Tuesday, 13 November 2012

Y30 bandsaw fence


 One of the curious things about old vintage bandsaws is they rarely have a fence. I am quite sure this was not an oversight but rather a very different approach to working. I suspect the idea of resawing  wood to create veneer would have been rather comical - they could still buy high quality, thick veneer of most species. But what about precise parallel cuts? Surely they would have required those? So with a little discomfort and curiosity - I decided to use the saw as it arrived and see how I got by without a fence. Here is what I have learned thus far.

Firstly - this saw continues to exceed my expectations on every front. It does everything I have thrown at it so far - and I can make out a faint taunting laugh “is that the best you got?” as I am working. Even resawing 16" sugar maple with a 1/2" blade... not an issue.

I have also come to realize that if I am able to scribe a line on a piece of wood - either parallel to an edge or a curve, I am able to cut accurately enough freehand that a single pass on the jointer will take care of the bandsaw marks. That was an astounding realization. The saw is so stable and cuts so cleanly that seeing and controlling a cut is remarkably easy. But... there are instances where I am not able to scribe a line and where I do need a very accurate parallel cut. When I am roughing out plane parts, I am often working with very odd shaped pieces and not able to scribe a line. So I concluded that a fence was still needed.

There were 2 fences that I used in a pinch. One was my 5' Festool track (see above photo) and the other was a tall plywood jig that I used to use on the table saw. It was a 90 degree fence that I would just clamp to the table top. The really interesting thing about these fences was I never measured anything to make sure they were parallel to the blade. I eye-balled their position and just clamped them down. Drift was a non-issue which was weird because it is a major issue on my Laguna bandsaw. If the fence was not perfectly parallel on the Laguna, drift would rear its ugly head and ruin the work. I have pretty good eyes, but there is no way I was able to place things that accurately. I have concluded there is yet another magical aspect to this saw - drift is just about a non-issue.

One of the hardest parts was where to start. There are quite a few after market fences available for bandsaws. None of which are large enough for a 30"x 28" table. So this meant fabricating one from scratch or finding an existing fence that could be re-worked. A friend of mine in Ottawa swooped in and saved the day. He had an old General table saw fence that he was not using and the size was similar to the Y30. What was really appealing about the table saw fence was it had both a front and back rail and the single lever at the front locked the fence at both ends. If it would work - it would be perfect. Thanks again Brian.

The original fence would have been mounted directly to the front of the tablesaw. This was going to be a problem because the the blade for the Y30 is removed at the front of the table. The fence would need to be offset by about 1-1/2" to allow for blade removal and installation. The other issue is that the edge of the bandsaw table was not square to the top so we would have to square it up.




I asked my friend Terry if he would be willing to give me a hand with this project. He is the same Terry who helped move the Y30 into the shop. Thankfully - he agreed.

We started by installing a square tube to give us the offset we needed. It is attached by way of two bolts tapped into the edge of the table. We filed the edge of the table square to the top in these two locations. Thankfully - cast iron is much easier to file than 01 tool steel. We used large washers as standoffs to keep the tube from contacting the edge. Terry made 4 standoffs to connect the square tube to the round rail. He used 1" drill rod. General has special shouldered bolts to attach the rails - so I had ordered these a while ago. The photo above shows the square tube, the standoffs and the front rail.







Two more views showing the front mechanism of the fence with the fence removed. 





The back rail installed.



Through some small miracle, the back rail was parallel to the front rail within 0.008" on the first go. We had built in some wiggle room so we could adjust the rail up or down. This was certainly a 2 person job - one person to hold the reference jigs to maintain the distance from the table top to the top of the rail, and the other to tighten the bolts.

The fence itself was short by 3-1/2" in length so we had to extend both the fence as well as the threaded rod that engages the locking mechanism at the far end. Both locking mechanisms work by way of a cam, and are fully adjustable with a single slotted screw in the front of the fence. It is rather ingenious actually. We were able to get the rear of the fence to clamp without much effort, but the front did not want to hold. So we took it apart and quickly realized the problem. Sadly, I did not take a photo of it. There are 3 parts to locking the front. There is a steel cam that the handle is attached to. This moves a lever that contacts a shoe that clamps against the round rail. This lever is connected to a threaded rod, that passes through the fence to the clamping mechanism at the end of the fence to lock it down. The shoe that grabs the front rail is also steel - the lever is cast iron... guess which part was worn? There was a part number in the casting but it would have taken about a week for it to come in. We were pretty close to being done and I was rather impatient. I proposed to cut a dovetailed key into the damaged area and install a piece of bronze. On top of that - the casting was nowhere near square - the top edge of the casting was off by at least 10 degrees. Installing a bronze wear plate would allow us to have a parallel bearing surface which could only help the situation. It was worth a shot.




Here are a few shots of the excavated area.







The fitted piece of bronze.




You can see how out of square the edge was - the bronze insert is perpendicular to the pivot point of the lever. It only took about 20 minutes to do this, cost nothing and allowed us to continue working.




With the new bronze insert installed and the fence put back together, it was time to test it again. With a little monkeying around, the fence was locking perfectly at the front and the back. It was not sliding too well though - so we removed the rust on the rails and gave them a light coat of wax. This solved the problem immediately.





We decided to use the original fence and sandwich it between 2 pieces of extruded aluminum with T-tracks in the faces. The T-track will allow auxiliary fences for resawing and stop blocks to be installed easily. I used masking tape applied to the original fence as shims to bring the aluminum square to the table.The entire fence assembly is just under 3" wide and extremely rigid.







With the fence pushed all the way to the left, I have 26-1/2" of room to work. I suspect it will be a very rare occasion where I need more space than that.

It has been interesting using the bandsaw for the last few weeks with the option of having a fence. I am finding myself scribing lines and free handing parallel cuts quite often - it is just way too fast and accurate - but there have already been many occasions where the fence has been used and is a great addition to an already amazing machine. Thanks again Terry for all your help with this.

5 Comments:

Blogger Kevin Brehon said...

There is something really satisfying about personalizing the machines in your shop and making them work better.

13 November 2012 20:49  
Blogger Tico Vogt said...

After reading these posts about your amazing band saw, I laugh when I use mine, thinking to myself "I'm glad Konrad isn't watching this!"

We all missed your presence in Cincinnati. Hope you're feeling better.

14 November 2012 08:18  
Blogger JW said...

What he said

14 November 2012 08:24  
Blogger Chris Bame said...

Resawing 16"sugar pine and it laughed at you!!
I'm dripping with envy. : )

14 November 2012 12:50  
Blogger Chris Bame said...

Resawing 16" Sugar Pine and it laughed at you !!
I'm dripping with envy : )

14 November 2012 12:52  

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