Bent Blade

[Rockytime]

Hi Hawk owners. I'm cutting a portrait from 1/8" BB using a #1 FD Polar blade. Cutting is going well, however, the blade bends at the top blade holder. The blade is placed to the top of the holder and the thumb screw is t9ghtened. I do tighten quite strongly as the tension is quite high. Backing off the tension allows the blade to wander so I cant do that. After tightening the blade a half dozen times the blade takes a forward bend making it difficult to insert into the top holder properly. Not sure if I am tightening the blade too much or what. The bend is forward and cannot be bent back easily without breaking. Just wondering if any Hawk owners or anyone else has had this problem. One of the other saw makers have a clamp screw with a tip that rotates but don"t know the thread size but the Hawk size is 10-32.

[spotsdad]

I don't have a Hawk and i am not familiar with them but it looks as though the blade the blade is hitting something on the up stroke. Is there an obstruction there?

Dick aka spotsdad

[Rockytime]

No because the blade is locked at the top of the holder. Thanks though.

[cmarsch]

Does the balde holder have a set screw for keeping the blade centered in the holder? If it does it may have worked itself out a little from the vibration of the saw. So when you tighten the thumb screw you are actually bending the top of the blade because it is pushing the blade into the hole where the set screw is supposed to be.

[SCROLLSAW703]

The reason your blade is bending at the top Rocky, is from over tightening. If you're having to tighten your blade that tight in order to keep it in the blade holders, spin out your thumb screw & have a look see at the end of if it. I'm bettin' you'll find it shiny & smooth;) take it & run it across a piece of 100 grit sandpaper a few times & you'll get your grip back. Ya may have to adjust your hex screw in the blade holder just a little to the inside. 

Ya might try backin' your tension off just a little, too. If your blade makes a high pitched ping when you tension it, that's plenty. The tighter the tension, the more pull it puts on your blade. In turn, is tougher to keep in your blade holder. And puts extra wear & tear on the wedge & threads at the back of the saw. 

Remember, the smaller the blade the more tension. The larger the blade the less tension. And in bb, ya might try usin' a piece of a candle, or soap on the blade for a little lube.

[dgman]

It is a product of over tightening. You should not have to tighten the clamp that tight. If the blade slips in the blade clamp, things need to be cleaned and dressed. I don’t know anything about Hawks, so I don’t know what needs to be dressed, but 220 grit sand paper will clean and dress the mating surfaces. Also I routinely sand the ends of my blades to clean off the oil on the blades. 

[Rockytime]

I'll try dressing the screw. I don't know why I have not done that as I made a dressing jig a couple of years ago. Just checked the screw and the end is in terrible shape. It is OK now. I'll try it tomorrow.

[OCtoolguy]

Les. it's the Dewalt that has the pivoting tip. And I'm not positive right now but I'll bet it would fit in your holder. I'm thinking it's 10-32 also. I'll go out and check after dinner.

 

[Rockytime]

If 10-32 I'd buy it even if I don't need it. It sounds like an ideal screw.

[JTTHECLOCKMAN]

Les I own 2 hawks and in my opinion there is no way you could ever bend a blade from tightening too much with a RBI blade holder. Can not be done. If the setscrew was too far in from vibration then the blade would have a dimple in it and the blade would not be centered in the clamp and traveling true up and down. So you need to check that adjustment from time to time. 

Sometimes it is harder to explain than what it is but will try. I am going to believe you have a quick release on the top arm. When you pull that arm down, the top of the blade should fall nicely into that blade holder with the top of the blade hitting the bottom of the rod that is just above the thumbscrew. The back of the blade should lay flat against the back of the clamp (thus the reason you can not ever bend a blade like that with those clamps) While holding that there tighten the thumbscrew. It is a dance that becomes so second nature and is so easy to do. 

Now to the reason possibly you are bending is because when you place the blade in the holder it is rocking backwards and the back of the blade does not sit flat against the blade holder. Or you are pulling it too far forward when you insert the blade. In other words the holder is placing the blade on an angle that is not straight up and down and when it starts to cut it now moves back into the straight up and down position thus bending the blade which would explain how or why that far down on the blade it is bending. You need to keep that holder pretty close to straight up and down when inserting blade. Second thing or suggestion is you are leaving too much blade stick up into the clamp and it is past that roller bearing on top of the thumbscrew. That bearing is the highest your blade can go or should go. If you go in front of that and then push the blade with force to get back to tighten the thumbscrew you now bent the top of the blade as you shown. 

Now if this stuff is just happening you got out of your routine and or there is something else going on. Make sure both clamps pivot freely when a blade is installed so they can rock with the motion of the arms going up and down. Yes it is a good idea to keep the thumbscrew and setscrew cleaned and roughed up abit. I always clean the ends of the blades on both sides with sandpaper before using. Takes off the oil that comes on blades from manufacturing and gives a little tooth so that the thumbscrew does not slip when tightened. Then I do not have to crank so hard on it. 

 

If none of this works then report back and we try something else.

Edited June 3, 2018 by JTTHECLOCKMAN

[kmmcrafts]

14 hours ago, Rockytime said:

If 10-32 I'd buy it even if I don't need it. It sounds like an ideal screw.

They are not the same size from my DeWalt/Excalibur to either of my Hawks. Randy (Hotshot) made some or had some made so he could put the inserts into the end of the Hawk thumb screws. 

Personally, I’ve never had an issue with the plain ends of the Hawk thumb screws. 

[Rockytime]

16 hours ago, JTTHECLOCKMAN said:

Les I own 2 hawks and in my opinion there is no way you could ever bend a blade from tightening too much with a RBI blade holder. Can not be done. If the setscrew was too far in from vibration then the blade would have a dimple in it and the blade would not be centered in the clamp and traveling true up and down. So you need to check that adjustment from time to time. 

Sometimes it is harder to explain than what it is but will try. I am going to believe you have a quick release on the top arm. When you pull that arm down, the top of the blade should fall nicely into that blade holder with the top of the blade hitting the bottom of the rod that is just above the thumbscrew. The back of the blade should lay flat against the back of the clamp (thus the reason you can not ever bend a blade like that with those clamps) While holding that there tighten the thumbscrew. It is a dance that becomes so second nature and is so easy to do. 

Now to the reason possibly you are bending is because when you place the blade in the holder it is rocking backwards and the back of the blade does not sit flat against the blade holder. Or you are pulling it too far forward when you insert the blade. In other words the holder is placing the blade on an angle that is not straight up and down and when it starts to cut it now moves back into the straight up and down position thus bending the blade which would explain how or why that far down on the blade it is bending. You need to keep that holder pretty close to straight up and down when inserting blade. Second thing or suggestion is you are leaving too much blade stick up into the clamp and it is past that roller bearing on top of the thumbscrew. That bearing is the highest your blade can go or should go. If you go in front of that and then push the blade with force to get back to tighten the thumbscrew you now bent the top of the blade as you shown. 

Now if this stuff is just happening you got out of your routine and or there is something else going on. Make sure both clamps pivot freely when a blade is installed so they can rock with the motion of the arms going up and down. Yes it is a good idea to keep the thumbscrew and setscrew cleaned and roughed up abit. I always clean the ends of the blades on both sides with sandpaper before using. Takes off the oil that comes on blades from manufacturing and gives a little tooth so that the thumbscrew does not slip when tightened. Then I do not have to crank so hard on it. 

 

If none of this works then report back and we try something else.

Hi John, I sent a response from my cell phone last night. Don't understand what happened to it. However, you are exactly correct. I had not been careful placing the blade in the top holder. With larger blades I do not even think about it but #1 and smaller it is pretty important as they take a bend easily. I've been scrolling this afternoon and everything is working nicely.  Many thanks to you for your response and advice which is excellent.

[fredfret]

Dewalt is metric I think m6. Bushton uses 1/4-20

Fredfret

[JTTHECLOCKMAN]

One other little trick I have been using for some time now and works well. I hardly ever adjust that tension rod in the back. In fact I can't remember the last time I did. I have mentioned here many times my go to blade is a FD silver reverse #5 and I have have both my rbi saws set up for that blade with tension. When I change blades they are usually longer than this blade. So instead of resetting to accept the blade I just shorten it so that it fits nicely in the holder. The tension is never too tight unless when using jewelers blades. Those things are very finicky and all bets are off. Many times I will switch to the Dewalt when using them because easier to set tension without all that adjusting. 

 

Hope things continue to work out for you Les.

[Rockytime]

3 hours ago, kmmcrafts said:

They are not the same size from my DeWalt/Excalibur to either of my Hawks. Randy (Hotshot) made some or had some made so he could put the inserts into the end of the Hawk thumb screws. 

Personally, I’ve never had an issue with the plain ends of the Hawk thumb screws. 

Thanks for the information. JT introduced me to the problem and the problem is me. Everything is now copacetic. I have no problem with my thumb screw I just think a rotating tip seems like a good idea. Some good ideas are not necessary but still are very cool. I'd like to get one just to see if I could make one just for the fun of it.

[Rockytime]

5 minutes ago, fredfret said:

Dewalt is metric I think m6. Bushton uses 1/4-20

Fredfret

You are exactly right! What was I thinking? Apparently not.

[kmmcrafts]

34 minutes ago, Rockytime said:

Thanks for the information. JT introduced me to the problem and the problem is me. Everything is now copacetic. I have no problem with my thumb screw I just think a rotating tip seems like a good idea. Some good ideas are not necessary but still are very cool. I'd like to get one just to see if I could make one just for the fun of it.

They are nice..because it's a cheap fix when the insert gets worn out you just pop a new one in.. no need to change the whole screw.. 

[Rockytime]

28 minutes ago, kmmcrafts said:

They are nice..because it's a cheap fix when the insert gets worn out you just pop a new one in.. no need to change the whole screw.. 

I looked at the Delta parts page. There are a million models. Can you narrow my search a bit? I'd like to fine that thumb screw.

[kmmcrafts]

1 hour ago, Rockytime said:

I looked at the Delta parts page. There are a million models. Can you narrow my search a bit? I'd like to fine that thumb screw.

Buy mine at Seyco.. as the DeWalt and the Excalibur have the same style.. 

http://seyco.com/quick-clamp-renewal-kit/

[Rockytime]

Thanks Kevin. I looked at the picture. There is not much to it. I might order one. I'll post if I do.

[lawson56]

My Hitachi saw did that, to all my blades.I had to keep a pair of plyers beside me at all times.My Hitachi didn't last long though. my saw now doesn't do that.Thank Goodness.

[stoney]

10 hours ago, Rockytime said:

Thanks Kevin. I looked at the picture. There is not much to it. I might order one. I'll post if I do.

Les I bought a Dewalt thumb screw to use on my Hegner top blade clamp.   It is easier to tighten than the Hegner quick clamp at least for me.   I need all the help I can get especially when ole Arther flares up.