Delta Miter Saw 36-070c Blade Guard Repair. Photo by Don Tai
I bought this Delta Miter Saw model 36-070c part no. 899880 (0012) used at Goodwill for a pittance, not expecting much, but it has been going strong for the last 5 years. A couple of days ago the blade guard did not retract when the saw goes down to cut. I had to manually move the blade guard up to make a cut, which was annoying. The repair required some accurate and slow drilling with my tiniest drill bit, and 3 tiny screws. Now the blade guard goes up and out of the way when the saw goes down to make the cut.
A Goodwill find, the blade guard had duct tape all over, which I found out was merely protecting the blade guard from scratches. It worked well right from the start, and saves me from hauling up my other Delta miter saw from the basement. I found the Delta 36-070 user manual, but it did not help me learn about the blade guard. The manual dates to the year 2000, so this saw might be 19 years old!
The blade guard has a metal cover in the middle, which has a little black knob that runs in a track. When the blade goes down the black knob runs in the groove of a metal arm attached to the saw. This sliding motion moves the blade guard up when the saw blade goes down, allowing you to make the cut. When the cut is finished the blade goes up, the blade guard should go down to prevent you from touching the blade.
The problem was the metal cover was not sufficiently attached to the blade guard. While the 8mm bolt in the middle was properly attached, the metal cover would rotate independently from the blade guard and therefore not move the blade guard out of the way. The metal cover had once been prevented from rotating by 3 small tabs of plastic, now long worn away. Here’s how I fixed mine. Ensure that your saw is disconnected from the power.
Delta Miter Saw 36-070c Blade Guard Repair. Photo by Don Tai
Delta Miter Saw 36-070c Blade Guard Repair. Note the black metal slider, attached to the saw body, the black round knob attached to the black metal slider. The plastic blade guard is held on with the metal blade guard cover. There is an 8mm bolt in the middle. The fix is to add the 3 tiny screws to the blade guard to prevent the cover from rotating. Photo by Don Tai
- 3 tiny 1/6″ screws, Philips “X” head. I had some really small ones from disassembling various small broken electronic devices and keeping the screws
- 8mm socket and ratchet
- tiny 2.5mm screwdriver, usually used for computer disassembly.
- drill with a 1/16″ bit
- medium file for sanding down plastic
Remove the blade guard from the metal arm
The metal arm has a groove, where the blade guard black knob runs in the middle. At the end of the metal arm is a hole. Move the saw up and down until the black knob can come out of the hole.
Remove the Blade Guard from the Saw
Ensure that your saw is disconnected from the power. Using an 8mm wrench remove the middle nut of the blade guard cover. The bolt at the back has a square head, preventing it from rotating, but once separate from the nut it will fall out the back, the channel where the blade runs. Be ready to catch the bolt.
Once the bolt has dropped out the cover, blade guard and spring can be completely removed. There is a metal backing plate that holds the square head bolt, held in with 2 Philips screws, but I did not need to remove it for this repair.
Drilling the Blade Guard with 3 Holes
You’ll notice that the metal blade guard cover has 3 indentations, or grooves. You’ll notice that the blade guard has 3 plastic bumps that have worn away. You’ll also notice that these these plastic bumps line up with the blade guard cover’s indentations. What a coincidence! The idea here is to replace the worn down plastic bumps with 3 tiny screws that will hold the blade guard cover from rotating.
File the plastic bumps flat if they stick out. The bumps are right on top of a thicker plastic wall on the blade guard. I used a 1/16″ drill bit and slowly drilled a hole into the wall of the blade guard. You could use a drill press for greater accuracy. You will notice that the inside of the blade guard has a spring, now removed, so if you drill into the inner section you might interfere with the inner spring. If you drill too far outside of the inner wall, the screw would not contact the metal cover. I drilled right into the middle of the wall, but not all the way through to the other side.
One of my plastic tabs was cracked, so I filed it down as best I could and filled in the crack with some CA glue.
Drilling needs to be pretty precise. You could use a drill press, but I went slowly and did it by hand. you only need to drill down 1/4″ or so, enough to get a tiny hole into the wall. The plastic seems to be ABS and is easily drilled. You do not need to drill very much.
The tiny screws need to be able to screw into the plastic without cracking, so you really need tiny screws. Carefully screw the tiny screws into the holes to ensure they fit. The screws are not meant to tighten down the blade guard cover, but to prevent it from rotating. I loosely installed 2 adjacent screws and was able to slip the cover under the screws, then could screw the last screw in.
Reassemble the Blade Guard
This might seem to require 3 hands, so bear with me. you will need to be patient with yourself.
- With the saw unplugged, slip the bolt into the saw blade channel, and out the blade guard rear plate. This plate has a square hole for the bolt. This is a bit tricky, and I have small hands.
- While holding the bolt, slip the plastic blade guard loosely back into place.
- Put the rear spring tab back into the hole in the rear. Grab the blade guard cover and slip the front spring tab in place on the blade guard. The spring does not need extra turning. The spring might want to go into the middle of the cover, so just move it to the side.
- With 2 adjacent screws installed in the blade guard, slip the cover under the two screws, and through the bolt, which you are hopefully still holding, your fingers right beside the blade.
- Tighten down the 8mm nut loosely.
- You can now install the final tiny screw.
The screw closest to the metal sliding arm will need to be tightened down enough to clear the arm, but the rest of the screws need not be very tight. They are only there to prevent the cover from rotating.
Reinstall the Blade Guard back onto the sliding Metal arm
Move the saw up and down to get the blade guard black knob into the hole in the metal sliding arm.
Your blade guard should go down and protect the blade when you raise the blade up. When you move the blade down to make a cut the blade guard should raise up and out of the way, exposing the blade to the wood.
Overall Product Quality
This delta miter saw is still going strong after 19 years. The repair was successful. That shows quality over a long period of time, as well as repairability. The quality of this Delta saw is pretty good. You learn a lot when you take a product apart.