Mini-Project...ZCI for my slider

[Jim Becker]

I've been meaning to make a true ZCI for my SCM/Minimax S315WS slider for a LONG time but never got around to it. Until today. I had time on my hands while spraying finish on another guitar build in a different area of the shop and decided to finally take care of this simple task. I had a piece of thin purpleheart long enough for the job, so I sliced off a 55mm wide piece, thinned it down to about 4.3mm to match the thickness of the standard aluminum insert, using the planer and then the drum sander. Holes were drilled and chamfered. And then it was time to cut the narrow slots for the blades.

IMG_7543.jpg

The blade slots were as simple as could be since the piece is held in place by four fasteners...raise them up all the way while the machine is running (with the riving knife removed) and slots suddenly appear for both the main blade and the scoring blade.

IMG_7544.jpg

To accommodate the riving knife, the main blade slot needed to be extended. I put the OEM insert back in and clamped the new insert down on top, offset so that raising the blade up all the way again while running would extend the slot. By clamping things with the blade raised a bit (not running), the new cut was indexed to the existing cut so that the alignment was correct.

IMG_7545.jpg

The side of the insert along the slider wagon is unsupported, so I installed a piece of half-inch plywood scrap vertically to reinforce it to avoid any deflection

IMG_7546.jpg

The end result from fabrication...

IMG_7547.jpg

Just to make it a little slicker, after sanding to insure it was clean and the edges were not splintery (a fun thing with purpleheart) I wiped on a little varnish to seal it up.

IMG_7548.jpg

I know this isn't an exciting thing, but since the sliding saws have different arrangements around the blade than North American style saws, I figured folks might benefit from the contrast. Different brands of saws have variations on the theme, of course, but in general, the insert on a slider is long and narrow.

I'll be doing another one to use as a dado insert since my particular saw supports that. I have an OEM version that I borrowed from Brandon Conover awhile back to use as a template and the rest of that piece of purpleheart, so that version should also go together with minimal fuss.

[Mike Wilkins]

LONG Time is the same situation for me also. I have been needing to fabricate a ZCI for my Laguna slider, so this is the next project for the shop after a finish is sprayed onto a shop cabinet just completed. Thanks.

[Tom Bain]

This is also on my never-ending, always expanding to-do list.

Jim -- Do you ever use a dado stack in your slider, and if so, is there a ZCI plan for that?

[Jim Becker]

Mike, the key for my machine was getting the material to the exact thickness and I suspect that will be the same with yours. There's not a lot of wiggle room on that, if any. So I snuck up on it with the drum sander. The other thing was that unsupported edge. Had I made it of aluminum (I actually intend to do one later that way on my CNC) this would be less of an issue, but the minimal thickness of the wood was a bit too flexible without that reinforcement.

[Erik Loza]

Awesome, Jim. I remember Sam doing these as a little side project back in the MM USA days. He used a couple different types of phenolic. Machining that stuff stunk the shop up to high heaven.

Erik

[Steve Wurster]

Nice work, Jim. These seem a lot easier to make than the ones for my Hammer K3. Those require recesses notched out on the bottom to accommodate some machine "bits" that are present in the opening. Also two of the screw holes are really close to the edge of the insert.

Here's a picture I took of two phenolic OEM inserts (one is installed), along with three that I made out of cherry. You can see where I routed out rectangular sections to mimic the recesses on the OEM ones. I've got two of my cherry inserts setup for specific dado widths, while the third one is still unused. I might use that last one for a 45 degree setup.

The upside-down OEM insert is the one that came installed on the saw, and is the one I use for all bevel cuts. Using that for bevel cuts almost always results in cutoffs going down into the cabinet, or banging off the open end of the cutout, hence my thinking of using that last cherry one for 45 degrees.

The installed insert was originally completely intact; I think Hammer/Felder expect customers to use that for dado cuts. I like your idea of putting the insert on top of another insert in order to cut the opening for the riving knife. I ended up cutting that opening using a 1/8" router bit on my table. I didn't cut an opening for the scoring saw, as I don't use that much.

Note that the space between the blade opening and the wagon side of the insert is quite narrow. I have no additional support under that for the installed insert; little-to-no downward or sideways pressure is ever really applied to that area of the insert, so I think it's okay like this. I know some folks online have made their inserts thicker in that area and basically extended them slightly under the table, but I didn't bother.

There is one guy online that plans on making these on a CNC and selling them; I'm waiting on him to do that so I can buy a few. I'm sure his price will be cheaper than the $70+ that Felder is currently charging.

Hammer ZCI.jpg

[Rick Potter]

It was exciting to me, Jim.

At least exciting my memory about this project being on my list. I am bookmarking this for the day I get to it.

Thanks,
RP

[Jim Becker]

Awesome, Jim. I remember Sam doing these as a little side project back in the MM USA days. He used a couple different types of phenolic. Machining that stuff stunk the shop up to high heaven.

Yea, Sam and I communicated about this a long time ago, particularly about the phenolic. I originally intended to go that way, actually, but I'm sure the smell while cutting it would be, um...tasty. At this point, wood was good for a start with the edge reinforcement and I do fully intend to do an aluminum version on the CNC. For that one, I'll have to be "not quite" zero clearance. Not that the blade will get damaged by biting into aluminum, but I'd rather just not cut it that way. So I can cut the slot so it's a bout a half millimeter wider and leave a hair more at the riving knife for good measure. That's easier to do on the CNC than manually.

[Mark e Kessler]

Wow Jim, Purple Heart sure makes it fancy 💪 - best I could come up with was a bright orange warning area for the scoring blade...

620F335F-EC90-440F-BD67-24C8A21C6363.jpgD270E847-1A47-4624-AD96-B11F0760653E.jpg7A7A1A62-87F4-4ABF-B854-1212829027F2.jpg

I've been meaning to make a true ZCI for my SCM/Minimax S315WS slider for a LONG time but never got around to it. Until today. I had time on my hands while spraying finish on another guitar build in a different area of the shop and decided to finally take care of this simple task. I had a piece of thin purpleheart long enough for the job, so I sliced off a 55mm wide piece, thinned it down to about 4.3mm to match the thickness of the standard aluminum insert, using the planer and then the drum sander. Holes were drilled and chamfered. And then it was time to cut the narrow slots for the blades.

IMG_7543.jpg

The blade slots were as simple as could be since the piece is held in place by four fasteners...raise them up all the way while the machine is running (with the riving knife removed) and slots suddenly appear for both the main blade and the scoring blade.

IMG_7544.jpg

To accommodate the riving knife, the main blade slot needed to be extended. I put the OEM insert back in and clamped the new insert down on top, offset so that raising the blade up all the way again while running would extend the slot. By clamping things with the blade raised a bit (not running), the new cut was indexed to the existing cut so that the alignment was correct.

IMG_7545.jpg

The side of the insert along the slider wagon is unsupported, so I installed a piece of half-inch plywood scrap vertically to reinforce it to avoid any deflection

IMG_7546.jpg

The end result from fabrication...

IMG_7547.jpg

Just to make it a little slicker, after sanding to insure it was clean and the edges were not splintery (a fun thing with purpleheart) I wiped on a little varnish to seal it up.

IMG_7548.jpg

I know this isn't an exciting thing, but since the sliding saws have different arrangements around the blade than North American style saws, I figured folks might benefit from the contrast. Different brands of saws have variations on the theme, of course, but in general, the insert on a slider is long and narrow.

I'll be doing another one to use as a dado insert since my particular saw supports that. I have an OEM version that I borrowed from Brandon Conover awhile back to use as a template and the rest of that piece of purpleheart, so that version should also go together with minimal fuss.

[Jim Becker]

Really nice work on that Mark!! The purpleheart was, um...convenient. I apparently re-sawed some years ago for a night stand project to not waste material and there was a nice piece that was not quite 6mm thick in my "thin shorts" pile. Since it was long enough and just a little thicker than I needed, one pass through the planer and then a few passes through the drum sander made it work for me.

[Dave Cav]

I made several ZCIs for my MM SC4E out of composite flooring I got from the ReStore. It has a slick face and I was able to dimension the thickness on the reverse side with my widebelt. Otherwise pretty much like Jim's only I cut the riving knife opening out on the scroll saw.

[Kevin Jenness]

What happens when you tilt the blade? Do you have to swap the original piece back in?

[Jim Becker]

What happens when you tilt the blade? Do you have to swap the original piece back in?

Yes, a ZCI like this cannot be used for cutting bevels unless you do the exact same process for a specific bevel angle. Most folks don't do that for any kind of table saw, based on my observation over the years. I don't cut bevels very often and changing out to the OEM insert only takes a few moments...4 screws with a 4mm hex wrench are the only things involved.

Where this is going to be very helpful to me is when cutting very narrow things that would easily slip into the larger spaces on the OEM insert. It will reduce the incidence of having to stop cutting to clear something that's parked itself in an inconvenient place.

[Todd Solomon]

Very nice Jim! Also on my to do list for my Hammer C3, which is patiently waiting for me to uncrate it. Just picked it up yesterday

[Jim Becker]

Used it for actual cutting today. Aside from a noiser start (it really is zero clearance at the moment) it clearly makes a difference when cutting including with dust/debris on the table. Much cleaner which is nice because I don't use overhead collection.