Levels for leveling a slider

[mark mcfarlane]

My Minimax CU300 has been up and running for about 18 months, and I feel like it is time to go back through and recalibrate all my machines to bring out the next level of precision.

> I'm curious what kind of level people are using to level their sliding table saw cast surface. I'm not speaking of the slider, but rather the main cast saw base.

I don't expect to get the cast surface perfectly level, but I want the left/right tilt to be identical on the infeed and outfeed side of the machine so that the top is planar, not twisted.

Would the level built into a Starrett combination square be suitable, maybe with some feeler gauges so I can get the bubble perfectly centered on the infeed side, then use the same feeler gauge thickness and location on the outfeed side...?

The precision levels that let you dial in an adjustment to the bubble would be helpful for this type of 'relative leveling', but I am having a hard time justifying spending $300 for something like Lamb Toolworks Precision Level for a once a year machine check.

[Erik Loza]

Mark, we’re talking about the saw/shaper cast iron table, right? Is it actually twisted? From what I recall, that top is mounted around the perimeter. One thing I remember is that sometimes there is an inherent cup in the middle of the table from the weight of the saw and shaper units. Not really a problem in the real world but it could drive you nuts trying to take it out.

Erik

[Richard Coers]

If you are after high precision, you need equivalent tools to measure that precision. Starrett does a great job with their tools, but that bubble in a combination square is not precision. I would assume Ebay would be the place to find a precision Starrett level and straightedge. I don't see the need to rush to buy new tools, it's been running like it is for the past 18 months.

[Jeff Heath]

I think most people would be pretty surprised at how much cast iron will twist, move, and settle. Leveling a machine with precision equipment is never a bad idea, but for woodworking machines, most don't even give it a consideration.

I have a Starrett machinists level (actually a couple), that I use to level my machines. To give you an example, when I first set up my metalworking lathe in my shop (a 10,000 lb. Monarch Series 61), it had several thousandth's of twist in the bed, and this is immediately noticeable in an precision part you are trying to make. After leveling the machine in both directions, slowly but surely, I was able to dial in the accuracy of the lathe. Did the same thing to my mill.

If your base is out of whack, and your floor is uneven, it would certainly benefit you to level your saw. I own a Martin T17 slider, and the literature from Martin clearly discusses the importance of leveling the machine to the accuracy at which it will perform. If you seek "next level" performance and accuracy from your machine, then I think the time invested in leveling it is well worth the cause. I spent a ridiculous amount of time hand scraping the cutterhead mounting blocks, and ways of my 16" jointer, when I restored it. I was rewarded with a jointer that is the most accurate I have ever had the pleasure of working with.

I don't think you need to invest in a Master Precision's Level (#199), but a good quality Starrett #98, which is what I own in a couple different sizes.....15" and 8", will quickly get you set up.

A big part of your process is going to be choosing leveling feet that are easily adjustable in small increments. I am not familiar with your saw, and am not aware of whether or not they are built in. My Monarch lathe has 8 leveling feet built into the monstrous cast iron base. If you go on youtube, you will find quite a few video's about making a decent set of screw-type leveling feet. Or you can certainly buy them online from McMaster Carr, Grainger, etc....

[mark mcfarlane]

To add to what I am trying to accomplish:

There isn't a bad twist in the cabinet, but it is not perfectly level front and back. I used wood and paper shims to level it initially. I think some new maple shims will do the trick.

I carefully set up the CU300 when it was new, and adjusted the slider so it sawed beautifully and accurately. 90 degrees was dead on,...

Then a year later I started working with the shaper. That was a nightmare. I spent 2 days in the middle of a project readjusting the slider so I could get repeatable results, e.g. a consistent groove along the length of a 48" board. The demands on slider accuracy for a shaper are much higher: the height above the cast iron at the cutter head cannot vary as the slider moves. That's not a big issue for sawing.

Strangely, the height of my slider above the cast table changes as the slider is moved. e.g. measuring at the saw blade I could dial in .002 on one point on the slider, but at other points along the slider it went below the cast table or much farther above. And these changes were not in a consistent manner, i.e. no simple geometry of two planes sliding past each other, so I concluded the slider or the channel it runs on is/are probably 'warped'

During the slider adjustments for the shaper I must have also changed my toe because 90 degrees is now off a hair.

So I want to start the process all over again.

I'll likely start a different thread for the slider setup next week, after I finish a project. FWIW, There are 7 bolts for the slider adjustment. 5 of them are obvious height adjustments (2 fore and aft, 1 in the middle of the carriage). The other 2 bolts are much thinner and I can't really figure out what they are for. They are not in the parts manual. I have ignored them so far. I wonder if they are something used during assembly that were supposed to be removed in the factory,....

[mark mcfarlane]

Mark, we’re talking about the saw/shaper cast iron table, right? Is it actually twisted? From what I recall, that top is mounted around the perimeter. One thing I remember is that sometimes there is an inherent cup in the middle of the table from the weight of the saw and shaper units. Not really a problem in the real world but it could drive you nuts trying to take it out.

Erik

Erik, There is a .011" dip along the left edge, between the saw blade and shaper spindle. I'm not too worried about that small dip, as long as I can hit the spindle at a repeatable height along the length of the slider's travel.

[mark mcfarlane]

I think most people would be pretty surprised at how much cast iron will twist, move, and settle. Leveling a machine with precision equipment is never a bad idea, but for woodworking machines, most don't even give it a consideration.

I have a Starrett machinists level (actually a couple), that I use to level my machines. To give you an example, when I first set up my metalworking lathe in my shop (a 10,000 lb. Monarch Series 61), it had several thousandth's of twist in the bed, and this is immediately noticeable in an precision part you are trying to make. After leveling the machine in both directions, slowly but surely, I was able to dial in the accuracy of the lathe. Did the same thing to my mill.

If your base is out of whack, and your floor is uneven, it would certainly benefit you to level your saw. I own a Martin T17 slider, and the literature from Martin clearly discusses the importance of leveling the machine to the accuracy at which it will perform. If you seek "next level" performance and accuracy from your machine, then I think the time invested in leveling it is well worth the cause. I spent a ridiculous amount of time hand scraping the cutterhead mounting blocks, and ways of my 16" jointer, when I restored it. I was rewarded with a jointer that is the most accurate I have ever had the pleasure of working with.

I don't think you need to invest in a Master Precision's Level (#199), but a good quality Starrett #98, which is what I own in a couple different sizes.....15" and 8", will quickly get you set up.

A big part of your process is going to be choosing leveling feet that are easily adjustable in small increments. I am not familiar with your saw, and am not aware of whether or not they are built in. My Monarch lathe has 8 leveling feet built into the monstrous cast iron base. If you go on youtube, you will find quite a few video's about making a decent set of screw-type leveling feet. Or you can certainly buy them online from McMaster Carr, Grainger, etc....

Thanks Jeff. That Starrett #98 is still over $200 for a 12" version. I'm wondering if this level from Amazon would be 'good enough' for what I am trying to accomplish. Another option would be to get the 6" Starrett #98 for $100 and just stick a 12" chunk of maple beneath it.

[David Kumm]

Brian Lamb at Lambtoolworks has a nice level for that purpose. Ebay and CL are also sources for machinist levels. Get pictures to show the base isn't bunged up and the vials are good and an old level will accomplish the same thing as a new one. level isn't as important as repeatability. Dave

[Peter Christensen]

Shars Tools has one for $80 and is more than good enough for leveling woodworking machines. If you need to measure over a longer distance the master level sitting on top of a high quality level like a Sabila works.

https://www.shars.com/products/measu...ecisions-level

[Mark Bolton]

Ive never leveled any of our tools with anything more than an 80" stabila level and a rotary laser. In all honestly in my opinion other than relation to adjacent equipment, or a CNC, some of your best tweaks will come from sound, eye, and test cuts. I setup a less than stellar slider 10 years ago and it still cuts dead square at 100" to this day.

I really dont think you need precision instruments for this equipment and Im not saying that wood isnt best cut at .001" if possible. CNC has brought that to the forefront. But you dont need an 1100 dollar level to get there.

[David Kumm]

I think some are missing what Mark is trying to do here. A sliding table on a saw can't be set well unless the cast iron is flat. Newer saws in particular with thinner cast tables and internals hung off them tend to have dips and waves in the cast iron top that makes it hard to set the sliding table. While the extrusion itself often bows a little at the extreme ends ( or ttips slightly at the end of travel ), it is pretty flat, often better than the cast iron. setting a machinist level all around the fixed table gives you an idea if there are areas that need adjustment. A long level is not useful. A bubble that measures in very tiny increments is needed as well. .005 might not sound like much but it will drive you crazy if it causes a slider to dip below the cast iron on part of the stroke but ride above it on another. If you want the slider to be at .002 all the way ( saw shaper needs this ) you need the level to make the cast iron flat, not level. Dave

[Warren Lake]

I started with a Stabila level and found setting up the old SCM a pain., Primitive bearing system on the sliding table made it more so. Other thing is that level was hard to get as the shims i put in that were laminate thick would raise one of four contact points and one or two others were then not making full contact. A threaded foot type thing would have dialed in much easier. This is not like a cabinet where things bend and distort. The machine has a thick steel base and the top is not going to change in flatness, it is what it is based on whatever from manufacturer, to the years its been around, how it was used and how much use. Look at a machine that had a power feed and after lots of miles it will be down in the pressure area of the feeder.

When I started checking the top I found the top was out, well out, never mind setting up to .002, I didnt have a chance if the top varies and was down .005 going by memory around the blade area I started to make my top flat and until its close other fine numbers cant be obtained.

Id be putting a straight edge on your top front to back side to side front to back and cross ways corner to corner and see what you are starting with. New or not.

[Rod Sheridan]

Erik, There is a .011" dip along the left edge, between the saw blade and shaper spindle. I'm not too worried about that small dip, as long as I can hit the spindle at a repeatable height along the length of the slider's travel.

Hi Mark, if you’re worried about a reference from the sliding table to spindle height, the cast iron table is irrelevant.

For example when making tenons, the work is on the sliding table, which is higher than the cast iron table. In fact, many tenon tables are much higher than the cast iron table, maybe 8 to 20mm higher.

Hopefully I’ve understood your question correctly........Regards, Rod

[mark mcfarlane]

Hi Mark, if you’re worried about a reference from the sliding table to spindle height, the cast iron table is irrelevant.

For example when making tenons, the work is on the sliding table, which is higher than the cast iron table. In fact, many tenon tables are much higher than the cast iron table, maybe 8 to 20mm higher.

Hopefully I’ve understood your question correctly........Regards, Rod

Thanks Rod. The machine in question is a CU300 combo machine. Shaper cuts on short sections of end grain, such as tenons, don't present the big alignment problem. The alignment gets trickier if you try shaping an 'always exactly centered' groove in the side of an 8' long board while still having good alignment at the front of the saw blade.

This is where I am coming from.

[Warren Lake]

show us what you are doing, material on the table how wide it is, see the distance of table fence cutter etc. If you are running a style to a shaper cutter to cut a slot and its flat on the table should be fine, if your material is not straight or your table is not straight should still be fine if you are using a feeder or a feather board because pressure is holding it down.