Hammer A3-31 fence
I have a newer model A3-31 (with the new fence). I have been having a heck of time squaring the fence to the bed. I have to really exert a lot of force to even get it square, and clamping it often puts it out. It seems like "square" is almost at the edge of the adjustment range. Adjusting the screw stops doesn't do anything since it is so far at the end of the range. Has anyone had any problems doing this ? And I can't figure out what I am supposed to use to read angles on fence adjustment... am I stuck measuring angles manually ? There's no obvious indicator or pointer to use.
The manual says very little about the process - well, really, nothing.
I also have the new fence. At the point the fence is set to 90*, I still have ~3mm on the adjustment bolt/ stop at the bottom of the support, meaning that I could adjust the angle to 88* to the table. Pic attached.
If you're out of adjustment travel, have you checked square along the whole length of the fence? Is there any problem with the fence being warped?
I have the older style Hammer A3-31, and the fence is the one thing I do not like about the machine. The aluminum fence is not flat across the entire fence - it is sort of wavy. The fence also has the same problem of squaring up. My fence has no set screw adjustments, so I shim between the fence and the fence screws with strips of paper. The long end of the fence is unsupported and can deflect easily, so I use a magnet behind the fence to back it up.
Adjusting the fence is done by the screw shown in Steve's picture, note there are two of these one one each side. You should also check to make sure that the rail that the fence slides on is not kicked up on one end. If you have any trouble with it, Call one of the technicians in Delaware.
Thanks guys, for your replies !
Steve and Carl, my adjustment screws are backed all the way out. They're not preventing me from getting the last fraction of a degree, something else is. There's a cutout near where the adjustment screws are that seems to be contacting a post and preventing the last bit of travel. I'm not sure why. That's true on both sides.
Carl, I will take a closer look at the rail that the fence slides on.
And David and Steve, I will take a look at the straightness of the fence. I sure hope that's not my problem - I think. Unfortunately for me, shimming won't help as I can't get the last little bit of travel I need, whereas you sound to have the opposite problem.
What is unfortunate is I only see my shop on the weekends so I'm pretty limited in how easily I can diagnose problems - my computer time happens to be mostly during the week, while shop time is exclusively on the weekends.
Thanks again !
I had the exact same issue on mine. It was easily corrected by adjusting the rail as Carl indicated.
Same issue here
I had the same issue too, but My rail was perfectly parallel to the table so it didn't seem to be the problem. The problem still somewhat exists, but one thing I noticed is that it does it worst when the bottom of the fence is not resting on the table itself but on the flimsy sheet metal off the the side when furthest right. I realized then that the fence design kinda sucks. When I would clamp it, it wouldn't always clamp in the same place (sometimes missing the strip of steel on the rail) and digging into the aluminum) based on how the bottom of the fence was resting. Seems like there should be something more than just that bit of clamping pressure (one screw on that aluminum rail!) to make sure all is held square.
Originally Posted by Daniel Platt
Not sure about the A3 31 , and certainly not about the new model (i have the previous model A 3 41 which as far as I know has a different fence to even the older A3 31) - and so no idea if these points might be useful.
They are examples though of the sort of issues that seem on occasion to sneak through though.
My fence extrusion when checked in situ proved to be cupped - although not along its full length.
Quite a large part of the issue turned out to be in the folded steel mounting bracket it was bolted to. When a 90 deg bend is made in sheet steel there's a tendency for the last part of bend at each end (at the top and bottom corners/edges of the sheet) to spring back a little - with the result that there can be raised area at each corner. When the fence extrusion is bolted down against a bracket formed this way the tendency is for those bumps at the top and bottom to push the extrusion (which is still pulled hard down in the centre) away a whisker.
The result was the cupping the fence extrusion.
Removing the fence extrusion and flattening and re-painting the mounting face of the bracket (that mated with the back of the fence extrusion - see photo which is upside down) using a coarse DMT diamond plate fixed it. (a wide single cut flat file would do it too - but it's important that the mounting surface is kept properly flat or it won't provide a stable mounting surface for the fence)
The other contributor to the problem was the balance weight bolted to the back of the fence. Being thick steel it cupped when being punched out, and it was turned so that when the mounting bolts were done up that it also pulled a cup into that end of the fence. Flipping it over solved the issue.
Once unbolted the extrusion sprang back more or less into flatness - and stayed that way when re-assembled on to the now flat bracket and fitted with the re-positioned balance weight. If it doesn't spring back flat then the problem is with the extrusion itself.
Another issue that surfaced was that the pair of black plastic blocks that act as bearings when the fence slides on the table (one is visible in the photo of the bracket) had been adjusted into a position where they prevented the lower edge of the fence from pushing back far enough to allow it to reach 90 deg. A few minutes with an allen key saw that fixed - the blocks are slotted and can be moved away.
Whatever about the relevance of the specific issued described (they at least point out the sort of issues that can arise) I guess I'm saying that it may be advisable to work through the fence and check it for stuff like this.....
Attachment 253707Attachment 253708
I agree with you on all points David. The fence is the one thing done poorly on the older A3 31's. I ran some tall stock on mine yesterday and that dang fence deflected all over the place. The extrusions would probably work if they were properly supported. I'll try the magnet trick to see if that helps, but I sure miss the cast iron fence on my old jointer.
Originally Posted by David Wong