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DeWalt 735 Issue

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Forum topic by Sawkerf posted 05-24-2012 01:51 AM 2076 views 0 times favorited 23 replies Add to Favorites Watch
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Sawkerf

1730 posts in 2528 days


05-24-2012 01:51 AM

I installed a set of Titan carbide edged knives in my 735 this afternoon. When I ran a piece of pine thru the planer, it was noisier than normal and the cut was really rough. When I opened it back up, it looked like one of the knife clamps was contacting the board. I took this picture of the knife and clamp on my workbench so you could see the wood on the clamp. This one is the only problem – the other two look fine.

Has anyone else run into a similar problem with replacement knives? The new knives are 3/32” thick so I suspect that the extra thickness is the root of the problem. I suppose that a bit of filing would fix the problem, but I would like to find out what others have done.

-- Adversity doesn't build character...................it reveals it.


23 replies so far

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fussy

980 posts in 2511 days


#1 posted 05-24-2012 07:46 AM

I hate to say it, but I believe you got a set too thick. I have stock knives for which I paid $42 for TWO RREPLACEMENT DOUBLE-EDGED SETS and have had no problem. SEND THEM BACK AND GO FOR THE STOCK BLADES. Used correctly, they go forever.

Steve

-- Steve in KY. 44 years so far with my lovely bride. Think I'll keep her.

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ChuckV

2880 posts in 2987 days


#2 posted 05-24-2012 11:45 AM

I’m not sure of the thickness of the stock knives, but I see some replacement knives that are 3/16”

Since just one of the knives had the problem, is it possible that there was something between the knife and the holder that prevented the holder from lying flush with the blade?

-- “Big man, pig man, ha ha, charade you are.” ― R. Waters

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Doss

779 posts in 1724 days


#3 posted 05-24-2012 03:59 PM

In what order did you tighten the screws? The order could make a difference (especially if you’re tightening from the outside in to the center). Also, make sure you have pushed the blades to the same side of the head (if you get a nick, you can move one blade to the other side to removed that nick from future passes.

-- "Well, at least we can still use it as firewood... maybe." - Doss

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Sawkerf

1730 posts in 2528 days


#4 posted 05-24-2012 09:23 PM

I believe that I’ve solved the problem. There was some very slight “slop” (~.001”) in the position of the knife clamp. I pushed it away from the knife edge and tightened the screws. Re-ran that piece of pine and it’s as smooth as glass.

I always tighten the screws from the inside to the outside. No particular reason, but it seems like a good idea.

-- Adversity doesn't build character...................it reveals it.

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Doss

779 posts in 1724 days


#5 posted 05-24-2012 09:48 PM

Glad to hear you got it straightened out.

Yes, on things like this, inside to outside is a good idea.

-- "Well, at least we can still use it as firewood... maybe." - Doss

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chuck24

48 posts in 2735 days


#6 posted 05-24-2012 09:57 PM

Im trying to flip my original blades but I am having a problem getting the screws loose….

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Sawkerf

1730 posts in 2528 days


#7 posted 05-25-2012 01:25 AM

Oh yeah, the problem is definitely solved :-) I ran some white oak this afternoon and it feels glass smooth. It will be almost sacrilegious to sand it. I will though, I wouldn’t know how to do a project without a sanding session. – lol

Chuck -
You want to be VERY CAREFUL loosening those screws. I make sure that the T-wrench is perfectly vertical and maintain a moderate downward pressure while I apply the rotation. I find that applying and holding moderate turning pressure will eventually let the screw “pop” loose. I’ve heard of people using an impact driver for this but I would be very reluctant to try it.

I’ve also heard that DeWalt is going to star drive screws in place of the hex drive. Might be worth looking into.

-- Adversity doesn't build character...................it reveals it.

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SnowyRiver

51452 posts in 2940 days


#8 posted 05-25-2012 02:38 AM

chuck24…I had the same problem the first time I flipped the knives. The screws were really tight. I was afraid I was going to break the t handle. I eventually got them loose however.

-- Wayne - Plymouth MN

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ChuckV

2880 posts in 2987 days


#9 posted 05-25-2012 12:43 PM

chuck24,

Since I’ve had my 735, I’ve flipped the knives and replaced them once. Both times, it was a bit nerve-wracking, but with some carefully applied force, the bolts all came loose. Sawkerf’s term “pop” is exactly my experience. The shaft of the wrench seems to start to twist a bit under the pressure, and then there is a “pop” as the bolt breaks free.

I make sure that I am in a good position to keep the wrench solidly in the bolt. Instead of reaching across the machine to loosen the bolts on the other side of the knives, I walk to the other side so that I am more above the bolt I am working on.

When you have the bolts out, it is a god time to check them and replace any that look to be getting worn so that you won’t have any problem the next time. I still have all the original bolts, but I do check them carefully.

-- “Big man, pig man, ha ha, charade you are.” ― R. Waters

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Cato

693 posts in 2772 days


#10 posted 05-25-2012 07:19 PM

I was in the same boat the first time I flipped my knives and was worried I would strip them out.

I used the same size hex bit with my socket set and a short breaker bar and it was much much easier to apply enough torque to “pop” them loose.

View whitewulf's profile

whitewulf

450 posts in 2397 days


#11 posted 07-13-2012 12:30 AM

If having problems damaging ALLEN head cap-screws, the problem might be Imported screws, Only us made screws are required Grade 8. Possibly they are Metric? some metric screws will accept Us wrenches a little loosely as they are fractional.

-- "ButI'mMuchBetterNow"

View PurpLev's profile

PurpLev

8523 posts in 3108 days


#12 posted 07-13-2012 12:53 AM

when releasing the screw you need to apply reversed-psychology on these screw:
1. apply inward force on the wrench (push it hard into the bolt throughout the process as if you are trying to push the bolt INTO the threaded hole
2. turn wrench CCW to unscrew it.

This process does 2 things. First it makes sure your allen wrench is in full contact and deep inside the bolt and does not ‘escape’ out which could ruin the allen hole in the bolt, and secondly it helps relieve some of the friction that exist between the bolt, and it’s mating threaded hole which is what really holds the bolt in place.

once the bolt is ‘releases’ from it’s grip you can reduce the inward pushing pressure against it and unscrew it in a normal fashion.

once bolts are out – it’s a good idea to coat them with machine oil (lubrication) so that once put back into place will not have so much friction (with the 4 bolts there will still be enough force holding things in place)

-- ㊍ When in doubt - There is no doubt - Go the safer route.

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Sawkerf

1730 posts in 2528 days


#13 posted 07-13-2012 03:51 AM

The T-wrench that comes with the 735 is the correct size and you want to be careful about applying too much down pressure. If you aren’t perfectly straight, heavy pressure can cause the wrench to slip and screw up the screw head. Firm pressure is good, but really leaning on it is gonna cause a problem sooner or later.

-- Adversity doesn't build character...................it reveals it.

View Doss's profile

Doss

779 posts in 1724 days


#14 posted 07-13-2012 04:29 PM

This post is not meant to be a put down or attack.

If having problems damaging ALLEN head cap-screws, the problem might be Imported screws, Only us made screws are required Grade 8. Possibly they are Metric? some metric screws will accept Us wrenches a little loosely as they are fractional.whitewulf

What are you talking about? First, there is no requirement that US screws are Grade 8. In fact, I’d say a majority are not. Most of them aren’t even made to meet SAE J429 specifications (Grade 2, 5, 8, 18-8 SS, etc.).

Also, metric bolts are not fractional… they are metric. That means they use metric (in this example) Allen wrenches and not SAE (US).

The metric grading system (classes) (ISO 898 | ASTM F568M) is comparable to SAE with SAE Grade 8 fasteners equaling Metric Class 10.9 fasteners.

An imported screw that meets metric equivalent standards to SAE grade standards may/will be considered equal in most applications.

Further, the strength of fasteners also changes as diameter (and other factors) of the bolt changes. So, while two different diameter bolts may meet Grade 8 specifications, that does not mean they will fail at the same stresses. The Grade 8 specification signifies that the bolt will meet a minimum level set by the grade.

Example: 2 Grade 8 bolts
1. 1/4” diameter
Shear (lbs): 4470
Tensile (lbs): 5009

2. 1/2” diameter
Shear (lbs): 17870
Tensile (lbs): 28785

Both are to Grade 8 standards and made of the same material but they will fail at completely different times.

Also, using higher grade fasteners is not always the answer. Some applications are specifically designed such that the fastener fails before more expensive components fail. Using higher-strength fasteners where they were not designed to be used may have you replacing parts that you shouldn’t have to.

-- "Well, at least we can still use it as firewood... maybe." - Doss

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whitewulf

450 posts in 2397 days


#15 posted 07-14-2012 05:43 AM

Doss

Allen wrenches are fractional. Some metrics are close to fractional (or viceversa, and some SAE fractional allen are mistakenly used, thus stripping socket)You and I would never MAKE such a foobar, I not too sure about you!

-- "ButI'mMuchBetterNow"

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