Adding Zero-Clearance to cast iron bandsaw table

Hi all, I think this is my first post here - been lurking around for the last year or so.

I have an Enco 360 bandsaw I picked up earlier this year. Two things quickly became evident:
- It would benefit from a fence, which was a nice little project to make
- The gap in the table for the blade is far too large for detail work or small parts.

This saw seems to be designed for grunt work light commercial use, maybe on larger sheet metal or other parts where "whoops it got sucked into the table" isn't a concern.

However in the home shop, once I cleaned up and started using this saw ... it was unsettling to work on any small parts, or parts with small off-cuts. Especially if small parts got sucked into the table, it was terrifying to picture a finger going down with it.

So I have been thinking for a while about how to add a pocket for a zero-clearance insert, and in the last few days spent some shop time implementing it.

Here are a couple "before" pictures showing the size of the hole in the table for the blade. I believe the blade is 1/2" wide, for scale. The "blade passage" hole is a roughly .380" wide and 1.280" long oval.



This table measures approximately 20x22". My mill is a Rockwell 21-100 with a 24" table. This *barely* fit the bandsaw table on it, with 1" to spare on either side for clamping. The ends of the table beyond the t-slots are not part of the table casting and are only held on with fasteners to collect coolant and hold the bearings for the Y axis screw, etc... so I avoided clamping against this with the step block. I had to use the smallest step blocks with 1-2-3 blocks to stay within the 1" clamping area past the bandsaw table.



I had under an inch to spare on reach with my dial indicator stand when sweeping to square the table up to the mill, and that still required getting creative with where the base was attached.

A lot of luck was involved in this setup. The table appears to have been machined on all sides, with the X and Y sides of it actually being square to one-another; and the top was surprisingly flat: zero runout across the 3-4" that I swept, just surface deviation. That is, the top was coplanar with the bottom surface, so it could sit straight on the mill table.


Close-up above, of the clamping setup used on both sides.



From the front you almost can't tell there's a mill table underneath this, looking like some crazy person bolted a plain machine table onto a mill.


My luck continued from here. The blade passage is not exactly centered on the table, it is an inch closer to the operator side of the bandsaw (facing the column of the mill here). If I run the mill X axis all the way towards the column, the bandsaw table hit the column just at the point where the pocket could end.

I wanted to use a 1" end mill with slow feeds and speeds to make a proper oval. However my 1" end mill is long... which would force me far enough down in the Z axis that the bandsaw table would hit the ways for the Z axis, losing roughly an inch of travel that was required. I ended up having to use a 1/2" end mill, and had just enough travel to come .300 past the blade passage in the table.



The resulting pocket is .875" wide, .125" deep, and 1.934" long - the latter dimension was a result of the limited travel, the length of the blade passage, and maintaining symmetry on both sides of the passage.


Laid out the insert on a 1" piece of bar stock. I ended up making two - the second one was much faster since I could now use the bandsaw to nip the corners off without having the off-cuts get drawn into the table (or the part getting unstable near the edge of the passage)



The stock was a bit over .125" thick, and I don't think it sat 100% flat in the pocket - so I took a quick pass with a shell mill to knock .010" off and add a nice surface finish. Then put the fence against the pocket and pushed it into place (with pushsticks) while the saw was running.

Thanks for reading. This upgrade should make the saw much more comfortable and safe to use for our intended purposes for years to come. I hope this helps anyone trying to envision a similar change in their shop, it was worth the couple hours of thought and execution! I cannot tell you how much luck was involved in being able to do this on my mill, with this particular bandsaw table. My dreams of using the mill to refinish this table's rough machining marks are pretty much dashed, and that's ok

 

I was wondering about this, and considering countersinking some tiny fasteners in to hold it to the table. I have a small box of 4-40 x 3/8 allen flat-head screws which would fit nicely into the insert, and there is plenty of meat in the table under the pocket to drill+tap into. The machine is metric, so ideally maybe I'll wait and pick up an M2 or M3 equivalent just for ... religious purposes.

I go to the same church as you.

 

Welcome to the forum.

Great job on improving your band saw I enjoyed your documentation of the process and the illustrations. I will have to keep that in mind. Very well done.

 

I wish my Enco band saw had a iron/steel table like yours. The later aluminum table is flexy and cheap, like overcooked ramen noodles.

 

Further peanut gallery comments: if I had it to do it again, I would not make my insert from aluminum. I'm using my saw this afternoon and looking at the insert, chips have become embedded on both sides and a rather difficult to remove. It is also "sticky" for parts to slide over it. This is my only experience so take it FWIW. I would maybe try Delrin or bronze? i will continue to roll with the aluminum, it's not bad but I think it could be better.

 

Further peanut gallery comments: if I had it to do it again, I would not make my insert from aluminum. I'm using my saw this afternoon and looking at the insert, chips have become embedded on both sides and a rather difficult to remove. It is also "sticky" for parts to slide over it. This is my only experience so take it FWIW. I would maybe try Delrin or bronze? i will continue to roll with the aluminum, it's not bad but I think it could be better.

If you are referring to my insert instead of just yours -- I'll clarify that mine is steel since I did not mention it elsewhere. No idea what alloy since it was a tiny off-cut I inherited in a box of junk, but some low-carbon steel that took a decent surface finish. Looking back on it, prototyping an insert out of aluminum just to confirm that I could file a decent radius... probably would have been a decent idea.

 

I'm sorry if my post seemed somehow critical to your solutions as my comment was only critical of my own inserts. I posted that personal thinking process just to share my own experience in case it proves useful to you or others. I think your choice of steel is better than my choice of aluminum. I have no idea how plastic would behave over time but I suspect steel or plastic would not share the problem of being sticky. I in fact feel like your choice of steel is likely the best option.

 

I'm sorry if my post seemed somehow critical to your solutions as my comment was only critical of my own inserts. I posted that personal thinking process just to share my own experience in case it proves useful to you or others. I think your choice of steel is better than my choice of aluminum. I have no idea how plastic would behave over time but I suspect steel or plastic would not share the problem of being sticky. I in fact feel like your choice of steel is likely the best option.

Hah no worries, just clarifying. Indeed I find myself surprised at how many products ship with plastic inserts, even in woodworking tools... I just don't see how it could hold up over time under anything less than perfect usage (no accidents and or nicks during blade changes, etc)

 

The first time my plastic insert in my Grizzly bandsaw disintegrated, I bought 3 or 4 replacements. I think I have 2 left now. When they go, I was planning to make one out of Delrin or Aluminum.

 

The first time my plastic insert in my Grizzly bandsaw disintegrated, I bought 3 or 4 replacements. I think I have 2 left now. When they go, I was planning to make one out of Delrin or Aluminum.

These are the ones I made for my Grizzly. I bagged the jig but I don't even remember what it's for. Locating pins and facing, I think.

 

These are the ones I made for my Grizzly. I bagged the jig but I don't even remember what it's for. Locating pins and facing, I think.

Is the black plastic round one of the originals that came with the saw? Quite the gap on that