Jessem Paralign doweling Jig Drill Bit

[Jack Clay]

Hi,
I wanted to get a second drill bit for my Jessem 08300 doweling jig setup so I wold not have to keep switching the collar. I looked at the parts list and it said 9.7 MM bit. So I ordered a 9.7 MM and a 3/8th collar. I received all the parts then drilled out the collar for the 9.7 MM. I went to put the drill bit in to set it up and it would not fit. The bushing and the drill bit that came with the kit are 3/8ths. I should have looked at the bit. So all this leads to the question what size should it be.

[Loren Woirhaye]

I have that jig and I just use a second 3/8" bit with a 3/8" collar. Just some old bit I had kicking around. It works fine for the dowels I use.

While using a dowel sizing plate may be tedious for big size changes, a simple shop made plate with a 3/8" hole can be used to knock irregularities off a dowel. I use the ones with the straight grooves.

[mreza Salav]

Call them and talk to them. Their service is good. I think they use different size bits and bushings for their jigs.

[Bill Huber]

Jessem used to ship a 9.7mm bit and bushing with the jig and from what I see now it is a 3/8 bit and bushings.

I got all my dowels from Lee Valley and they are the expansible ones and I use a 9.7mm bit for them. I have found that a 3/8" bit is just a little tight for these dowels.

As Mreza stated I would give Jessem a call and talk to them about it.

If you are going to get another bit so you can have it set for a different depth like for end grain and then one for the face you may want to build one of these, it sure makes it fast and easy.

http://www.sawmillcreek.org/showthread.php?153582-Drill-bit-collar-jig-for-Jessem-or-DowelMax-dowel-jigs&highlight=Jessem+doweling

[Jack Clay]

Jessem used to ship a 9.7mm bit and bushing with the jig and from what I see now it is a 3/8 bit and bushings.

I got all my dowels from Lee Valley and they are the expansible ones and I use a 9.7mm bit for them. I have found that a 3/8" bit is just a little tight for these dowels.

As Mreza stated I would give Jessem a call and talk to them about it.

If you are going to get another bit so you can have it set for a different depth like for end grain and then one for the face you may want to build one of these, it sure makes it fast and easy.

http://www.sawmillcreek.org/showthread.php?153582-Drill-bit-collar-jig-for-Jessem-or-DowelMax-dowel-jigs&highlight=Jessem+doweling


I called them and they said I was suppose to have a 3/8th bit. Bill Did you drill yours out or did you get the 9.7mm with your kit. My dowels are tight (hammered IN). They said to put them in the microwave and then try them and try them again.

[Cary Falk]

I could have sworn that when I bought mine they were shipping with an oversized bit also. I just looked at mine and it is indeed a 3/8 bit.

[mreza Salav]

They used to make it with 9.7mm bits. Now it is 3/8. This topic has been discussed extensively.
3/8 bits are too tight for 3/8 dowels. I have found that you typically want about 0.002-0.003" oversize bits. For 3/8" dowels the letter V drill bit is just about
the right size (at 0.377"). You can wrap some sand paper around a smaller (1/4" e.g.) long dowel and enlarge your bushings a bit by hand so that a V drill bit fits.
You can also try 9.6mm drill bit that is also slightly oversized.

[Bill Huber]

I called them and they said I was suppose to have a 3/8th bit. Bill Did you drill yours out or did you get the 9.7mm with your kit. My dowels are tight (hammered IN). They said to put them in the microwave and then try them and try them again.

Mine came with 9.7mm bit and bushings.
I don't know why they went to a 3/8 bit, 3/8 is just to small.
Maybe you could call them back and see if you could get the 9.7mm bushing, you can get a bit on Amazone.

I just did a little testing on my dowels.
The dowels measured out at .376 - .378 right out of the shop.
Put them in the Microwave for a minute and they are now .365 - .368
So the microwave will do it.

[Jack Clay]

I used the microwave on a brand new order of dowels from LV and it worked very well. I guess the question is do I want to microwave dowels every time before I start assembly. How long before they swell again? I did see 9.6 mm drill bit at a good price. Has anybody tried the 9.6mm bits?Thanks for the help.

[Mel Fulks]

I drive dowels thru a one inch thick piece of scrap steel with chamfered holes. Removes no wood , just squeezes them a
bit smaller. Usually using yellow glue slightly thinned with water. Easy to get joints pulled up and never splits the wood,the dowels swell quickly so they don't need much time in clamps. Very common practice before mail order gadgets.

[Bill Huber]

I used the microwave on a brand new order of dowels from LV and it worked very well. I guess the question is do I want to microwave dowels every time before I start assembly. How long before they swell again? I did see 9.6 mm drill bit at a good price. Has anybody tried the 9.6mm bits?Thanks for the help.

I think I will stick with my 9.7mm don't want to micowave or push my dowels though something.
There has to be someplace you can get the bushing and a bit.

[Jack Clay]

I think I will stick with my 9.7mm don't want to micowave or push my dowels though something.
There has to be someplace you can get the bushing and a bit.

How loose are the dowels with the 9.7 mm bit? I worked on a project this weekend and microwaving dowels gets old quick.

[Bill Huber]

I really don't think they are loose at all, when dry fitting I still have to pull some out with pliers.
When gluing things up I push them in and get glue to come out all around the dowels though the ridges on the dowels.
I do keep my dowels in a sealed container.

[Phil Thien]

I have the Paralign with the 9.7mm drill bit and initially felt that the dowels were way too loose, but haven't gone back for more testing. I was just experimenting and needed to move onto other things, but thought I'd try a 9.6mm drill bit to see if things improved.

The thing with dowels is, there are many ways to reduce their size but increasing their diameter is a bit more difficult. All I could do is try to increase the moisture content and who knows how long that will last?

So I'd rather have dowels that are too snug, than too loose.

[mreza Salav]

9.7mm is too loose for 3/8.
9.6mm works fine.

[Bill Huber]

9.7mm is too loose for 3/8.
9.6mm works fine.

I think a lot of it depends on where you get your dowels and where you live, the humidity levels in your area.
The dowels I have if I use a 3/8" bit I have to hammer them in and that is just not very good to get the glue all around the dowel.

[mreza Salav]

It could be true Bill. But 9.7mm is about 0.006" larger than 3/8". If you make a M/T joint with that much gap you'll see how loose they are.
My dowels are mostly very close to 3/8" and I find 9.7mm way too loose (like they'll fall out of the hole if you keep the piece up side down). That is not right IMO.
If your dowels are larger than 3/8" then the fit might be good.

[Chris Padilla]

Let's see here:

3/8" = 0.375" = 9.525 mm
9.6 mm = 0.378"
9.7 mm = 0.382"
V bit = 0.377" = 9.5758 mm

If we knew what KIND of wood the dowels were made of, we could look up info on how much they could shrink or grow depending upon moisture content. At these tiny changes between sizes, I'm almost CERTAIN the local humidity and wood species plays a significant role in the dowel's effective size.

[Bill Huber]

It could be true Bill. But 9.7mm is about 0.006" larger than 3/8". If you make a M/T joint with that much gap you'll see how loose they are.
My dowels are mostly very close to 3/8" and I find 9.7mm way too loose (like they'll fall out of the hole if you keep the piece up side down). That is not right IMO.
If your dowels are larger than 3/8" then the fit might be good.

I understand what you are saying and if you notice I also said in post number 13 that I have to pull them out with pliers so I would thing that is tight enough, wouldn't you?

[Mel Fulks]

That's what we liked about the plates I described, the dowels go in easily and glue gets between dowel and work. You can
make a test piece ,then rip it along length of dowel and find it's glued so well that you can break dowel in half and find you are removing big chunks of the structure. Even when we bought long dowel lengths in quantity their sizes varied.

[Jack Clay]

Thanks to all for the help.

[mreza Salav]

I understand what you are saying and if you notice I also said in post number 13 that I have to pull them out with pliers so I would thing that is tight enough, wouldn't you?

That would be tight. Maybe our dowels have different sizes or maybe your climate is a lot more humid than ours.
Anyway, I think if the OP has too loose of hole the proper solution is to get a smaller drill bit that is closer to the dowels he uses.