Adjustable Reamers

[DanielParticipant @daniel]

Hello All,

I feel a complete dunce; but could somebody explain to me how to adjust an adjustable reamer ?

Playing with the nuts at either end doesn't seem to have any effect, other than trying to twist the blades.

Any help would be greatly appreciated.

Daniel

[DanielParticipant @daniel]

[JasonBModerator @jasonb]

To make it larger you loosen the nut nearest the handle end and then tighten the lower one. The slots the blades are in have a tapered bottom so as the nuts push them further towards the handle end they move outwards. Some can be quite stiff to turn the nuts on.

[DanielParticipant @daniel]

Thank's Jason for the clarification.

I'll go and try it right now

[Clive HartlandParticipant @clivehartland94829]

Daniel, take care with the amount of adjustment you do, the adjustable reamer is for cleaning out a hole not cutting to a diameter. It will stick if you put on too much of a cut and you must not try and reverse the rotation.

Clive

[Speedy Builder5Participant @speedybuilder5]

Make sure the blades are in the right war around ?
BobH

[MWParticipant @mw27036]

I always thought the whole idea of a reamer was to create a fixed absolute size. The whole idea of adjustability in that seems bizzare to me.  Although they could be useful for cleaning out holes, i can't see myself using them to create an absolute size if i can't set it right anyway. Each to their own but i'll stick to HSS ones thanks.

Michael W

Edited By Michael Walters on 12/08/2016 11:05:26

[DustyParticipant @dusty]

Adjustable reamers to my mind are the devils creation. The original use for them was to enable fitters to take a scrape out of a hole to enable a shaft etc to fit. Yes they do have their uses but great care need be used as they have a nasty habbit of creating holes with lobes in them i.e. not round. Reamer's of any description are for creating holes of a certain size, not necessarily round or of a good finish.

[DanielParticipant @daniel]

Thanks everyone for the input.

Clive – thanks for the heads up. It was, in fact, to clean out a hole, where a cross hole had been drilled.

In this case, an exact diameter wasn't required, as I simply turned the mating shaft to fit the cleaned hole.

Michael – Quite agree with you. Would normally use a fixed type reamer, just this time I didn't have one to fit and the finished size wasn't really important.

Thank's again everyone

Daniel

[HopperParticipant @hopper]

I use them a lot and quite like them. You can sneak up on the dimension and get the exact fit you want, whereas a fixed reamer will usually go a bit over the nominal size ( a very small bit but sometimes its the small bit that counts.)

[AjohnwParticipant @ajohnw51620]

Posted by Michael Walters on 12/08/2016 11:04:10:

I always thought the whole idea of a reamer was to create a fixed absolute size. The whole idea of adjustability in that seems bizzare to me. Although they could be useful for cleaning out holes, i can't see myself using them to create an absolute size if i can't set it right anyway. Each to their own but i'll stick to HSS ones thanks.

Michael W

Edited By Michael Walters on 12/08/2016 11:05:26

Normal reamers do create a hole with a certain tolerance and can leave a decent finish if they are sharp.

Adjustable ones are a bit mixed. Differing tightness on the nut can even produce a different sized hole but that's not the main problem. Try measuring diameters over several pairs of blades. They are often all over the place in terms of reamer type tolerances and that can even change when they are adjusted. The lead in is also often a bit short for hand use. Some have a smooth portion on the end intended to act as a guide. I have never had much luck with one of those but maybe I should have used a square to keep checking that the reamer was still axial.

Both types have another problem. If the drilled hole isn't true to the axis of the reamer when it's used the hole is unlikely to come out correct.

There can be another problem as well which isn't as obvious. The part that's been pushed into a reamed hole might not be round. If the parts have a very close fit lathe roundness errors can mess it up..It doesn't take much of an error. Same applies in different way to reamers that aren't running dead true.

I've seen suggestions in ME that precision work should be done on a tailstock drill plate. Assuming that this will all be dead true. Pity decent sized drill plates aren't still around. They are assuming that this set up will be better than many home owned drilling machines. It could be.

You might say bad workers blame the tools but sometime the problem is the tools and not the user.

John

–

[JasonBModerator @jasonb]

I'm with hopper they can be useful for sneaking up on a size and saves having to have a load of over/under reamers. Often hands for BMS shafts which can be a few thou below nominal. Still have most of the common sizes to give an H7 hole which is quicker in most cases.

Another common use is to true up worn bearings and then fit an oversize shaft, still have one for the Austin 7 king pin bushes where you coul dbuy various oversize pins to fit your newly reamed bearings

[AjohnwParticipant @ajohnw51620]

I suspect my Boxford had 2 previous M E owners. It came with a lot of reamers adjustable and fixed. I use the adjustable if I need to as well. Biggest problem with the fixed size ones is finding the one I need. Boxes aren't a good place to keep them.

I also bought a set of H7 2 morse metric machine reamers of harryuk on ebay. Size wise they are pretty good. Other than the adustables and a few I have picked up at times all my other reamers are smaller sizes.

For a lubricant I would recommend animal tallow with rendered pixies and elves. My stock from training ran out a long time ago. No idea what was in it really but it wasn't pure white.

John

–

[Clive HartlandParticipant @clivehartland94829]

Rendered lard mixed with a white candle will give you a good mix, vary amount to get viscosity right.

[AjohnwParticipant @ajohnw51620]

I suspect it had some of that brown jelly that forms under the fat from cooked meat Clive. Not much chance of finding out if it works though – I love it on toast.

The stuff from training was pretty stiff. It would be scraped onto reamers and taps and a bit poked into a die or rubbed onto the bar. They used to get huge chunks of it in and we kept some in a tobacco tin. It had to scraped into that as well.

John

–

[JasonBModerator @jasonb]

Sounds like Tallow to me

[MWParticipant @mw27036]

Maybe i've been missing out, I've looked at them before with a degree of suspicion about just how tight they hold together under load. Perhaps this is something i'll consider when my balance is so low as usual!

Anything word + reamer =£££ regardless of size (unless you make one out of SS)

Michael W

Edited By Michael Walters on 12/08/2016 17:15:52

[AjohnwParticipant @ajohnw51620]

This looks like the large set I bought

**LINK**

No idea what din208 means. They look to have gone up in price a bit as well.

Jason – all of the tallow I have seen is stated to be very white as if it's some sort of virtue. Some is sold for lubrication.

John

–

[Chris Evans 6Participant @chrisevans6]

I use adjustable reamers to size a little end bush after pressing in to a con rod (Car and Bike engines)

Avoid the cheap nasty carbon steel bladed ones for this kind of work they tend to dull quickly and then chatter. HSS is the way to go.

[colin hawesParticipant @colinhawes85982]

If an adjustable reamer does not adjust easily or seems to have an oversize blade it almost certainly needs to be dismantled and cleaned with a degreaser. I was recently glad I had one to ream a very tight small end bush.

Colin

[Clive HartlandParticipant @clivehartland94829]

Tallow is rendered beef fat, usually found around the kidneys. It is the same as suet but for use in cutting tools needs rendering and filtered. Will keep for a long time without going rancid. if kept closed up. As said a small qty. of candle will stiffen it for other use. Also used for lubing the slipways on ship launching.

Clive

[Author]

Posts