Back to Reamers

[Bluechip]

Hi Folks

Bernd suggested in a previous topic we start a post on reaming. Here it is.

I have trouble getting a decent finish in reamed holes. This has been going on since 1971 in my case.

I use reputable UK made reamers, not worn out, hand reamers with a taper, in a Jacobs chuck fitted in the tailstock.
The Myford has been set up with 2MT alignment bar and has no significant error. It turns parallel to .0008" in 10".
Good enough for me.

If I ream FCMS, the hole is OK. Nice smooth finish, no, or little, chatter pattern etc.
Brass and Ally, either chatter or score marks, usually both  

Been fooling about this AM with brass, trying different degrees of cut from about .002" to .020", revs from 40 ish to 900 ish, just the same. Tried smacking it through and very slow. With & without lube. ( Rocol RTD ). I always get some marking in the bore.

Would some kind soul drop a few ideas in re: where I'm going wrong.

 

Dave BC

[sbwhart]

Hi Dave

The problem may be that the reamer is too sharp try a blunt/well used one to see what you get, or taking the edge off a reamer with a stone or diamond hone.

Cheers

Stew

[bogstandard]

Dave,

hand reamers with a taper, in a Jacobs chuck fitted in the tailstock

If you mean a tapered lead in, and a square drive on the back end for a tap wrench.

That just might be your trouble, hand reamers are for use by hand, machine reamers are for use on a machine. Straight flutes are for thicker materials, spiral flutes are usually used on thin material to give a little bit more support.

I have just got back in from machine reaming a load of bores in brass. 3/8" bore, 23/64" pilot drill (approx 0.015" smaller), 300 RPM, no lubricant, every one perfect.

For a hand reamer, I would keep that difference to about 0.005" or even smaller.

I don't think you can run your machine slow enough to use a hand reamer. How fast can you turn a reamer if you do it by hand? Most probably about 20 RPM if you really went at it, which you don't want to do any way.


Bogs

[kvom]

I'll just parrot what I've been told at school:

1) Drill 1/64" smaller for holes up to 1/4", and 1/32" smaller for larger holes.

2) Speed for reaming about 1/3 that for drilling

3) Use machine reamer, and chuck to keep as long as possible.

4) Cutting oil

5) Smooth continuous feed into the hole and out again.

Seems to work for me.

[Bluechip]

Hi Stew , John, Kvom

Thanks for replies. I will try dulling a reamer to see what happens. I have one parallel reamer, 1/4" , 2 straight flutes, that does seem to be better, so I think John is right. I've always been annoyed 'cos they all work fine in FCMS.
The Myford goes down to 25 rpm ( just had to have a look   ), so I'll have a go at that. As an aside, for many jobs, it doesn't matter too much. The hole is not seen usually. Irksome, 'cos I know the rough hole is there.

Maybe I should get a machine reamer or two, maybe 1/2" & 5/8", for small cylinders. If they're OK then it's not me.
Although that's usually the case  

Dave BC
 

[bogstandard]

Dave,

I actually bought a full set of machine reamers up to 1/2" in 1/64ths from Tracy Tools, all 1MT shanks for 60 squid.

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

Look at the very bottom of the list.

They are not all the same profile or the same manufacture, but are all good quality and brand new, and do a wonderous job if you are into reamers.

But they do single ones for about 8 squid upwards. Make sure you get the tapered shanks, then you know they are for machine reaming.

Bogs

[Bluechip]

Bogs,

Thanks for the link, I have used them in the past for tools, always been happy.

I have been trawling around and I've been baffled. Can you please give a hint or two about this 'Machine Reamer' business? Some seem to me to be just like hand reamers, ie, spiral flute, but with a MT shank. So, apart from being a more rigid set-up than a chuck, why would they be better? Is the lead different?

And what is a 'Chucking Reamer'? Some are described as 'Machine Chucking Reamers'. Much the same as my thoughts. (I had a slightly different spelling.)  Parallel shank, spiral flutes on these.

It all seems so simple. Drill a hole a bit smaller, poke a reamer through, and there you have it. Nice, accurate, well finished hole. Well, NO. I don't. Apart from FCMS.

Another small point. If you have a close look at some Pics. in ME & MEW, I'm not alone ... nothing to do with Mechanical Dandruff either ...

Dave

 

[bogstandard]

Dave,

I hope I can help, but don't expect it to be 100%, I hope someone will pick me up and correct it.

This is for parallel reamers only.


Hand Reamer

Will have a square end on it, so that it can be turned with a tap wrench.

Can be straight or spiral flute. Straight is usually for deeper holes, spiral for shorter holes or plate.

Normally, there will be a rather long lead taper on it. So the reamer has to penetrate thru the hole by at least the taper length, or else you will end up with a tapered hole. I personally have never come across a bottoming hand reamer, for use in blind holes, and so has no lead in taper, but they might exist.


Machine Reamer

Can have almost any shaped shank, either plain straight, or morse taper. They will not have a square drive end on them.

Normally they have only a very small or if a bottoming reamer for a blind hole, no lead in taper.

The cutting heads come in all shapes, depending on the use they are made for.

Chucking reamers, as far as I can understand are just another name for a machine reamer, and have just plain shanks for holding in a drill chuck.

The sets of adjustable reamers you can buy are for hand reaming only. There are some machine adjustable reamers, but are a totally different and more robust design.

Hope this explains a little towards what you need to know.

Bogs

[raynerd]

Excellent post so far... I`ve only just started using reamers and building up a small set for the sizes that I have needed. Currently I have only purchased hand reamers but I did get a small collection of very odd sized reamers in all the tooling that came with the lathe. Bogs post has gone some way into explaining the different uses but I`m still not entirely clear when one should use a machine reamer and when to use a hand reamer. Clearly as bogs has explained there are different profiles of each reamer but how do you know quite simply when to use a hand reamer or a machine reamer?

Sorry, perhaps this has been explained and I have not understood.

Chris

[John Hill]

Reamers are as yet still items to be discovered by me so I am watching this topic with great interest.

[bogstandard]

Very easily explained.

Hand reamers when you can't get it on a machine to ream the hole.

OR

You've only got hand reamers in the size you want to use.


Bogs

[raynerd]

Ahh! - so since the majority of the work I have done could have been done by machine really I should be going down the route of purchasing and using machine reamers. Cheers
Chris

Very easily explained.

Hand reamers when you can't get it on a machine to ream the hole.

OR

You've only got hand reamers in the size you want to use.


Bogs

[Bluechip]

Hi Bogs & others ..

I think the light may have come on .. Just been miking some reamers I have ..

The hand reamers seem to have about 1" of lead on them. The 1/2" one does anyway. So ...
If it has 6 cutting edges, I have circa 6" length of cut on. Not a lot of depth, but I would expect an awful amount of chatter if I did it on the lathe. I would not dream of attempting it. But, in effect, that's what I do using a Hand Reamer in the tailstock chuck.

The 1/4" reamer with straight flutes appears to have virtually no lead at all. It's difficult to measure in practice.
This is OK.
Maybe that's the reason? If it is why didn't I think of that 38 years ago ?

I have one very ancient 1MT 11/32" reamer. Got it with the Myford. Never used it 'cos never wanted a 11/32" hole. But, it reams brass beautifully. What a b*gger.

It looks about worn out too, maybe Stew's theory about dubbed edges is right too.

Tracy Tools will get an order tomorrow ..


Live and learn ..

Dave

EDIT 2 MT 11/32" !

[Darren]

Here's my modest collection of reamers

top four are hand reamers and the bottom one is a machine reamer. With an old bush on it to protect the flutes.



The machine reamer is an adjustable type with a tapered screw in the end. I have used this one a lot. made about a hundred or so replacement bushes for record players.



To use I simply drill the hole in the brass (I have used leaded PB1 and aluminum brass) and run this through at around 600rpm holding it in the tailstock. It's 31/64 or just under half inch.

Never had a moments bother with it, it just does....

I used this type because every bush, or I should say the shafting was slightly different in size and close tolerances were the order of the day.

[Bernd]

Also reramers do not cut on the side flutes. The small chamfer on the end of the reamer does all the cutting.

Also NEVER EVER run a reamer backwards in the work. You'll ruin it.

These are my 2 cents worth of info on this thread. 

So far from what I've all read you guys are doing quite good in sorting out all the tricks with reamers. For those with a chattering problem, I've heard and read that a lard, such as Crisco is good to use for a lube. Really don't know as I've never tried it.

Bernd

[Bluechip]

Hi Troops

Many thanks for the advice & suggestions. Done a bit of a trade today .. swapped some Imperial ballraces for Machine reamers ..



We will soon find out if it's me or the hand reamers  ..

Dave BC

[Stilldrillin]

Good luck Dave!

They really shouldn`t ha been clunked together. Dings on the lands = oil grooves in bore....... 

Good to practice with though. 

David D

[bogstandard]

Very nice starter collection there Dave, a very good swap.

Now lets see if it is really the type of reamer that is causing all your problems.

By measuring these up, and comparing the readings you got with the hand ones should explain what we were on about with the taper lead in.

Dave D. is perfectly correct by the way. If you put each one in a small plastic bag, or wrap a bit of paper around them and tape it up (NOT in a damp environment, it can cause them to corrode, unless you give the paper a coating of oil first. Then the tape doesn't stick) will help to protect the precision cutting edges. If my good reamers are not in a plastic or cardboard protection box, a bit of dry drilled wood is used for a stand, again in a damp area, get some oil into the wood before using.

Bogs

[Bluechip]

Hi Folks..

They are like that for 'illustration' purposes. When I got 'em they had PVC insulation tape wrapped around them, which had gone 'orribly slimy, as is it's wont. So, I cleaned 'em off with thinners. I must see if I can get some more of the plastic mesh sleeving, which is what I used to use. Dunno what it is called though. You've seen the stuff, looks a bit like co-ax outer, but made of grey plastic. Used in cable forms. Probably no longer made, like owt else that's useful  

Dave

Edit .. Good Grief, it still exists .. memo to self: lie down in darkened room to recover ...

http://www.rapidonline.com/Cables-Connectors/Sleeving-Heat-Shrink/Sleeving/Expandable-braided-sleeving/71513/kw/sleeving

[Stilldrillin]

Hi Folks..

They are like that for 'illustration' purposes. When I got 'em they had PVC insulation tape wrapped around them, which had gone 'orribly slimy, as is it's wont. So, I cleaned 'em off with thinners. I must see if I can get some more of the plastic mesh sleeving, which is what I used to use. Dunno what it is called though. You've seen the stuff, looks a bit like co-ax outer, but made of grey plastic. Used in cable forms. Probably no longer made, like owt else that's useful  

Dave

Edit .. Good Grief, it still exists .. memo to self: lie down in darkened room to recover ...

http://www.rapidonline.com/Cables-Connectors/Sleeving-Heat-Shrink/Sleeving/Expandable-braided-sleeving/71513/kw/sleeving

Blummin good idea young man! 

David D

[CrewCab]

memo to self: lie down in darkened room to recover ... 

It's almost like one of those "take more water with it moment's"     .................. which I have frequently 


CC

[Bluechip]

memo to self: lie down in darkened room to recover ... 

It's almost like one of those "take more water with it moment's"     .................. which I have frequently 


CC

I see from your 'Changes Afoot' pic. ... You're not joking .. libation does not look over diluted, does it ?

Dave BC

[CrewCab]

Ces't la vie mon ami  ..................... etc    in the pic, believe it or not, (this time) it was Alcohol Free Lager  ............. though my two lad's may have missed that "bit on the label"  ............. we keep it in stock for Mrs CC who is diabetic 

Anyway, how's the reaming going, ...........as for me milling is suspended till I'm allowed back on mi' feet ............and even then I 'spose bloomi'n work will interfere with playtime 

CC 

[Bluechip]

Hi CC

Reaming? .. chance would be a fine thing. Started this AM fixing a mates Inverter, after I found some FET's. Crappy Chinese device. Then took it back, went to another mates house to attend to his greenhouse, pinched some peppers tho. Got some groceries. Came home. Freakin' oven wont work !!
Decided to have a look, door interlock appears knacked. No big deal ? Wrong!! Tried to get side off, can see switch, can't get at it. Need to take side off. Side won't come off until back is off. Back won't come off until top is off. Top won't come off until the entire lousy double oven is completely out. What a bl**dy pantomime. Unscrewed about 10 ^ 6 self tappers, sorted loose switch out in about 30 secs. Then took another hour to get the oven re-installed. Roll on WW3, then I can bomb the crap out of AEG. I have used my entire allocation of profanities until Jan 23 2010. Yeah, reaming. I seem to have a vague recollection of reaming from the distant past. Must try it some day, if I get the time

PS What's 'alcohol free Lager' . Strange phrase. Reminds me of 'Slightly Pregnant' 


Dave BC