Miter saw fence problem: solved! (in theory at least)

[KingwoodFan1989]

Well, I got the new fence delivered earlier today. Unfortunately, although it was a bit flatter than the original fence, it wasn't perfect. I still tried, though, and I could get it to within a bit less than .004 of straight (and that was only at one spot). Still, when I checked for square (both directly and through cutting), it wasn't much more up to par than before. I made a discovery though, which just so happens to be, I believe, the MAIN culprit, which actually is NOT the bowing of the fence: the orientation of the fence in relation to the blade (compounded by the design of the screws and screw holes, as discussed in my other thread).

Here's how it happened: I tried loosening all the screws, thinking that maybe the fence overall wasn't mounting properly. I noticed A LOT of play in the fence on the right side of the table, so I tried screwing just the endmost screw on the left in and pushing the fence on the right side back as far as it would go. Then, I checked the right side of the saw for squareness...it was pretty much perfect! 

Of course, the screw design that I brought up prevents any type of adjustment more than a few thousandths, and this would require at least 1/16" or so (pics below of where the fence sits with the screws all the way in vs. how the fence NEEDS to be (the one with my hand pressing against the fence is this one)). I've made my final decision about this: As much as I wish the stock parts were up to par, I'm gonna have to get my own screws and washers and use that method to hold the fence in place. 

As my and Stwood jointly discovered in my first thread on this issue, the mounting screw designs seem to have changed on these DeWalt miter saws recently. I actually spoke with a DeWalt technician earlier today to ask about it, and although it took some searching on his part, he did find the previous generation screws. Unfortunately, they're discontinued, so that confirms the key design flaw here: the mounting screws and their holes. I let him know on the phone about the lack of being able to adjust the fence with this new design, and he saw my point and said he'd pass the word on. I'm still going to send a formal e-mail to them, though, once I get the issue fixed (with pics) just to make it stone-cold crystal clear that this new screw (and screw hole) design was a HORRENDOUS idea. 

Here's the thing, though...I know I need a washer that would be a tad bigger than the upper lip of the holes (DeWalt technician specified this as well), but would I need to put one or two smaller ones underneath just so there is some additional support? Also, in looking up how to re-align a dovetail jointer, I found a video by Grizzly Industrial that said you can take small metal shims and insert them where needed. I think it might make the fence fix more permanent if I could find something to put in the track in my miter saw's table that would help hold the fence tightly in its rightful position. I'm glad this will be a dirt cheap fix rather than something expensive, and even though it's technically a mod, it's not something major or surgical in nature.

I REALLY hope DeWalt either takes my advice straight to the top or gets a BUNCH more complaints about the screw design from others. It's a BAD, BAD design, and it certainly is not up to the caliber of the rest of the saw.

[Phil Thien]

You don't have a lot of room there for washers.

The advantage of the FH hardware is that it would never go out of alignment, but it needs to start life in alignment.  I imagine the manufacturer (whoever makes these for DeWalt) changed their line so the holes are machined with the units partially assembled and the fence aligned.  BUT, something is out of whack.

I'd still advise sending it back, it looks like a giant compromise to me.

[KingwoodFan1989]

You don't have a lot of room there for washers.

The advantage of the FH hardware is that it would never go out of alignment, but it needs to start life in alignment.  I imagine the manufacturer (whoever makes these for DeWalt) changed their line so the holes are machined with the units partially assembled and the fence aligned.  BUT, something is out of whack.

I'd still advise sending it back, it looks like a giant compromise to me.

*Sigh*...I REALLY like this saw other than this, though. Are you sure I couldn't get aftermarket screws to secure the fence the way I want? I'd rather not have to package this thing back up. Anybody got a solution that would work to hold the fence in the backmost position? I know I mentioned the shims, but I'd also like something to fasten it down.

I'll still e-mail DeWalt these pictures, though. 

[jteneyck]

The fence on my Bosch isn't flat either; it's concave when looking at it from front.  A straight edge placed across shows a gap of at least 0.010" at the last point closest to the blade on both sides.  I had compensated in the past by adding an L-fence but I really wanted the stock fence to be straight.  There's no way to bend it straight but it does flex.  If finally realized that it might be possible to tighten the two screws on one side and then push the other side until it was straight.  That would have worked great except the stock bolts don't allow for that much adjustment - same problem you're having.  

The bolts are standard hex head machine screws, 8 mm x 1.25.  I changed them to socket head cap screws.  I still had to file the bolt holes in the fence oblong on both ends but, together, that gave me enough adjustment range that I could get the fence aligned perpendicular to the blade and straight across.  Maybe a similar solution will work with your fence.  

I bought the Bosch CMS because of how many great reviews there were with many people raving about how it was perfect straight out of the box.  In reality, nothing about it was perfect.  I would sell it in a heartbeat if I could get coffee money for it.  

John

[KingwoodFan1989]

The bolts are standard hex head machine screws, 8 mm x 1.25.  I changed them to socket head cap screws.  I still had to file the bolt holes in the fence oblong on both ends but, together, that gave me enough adjustment range that I could get the fence aligned perpendicular to the blade and straight across.  Maybe a similar solution will work with your fence.  

I bought the Bosch CMS because of how many great reviews there were with many people raving about how it was perfect straight out of the box.  In reality, nothing about it was perfect.  I would sell it in a heartbeat if I could get coffee money for it.  

John

I think you must have an older Bosch. I looked at pics of the newer glider models and they seem to have 2-piece fences.

What kind of file did you use? Notice how offset the holes are in the table compared to the holes in the fence...would I even be able to file it that much? I almost feel like I should just clamp the fence where it's needed, drill my own holes, and use a nut and a flat-bottomed screw with a washer to secure it that way. If I absolutely HAVE to do a surgical mod, I'd rather do that at this point than pack such a large item back up and return it. 

Hopefully DeWalt will get with the program and use elongated holes with flat bottomed screws and washers rather than this cruddy system on the current ones...then I can buy the improved stock fence and be able to recommend this miter saw without any reservations.


EDIT: I e-mailed DeWalt about the issue and included the two pictures I put in this thread. I'm going to paste my message to them below, only editing out my last name. I tried to be as respectful as possible but also as clear as I could about my dissatisfaction with the current fence screw and hole design. I hope it doesn't come across as too self-important, but I feel the best thing I can do at this point is just report my findings and try to come up with some way to keep the fence secured in its proper place. Anyway, here's what I wrote them:

"Hello, my name is Matt, and I have had a few phone conversations with your customer service recently. I essentially figured out what the problem was afterwards, and I'd like to let your company know about it more formally.

I'll start from the beginning: I recently got a 709 model miter saw from Amazon. I noticed that I couldn't get a square cut on the right side of the fence (or when cutting a board that touched both sides at once). I tried adjusting and checking for square in numerous ways, but nothing fixed the issue. I did notice the fence was a bit bowed, so I thought that was the problem. I called your customer service and they sent me another fence. This one was closer to flat, but not perfect. I was still able to bend it into submission to where it was within a few thousandths of an inch of being perfectly flat, but I still was only able to get the blade square to the fence on one side, not both. I eventually figured out the problem, and it actually wasn't the fence being bowed after all; it was the orientation of the fence holes to the holes in the table as well as the screws used to mount the fence to the table.

Here's what I mean: the countersunk holes which receive the underside of the screws pretty much force the fence into not being adjustable beyond a few thousandths of an inch. What I noticed is that when I left just one screw all the way in (the farthest one down on the left side of the saw), there is a lot of play in where the fence can sit on the other side. This is good, because this would normally allow for fine adjustments. I even noticed that when I pushed the fence all the way back and checked for squareness to the blade, it was now square on both sides. However, when I try to hold the fence in that position and tighten the screws down one by one, as soon as the underside of the screw head starts to contact the countersunk edge of the hole in the fence, the fence begins to be forced back out of proper orientation with the blade. I tried doing just one screw at a time, starting with different screw holes, etc., but nothing allowed the fence to stay properly aligned due to the way the screws and fence holes work with each other.

At first I was thinking of getting some washers and screws of my own, but due to the discrepancy between the hole in the fence and the one in the table, I'm not sure any type of washer would even work here.

Here's the thing...I had the same issue with the fence that came with the saw, and I'm sure that even that one could have been made to work if it weren't for one key problem: the screws and the fence holes. I talked on a woodworking forum I am a member of about my issue, and one member, who has many DeWalt miter saws between him and his son, said that he thinks the screw designs used to be different. He took pictures and they were indeed different. A DeWalt technician I talked to earlier on the phone confirmed for me that the older screws were different, but those are now discontinued. The screws from before seemed to allow for much more adjustment range to the fence (something that forum member told me he has been able to achieve), and the technician I talked to understood what I meant and said he'd put in a word about it.

Still, I thought I should let you know about this issue directly, as it is a major design flaw that seems to be several steps backward in terms of user-friendliness compared to the older design. I feel that the fence should be adjustable by more than just a few thousandths. I need at least 1/16" or so of room to make my fence sit in the correct position, but again, these screws force the fence back out of alignment. I included a couple of pictures that show where the fence sits when the screws are tightened down and where it needs to sit. You'll see my hand pressing against the fence in that latter picture, and you'll notice how far off the holes in the table are. At this point, I've almost considered clamping the fence in the right position, drilling my own holes, and using an aftermarket screw and nut to secure the fence.

To end with, I'm VERY disappointed that the screw and fence hole designs were changed, because the rest of the saw is fantastic. I love how it feels to use, how it cuts, and how easy it is to adjust the angle of the miter table to the blade. The capacity is also perfect for what I do as a hobbyist, and the saw even looks good. Still, something I like to have with my tools is the ability to recommend what I own to others without any major reservations. Unfortunately, this poorly-devised update to the fence screws and holes causes me major reservations due to it not allowing for significant adjustment. I know this is just one person's complaint, but I strongly recommend that you forward my message to the people in charge of research and development at DeWalt. I feel the design should be changed as quickly as possible so that customers aren't having to do surgical modifications and buy aftermarket parts just to get the saw to do what it could have done out of the box had the design for the fence screws and holes been either thought through better or just not changed at all from what sounded like a pretty adjustment-friendly design before.

I believe having some kind of elongated holes and a screw with a flat underside on its head (along with a washer) would be a much better option. Even the previous design sounded like a much better idea, but elongated holes slightly wider than the screw's threaded portion would allow for a lot of freedom to adjust the fence. I can force the fence to be basically perfectly straight in and of itself with the current design, but I unfortunately am unable to adjust the fence's overall orientation to the table and blade at this point. The only way I can see for me to do so is some kind of modification on my part, which is something I firmly believe should never have to be done to a new tool other than for extreme cases.

I hope you will consider and be able to see eye-to-eye with my comments and push for a quick revision to how the fence is mounted to the table on your miter saws. When and if that gets done, I'm certainly going to order an updated fence for my saw. At that point, I will definitely be able to recommend this saw to others with no reservations.

Sincerely,

Matthew"

[Roly]

It seems like you are squaring the fence to get to 90 degrees.   What happens if you just bolt the fence where all the bolts want to fit without regards to 90 degrees and then adjust the detent so it cuts at 90 degrees ?  Roly

[jteneyck]

Yes, my Bosch must be about 10 years old now.  A two piece fence makes a lot of sense and I was prepared to cut the one on my saw in two had the remedy I tried failed.  

I used a chainsaw file to elongate the holes in the fence.  No issues.  

My comments about all the great on-line reviews for the saw while the one I got being the polar opposite was meant to highlight that on-line reviews aren't worth the electrons they consume.  Since then I've come here and to other forums to seek input on which machines, tools, etc. are worth my money.  

John

[KingwoodFan1989]

It seems like you are squaring the fence to get to 90 degrees.   What happens if you just bolt the fence where all the bolts want to fit without regards to 90 degrees and then adjust the detent so it cuts at 90 degrees ?  Roly

Doing that only gets the saw to cut square on one side. I've tried to adjust it the way it is numerous times and it just doesn't work out for some reason. It seems like it should on paper, but it doesn't end up that way.

I think I'll pick up some screws today (like Stwood said) and figure out a way to make some kind of brace to go inside the holes that will work. I don't think a regular washer will do that...it would have to be something crescent-shaped since the holes in the table are on the very edge of the holes in the fence when it's lined up correctly.

And Simon, yeah, you're totally right about the reviews. I think that's the main reason why Harbor Freight's SCMS has even as many good reviews as it does...people don't review it after several months or years of use. Those who have done so for that saw seem to all point out to a loss of consistency.

[Stwood_]

Those older screws are still available in the UK.

https://www.partshopdirect.co.uk/dewalt-...330045-33/

I would just take your present screw down to the hardware store and get the same screw but in a hex head.

If that doesn't work out for you, I'll send you some used ones. More than likely you will have to grind the heads down some to get clearance to adjust.

[Handplanesandmore]

Most online reviews are superficially done after the box is opened for the first time , and the item used a few times, or for a day or two. Almost everything looks perfect like that....

Simon