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.
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.
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
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.
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.
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
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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