Adapter for table saw arbor?

[Spindle]

Aluminium sulphate in Camelford :wink:

http://en.wikipedia.org/wiki/Camelford_ ... n_incident

 

[wizard]

:lol: fish

 

[seaco]

I was hoping to avoid that to make any modification reversible. Could one use loctite or something instead, then it ought to be very firmly there. Perhaps red loctite which would require heating the part to get it off again.

That is also why I was thinking the internal threaded part would only be as long as the threaded part of the arbor, the rest would be smooth. I also don't want to be taking the arbor off the machine, that veers into too much work/effort to be worth it.

Dennis I must admit you do seem to know exactly what you want already so asking opinions on here does seem a little fruitless. I personally think a physical connection between the two arbors is a must but obviously your entitled to your opinion (sorry but I retract my offer to make it as I don't want your health on my conscience) if you get it made I'm sure members here would like to here the results...

I do use a dado on my Unisaw so an extended arbor doesn't bother me, your safety does... :wink:

 

[wizard]

It was nice of you to offer

 

[DennisCA]

Dennis I must admit you do seem to know exactly what you want already so asking opinions on here does seem a little fruitless. I personally think a physical connection between the two arbors is a must but obviously your entitled to your opinion (sorry but I retract my offer to make it as I don't want your health on my conscience) if you get it made I'm sure members here would like to here the results...

I do use a dado on my Unisaw so an extended arbor doesn't bother me, your safety does... :wink:

I don't know what is safe or unsafe, I don't have experience to know that or not, my idea was just a suggestion I threw out so I could learn if it was good enough or not, obviously you don't feel it's good enough. I never said I'd refuse any other solution. But OK.

 

[monkeybiter]

Obviously after switching off the motor and as the motor/pulleys slow down, any cutter will try to unscrew it's self until stationary. Clearly for a single blade a tight nut is sufficient, even with any braking system. However with a more massive cutter the 'unscrewing forces' will be greater. As suggested earlier a positive mechanical lock holding the spindle extension and/or retaining nut would be inherently safer than a reversible bonded retention method. I'd go for grub screw breaking into the path of the threads as an easy and positive method that could be removed without removing any original function.

 

[Spindle]

Hi

Whilst I appreciate the concerns for the safety of the OP I have to point out that the torque at the spindle tending to tighten the LH thread during start up will be far greater than the torque tending to loosen experienced during run down on a non braked spindle.
Using a locking feature can actually be detrimental in that it prevents the spindle self tightening under start up.

Hence lathe chucks only needing to be positively locked if the lathe is run in reverse.

Regards Mick

 

[monkeybiter]

Good point, thank you.

 

[doorframe]

Is there something in the water in cornwall.

Trolls.

 

[seaco]

Hi

Whilst I appreciate the concerns for the safety of the OP I have to point out that the torque at the spindle tending to tighten the LH thread during start up will be far greater than the torque tending to loosen experienced during run down on a non braked spindle.
Using a locking feature can actually be detrimental in that it prevents the spindle self tightening under start up.

Hence lathe chucks only needing to be positively locked if the lathe is run in reverse.

Regards Mick

Good point Mick but on the other hand a mechanical fixing will stop any movement in either direction so in my opinion would still be safer!

 

[Spindle]

Hi Lee

Each to their own - but have you ever considered why grinding wheel retention nuts aren't locked?

Regards Mick

 

[seaco]

Hi Mick

With due respect we aren't talking about a nut or a chuck for that matter we're talking about an adapted arbour sleeve when the new sleeve is fully tightened a mechanical fixing is the best way to stop any possible movement in either direction...

 

[DennisCA]

I was wondering about that, might the existence of such a screw contribute to a weight discrepancy and introduce possible vibrations? Perhaps if one made two screws 180 degrees opposite from each other? Or is it not large enough to be noticeable?

(disclaimer: this is just me asking a question, not me making my mind up or rejecting any counsel or advice).

 

[Spindle]

Hi Lee

It doesn't matter how you look at it - it is a screw thread which has been designed to have a natural tendency is to tighten in use, adding a locking feature will prevent it doing this. If a locking feature were necessary manufacturers would have fitted one, (I can't think of an instance where this is the case).

Regards Mick

 

[pcb1962]

Motor is big enough no problem there, all you need to do now is cut the existing thread to the full extent of the shaft

You don't want to do that, you need the existing plain section of the arbor to register with the extension to ensure concentricity, a thread cannot play any part in that.

 

[heimlaga]

Motor is big enough no problem there, all you need to do now is cut the existing thread to the full extent of the shaft

You don't want to do that, you need the existing plain section of the arbor to register with the extension to ensure concentricity, a thread cannot play any part in that.

I agree. That longer thread would make the arbour useless. The flanges would start to wobble and even if this was resolved there would be a much higher risk for metal fatigue and a sudden break in the arbour.

 

[DennisCA]

This reminds me, while I need the smooth portion of the original arbor to index against, I noticed that on longer dado capable arbors they can mount the blades right on the threads, they use a thicker acme thread. I would need the same setup on the sleeve if I want to use this to mount a dado stack.

On my current arbor I believe the threading is M18x1.5 LH and it is smaller than the un-threaded part of the arbor, so you cannot mount the blade anywhere but on the smooth part.

I am not sure if I should leave any un-threaded surface on the newer sleeve? Or should I got for threading all the way, like american TS arbors seem to be. The coarse acme thread seems sufficient for a mounting a blade.

 

[Spindle]

Hi

The only way to ensure the blade or dado stack runs concentrically is to mount it on to a matched plain arbor - if you mount it onto a threaded section the thread clearance will result in the blade / dado stack being a loose fit, the outcome of which will be a lack of concentricity and balance.

Regards Mick

 

[DennisCA]

American table saws seem to have no clearance from what I can gather and the acme style thread seems to be designed so a blade can be mounted directly on it without clearance. My euro arbor has clearance and so it can only be used on the plain section.

This seems to me, to be the only way one could make an arbor that is both capable of taking just one blade as well as a dado stack, from what I can determine on ameican saws, the arbor is designed so it can take one regular blade + flanges on it's smooth portion, then the rest of the arbor as an acme thread without clearance that is capable of mounting more blades without the issues you describe, though apparently there can be issues with shims falling into the valleys of threads as is mentioned here:
http://newwoodworker.com/usngstkddados.html

 

[Spindle]

Hi

I'd go for a plain arbour and a cup washer system with a series of spacers to allow differing width of blades to be installed.

Hope the diagram makes sense

Regards Mick