dowel pins too tight (follow up on Jessem dowel jig)

[Paulh Tremblay]

On the suggestion of members of this forum, I bought the Jessem doweling jig. It seems a nice tool, but I won't know until I make some successful dowel joints.

I tested it tonight by drilling 9 holes for edge joining two scrap pieces. I never got to actually observe the fit of the dowels, because the 3/8'' dowel pins would not fit in the holes. To be clear, I do not mean that the holes did not align. (In fact, as far as I could tell, they did align.) I mean that I could not push the dowels into the holes with my hand.

I could have used a mallet to hammer the joint together, but I don't believe you should fit dowel joints together that way. The videos for Jessem and Dowelmax show the joints going together easily with the push of a hand.

So I think I have bad dowel pins. The 3/8'' pins seem exactly that width--3/8''. You can only fit a 3/8'' dowel into a 3/8'' hole with force. Shouldn't the dowels be a bit smaller? I used the bit that came with the Jessem jig. I either need to use a slightly larger big (25/64""?) or get different pins. Where should I buy my pins? Should I try a different bit?

[Mike Henderson]

You can make a dowel plate or buy one. You make it out of steel and drill a hole the size you want. Then you pound your dowels through the holes. LN makes a dowel plate.

Mike

[Loren Woirhaye]

Take a big coffee can and fill the bottom with dowels. Put a 75+ watt incandescent light with the bulb inside the can. This is a "shop oven". You can also shrink dowels with a toaster oven or a microwave. After they are shrunk you can encourage them not to expand by putting them in an airtight container with a dessicant packet... those little packages that come in all sorts of things. I think the blue crystal cat litter will work as well.

I bought big bags of dowels from McFeeleys. In Los Angeles I don't have many problems with oversized dowels but it's pretty dry here in general.

[Paulh Tremblay]

This thread actually throws some light on my problem:

http://www.sawmillcreek.org/showthre...tight-is-tight

The drill bit should be larger than the actual dowel pin. I believe Jessem's drill bit is larger; I probably just have bad dowel pins. (I did microwave them.)

I ordered more pins, and will test again when they arrive. I also emailed Jessem.

[Loren Woirhaye]

Jessem's drill bit works fine with the McFeeley's dowels. For me anyway. Sometimes in dry fitting I have to pull a dowel out with pliers. Sometimes a dowel gets chewed up and I throw it away. The glue does provide some lubrication. I use the dowels with the long grooves in the sides, not spiral ones. I also have another 3/8" drill I use with another collar since I use two different dowel lengths with the Jessem. Both bits work fine for the dowels I use.

[mreza Salav]

The original (bigger) Jessem jig came with 9.7mm drill bit which is larger than 3/8", in fact I think too large as the dowel fit would be too loose. The newer (cheaper) version that they have comes with 3/8" drill bit which causes this very snug fit with dowels. You can try 9.6mm drill bit or the V-drill bit that are just slightly larger than 3/8" and they work fine.
You might have to enlarge the jig holes a little too to ge those bits in ( a smaller dowel with a sand paper rolled around them and sand it down a few strokes).

[Paulh Tremblay]

Late last night I tried fitting a 25/64'' bit into the Jessem. It would not fit. I then got the idea to fit a 3/8'' dowel into the same hole, but the diameter of the pins wouldn't allow to put them through. In other words, my pins are much too wide.

What exactly is a V bit? I gather from the other thread it is one size bigger than 3/8''. But where does one get one?

[Bill Huber]

Late last night I tried fitting a 25/64'' bit into the Jessem. It would not fit. I then got the idea to fit a 3/8'' dowel into the same hole, but the diameter of the pins wouldn't allow to put them through. In other words, my pins are much too wide.

What exactly is a V bit? I gather from the other thread it is one size bigger than 3/8''. But where does one get one?

This chart will show you the different drill bit sizes. http://www.csgnetwork.com/drillsizeconvert.html

To answer your question a V bit is a letter bit (.3770 in.), there are 26 of them, A-Z there are also number bits that go from 1 to 80.

As I stated in that linked thread I use a 9.7mm bit and I get all my dowels from Lee Valley.

[mreza Salav]

As that chart (linked by Bill) shows V bit is 0.377 inch (vs 0.375=3/8), so it is oversize by 0.002".
9.7mm=0.381" which is oversize by 0.006". I find 9.7mm bits too big for 3/8" dowels. You can try 9.6mm=0.378" which is oversize by 0.003".
You can get the V bit from LV and probably from other suppliers.

[Von Bickley]

Paulh,
When I ordered my Jessem Jig, I also ordered these dowels and they fit perfectly.

http://www.thetoolstore.ca/viewItem.asp?idProduct=16725

[Paulh Tremblay]

I received dowel pins from Woodcraft, and they fit. I drilled 9 holes with the jig in 2 feet of wood, and the joint fit together just like the video. I also ordered the pins that Jessem makes but have not gotten them yet.

I learned a good trick in the process: push the pins through the bushing on the jig. If they don't fit through the bushings (as my original ones did not), they certainly won't fit in the drilled holes.

[Von Bickley]

I received dowel pins from Woodcraft, and they fit. I drilled 9 holes with the jig in 2 feet of wood, and the joint fit together just like the video. I also ordered the pins that Jessem makes but have not gotten them yet.

I learned a good trick in the process: push the pins through the bushing on the jig. If they don't fit through the bushings (as my original ones did not), they certainly won't fit in the drilled holes.

Which jig did you go with?

[pat warner]

The hole and the dowel diameters have to be attended to for every session. Dowels should be sized through a steel plate before use and some material should be shaved away to verify the sizing.
Then the hole has to match the dowel, less ~.002"-.003" max.
It may take a reamer to hit that dowel slop/fit. Drill diameters are good guesses; they're not meant to = their stated diameters. They can be big or small. Reamers are to tenths, very reliable.
Testing is essential. Blow one assembly with a frozen dowel and and you could ruin the whole megillah.
**************************
Hole diameter sentence ambiguous. Hole should be .002" - .003"max larger than the dowel. Hole = the dowel diameter, will jam the dowel.
Cheap reamers = a dime a dozen. Machine tool houses behind every rock.

[Paulh Tremblay]

The hole and the dowel diameters have to be attended to for every session. Dowels should be sized through a steel plate before use and some material should be shaved away to verify the sizing.
Then the hole has to match the dowel, less ~.002"-.003" max.
It may take a reamer to hit that dowel slop/fit. Drill diameters are good guesses; they're not meant to = their stated diameters. They can be big or small. Reamers are to tenths, very reliable.
Testing is essential. Blow one assembly with a frozen dowel and and you could ruin the whole megillah.

I've looked for reamers but have actually never found one for sale.

[Paulh Tremblay]

I went with the Jessem Paralign jig.