SCM SC4E wagon tolerances

[Ned Otter]

Hi everyone --

Still waiting for the electrician to wire up my equipment, but in the mean time, I'm checking what I can check.

I have 3 magnetic bases, each with a dial indicator, and wanted to verify how consistent (or inconsistent) the wagon is, relative to the cast iron table. I have 2 dial indicators on either side of the cast iron table, measuring the edge of the wagon that's closest to the iron. The other dial indicator is for the far side of the wagon.

Setting everything to zero with the wagon locked, I'm seeing deviation of up to 0.010 across the length. Wondering if this is considered "in spec".

If not, I would imagine that changing this is not possible/recommended by an end user, that it would require a service call.

Thanks in advance --

Ned

[Ned Otter]

Forgot to mention that I have the outrigger attached, which is probably not ideal. Then again, applying even modest pressure to the outrigger resulted in moving the dial indicator fairly significantly for the side of the wagon closest to it. Heavy lumber would do the same or worse.

[Kevin Jenness]

If you are measuring a variation in the height of the wagon as it moves along the fixed table, there is no adjustment on any saw I have worked with. The overall level of the wagon support can be raised or lowered but the straightness of the travel is determined by the fixed position of the ways. If there is any way to adjust the ways it should be obvious and you could attempt it yourself. You might ask Sam Blasco, who is a SCMI rep.

The good thing is that .010" in that orientation is not huge. The main practical effect will be seen on long bevels. I worked with a Martin saw that had about that much of a hump in the travel and it really wasn't a problem. If you set the carriage height so it is not below the main table at any point in its travel you should be all right. I would be more interested in how straight the carriage travel is in the horizontal plane.

Extruded aluminum tables are not that stiff. Even a relatively heavy one can be made to bind with heavy pressure from a clamp anchored in the t-slot. Get the wagon and extension parallel with the main table as close as possible, don't torque or lean on them too hard, and carry on. If you get unacceptable results then you can start worrying.

[Ned Otter]

Thanks, Kevin

I had watched the YouTube video by David Best about how he adjusts a Felder to compensate for the type of variance I'm seeing, video can be seen here:

https://www.youtube.com/watch?v=9s2a02XI3BQ

and I thought perhaps SCM had a similar method of adjustment.

If by "I would be more interested in how straight the carriage travel is in the horizontal plane" you mean relative to the blade, I'll be checking that later today.

Ned

[Erik Loza]

Ned, just an observation: I sold many SC4's during my Italian time. We generally never had to commission that aspect of the saw. In fact, I don't think that tolerance is called out in any of the literature. Felder does but perhaps others don't. The vast majority of calibration issues we had to deal with that affected the travel the slider through the blade were from the adjustments to outrigger telescopic arm and specifically, the plastic wheels. Detectable "bumps" during the cut, etc. If you're not experiencing any of this during the cut, I would just square up the crosscut fence and not worry about the rest. Hope this helps,

Erik

[Ned Otter]

Thanks for responding, Erik, appreciate your feedback.

[Kevin Jenness]

Thanks, Kevin

I had watched the YouTube video by David Best about how he adjusts a Felder to compensate for the type of variance I'm seeing, video can be seen here:

https://www.youtube.com/watch?v=9s2a02XI3BQ

and I thought perhaps SCM had a similar method of adjustment.

If by "I would be more interested in how straight the carriage travel is in the horizontal plane" you mean relative to the blade, I'll be checking that later today.

Ned

I took a peek at that video. If your saw has jack screws in the center of the beam support like the Felder, you should be able to adjust the table travel straighter. If you are willing to take the time and go at it with care there's no reason to call in a tech.

By straightness of carriage travel in the horizontal plane I mean in an absolute sense. I wouldn't bother trying to measure that except by results - when you get the saw running, cut straight edges on two long pieces and put the two edges together. They should fit together tightly. If there is a discrepancy you might be able to deflect the beam sideways slightly and lock it in place with the central jack screws (if any).

The carriage travel in relation to the blade (toe-in/out) you can if necessary adjust by measurement either parallel or with a slight toe-out as spec'ed by the manufacturer.

Basically, I suggest you make some cuts before you start tweaking the table supports. If you get unacceptable results, then settle down to some fettling. If it works, don't fix it.

[Jim Becker]

I agree with Erik. KISS method for sure. Square is what you need to check and make any adjustments for. Any minor things with the wagon around what you were looking at really are not going to matter, IMHO.

[Warren Lake]

interesting video, his bases are all better than the type I have. Maybe i missed it did he measure the table saw top to see how flat it was. I stuck my dial on my carriage then went across the table top near the edge and it was not flat. Straight edge showed the same.

[Mark e Kessler]

0.010 is considered high for some but thats about were i like it. Mine mine actually shoots up a bit at the last foot of travel, can't remember exactly maybe 0.020 but doesn't matter its not like I am doing a long dado where I would want a consistent depth and even that amount of variation wouldn't matter at least for me. what's more important to me is that the slider is co planer with the cast top, sounds like your setup for measuring as I use 3 dial gauges as well. (blade 90 to cast > slider 90 to blade = blade 90 on both sides of it)

[Warren Lake]

I didnt to many measures like he did some similar and only used one dial as only have one dial base. I have a totally different saw and adjustment. I just thought its logical to see how flat the table top is before doing any measures.

[Ned Otter]

I have the exact same setup as David - 3 bases/dials.

My current issue is that once adjusting the Lamb parallel fence I have with the operater-side of the wagon, it can't make it all the way across the wagon without coming into contact with the wagon. That means the iron-side if the wagon is too high.

Will think on this.

[Mark e Kessler]

Pictures of your issue would be helpful

[Kevin Jenness]

My current issue is that once adjusting the Lamb parallel fence I have with the operater-side of the wagon, it can't make it all the way across the wagon without coming into contact with the wagon. That means the iron-side if the wagon is too high.

Sounds like you need to adjust the pitch of the attachment bracket so the slide is parallel to the table surface.

[Ned Otter]

When I do that, it flows easily over the operator side of the wagon, but catches on the far side. Raising the fence further only makes it worse, of course.

I could leave it at a lower-than-parallel level, and it would clear all sides of the wagon. Not sure I want to jump down the rabbit hole required for fixing the wagon plane(s).