TNG needs help with DeWalt 788/blades and cutting

[Tim Stanford]

Hopefully this is an easy one and thanks in advance for anyones help.

Cutting out one of Jean-Bernard germe patterns out of one inch oak. I started with a #9 Super Sharp then switched to a Pegus #7R because the #9 was too aggressive.   I have  checked the blade, the tension (set at 4 1/2 to get ping) and the position of the blade in the holder.

One issue is the bottom of the blade bends to the right. I found this out after I changed the blade.

The second issue is the front side of the pattern looks pretty good but the back has thined out (See pictures)  I have had this issue on other patterns but it is not consistent between blades nor type of wood. 

Anyone have any ideas?

Question #2

I have always liked the Pegus 21 inch saw. Anyone have an opinion on if the Pegus would be a better choice? I do know I can change the head on the DeWalt and get a Pegus head fron Bear Woods Supply which some say would help all around the sawing experience. 

I am out of ideas on fixing the issue and checking the tolerances on the saw. Any help would be very much appreciated. 

Thanks,

Tim

 

 

[Wichman]

No opinion on question #2.

Question #1. Sounds like the set screw on the bottom clamp has backed out a bit, throwing out the alignment ( the bending of the bottom of the blade ). I believe that the blade is supposed to be centered in the clamp. The other possibility is the vertical alignment is not 90*. The quick test is to use a scrap piece of 2X wood and cut a 1/6" into the scrap, turn off the saw, slide the scrap around to the back of the blade and see if the blade will fit perfectly in the slot. If not adjust until it does.

Adjusting the blade clamp may be the answer to both problems, so try that first. 

[JTTHECLOCKMAN]

You can use a dremel old style saw it does not matter. It is not the saw and not the blade. It is the operator. Sorry to say. 1" is thick, yes but I have cut 1" with a #5 double tooth revers FD silver blade. Is that actually 1" oak or 3/4" oak? 

First thing first. Make sure your blade is parallel straight up and down. Use a small square to check this. Install blade and lay square next to it on the flat sides. Check both sides raise the blade by hand and check again. If it is parallel that is great. If not then you need to adjust either the top sccrew or bottom screw in the clamps to center the blade. What I like to do is to set the setscrews just even with the flat side of the clamp. So when you now screw the thumbscrew to tighten the blade it just tightens against the side of the clamp and does not pinch the blade and bend it. Now cutting that thick wood you need to be able to cut squarely but also make the turns. But in that pattern you can get away without turning and just nibble at the corners. This will save you from putting sideward pressure on the blade if you turn and do not straighten up again. Thus the blade stays bent as you continue to cut and thus the angle of the cuts and the thin backside of pattern. That is what is happening. You are applying too much sideward pressure when turning and not letting the saw do the cutting The thicker the material the slower the cut will go. Just fact no matter what blade you use. I would use a #7 skip tooth blade of any brand. Does not have to be a precision blade. 

Edited November 29, 2024 by JTTHECLOCKMAN

[Roberta Moreton]

On 11/28/2024 at 10:43 PM, Wichman said:

No opinion on question #2.

Question #1. Sounds like the set screw on the bottom clamp has backed out a bit, throwing out the alignment ( the bending of the bottom of the blade ). I believe that the blade is supposed to be centered in the clamp. The other possibility is the vertical alignment is not 90*. The quick test is to use a scrap piece of 2X wood and cut a 1/6" into the scrap, turn off the saw, slide the scrap around to the back of the blade and see if the blade will fit perfectly in the slot. If not adjust until it does.

Adjusting the blade clamp may be the answer to both problems, so try that first. 

I agree! This is definitely the problem. The Dewalt 788 is the saw I use. 

[Tim Stanford]

On 11/28/2024 at 9:45 PM, JTTHECLOCKMAN said:

You can use a dremel old style saw it does not matter. It is not the saw and not the blade. It is the operator. Sorry to say. 1" is thick, yes but I have cut 1" with a #5 double tooth revers FD silver blade. Is that actually 1" oak or 3/4" oak? 

First thing first. Make sure your blade is parallel straight up and down. Use a small square to check this. Install blade and lay square next to it on the flat sides. Check both sides raise the blade by hand and check again. If it is parallel that is great. If not then you need to adjust either the top sccrew or bottom screw in the clamps to center the blade. What I like to do is to set the setscrews just even with the flat side of the clamp. So when you now screw the thumbscrew to tighten the blade it just tightens against the side of the clamp and does not pinch the blade and bend it. Now cutting that thick wood you need to be able to cut squarely but also make the turns. But in that pattern you can get away without turning and just nibble at the corners. This will save you from putting sideward pressure on the blade if you turn and do not straighten up again. Thus the blade stays bent as you continue to cut and thus the angle of the cuts and the thin backside of pattern. That is what is happening. You are applying too much sideward pressure when turning and not letting the saw do the cutting The thicker the material the slower the cut will go. Just fact no matter what blade you use. I would use a #7 skip tooth blade of any brand. Does not have to be a precision blade. 

First off, no worries on anything you said. I am a 68 year old retired Marine Corps Colonel so if your not learning your dying.   I would rather folks be straight forward than pussy foot around a subject.

I got the 1"oak at an estate sales where the woodworker had glued up about 50, 6"x24" to 36" boards. I got all of them for under $50. Quite a steal and I have plenty of oak to work with.

The below pictures show the best "square" I could get by doing everything folks suggested.  From there with a #7 pegus skip tooth I tried again. All's I got was about 46 seconds of good work and the bottom clamp gave way and the blade bent. I tried readjusting the blade, cleaning and lightly sanding the end part of the blade. I tried various variations but I got the same result.  And, of course,  I checked for Operator error and placement of the blade.  

So, I will give it a day and try again from the beginning. 

Thanks for your help and ideas

Tim

 

[JTTHECLOCKMAN]

According to the square if that is a new blade , then your setscrew alignment is off. You need to adjust till you get the blade straight up and down. I gave you my recommendation as to what I do for those things and how I set the blade up in the clamp. I do not like to have the blade resting against 2 little set screws. Good luck.

[Wichman]

Retired Army SSG 23 Years of service, 65 yrs old.

Thank you for your service.

That blade looks curved, is it? If it is curved it doesn't have enough tension.  If you pluck the blade (like a guitar) you get a nice "ping" sound, not a "plunk" (not enough tension), not a "plink" sound (too much tension).

I agree with JT about adjusting the set screw, my previous post was referring to the manufacturers recommendations. When I adjust the set screw, I back off the set screw just a bit, then I take my thickest feeler gauge, .035" and lay it in the clamp, tighten the thumb screw just snug and then tighten the set screw just snug as well.  Remove the feeler gauge. I finish by snugging up a fingernail emery board and roughing up the clamping surfaces just a bit. One or two strokes at the most.

[Tim Stanford]

Thanks evfor all your help. Each one of you added some great information to solve. A special shout out to JT for his depth of information!