Dewalt DW738 / Elu EBS3401A1 Bandsaw Blade Tension

[Dhenry]

Hi

I recently bought a Dewalt DW738 bandsaw (it’s actually branded Elu but otherwise identical). Overall the saw’s in pretty good condition but I can’t get sufficient tension in the blade to stop the blade wandering. Looking at the tensioning mechanism more closely, I suspect that either the threads on the bolt, or in the nut, that form part of the tensioning mechanism are shot. I’ve started taking the mechanism to bits but can’t figure out how to get the tensioning bolt out.

Has anyone done this before, and if so, how did you do it/do you have any tips?

Thanks

David

 

[sunnybob]

DONT FIDDLE!

If the thread actually pulls the mechanism up then it aint broke.
Is the blade new? if not, its almost certainly rubbish.

DO NOT MAKE ANY ADJUSTMENTS untill you have a new blade. Only then can you start to get it working properly.
Buy one from Ian at tuffsaws
https://www.tuffsaws.co.uk
Then watch this video, which will answer most of your questions before you ask them.
https://www.youtube.com/watch?v=wGbZqWac0jU

 

[Dhenry]

Thanks Bob.

The thread isn’t pulling the mechanism up which is why I think it is broken. It’s sharp blade in the machine although not a tuff saw blade. My spare blade is a new tuff saw blade although I’m not convinced it will make much difference given how slack the current blad3 is.

Thanks

David

 

[sunnybob]

Ok, what we need now is pictures of the thing. Then we can give more advice

 

[Steve Maskery]

I don't understand why the tensioning knob does not tension the blade.
It is possible to strip the thread, but it is a very simple mechanism and it should be a straightforward job to to put in a new bolt if it is stripped. M8 IIRC.
If it is max tension, the spring is compressed and it is still not tensioning the blade, then it is possible that the blade is too long. It doesn't need to be much too long to be untensionable, especially on a small machine like that.
Are you sure you are making all the other adjustments properly? There is much more to blade drift than tensioning.

 

[sunnybob]

You need to clarify;
Is the thread not pulling the mechanism at all?
or is it pulling tight but not tensioning the blade?

A blade only needs to be 5 mm overlength for the adjustment not be enough to tension.

 

[Robbo3]

Yes, it's a common fault. Because the threads have either stretched or stripped the hard bit is getting access to remove the bolt. Probably easier these days with a Dremel.
I tried to source a tempered 6" (IIRC) carriage bolt but in the end bought several BZP ones & changed the bolt every couple of years.

 

[Dhenry]

Thanks all for your comments. As an update, I had another look at the bandsaw yesterday. The threads on the carriage bolt were indeed stripped which was why I could not properly tension the blade.

To get the carriage bolt out, I ended up following Robbo’s suggestion and cut it in half with a dremel (it seems the only way to get it out if the threads are shot). Once the top half of bolt was separated, I was able to use a hammer to get the bolt and nut out of the plastic handle at the top of the tightening assembly. I’ve ordered half a dozen new carriage bolts (I struggled to find tempered ones also Robbo) and should hopefully have the saw back in buisness with a new blade next week. Fingers crossed that’s the end of my drifting cut issues!

Thanks again all

David

 

[sunnybob]

sounds like there was too wide a blade fitted at some time, and thus the nut was overtightened to try to get the blade taut.