UJK MK-II, snug holes

Rick Herrick

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Feb 7, 2020
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There has been a lot of discussion recently on the holes being tight, in some instances.  I have made a couple of tops, all in basic $40 plywood.  I find a number of holes probably swell to some degree and are hard to use.  I picked up the reamer below.  Have to say, I am very happy with it.  Tested a hole with one of the TSO Double-Groove 20mm holes.  I could push it in but it look effort.  I put this reamer in and twisted, probably not even 2 turns and the dog now fits in very nicely.  It was too inexpensive not to at least try it.  Glad I did.

20mm reamer tool
 
Thanks for the tip Rick. I'm going to order one of these too.

I have maybe 175 holes in MDF and BB ply spread across my MFT, long rip cutting table and a handful of jigs, fences and mounting fixtures.  All are drilled with my MK-II, most are so tight that I struggle to remove close fitting Parf dogs even with a version of the removal tool described by Peter P in one of his videos.  (I keep a piece of 1/2" dowel handy to pound the really tight ones out from below)

Are you using any sort of pilot to keep reamer vertical or does it have end taper such that it enter holes easily?
 
IMO, the snugness is because of humidity, or something that has made the fibers inside inflate a bit.  Because of that, I just set the reamer in the hole and gently twisted it.  I have never used a reamer of any sort so I just went carefully.  Once I made a full turn, just hand turned, the reamer would drop down and I could do another turn easily.  I guess this depends on the material your top is made from.  So no other tools needed, just patience.  I am only doing certain holes that I use for dogs in my cutting station set ups.  The remainder of the holes are for clamping so those don't really need much care.  BTW, this reamer is a hefty piece of equipment.
 
I have the same problem - I used the UJK Parf II. Some of the close fit dogs I have to use pliers to get out - I've ended up marring the surface of a few because it's so tight - I only drilled the holes a few weeks ago.
 
I just hand turned it, slowly.  Probably not scientific but it was easy and did the trick just fine.
 
Cheese I had several sizes of the adjustable reamers in my bike shop that we used on frames and forks, primarily to remove burrs or fix bores that were monkeyed up inside from (bad) welding. Be aware they are actually tapered and in a MFT would likely give inconsistent diameters.

Rick, I think that you can turn reamer by hand with no handle is a good sign in that the tool is likely only cleaning up a tiny bit of rough surface in what should be a 20mm hole.  Possibly coming in from bottom might be good technique as tool will self align as it enters the hole.

Have one on order so thanks again for the tip, much appreciated.
 
Vtshopdog said:
Cheese I had several sizes of the adjustable reamers in my bike shop that we used on frames and forks, primarily to remove burrs or fix bores that were monkeyed up inside from (bad) welding. Be aware they are actually tapered and in a MFT would likely give inconsistent diameters.

Ya I've used adjustable reamers in the past for reaming out king pin bushings. The bottom 1/3rd of the reamer is undersized by .010-.015" and it's the final 2/3rds of the reamer that needs to be driven completely through the hole/bushing for sizing purposes. They do come in handy for sneaking up and enlarging hole diameters uniformly.

Here's a Critchley adjustable reamer and the pilot that attaches to the end to keep things straight.

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I think I saw someone, maybe on this site, using a simple "flap sander" – more or less a dowel with a piece of emery cloth in a slot and then chucked in a drill to ease swollen holes. Not nearly as precise as a reamer, but perhaps close enough and they said it was quite fast.

I shellac my MDF tops and try to get some in the holes and that seems sufficient to stabilize them in an unheated shop here in our maritime climate.
 
Its odd to read these issue because I never had an issue with mine in MDF.  The really short ones could be tough since there was not much to grab but perhaps thats because we dont get a large swing in humidity here its just always humid so the MDF starts off swelled.
 
Rick Herrick said:
Peter Parfitt said:
They have introduced a reamer which has already been trialed:
https://www.axminstertools.com/ujk-parf-system-reamer-for-20mm-holes-107586

Peter

Thanks Peter.  This looks very nice.  I like that it looks easy enough to fit to a drill.  The reamer I found does work but using it by hand can take a while if doing a lot of holes.

Hi Rick

I have asked Axminster to send one to me so that I can show it in a video. I can see how it should work.

Cheers.

Peter
 
If we need really accurate holes in our toolroom they first drill out the hole and then use a reamer to shave a couple of thousandths off the inside diameter.

I was curious at how the cost of a wood reamer compared with the cost of a machinists' reamer. 

The Axminster reamer is $20.00 + shipping and tax.

A decent quality high-speed steel reamer for a machine shop costs $86.00.  and has 6 or 8 flutes and is produced to a very tight tolerance--much tighter than is required for woodworking.  So if the Axminster offers good durability it is a reasonable purchase.
 
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