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View Full Version : reamers - eBay lot vs Shars set - over, under, or exact



PStechPaul
02-23-2015, 11:25 PM
As I make the parts for the wobbler air engine for class, I want to get some of the tooling required for my home shop. I don't have any straight chucking (or hand) reamers, and I need at least a 3/16" and 3/8" for a force fit as well as an RC5 fit. When I reamed the 3/8" hole in the aluminum crankshaft, the dowel could be inserted by hand, meaning it was too loose for a force fit. I reamed another hole more quickly, and it seems like just barely a force fit. The reamer was supposed to be an exact size, but it miked a few tenths over.

I found what appears to be a good assortment of used reamers (including an MT1 shank 3/8")
http://www.ebay.com/itm/11-Supeream-Chucking-Reamers-Between-3-16-and-1-2-Inch-1-Other-3-8-1MT/311278121925

http://thumbs2.ebaystatic.com/d/l225/m/mFi3Rf_7-SNeYwreQMYQswA.jpg

The same seller has a large number of other items from a machinist's estate sale:
http://stores.ebay.com/WVTools/Machinists-/_i.html?_fsub=1352543&_sid=5370352&_trksid=p4634.c0.m322

Another lot:
http://www.ebay.com/itm/281583625970

I was going to buy new 3/16" and 3/8" reamers from Enco, using the 15% + free shipping coupons, but I decided to look elsewhere. Those two reamers would be about $20 - not bad, but I would like a wider assortment, and I'd like advice on whether to get an over/under set or exact sizes. I probably won't need to use them very often and I don't need extreme tolerances. If a situation arises where I need specific sizes, I can always get them.

http://www.ebay.com/itm/SHARS-14-PCS-0-124-0-501-HSS-Chucking-Reamer-Set-NEW-/330919956166 (http://www.ebay.com/itm/SHARS-14-PCS-0-124-0-501-HSS-Chucking-Reamer-Set-NEW-/330919956166?pt=LH_DefaultDomain_0&hash=item4d0c5dcec6) (Over/under $67 + $6 ship)

http://www.ebay.com/itm/330966664843 (7 piece $40 - out of stock)

http://www.amazon.com/Grizzly-T10085-7-Piece-Chucking-Reamer/dp/B006SJK3BI/ref=sr_1_3?ie=UTF8&qid=1424751664&sr=8-3&keywords=Reamer+Set ($62)

oldtiffie
02-23-2015, 11:50 PM
Use "spring" or "grooved" dowel pins:

https://www.google.com.au/search?q=dowel+pins&biw=1536&bih=732&tbm=isch&tbo=u&source=univ&sa=X&ei=iALsVNSDEMe2mQW2r4HIDQ&sqi=2&ved=0CC4QsAQ

https://www.google.com.au/?gws_rd=ssl#q=dowel+pins

MichaelP
02-23-2015, 11:58 PM
Use "spring" or "grooved" dowel pins:

https://www.google.com.au/search?q=dowel+pins&biw=1536&bih=732&tbm=isch&tbo=u&source=univ&sa=X&ei=iALsVNSDEMe2mQW2r4HIDQ&sqi=2&ved=0CC4QsAQ

https://www.google.com.au/?gws_rd=ssl#q=dowel+pins They are called roll pins or spring pins here. They come slotted and coiled.

As far as the original question regarding the reamers, both sets, exact and over/under, are helpful in different situations.

Juergenwt
02-24-2015, 12:34 AM
You do not use spring-or grooved-or roll pins for precise locations. Standard 3/16 (.1875") dowel pins are +.0002". Use a .1873" reamer. Standard 3/8 (.3750) dowel pins are +.0002". Use a .3748"
reamer. Ream at slow speed and lubricate. If you can not get a reamer that is .0002 undersize than use a full size reamer and lightly stone the top of the flutes. Careful when reaming aluminum! Use a lubricant approved for aluminum.

PStechPaul
02-24-2015, 01:40 AM
The dowel pins are used as axles (shafts) so the spring type won't work. For aluminum, it seems like the hole can be enlarged slightly just by running the reamer a bit longer or with multiple strokes. If I were designing the engine, I would use steel for the crank, and I might use drill rod (which can be machined to either a force fit or clearance fit), and I'd probably use bronze oilite bushings or ball bearings. I have also made a force fit hole in aluminum by using a machine taper reamer from both sides just large enough for the shaft. It may also be good to knurl the shaft for the force fit, but that won't work for dowel pins if they are hardened. The instructor suggested Loc-Tite.

I found a pretty good calculator for fits:
http://www.amesweb.info/FitTolerance/FitToleranceImperial.aspx

An RC6 running fit for 0.375" is -0, +0.0014

RC5 is -0, +0.0009

FN2 for 0.375" is -0, +0.0006

For 0.187" it is -0, +0.0005

I'm not sure how to achieve such tolerances, or to measure the hole. I do see that McMaster has reamers that can be specified in increments of 0.0001", so I guess you just have to obtain the exact size for the spec.

peekaboobus
02-24-2015, 08:15 AM
Those reamer sets are so expensive. I am still looking to get one but at $200 or so, and I will need to get both a metric and imperial set to be complete, thats a good $500 or more, and before you include shipping.

Mostly I end up buying what I need as most of the time, I figure even if I have a set, I probably won't use the majority of them. I just like the idea of having a set, because its flexible and I can pick and choose if I ever need it.

boslab
02-24-2015, 08:38 AM
I had the same happen, turned out to be the tailstock was out 1/2 a thou and making the hole bigger, worth looking in case
Mark

ironmonger
02-24-2015, 09:13 AM
If you have a reamer or drill that is slightly oversize, and you have eliminated the mechanical sources as bobslab suggests, you can use a controlled etch to remove a few ten thousandths.

Copper sulfate/sodium chloride is relatively harmless and nice and predictable. see this (http://www.nontoxicprint.com/etchzincsteelaluminum.htm).

I experimented with it a few years ago as an alternative for etching pattern welded steel for knife making. WWAN, but IIRC the rate was on the order of .0006" per hour. All the ususal chemical warnigs and cautions. You must also remove all traces of oil for this to be effective. A hot solution of calcium carbonate, washing soda, or powdered dishwasher soap works great for this.

paul

Rosco-P
02-24-2015, 10:04 AM
Out of context quote..........


The same seller has a large number of other items from a machinist's estate sale...

Why not pursue that same route to buy your reamers? Garage/estate/tag sales, machine shop auctions, etc.? If they are not wrapped, tubed, dipped in tool dip or covered with tool netting, don't buy them. Reamers shouldn't be rolling around in a box like common nails.

If you think your going to acquire complete sets, then you'll want #1-#60, 1/64"-1/2", letter A-Z, over and under dowel pin sets.

gzig5
02-24-2015, 10:21 AM
I've never had any luck buying used reamers that are sharp. Dull reamers don't cut correctly or on size, so I've given up and just buy new ones in the sizes I need. For me, it is cheaper in the long run.

MichaelP
02-24-2015, 10:32 AM
I'm not sure how to achieve such tolerances, or to measure the hole. do see that McMaster has reamers that can be specified in increments of 0.0001"You don't need such high tolerances for building simple model engines. An inexpensive set of gage pins (.001" steps) would be very handy and sufficient for your needs. Mine are Chinese in MINUS .0002 tolerance, and I found them to be quite useful.

DR
02-24-2015, 10:55 AM
Without the correct method of holding a reamer talking about reaming to tenths is meaningless.

The holders I have are specifically made to hold reamers and have radial float. That is, they can self locate on an existing hole to follow it.

Holding in a drill chuck or other rigid device may not work since they can guide the reamer not allowing it to follow the hole. If the rigid holding device is not perfectly centered on the bore it can act more like a boring bar and enlarge the hole by its amount of un-centeredness.

JCHannum
02-24-2015, 11:06 AM
You can make a reamer cut over or under its size by stroking the cutting edge with a HSS lathe bit. Use on the inner surface to make oversize, outer surface to make undersize.

For one off reamers, D reamers can be made from drill rod in a few minutes. It is a worthwhile project to undertake as it is unlikeky you will always have the reamer needed, and waiting for shipping or driving to the tool supply every time a size is needed is not a good use of time or financial resources.

projectnut
02-24-2015, 11:30 AM
Keep in mind chucking reamers are different than hand reamers. Chucking style reamers have straight cutting edges. In your first link all except the one 4th from the right are chucking reamers. They are meant to be fixtured in a collet or floating holder. They will never give you a true bore when used by hand.

Hand reamers on the other hand have spiral flutes like the one 4th from the left in the first link. They literally screw themselves through the hole reaming to size. Having said that I doubt you'll be able to ream to within .0001" by hand. Over the years I've reamed thousands of holes for dowel pins and never had to be within .0001".

Most standard ground and hardened dowel pins are .0001" - .0003" oversize so they can be pressed into place.

Undersize dowel pins are generally .0002" under the specified size.

Oversize dowel pins are either listed as .001" oversize or .002" oversize. Even then they have a tolerance range. The .001" oversize a have a range of +.0009 to +.0012. The .002" oversize have a range of +.0019" to +.0021".

Attempting to ream to .0001" is an exercise in frustration. I doubt you'll be able to hold that tolerance more than 10% of the time unless you have a precision jig borer something like this:

http://www.ebay.com/itm/Moore-Jig-borer-N3-24-x-11-Seria-B656-3-PH-3-HP-550V-INV-16690-/321677984710?pt=LH_DefaultDomain_0&hash=item4ae58083c6.

JCHannum
02-24-2015, 01:35 PM
Chucking and hand reamers can both be had in spiral or straight flute styles. Straight flute are for use in plain bores, spiral flute for use in bores which are interrupted such as those with keyways.

PStechPaul
02-24-2015, 02:54 PM
I'm sure you are right about not needing 1/10 tolerance on a simple wobbler model engine. I need an FN2 fit for the 3/16 and 3/8 dowels for the crank, and that is in 6061 aluminum, which I think is the wrong material for that. When I reamed the 3/8" center hole at the school shop, I used the only reamer of that size I could find (among the assortment dumped in a box), and I held the piece in soft jaws of a 3-jaw chuck while the reamer was held in a Jacobs chuck (with a chewed up taper) in the tailpiece. So there were many reasons why the hole did not have a good finish and may have been oversize for a good press fit.

I think there was an oversize 0.378" reamer in the box, and that will probably be OK for the RC6 fit in the flywheel (which I made from 1117 steel rather than the prescribed aluminum), and the RC5 fit in the manifold (1018 steel). The aluminum cylinder will have a 0.625" blind hole 1.344" deep which will be bored to -0, +0.002 tolerance. We are probably supposed to use the Bridgeport for that, but I'm thinking it might be better to use a 4 jaw on the square stock and bore it using the lathe. Lots of different ways to do the same job, but some of the work is supposed to be done on specific equipment in a certain way as an exercise.

Thanks.

chrisinestes
02-24-2015, 03:42 PM
On topic: Are the adjustable reamers worth a darn? For instance this type: http://www.use-enco.com/1/1/93659-hss-hand-adjustable-reamers.html I realize they don't go down to small diameters like you'd need for model engine building, but how about for larger stuff?

Slightly off topic: I'm new to machining, and I saw a post above that I didn't know about but see as really useful... Pin Gauges... I see cheap sets 1/16" to 1/4" plus & minus sets for as low as $40, and then 1/4" to 1/2" plus & minus for as little as $100. So for $150 I could go from 1/16" to 1/2"... not a ton of money, but I'd likely never use 90.124% of them. So are there sets that are +/- 1/16", 1/8", 3/16", etc... by 16ths to say 1/2" or maybe 3/4" or 1"? Or maybe smaller +/- sets I can buy by the particular size I want?

Thanks,
Chris

projectnut
02-24-2015, 04:08 PM
Chucking and hand reamers can both be had in spiral or straight flute styles. Straight flute are for use in plain bores, spiral flute for use in bores which are interrupted such as those with keyways.

You're absolutely right about the reamers. I'm not sure what I was thinking. Maybe I should have a second or third cup of coffee before I start typing.

Rosco-P
02-24-2015, 04:21 PM
Slightly off topic: I'm new to machining, and I saw a post above that I didn't know about but see as really useful... Pin Gauges... I see cheap sets .....? Or maybe smaller +/- sets I can buy by the particular size I want?

Thanks,
Chris

See http://www.newmantools.com/meyer/pluggage_ABC.htm for a start.

PStechPaul
02-24-2015, 05:20 PM
I found a source for inexpensive reamers in exact fractional sizes:
http://buydrillbits.com/products/hss/gp2.php?c=Reamer-Chucking

I'm getting six reamers 1/8", 3/16", 1/4", 5/16", 3/8", and 1/2", for about $33 plus shipping of about $8.

They also have other tools, but nothing I need right now. The pricing on the reamers is a bit odd, where some "unusual" sizes (like 27/64) are much cheaper than the nearest "usual" size like 7/16". I'll let y'all know how they are when I get them next week.

[edit] This set along with the Shars 14 piece over/under set for about $75 will give me pretty much all the capability I might ever need for what I foresee building. I can always get specific size for anything else.

oldtiffie
02-24-2015, 08:23 PM
I've always run the lathe/reamer/mill/drill slow and the feed in (and out) as fast as possible - "feel" is important here - do not reverse or hesitate.

Cutting fluid (kerosene/paraffin) should do the job - particularly in aluminium. Use plenty of it to prevent "galling".

Check Machinery's Hand Book for drill/bore limits/tolerance.

Do a couple (at least) "trial runs " to get the feel and sizes of/for it.

Black_Moons
02-25-2015, 12:05 AM
On topic: Are the adjustable reamers worth a darn? For instance this type: http://www.use-enco.com/1/1/93659-hss-hand-adjustable-reamers.html I realize they don't go down to small diameters like you'd need for model engine building, but how about for larger stuff?

Thanks,
Chris

Agreed, Anyone who has uses these can you tell us just how useful they are? They seem like to me that it would be very hard to set for any kind of precision diameter and they might end up tapered along their cutting length if your not careful in setting them.

oldtiffie
02-25-2015, 06:00 AM
Originally Posted by chrisinestes
On topic: Are the adjustable reamers worth a darn? For instance this type: http://www.use-enco.com/1/1/93659-hs...e-reamers.html I realize they don't go down to small diameters like you'd need for model engine building, but how about for larger stuff?

Thanks,
Chris


Agreed, Anyone who has uses these can you tell us just how useful they are? They seem like to me that it would be very hard to set for any kind of precision diameter and they might end up tapered along their cutting length if your not careful in setting them.

It is very hard to set very accurately as when the clamping nuts are loosened there is no real guarantee that they will be re-set straight and parallel.

Realistically they need to be re-set and re-sharpened on a very good tool and cutter grinder after each re-set.

dian
02-25-2015, 06:21 AM
the size of the hole will very much depend on what you use as lubricant: dry, oil, waterbased, alcohol, acetone. alcohol reduces the hole, oil makes it larger, at least in stee. might be differend in aluminum. worth a few experiments.

raceneer
02-25-2015, 09:07 AM
Push through a precision ball bearing. ;)

JCHannum
02-25-2015, 09:19 AM
It is very hard to set very accurately as when the clamping nuts are loosened there is no real guarantee that they will be re-set straight and parallel.

Realistically they need to be re-set and re-sharpened on a very good tool and cutter grinder after each re-set.

Utter nonsense. They work very well and have been used successfully for years. One does need to know how to use them it is not difficult, keep them clean and lubed with cutting oil, loosen one adjusting nut and tighten the other to move the blades in the desired direction. Make sure the nuts are tight.

They should not be expected to remove large amounts with each pass, but gradually approach the desired dimension. Very fine adjustment with partial turns of the adjusting nuts permits very fine removal of material for close fits. I have had good experiences with quality made adjustable blade reamers, and poor experiences with the ENCO reamers, you get what you pay for.

boslab
02-25-2015, 09:58 AM
Sure a floating head reamer holder exists for tail stocks and drills, I wonder?
Mark
Oh does exist and not a hallucination

PStechPaul
02-27-2015, 09:54 PM
I purchased the six reamers as mentioned above, and they arrived today. They look pretty good:

http://enginuitysystems.com/pix/tools/Reamers_1754.jpg

http://enginuitysystems.com/pix/tools/Reamers_1755.jpg

http://enginuitysystems.com/pix/tools/Reamers_1756.jpg

Blogwitch
02-28-2015, 04:30 AM
Someone mentioned about having a floating head to hold a reamer when working with a lathe tailstock.
This is just a bit of info that I picked up when working in a production model shop working to very close tolerances, in fact we were making prototype hard disk drives.
Even though we had superb machinery to work with (Hardinge) we always used a floating reamer head when reaming on a lathe.
Hemingway in the UK makes a kit for one, and I have such a kit, to be made at a later date. A little expensive for what it contains, but I just needed the plans so that I could modify it for what I have to do, plus make it a lot shorter.

http://www.hemingwaykits.com/acatalog/Floating_Reamer_Holder.html

John

oldtiffie
02-28-2015, 04:37 AM
I've tried to raise Hemingway recently by email on another matter and cant get a reply.

PStechPaul
02-28-2015, 05:23 AM
I understand why a floating holder may be better, but how does this compare to reaming a hole using a milling machine?

Otherwise, how would it be to use the toolholder (which was used to hold the boring bar), and adjust the location to the center of the hole? My thought would be to install a rod, perhaps with a slight taper, and a shank of the same size as the reamer, into a mating hole in the toolholder. Then adjust the cross-slide and height until the taper seats in the hole to be reamed. Replace the rod with the boring bar, and it should align well enough.

If a floating holder is better, how would it be to wrap the shank of the reamer with a piece of rubber hose, and clamp that in a collet in the tailstock? Various materials and thickneses could be used depending on the rigidity required.

If I were to ream the 0.625" hole in the cylinder for this air motor, I would have to re-align the four jaw chuck to get the bore on center, and I wonder what the best way to do that might be. A large or bull-nose center in the tailstock might work.

Also I wonder how much the flex of the rather long shank of these reamers would function in a way similar to the floating holder. Certainly it would not take much radial pressure on the cutting teeth to bend it by 0.0005", so unless the tailstock were more than about 0.001" off center to the spindle, I don't think it would affect the reaming very much.

Thanks for the information. I think I will ask the instructor about this.

Blogwitch
02-28-2015, 06:45 AM
PS,
I have no trouble with reaming on a mill, as long as everything is locked up before starting. Then it is just a matter of drilling, boring if you have to, then following down with the reamer. But it is something totally different when using your tailstock.
Tailstocks have a bad tendency not to go back into their original position after being slackened off, and that misalignment could be both angular and offset.
That is where the holder comes into it's own, it will allow the reamer into a position, either up/down, side to side or angular offset until the reamer can follow the drilled or bored hole. Nothing more, nothing less.
It isn't a magic panacea that will cure all, but you are certainly better off using one than not.
BTW, I will be making mine so that it can hold the plain shanks of chucking reamers, plus using it with the MT shank sets I have.

John

JoeLee
02-28-2015, 07:52 AM
Without the correct method of holding a reamer talking about reaming to tenths is meaningless.

The holders I have are specifically made to hold reamers and have radial float. That is, they can self locate on an existing hole to follow it.

Holding in a drill chuck or other rigid device may not work since they can guide the reamer not allowing it to follow the hole. If the rigid holding device is not perfectly centered on the bore it can act more like a boring bar and enlarge the hole by its amount of un-centeredness. I would like to see a picture of those holders. I've often wondered about trying to hold tenths when reaming if the lathe's tail stock is not dead on.

JL...............

JCHannum
02-28-2015, 08:50 AM
Floating toolholders are quite common and come in a variety of types for reamers as wall as taps and drills.

http://www.fltoolholders.com/tooling.html

Blogwitch
02-28-2015, 05:06 PM
There are the designs of the one for the Hemingway one on the website I pointed people to and there is this one which came from Chris Heapy's stable. 2 in 1, left hand is a tapping fixture, right hand is the reamer holding job.

http://i202.photobucket.com/albums/aa102/bogstandard_photos/Later%20pics/Heapies%20reamer%20holder_zpsnftxdjsl.png

John

PStechPaul
02-28-2015, 08:47 PM
It looks like the idea is to allow a certain amount of runout so the reamer can self-center and only be pushed into the work with the tailstock. It uses a handle to provide torque. A similar means might be a flexible motor shaft connector, which would also provide torque, and it could also be used to pull the reamer back through the bore.

https://www.nbk1560.com/en/products/coupling/couplicon/?gclid=CK63892DhsQCFUo8gQodCLUA2Q

https://www.nbk1560.com/images/en/product/crossjoint_type/XUT-C/UID5451f83984cb17.28546331_s.ai.jpg https://www.nbk1560.com/images/en/product/bellows_type/MFB-C/UID54520c1b4a3395.30669686_s.ai.jpg

I have this coupling, shown with a 1/4" shaft reamer in one side of the coupling, and a 1/4" drill in the other:

http://enginuitysystems.com/pix/tools/Shaft_Coupling_1757.jpg

http://enginuitysystems.com/pix/tools/Shaft_Coupling_1758.jpg

I found some more information as I am trying to understand how these work:

http://firearmsdesigner.com/?p=131

http://www.practicalmachinist.com/vb/gunsmithing/homemade-floating-reamer-holder-279770/

http://www.greentechnologies.biz/reamerholders.htm

http://lathetools.net/shop/floating

JoeLee
03-01-2015, 08:25 AM
This can be a pretty expensive set of additional tooling just to hold your reamers. I'm trying to imagine just how many different sizes you would need??
Also, I'm not crazy about locking the reamer in the holder by means of a couple set screws. Are these really worth having ??? or are these someone;s innovative idea???

JL.................