Acme thread? New Arbor?

[Woodwork Journey Dean]

I’ve asked a few questions recently and not had any answers, so maybe there will be more luck with this one.

Does this look like an Acme thread to anyone else?

I need a nut for my possibly 1990’s Rexon RXW-10 saw. Zero information online about it

I think it’s a 5/8” Acme left hand thread possibly. I’ll have to count the TPI, but it may be easier to change out the whole arbor?

Any advice appreciated

 

[Phill05]

Hard to tell with all the dust in the threads give it a wire brush clean and take another image

 

[Tweedy]

Looks like a square form thread, but hard to tell with the muck.

 

[Ttrees]

It appears you might be able to get one cheaply,
i.e unsure if Charnwood ones might work...
https://charnwood.net/product/blade-locking-nut-for-laguna-table-saws/
Or perhaps Draper, SIP, or other big names might have spares.?

 

[Woodwork Journey Dean]

It appears you might be able to get one cheaply,
i.e unsure if Charnwood ones might work...
https://charnwood.net/product/blade-locking-nut-for-laguna-table-saws/
Or perhaps Draper, SIP, or other big names might have spares.?

It’s the reverse thread that’s the nightmare and strange pitch

 

[ChaiLatte]

ACME threads are 95% used for moving things about rather than securing two objects together. On that basis, I think it is unlikely to be ACME.

As an alternative to changing the arbor, find someone with a lathe who can turn off the old threads, build it back up with weld and then cut a more standard 5/8" LH thread onto it (preferably one for which you have already sourced a nut).

 

[Ttrees]

I was under the impression most newer saws, than my early later model Startrite 275
had a left hand thread arbor nut.
Not sure if Startrite changed this, but spares are available should they have done so,
which I can only guess would still have the same arbor size, and take the same size blade.

 

[Sachakins]

Looks more like a square buttress thread?

 

[Phil Pascoe]

I'd think the raison d'être of a buttress thread is that it isn't square?

 

[Daniel2]

 

[Sachakins]

I'd think the raison d'être of a buttress thread is that it isn't square?

Sorry, you're totally right, just a senior brain fart moment on my behalf.
I was thinking buttress initially because of the muck, but then thought more likely square.
So I'll get my seniors dunces cap on for the day in contrition for my brain fart

 

[recipio]

Do you not think it will be easier to find a nut rather than changing out the whole abour. ? It looks identical to my American imported DeWalt 746 which I always assumed it had an ACME thread to allow dado blades to be fitted without damaging the threads. I'd say a 5/8" ACME nut will fit - if not you have just lost the price of a nut .

 

[Sachakins]

View attachment 170740

I’ve asked a few questions recently and not had any answers, so maybe there will be more luck with this one.

Does this look like an Acme thread to anyone else?

I need a nut for my possibly 1990’s Rexon RXW-10 saw. Zero information online about it

I think it’s a 5/8” Acme left hand thread possibly. I’ll have to count the TPI, but it may be easier to change out the whole arbor?

Any advice appreciated

Try this thread https://www.woodworkingtalk.com/threads/arbor-nut-for-rexon-table-saw.221567/

 

[guineafowl21]

5/8” Acme is usually 8 tpi. Square thread is quite rare - even the Machinery’s Handbook is brief on it, but might be 11 tpi at that size. There is also a 10deg ‘slightly’ square thread!

You could buy each of the thread gauges mentioned above, and see which one fits best. Then you’d need either a suitable tap or internal threading tool on the lathe to make up a nut.

It’s all a bit specialist for a one-off job. Why not contact Doubleboost from Youtube? Send him the arbour and he’ll either make a new one or somehow rustle up a nut to fit. You’ll also need a clamping washer.

He gives his email out freely, so:
John
at
DoubleboostDOTvideo.

 

[Fergie 307]

If you can take it off then just take it to a local engineering shop. They will undoubtedly be able to identify the thread. The cutting tool might be quite expensive, actually making the thing once you know the thread is pretty straightforward.

 

[Woodwork Journey Dean]

Do you not think it will be easier to find a nut rather than changing out the whole abour. ? It looks identical to my American imported DeWalt 746 which I always assumed it had an ACME thread to allow dado blades to be fitted without damaging the threads. I'd say a 5/8" ACME nut will fit - if not you have just lost the price of a nut .

It seems that the nut for your saw may indeed fit but it looks like they’re not made any more either!

 

[Woodwork Journey Dean]

5/8” Acme is usually 8 tpi. Square thread is quite rare - even the Machinery’s Handbook is brief on it, but might be 11 tpi at that size. There is also a 10deg ‘slightly’ square thread!

You could buy each of the thread gauges mentioned above, and see which one fits best. Then you’d need either a suitable tap or internal threading tool on the lathe to make up a nut.

It’s all a bit specialist for a one-off job. Why not contact Doubleboost from Youtube? Send him the arbour and he’ll either make a new one or somehow rustle up a nut to fit. You’ll also need a clamping washer.

He gives his email out freely, so:
John
at
DoubleboostDOTvideo.

I would absolutely buy those threads gauges if I could find them!

I do think it’s 10, 11, or 12 tpi though

 

[Woodwork Journey Dean]

Hard to tell with all the dust in the threads give it a wire brush clean and take another

Done

 

[J-G]

A good clean up and a new photo would help . . . . . New photo arrived - - -

I was about to say that if that is 5/8 Ø then it is a 12½ TPI - utterly non-standard even for an ACME thread - and they can be weird.

The new photo - with the rule for scaling - nearly confirms my previous measurments but I would ere towards it being 13TPI .

Working from a photograph is never the optimal means of determining the true form but I would not have expected to measure ~40° if the form really is ACME. I would not expect to get an exact 29° due to the fact that even the best part of a photo taken 'square on' will still show part of the thread beyond the centreline but 40° does seem excessive.

Here is an image created by drawing around the edge of a massively enlarged copy of the new photo.

The figures are the measured angles.


[EDIT]
I've now also measured the depth of thread and find that it is ~ 0.038" whereas I would expect a 13TPI Full ACME thread to be 0.0484"

 

[Phill05]

It looks to me as it is 12 tpi Acme.

This image is a square thread