21829 top isn't flat

[unknown poster]

I just picked up a 21829 today. I put it together and checked it out. There is some horizontal slop in the SMT that needs to be adjusted out and the stand is going to need some tweaks because it's not rigid enough, both of these can be overlooked for most usage.

There is just one major problem that I've found, the top is not flat. If I put the aux table next to the main table and run a straight edge over the two, there is at least 1/8" of a gap on the far side of the main table with the straight edge flat on the aux table. If I put the aux table on the left side of the blade I've got closer to 1/4" gap. If I put the SMT beween the two tables the SMT is higher than either by at least 1/16-1/8", it varies accross the table.

Is this normal?
Can I adjust this out (I don't see how)?

[LCHIEN]

I just picked up a 21829 today. I put it together and checked it out. There is some horizontal slop in the SMT that needs to be adjusted out and the stand is going to need some tweaks because it's not rigid enough, both of these can be overlooked for most usage.

There is just one major problem that I've found, the top is not flat. If I put the aux table next to the main table and run a straight edge over the two, there is at least 1/8" of a gap on the far side of the main table with the straight edge flat on the aux table. If I put the aux table on the left side of the blade I've got closer to 1/4" gap. If I put the SMT beween the two tables the SMT is higher than either by at least 1/16-1/8", it varies accross the table.

Is this normal?
Can I adjust this out (I don't see how)?

There'll be some slop in the knobs that attach and tighten the rails, you can tilt or raise or lower the rails according to how you set that.
Generally on the BT3000/3100 there were few complaints about leveling the aux table but the SMT was often found to be about 1/32" or less higher than the main table. No one from Ryobi ever answered why but its conjectured that the extra height of the SMT was designed to keep items on the SMT from dragging on the main table. I don't recall anyone ever saying their Aux table was hight than the main table by 1/4" or anything like that - did you check that the tab at the rear of the aux table is in the slot for it and you have the correct rails mounted in the correct places?
Ites been recommended that if you don't like the SMT being higher than the main table then there's some plastic strips on the bottom of the SMT slides that ride on the rails you can remove... this will lower the SMT about .025 to .033" and match the hight of the main table more closely.

[unknown poster]

If it's designed to be higher I'll just remember not to put the SMT in between the aux table and the main table.

The aux table being off really baffles me. If you're saying that I can adjust the rails, won't I have to do that every time I move them? I would expect they'll get moved fairly often and throw everything out of whack again. Also, the rails were pretty snug when I put them on, I'm not sure there's that much slop to be taken out. Is this a common complaint or do I just have a lemon?

[LCHIEN]

is the aux table high in front and back or just in back?
1/4" is a lot. If its just in back then I think you have not placed the lip of the aux table under the slot in the rear rail that keeps it from lifting up when in use. But the 21829 aux table is different, maybe the lip is too. On the BT3xes you have to insert the lip into the front of the rear rail and then lower the front of the aux table onto the front rail and then lock the front.

I really don't think adjusting the rails is going to make a big difference, altho I have never tried, it I imagine the T-nuts the rails are held on with have a bit of play in the slots.

[leehljp]

It has been a loooong time since I have seen a discussion on this misalignment. I don't remember everything about it and it seems that the misalignment was not this bad, from what I remember.

The problem was that - 1. the rails were not set on the boss correctly and 2. it seems like there was a problem a long time ago with the bolts/nuts that held the rails on were not exactly square and could be turned one way or another to cause the rail to be higher on one side if not done correctly. The wrong way caused misalignment. I am not at my saw at the moment (it is night and cold outside) or I would check.

It seems like I saw this only a couple or three times in the 7 - 8 years I started with the Ryobi forum and even with this forum. (Then again, that could have been only figment of my imagination.)

[sparkeyjames]

The SMT is higher because of the slide tape on the underside of the SMT tray. Remove it and the SMT fence drags on main table. Solution... Take the tape off the underside of the SMT and replace with thinner tape till the fence no longer drags. This will reduce the amount of rise in the SMT surface over the main table.

[DonHo]

I've had my 21829 less than a year and I had a similar problem(although I discovered my problem with the SMT fence dragging on the top), not as much off as 1/4" though. My problems was with the rail attachment, I was able to level the rails to the top with a little fiddling( as I remember I might have had the rail attachment nuts backward), once I got the rails lined up with the top, I've had no more problems. I do have my saw on a mobile cabinet instead of the stand that came with it so I can't speak to a problem with moving the rails because I haven't moved them.

Good luck,
DonHo

[dkerfoot]

What you describe is not normal and sounds well beyond something being misaligned from the factory.

Either something is broken, or you assembled it wrong. I'd go back and check each assembly step. I'd look at the rails first and make sure they are correct.

As for the rigidity of the stand, I was a bit concerned when I first got my 21829, because if you deliberately try wobble it, you can feel some play. What I have found is that it is never noticeable in actual use. Get busy on a project and I think you will find the same result - it is quite stable where it needs to be while in use. I consider the stand to be a wonder of modern engineering. I wouldn't "tweak" it unless you have used it a while and it is bugging you.

[Black wallnut]

Over the years others have posted similar problems that went away as soon as they trued up the stand. I'm not up to speed on all of the CM models so this may or may not be a problem. If it has a non-colapsable stand you might try removing the saw, trueing up the base then reattaching the saw. If the Stand or what it is sitting on is putting the saw in a bind then the rails may not be co-planer and or level.

[LinuxRandal]

The only 21829 stand I delt with was the demo model. Screwed together completely it was fine, but if you didn't use it's levelers, it did rack some. Use the levelers and it straightened out.

I then tried the Bosch gravity rise stand, which is similar in design, but with heavier tubing. While it felt better closed up, open, it could have some of the same issue. I still prefered it due to it's heft.

[leehljp]

Over the years others have posted similar problems that went away as soon as they trued up the stand. I'm not up to speed on all of the CM models so this may or may not be a problem. If it has a non-colapsable stand you might try removing the saw, trueing up the base then reattaching the saw. If the Stand or what it is sitting on is putting the saw in a bind then the rails may not be co-planer and or level.

What Mark wrote was another thing I meant to note above. His suggestion is what fixed several mis-alignment problems. Try a level floor and square up the stand and tighten the nuts/bolts on that before anything else.

[unknown poster]

Thanks for all the advice folks, community like this is one of the things that drew me to the BT series of saws. I went out and took took some better measurements and my gaps are between 1/16 and 1/8, not 1/4" as previously stated.

I think Randal probably nailed it, I didn't pay a lot of attention to the levelers and I know they're not perfect. I'm going to take the rails off, make sure the nuts are square, level the stand, and try it again.

I also found that my aux table has a crown of about .010 (a lot more if I measure to the far ends of the miter slots), and the SMT has a bow of about .020. Enough for me to see and enough to make me worry about square cuts with some projects but probably fine for most applications. I suspect that the BT tables with grooves were probably ground flat while the Craftsman table are cast and painted with no machine work so asking Sears for a new table probably won't net much of an improvement.

The SMT being high really bothers me because it means that I can't use it when taking rip cuts without distorting the alignment of the material to the blade. What type of tape should I use when I lower it?