Reamers question

[AdeV]

Again, apologies for asking this, if it's supposed to be dead obvious...

Currently, I don't have any reamers, just drill bits & end mills/slot drills. I do have a large boring bar, but it won't fit in the mill (it WILL fit in the lathe, however, when I finally get it), and I don't have a boring head for the mill either (that's a future project...)

I'm kind of assuming, therefore, that I need to get some reamers in order to make properly sized holes? But... what to get? I'm guessing chuckable (rather than hand-held - I'd want to use them on the lathe and/or mill)? What's best, straight or spiral flutes? Aren't spiral fluted reamers basically just long thin end mills? Should I get tapered or straight reamers? They look a bit pricey too; where's the best place to get a low-priced starter kit? (I just spent all my spare £££ on the lathe, and other "projects")

So many questions.... I've got lots more stacked up, but it's too late in the evening to ask them now...

Thanks in advance for any replies  

[sbwhart]

Hi Adev

Your right reamers are costly, I've got a few thats I've got over the years when I was stuck and had no alternative but to buy.

Types of reamers:- hand and machine, and lots a variations in between.

Hand reamers are usually straight fluted and are ground tapered, you need to pass them compleatly through the hole to get size, they have a parallel shank with a square on the end to take a tap wrench.

Machine reamers usually have a spiral flute and are ground parallel, the shank can be parallel or it can be morse tapered.

A reamer is used as the finish cut you have to drill a hole thats slightly below the (0.5mm ish) use a low rpm a slow feed and plenty of coolant, the reamer should give an accurate hole size with a good finish.

Poor mans reamers:- drills

Get yourself some good quality drill sets, metric, imperial, Number and letter sizes.

To get the best out of them:- again as you would a reamer drill the hole slightly under size and then put your drill of the required size through, you should end up with a hole that for most uses perfectly acceptable.

Another poor mans reamer is silver steel (drill rod) you can make D bits or by simple filing a flat at say 15 deg until you got something that looks like a pen nib harden it up and then use as a reamer you can get acceptable results there is a pic of this somewhere on the forum.

Hope this helps

Stew

[kvom]

All the machine chucking reamers I have are straight flute and straght shank.

I was taught to ream at about half the speed used for drilling, use cutting oil, and feed in and out smoothly.  The drlled hole is 1/62" smaller if less than 1/4", and 1/32" smaller above that.

In addition to the "standard" hole sizes, a set of over/under reamers (+/- .001") are useful when you want a press or sliding fit.

[75Plus]

A cautionary note regarding reamers. NEVER ever turn the reamer backward. Doing so will dull the cutting edges, quickly.

Joe

[rleete]

This is probably not the answer you're looking for, but I don't think you need reamers at all.

We're not making anything that needs that perfect diameter.  Well, at least I'm not.  You make the bore, and make it smooth.  If it works out to .250 or .240 or .260 doesn't really matter, because you can make the piston or valve to fit that number.  It's the fit that's important, not the actual size.

So, you drill or mill or bore, and then lap.  Nice shiny, smooth hole.  Take a measurement, and start cutting whatever goes into that hole.  When you get close, you start checking whether that part will fit into your smooth hole. Take a bit off - another cut, a file or even just some emery paper.  Keep checking, more and more, the closer you get.  Using this primitive method, I can get anything from a nice sliding fit to a light press fit.

The only caveat to this is if you are making something like a multi cyclinder engine.  In that case, you can still use the above method, but you'd better be sure to mark the parts in some way to ensure that the parts are a matched set.  I use a tiny carbide scriber to mark the parts in an inconspicuous location.

[Krown Kustoms]

I normally use an endmill as a reamer.
Be careful of your endmills though, they can be a couple thous off +/-.
They are one of those things where you get what you pay for -2 dollar endmill = 2 dollar grind-
I have used drill rod (silver steel) but they keep gtting turned into axles and shafts for some reason.
Every time I need one I have used it for something else and need to make another.
-B-

[bogstandard]

There is a rule of thumb for straight and spiral reamers.

Spiral reamers are normally used on thinner materials so that there is more of a supporting cutting edge in the hole to help keep it straight.

You can get some chucking or machine reamers with a screw in the fluted end. People think that this is to adjust the size, which is downright silly, because you would end up with tapered flutes from the wrong direction. If you do come across one, DO NOT touch the adjusting screw, otherwise, if you do, you may as well throw it away. The screw is there so that when the reamer goes dull, the flutes can be expanded slightly and the reamer ground back to it's original size. A thing not possible on a normal reamer, when they are reground, it is usually to the next size down.

I was only talking to Darren the other evening on Skype about how I had found a few new chucking reamers, 1/4", 5mm & 8mm for very low prices. By searching around on the web, you can pick up a few odd ones and gradually build a set up for rather little money.

At the bottom of the list on here, you can buy tapered shank (machine reamers) reamer sets for very reasonable money.

http://www.tracytools.com/reamersassorted.htm

You really need to phone them up and see what they can offer you, just to make sure you get the correct type for what you want. I managed to get a set of 1/8" to 1/2" in 64ths for just over 70 squid, nearly 30 reamers, and all high quality HSS.


Bogs

[trevoratxtal]

Hello AdeV
As I see you are in the  UK then
May I add three other possible ways of building up a set of reamers.
1. A set of adjustable reamers (the Chinese imports with care can get you out of a hole, no pun intended)
Ebay sometimes have them.
2. Government surplus stores, there are still many about, and prices are often very low.
3. The best of all Car Boot sales. over the  last few years I have found over 100 imperial and metric reamers for silly prices.

Best of luck
Trev.

[AdeV]

  Many thanks again chaps, some great info there

Trev - yeah, carboots & the like will be my source, I think. Although it's not really the season at the moment; but no matter...

Krown Kustoms - I like that idea; I did wonder if an endmill would be suitable. I'd have to hold them in a drill chuck, though, I don't have a collet system for my lathe yet (mmm,  strikes again I think).

rleete - any answer that involves not spending money is an answer I want to hear  Appreciate that when making model engines & stuff, it may not matter about the hole size; but for repair work or new parts, it just might. But for now, I'm happy to go with your suggestion 

[bogstandard]

AdeV,

Before you go considering tools from places like car boots, if it ain't in it's protective box or packaging, leave well enough alone. Unless of course you possess a tool and cutter grinder.

I have thrown away better than most you see at places like that.

If they haven't had the correct protection during their life, you can almost guarantee they will be dull, and absolutely no use for anything other than grinding up to make a centre punch out of.

I have seen boxes upon boxes of drills, reamers, taps and dies, all piled together, so don't even bother rooting thru them, they are worth nothing more than their scrap value.
 
On the other hand, I have bought boxes of brand new and protected tooling from car boots, and found them to be ideal, just don't ask where they came from. But they are very rare finds nowadays, in fact I don't think I have bought anything concerning cutting tools for at least a couple of years, maybe longer.

If you are tight on finances, then you will be much better off saving your pennies, and buying new individual ones only when they are required. If looked after, they should last a lifetime with the sort of work you will be doing.

It is truly a false economy buying old junk tooling, and having to throw it away or stick it under the bench, after you have ruined a perfectly good job with it.


Bogs

[AdeV]

I have (or will have) a pair of tool grinding wheels, when I pick up the lathe, but I think they're really only for grinding lathe-type cutters, rather than end mills & other complex shapes. So I shall heed your advice & be careful of what I choose. I may still pick up "some" cheap used reamers, just to practice with; but they will just have to be pennies.

WRT rusty tooling; yeah, I saw a lot of that at the Malpas vintage festival. There were a couple of stalls with decent looking stuff in them, and I managed to pick up a long 1/2" end mill (in it's protective plastic box) which cut my finger just as soon as I looked at it...

Anyway, must go, picking the lathe up tomorrow....

Thanks - again - for sharing your wisdom! 

[sorveltaja]

A cautionary note regarding reamers. NEVER ever turn the reamer backward. Doing so will dull the cutting edges, quickly.

Joe

I'll second to that.