tjcebula Posted February 17, 2014 Report Share Posted February 17, 2014 Hello All Well, I have a bit of a small problem I have a Dewault scroll saw and lately it seems like when I set my blade in and turn my knobs to tighten down on the blade and tension the blade I usually tension it between 3 and 3.5 I can hear the blade loosen up, I Took apart my whole scroll saw found nothing wrong or wearing, it seens like the knobs that i turn to pinch in the blade seems to loosen even when I crank down on it, I looked at the end of the knob area where the blade would be pinch against it and its really smooth should i somehow rough it up a touch so it has some bite on it so the blade doesn't slip out ( Note: This doesn't happen all the time, everyonce in awhile and or when I'm working on a long time of cut ) Thanks Quote Link to comment Share on other sites More sharing options...
Multifasited Posted February 17, 2014 Report Share Posted February 17, 2014 Clean ,the clamp tip ,and the blade ends ,w/ alcohol ,or mineral spirits ,excessive heat on the blade will allow it to stretch lessening the tention ,check work see if there is a bow ,usually caused by side ward pressure while cutting .If tention knob is not moving from set point,it's blade slippage ,either you only had silght contact on the clamp ,Blade not all the way back in the clamp ,or slipage from oil on contact area ,listening to your saw change sound as you cut is first indication of slippage .If your tention indicator is moving off set point go to( Ricks scroll saw) on this forum ,vast wealth of information on the 788 Excellent ,There are probabably 30 posts on this subject here on this site under tools and blades or info exchange ,just look at older pages .Reviewing these older pages will save you a lot of frustration and delays ,most everything is covered you can think of ! I hope that helps ,post some pix of your projects when you can ,Good luck !! Clayton717 1 Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted February 18, 2014 Report Share Posted February 18, 2014 I have had a problem like this but i don't touch the ends of the blades anymore .Oil from my skin comes off on the blade ends where i used to pick up the blades..i also put doubled over 220 grit sand paper in where the blade goes and tighten the blade clamp lightly and slide the paper out scoffing up the contact points.also i let the saw do the work ,not pushing to fast like a table saw ,Just little things make a big difference.On a new dewalt the tension knob is tight around 1 to 2 .older dewalts with lots of use will require more ,maybe to 3 on the dial.hope this helps ,there are other causes but this is the general causes of blade slippage. Great question! Quote Link to comment Share on other sites More sharing options...
heppnerguy Posted February 18, 2014 Report Share Posted February 18, 2014 One other thought for you. Check that the set screw (opposite the tention knob sido f the blade) and make sure that it has not backed into it's female contact. Be sure the set screw is pretruding enough to make good contact on the blade. The sanding of both sides of the contacts is often helpful, Like Kevin suggested. I would not recommend that you use any kind of tightening device on your thumb screw. I know a lot of people do it, but it everything else is properly adjusted, it should not be necessary. the problem that I have often heard about it it usually causes the thumbscrew to eventually strip out. That is my take on your problem. It really isn't a big problem to take care of if you do what is suggested to you Good luck. let us know if you still have a problem. Dick heppenrguy Lucky2 1 Quote Link to comment Share on other sites More sharing options...
rjR Posted February 18, 2014 Report Share Posted February 18, 2014 Everyone has given good advice. I wish to add a slightly different point of view, an addition, not a revision, as they are correct. As I have arthritis in my whole body, I had to make a tightening knob that was large and did strip the screw. I also did repair it and now am a little more careful when tightening the blades into the holder. I also have gone to a clamp to hold the blades in position while I feed them into the clamps. I have a cheap long, clothespin type clampt that I use for this. It holds the blade in position while I adjust front to back and vertically to get it better to start. There are tiny floating grips that can become glazed. Use a very fine sandpaper/diamond file etc.to scuff these hardened pieces up enough to grip better. Be VERY careful to keep them flat while doing this. I had put them into a piece of scrap wood and in my vice to do this. I have machinists vice and use homemade adaptor plates for the wood things I use it for the most. Works as well as most actual woodworking vices. Quote Link to comment Share on other sites More sharing options...
rjR Posted February 18, 2014 Report Share Posted February 18, 2014 Everyone has given good advice. I wish to add a slightly different point of view, an addition, not a revision, as they are correct. As I have arthritis in my whole body, I had to make a tightening knob that was large and did strip the screw. I also did repair it and now am a little more careful when tightening the blades into the holder. I also have gone to a clamp to hold the blades in position while I feed them into the clamps. I have a cheap long, clothespin type clampt that I use for this. It holds the blade in position while I adjust front to back and vertically to get it better to start. There are tiny floating grips that can become glazed. Use a very fine sandpaper/diamond file etc.to scuff these hardened pieces up enough to grip better. Be VERY careful to keep them flat while doing this. I had put them into a piece of scrap wood and in my vice to do this. I have machinists vice and use homemade adaptor plates for the wood things I use it for the most. Works as well as most actual woodworking vices. Quote Link to comment Share on other sites More sharing options...
Doug Posted February 18, 2014 Report Share Posted February 18, 2014 All of the advice is good - your one comment "Took apart my whole scroll saw found nothing wrong or wearing, it seems like the knobs that i turn to pinch in the blade seems to loosen even when I crank down on it" struck me as a problem I once had. When I first started scrolling I thought I need to tighten the thumb screws as tight as I could and I managed to strip the threads in the clamp. It may not be noticeable when tightening the thumb screw but with the saw action it permits the thumb screw to slightly loosen. If the other fixes do not work, consider installing a new clamp for the thumb screw and set screw and see if that solves the problem. I would probably change both upper and lower and while at it I would order an extra clamp or two to have on hand and one or two extra thumb screws and set screws - I hate down time while waiting for something. After learning that tightening firmly but not as hard as I could worked well, I have not have any problem. As a result I do still have extra clamps, thumb screws, and set screws on hand. You really do not have to "crank down" on the thumb screw. Quote Link to comment Share on other sites More sharing options...
Multifasited Posted February 19, 2014 Report Share Posted February 19, 2014 Identifing the slipage problem is the problem ,brute force is seldom a good answer ,the addition of the knob ,is mainly for people with grip and pain issues in thier hand or due to repeated hundred hole changes cause hand problem's ,everything you modify ,you also have to modify the control to stay with the limits of the force required in its use ,If you can't control it DON'T USE IT ! Like everything else It has its place and can save some people a lot of grief and allow them to do things they can do with out some kind of aide .What works for ME may not for YOU ,and vice versa ,Find what works for YOU .! Quote Link to comment Share on other sites More sharing options...
patrol681 Posted March 17, 2014 Report Share Posted March 17, 2014 Well, friends, I have just got my new DeWalt 788 and while I am generally very pleased with it, however, I seem to have a problem. Maybe it's minor, but it doesn't seem to be quite right. When I set up the blade, and tension it, then check it for true travel etc. I see that it is dead on track vertically, when viewed from the front, but when I look closely from the side, I see that it travels backwards a little, (kind of like the movement you would see in a "C" frame scroll saw) and not straight up and down. Is this normal to some extent? if i set a piece of wood on the table behind the blade, it will just kick it over. Am I asking too much, or 'nit-picking' do you think? I have looked on You Tube, and see that the Excalibur 21 can be adjusted for this 'back travel' by adjusting the three screws on the motor mount. Having considered myself darn lucky to afford a DeWalt to start with, (never mind an Excalibur,) I am at a loss as to a fix for this unit of mine. I tried to find the post that about "Ricks scroll saw" (that might address this problem,) that the post by 'multifasited' directs me to, - but as of the moment, have not found it. (I will try again after posting this,) in the meantime any suggestions, (of the helpful kind ;o) will be appreciated. Quote Link to comment Share on other sites More sharing options...
Doug Posted March 17, 2014 Report Share Posted March 17, 2014 Well, friends, I have just got my new DeWalt 788 and while I am generally very pleased with it, however, I seem to have a problem. Maybe it's minor, but it doesn't seem to be quite right. When I set up the blade, and tension it, then check it for true travel etc. I see that it is dead on track vertically, when viewed from the front, but when I look closely from the side, I see that it travels backwards a little, (kind of like the movement you would see in a "C" frame scroll saw) and not straight up and down. Is this normal to some extent? if i set a piece of wood on the table behind the blade, it will just kick it over. Am I asking too much, or 'nit-picking' do you think? I have looked on You Tube, and see that the Excalibur 21 can be adjusted for this 'back travel' by adjusting the three screws on the motor mount. Having considered myself darn lucky to afford a DeWalt to start with, (never mind an Excalibur,) I am at a loss as to a fix for this unit of mine. I tried to find the post that about "Ricks scroll saw" (that might address this problem,) that the post by 'multifasited' directs me to, - but as of the moment, have not found it. (I will try again after posting this,) in the meantime any suggestions, (of the helpful kind ;o) will be appreciated. Edmund to get to Rick's http://www.scrollsaws.com/ I think the best explanation of what you are seeing is on the menu on the left side titled "Why square the blade." You are likely to have some out of line from perfect vertical on front to back but it should be miniscule. Does it change at all when it is at the top of the stroke from what it is at the bottom of the stroke? I think - I am not an engineer and have not gone out and checked my DW - but where you probably should have nearly vertical on front to back would be in the middle of the stroke. Quote Link to comment Share on other sites More sharing options...
patrol681 Posted March 18, 2014 Report Share Posted March 18, 2014 Thank you very much, Doug! You hit it right on the mark with directing me to Rick's page. ( I had thought it was a post on the S.S.V. site here, - no wonder I couldn't find it.) Anyway, it addressed my concern exactly so the short answer is; yes, I guess I was being a bit 'picky' on looking back, it would seem that a little back to front blade movement is acceptable. Thank you for helping me get that cleared up. Ed Quote Link to comment Share on other sites More sharing options...
ike Posted March 19, 2014 Report Share Posted March 19, 2014 I had all kinds of problems with blade slippage on my DW 788 I went to the hardware store and bought a tube for $5 and applied it to both tighten and have not seen any problems since screws. For $5 its well worth trying. Quote Link to comment Share on other sites More sharing options...
Kepy Posted March 19, 2014 Report Share Posted March 19, 2014 I have found that I rarely tension more than 2.5 and usually only 1.5 or 2 without a problem. Quote Link to comment Share on other sites More sharing options...
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