DEWALT DW744X Blade Height Play

[carbureted iron]

While dado-cutting finger joint slots, the depth of cut is always one-sixteenth too deep despite perfect blade height adjustment.

Owner's manual doesn't list this specific problem within the t'shooting section. So I post here in the hopes someone has experienced this same issue with their DeWALT job saw and can explain to me the exact procedure to fix this annoyance.

I found vertical movement when I grip the riving knife and lift; meaning, the aft portion of the carriage pivots up in an arc (approximately 1/16 inch ...ah HA!) from whatever its current resting position is set at and appears to pivot on the fore portion of the carriage. I flipped the thing upside-down and looked for some loose widget in the motor carriage assy. I can't find what is loose, worn, or out-of-adjustment.

Any DeWALT DW744X owners recognize this issue?

 

[carbureted iron]

I located the source of the issue. And in doing so I also determined that the saw is safe to use. So those are both wins.

Turns out the cause of the movement is at the linkage sliding joint between two parts: Link 153419-00 and Follower Nut 386158-00. Specifically, the a slot in the Link 153419-00 part has too much clearance, allowing the entire part to pivot a fraction of an inch against the Follower Nut 386158-00 when the saw blade is spinning. This movement translates at the apex of the cut as ~1/16-inch vertical movement.



The saw is circa 2012, but I genuinely doubt the cause is due to worn parts. I suspect crappy design of this sliding joint has been lurking in my stalwart saw all these years. Either the diameter of the dowel pin on the Follower Nut was machined too small for the slot it rides in and/or the slot stamped into the plate that levers elevation to the motor and blade assembly is too large by a few thousandths.

This problem only affects “top-of-blade” cuts, such as slotting, grooving, rabbeting, dado'ing, etc., and does not affect typical leading-edge cuts such as rip/crosscut/miter cuts. Explains why I hadn't noticed this vexation till now—I can't remember the last time I broke out my dado kit. Regardless, I need precise-height cuts at the moment, so my project is at full stop till I get this matter sorted out. I may just put a few wraps of aluminum or brass tape around the dowel pin on the Follower Nut to take up the slop in the guide slot and see if that serves as remedy for the time being.

 

[RTM]

I need precise-height cuts at the moment, so my project is at full stop till I get this matter sorted out.

Set the blade 1/16" lower than you need? Let nature take it's course for a while?

 

[carbureted iron]

Honestly, I tried. ...many times. Cuts vary btwn too deep or too shallow with the hardwood I'm slotting—I just can't get the dado stack depth dialed in under current circumstances. In fact, it was only after I got the required slot depth with some pine scrap did I step back and go "humph... thar's somethin' screwy goin' on here."

I just need to get the slop out of the blade height adjustment sufficiently so the thing will cut accurately for many, many cuts.

 

[RTM]

I just need to get the slop out of the blade height adjustment sufficiently so the thing will cut accurately for many, many cuts.

So, looks like your "red" slot won't be easy to fix. IS it close enough to right that you could slide a bushing over the shaft, rather than wrapping it? Maybe find out how much a new one costs and if reasonable, buy it and try to modify one of them if they are both the same, have someone weld it bigger, then turn down to what you need? Maybe a Delrin sleeve so it slides better? (I'm good at spending other people's money.)

 

[carbureted iron]

A fellow in another forum posted the insightful comment that I was attempting a precision joinery cut on a job site saw; IOW: wrong tool for the job. I got the job done on a router with a jig.

"Shove me in the shallow water before I get too deep." — Edie Brickell