How to repair table saw?

Hello @TekBoffin

I can relate to how you feel at the moment. I purchased a second-hand pushmower and I gave it a thorough clean, inside was a free-wheeling self returning jumping gear. It's supposed to lock the rotating blades when pushing the mower forward, but for the life of me, I could not figure out how it was installed.

In your case, I recommend trying the following technique:

Positioning the winder to its lowest level.
Position the motor housing until it moves the hex bolt to the end of the spindle bolt.
Make sure the locking nut at the end of the spindle bolt is locked into position with the washer on the inside of the assembly.
Move the other locking nut on the inside right next to the hex bolt and make sure to leave a gap so that the spindle bolt can turn freely and not trap the hex bolt. Please keep in mind to position the washer on the inside next to the hex bolt.

I've placed an image below to give you an idea of how to position the locking nuts. However, it will be necessary for you to adjust the level of the saw until you find that sweet spot where the saw is at its maximum safe height.

Let me call on our experienced members @TedBear and @JoeAzza for their recommendations.

If you need further assistance, please let us know.

Eric

Lovely schematic again Eric. 👍 @EricL

And I think you're spot on with your mechanical logic - the nuts are locked in place with just enough play to allow the spindle to move freely and 'push/pull' the hex shaft.

Under mine is a worm gear system...there is a problem with this method.

Hi @Noyade ... that is poorly thought out design. Maybe you could mount a toothbrush to wipe against the teeth. That way you could wind the saw up and down occasionally to clean the system.

I am pretty sure that my own saw is similar to @TekBoffin so I will check and send a photo asap if it is. (Unfortunately I am not able to do that this morning. )

But @EricL 's suggestion seems like a good approach (of course).

Hi Ted @TedBear

"Maybe you could mount a toothbrush to wipe against the teeth."

Thanks for the suggestion, but sawdust isn't the problem. It's powered by an induction motor that's hinged at the back which creates the tension on the belt. However at some saw blade depths the belt angle changes and with it the tension, so you sometimes get a "clatter" between the worm gear threads. Usually stops when you raise or lower the blade by a few millimeters. Hard to explain in words. But yeah, I think it's a poor design.

Much better is a very old saw bench from the 40's. The induction motor is below the blade - constant belt tension. This is the blade depth adjustment...

Hi Eric,

Thanks for that suggestion. I just tried it and unfortunately it didn't work. The reason it didn't work, is that the hole in the hex shaft is threaded! So it jams as soon as it hits either set of nuts.

Now as I type this, that means that the two sets of lock nuts must be at the two extremities of the spindle bolt travel. They must act as stoppers. I will go back down to my shed and try that. I did look at that yesterday and couldn't get it to work, but I'll have another play.

And I agree, it is a very nice image that you drew!

Cheers,

Greg

Hi again Eric and all,

I got it worked out.

Here is a photo of the threaded hex shaft

threaded hex shaft.jpg The hole in the shaft would have to be smooth for it to work with the lock nuts right up near the hex shaft. I did consider boring out the thread, but dropped that idea just as quickly!

But there was another problem: the blade tilt is adjusted by turning the big outer surround of the handle. (I haven't used any other table saws, but I think that might be pretty standard.) Anyway, the tilt is driven by a bush that sits on the spindle bolt and goes through the table frame. It has a spline on the outside to mesh with the handle and it has a cog on the inside that meshes with a semi-circular toothed piece, which is driven up and down when the tilt handle is turned.

I found that this bush kept slipping along the spindle bolt away from the frame and out of the toothed section. I also found that the blade height handle would move away from the frame as I turned it. So, I realised I needed to stop the blade height handle from moving out and the bush from moving in. By locking the left hand set of nuts up close to the frame/bush (but not tight against it) that kept the handle and bush in place. Now when I turn the handle it moves the hex shaft along the spindle bolt. The right hand set of nuts acts as a stopper to prevent the spindle from winding right through the hex shaft.

Here are photos of the rectified situation, showing highest and lowest positions.

Blade set high Blade set low

It all makes sense now. Thanks for your help. Sometimes I find that just by explaining the problem to someone else, I can get a better understanding of things. But I love this forum!

Cheers to all,

Greg

Hello @TekBoffin

Thank you so much for posting those updates. It's good to hear that you've sorted out your table saw mechanism. It's definitely one of the things that I did not consider that the hex bolt had a threaded shaft. I forgot to mention how ingenious your repair job is for the winder.

We look forward to seeing a test cut of the table saw.

Eric

Hi @TekBoffin, I have attached 2 photos of my saw table's mechanism that has some similarity to yours.

Sorry that they are a bit blurry, they looked ok on the phone screen, but less so on my PC screen, but hopefully you can get the idea....

My saw mechanism pivots at the white-looking bolt at the back of the lower picture, whereas yours appears to pivot in a larger arc from the top left corner of your picture.

Mine has the same hex-shaped threaded pusher but also has another thinner plate set in place after that, which just keeps the winder threaded winder-bolt in line.

My assessment of how yours would have been is - after the threaded winder-bolt passes through the front, there would be a washer and two of the nuts locked together, then another washer. This would locate the handle end of threaded bolt against the front, so it can then push the hex-shaped pusher away from the front when the handle is turned or pull it back when turned the other way.

The other two nuts with a washer would go on the far end of the winder bolt to prevent the threaded Hex pusher from winding off the end of the bolt when you get to the maximum travel. I guess you would be able to set the maximum travel by those if need be.

I hope this helps you to see the how and why of your mechanism.

Lifter Mechanism at Max HeightLifter Mechanism at Min Height

Hi again @TekBoffin, I should have looked further down this thread before posting my pictures, but at least it is working now, and I am relieved to see that it does work as I had explained it, even if a bit late.

It's a great feeling when you solve such a problem isn't it?

Thanks Tedbear, you were spot on!

It works a treat now. Previously I had to try to grab the yellow plastic piece and try to turn it.

I'm very pleased to have it sorted.

Cheers,

Greg

"I forgot to mention how ingenious your repair job is for the winder."

There were 6 plastic fins on the inside of the yellow piece, a bit like wheel spokes. I cut some 1mm steel into a circle with an arm to be bent into the handle mount. Then drilled a hole in the centre and cut gaps for the spokes - a bit like a spline fitting. Then a couple of extra bolts to make sure it stayed put.

When I got it all together and working, I realised that the dowel handle was awkward to use, so I cut the rounded end off on old shovel handle. Drilled and mounted it on a bolt. I shaped it by using my drill press as a make-shift lathe (fairly high-risk activity, so proceeded with extreme caution.)

The end result is much better and even looks cool!

Thanks for all the help and encouragement!

Cheers,

Greg

New Handle

Hi @TekBoffin

Thank you for sharing that extra information about the repair steps you took to fix the winder. There is nothing like a custom repair job that makes a tool useful again. I'm sure our members will find this solution quite useful.

Eric

Thanks @TekBoffin for posting that query... as a result of upturning my saw unit to take photos I removed heaps of extra sawdust and more importantly I saw an opportunity to add a push bar across the front to press against the off button. I am a bit of a safety freak, so it has always annoyed me that turning the unit off requires reaching under and pressing a small button. Now I have a long bar to bump

Instead, which is much safer. It's the aluminium strip below the green On button on the left. The off button is now hidden below that.

Hi @TedBear

That is such an excellent upgrade, what's holding the aluminium in place? I'm in total agreement that it is much safer to turn the unit off. No more searching for the off button just bump the bar and it's off with no second thoughts.

Thank you for sharing such a clever idea.

Eric

https://www.kmart.com.au/product/suction-shower-mat-42623397/

Hi @EricL

That's from another lucky coincidence - my wife had just bought a new suction shower mat from Kmart ($10).

and there was a wide, strong plastic strip used in the packaging to enable the mat to be hung up for display purposes.

Instead of ditching it I kept it. (I keep almost anything that might come in handy one day/year.)

I cut it to length which provided both a hinge and support for the aluminium strip, which supplies the necessary stiffness.

The end that's screwed to my saw unit is the bit sticking out of the bottom of the rolled up mat (pictured below).

mat rolled with hanger strip in centre

Very clever Ted! 👍

My father's switch 'solution' to his old table saw. 😁

Great to see someone using the basics - such as just shutting the power off.

I also use a slightly more modern version of that - I have a remotely controlled switch unit which uses an infra-red sender.

I have the sender unit mounted in a plastic box with the lid attached to it's switch - such that if I hit that lid, the button gets pushed and the power gets shut off. The box has felt on the bottom to absorb vibration and to keep it still.

I have it sitting on top of whatever I am feeding through, or nearby, so I can hit it if need be.

The bump strip is a more directly operated back-up to that. I like that I can bump it off with my leg if I don't want to let go of the work.