my first effort was also the 10V and I
just used D-bits made out of silver steel.
Worked fine.
All the best,
Peter
Stuart,
I started, like you, on a Stuart 10V over 20 years ago, having
absolutely no background or training in metalwork.
It's hard to remember now, but I *think* I bought 1/4" and 5/16" Presto
reamers to do the 10V. I later bought a set of imperial reamers - IIRC
from Tracey Tools of Devon. These have been fine for the rather limited
use I have given them over 20 years. I have supplemented them with some
decent quality larger ones, and some metric ones, bought quite cheaply
at exhibitions. Like you, I don't much care to buy cutting tools after
they have been rattling round in a pile for months, but if you look
around you can usually find boxed or plasti-dipped ones. IIRC, my
largest reamer is 3/4", and you wouldn't want to buy many of those at
full retail. Anything this size or above (or even quite a bit below) is
best done by boring anyway, especially if you want a good bore.
BTW, I prefer reamers which are spiral cut; I think (though I have no
hard data) that they are less prone to chatter. This can happen all too
easily with straight flute reamers and leaves the bore looking like it's
corrugated. Not sure why, probably using too high a speed.
If you are careful, you should be able to manage without reamers for a
project like this. New reamers cut a few tenths of a thou oversize, to
give a good fit for rotating shafts; drills are often a couple of tenths
undersize but (as Dave Baker explained in a very useful post in April*)
if you run them too fast they will cut oversize. Used carefully you
should be able to get a decent shaft fit with a new drill, especially if
you drill undersize by 0.5mm or so first.
One of the problems with reamers is that most of what you can easily buy
are "hand reamers", which have a long lead-in (which does the cutting)
and are bloody useless at sizing blind holes. Using them by hand, as the
name suggests, is asking for an off-centre hole. Machine reamers have a
very short 45 degree lead, and will size a blind hole, but are even more
impossible to use by hand. I am building up my small collection of
machine reamers for blind holes.
As for adjustable reamers, I bought a set of these (also from Tracey
Tools) about 20 years ago, and I have yet to find a use for them! Others
may tell you what they are useful for, but I can't.
David
* Look for thread entitled "Reamer reaming oversized", late March/early
April 2009
Stuart,
I have some ST documentation which may be of interest to you, but I
was unable to use your email address. Send me a direct mail to:
airforce at toucansurf dot com
Richard
For some of the castings - I think one requires a 5/8 reamer IIRC, have a
think if the part can be mounted on the lathe and bored to size - the
flywheel on my machine has a 7/16 reamed hole specified, which seems a bit
pointless when the wheel is on the machine already and set up ready to be
bored! Point is the big sizes get very expensive quickly, and boring is an
alternative.
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