Do you own an older Multitool belt grinder?

[Grahame Collins]

The bench grinder motor that powers my Multitool belt grinder lost its blue smoke so I purchased a new bench grinder.

When I fitted up the frame to the new motor I manged to push the pulley on too far past the suggested installation specs. To correct the misalignment I now need to pull the drive wheel back off the 16mm grinder spindle. As the pulley ran spot on in the last one I am loathe to use screwdrivers etc. against frame to lever it out.

The pulley wheel on its nylon spacer is stuck like poo to a wet blanket and refuses to be screwed off in the same way I removed it from the dead motor.

Its a 20 + year old model and quite different from the current one, in as far as the pulley/drive wheel is made completely different from the current model. It has a small circular plate 30mm od in diameter with 3 threaded mounting holes.

I am not sure what the thread is. Its is a fairly coarse pitch and metric does not want to start. I tried unc and its no go there either.

I am surmising it may be a 3/16 Whitworth thread but have no Whitworth thread to try in it.. Does anyone who has an older Multi Tool, know what the thread might be.
I have sent an inquiry off to PA the manufacturer but won't know until they reply.

Thanks

Grahame

[Gavin Newman]

Grahame

Are you talking about the cover plate on the outside of the belt drum?

I had a quick look at mine which would be older still, I would have had it at least 30 years now from new but the plate on mine is around 2.5" diameter. The screws on mine are 19 tpi but they look like they are slightly tapered as well, the major diameter is slightly under 3/16". On mine they're definitely not a standard 3/16WW thread.

[BobL]

We're going to need some pictures Graeme.

Not sure what you mean by pulley wheel , do you mean the Drive Drum?

The drive drum on mine is not screwed on but just held between two flanges - there is no thread to screw the drum on/off.

The position of the drum on the grinder shaft is determined by spacers up against a step in the drive shaft

[Grahame Collins]

Grahame

Are you talking about the cover plate on the outside of the belt drum?

I had a quick look at mine which would be older still, I would have had it at least 30 years now from new but the plate on mine is around 2.5" diameter. The screws on mine are 19 tpi but they look like they are slightly tapered as well, the major diameter is slightly under 3/16". On mine they're definitely not a standard 3/16WW thread.

Yes! The cover that gives access to tighten/ undo the spindle nut. The cover is long gone, the hole being until just recently covered by the velcro for holding the abrasive discs. The cover, if present, I estimate would be about those dimensions.

I would take a punt and say its the same. If they are some proprietary thread I might just tapt them to something modern there's enough meat around the hole to do it. It is only nylon on steel, so once I get it moving there should not be too much stress on them.

Thanks for talking a look and replying.

[Gavin Newman]

Grahame. I suspect tapping is the way to go. The thread form is not like a machine thread or bolt thread, it's very acute or "sharp" like a woodscrew.

[Grahame Collins]

We're going to need some pictures Graeme.

Not sure what you mean by pulley wheel , do you mean the Drive Drum?

The drive drum on mine is not screwed on but just held between two flanges - there is no thread to screw the drum on/off.

The position of the drum on the grinder shaft is determined by spacers up against a step in the drive shaft


Hi Bob,
yes Drive drum
The info about the positioning of the drive drum was determined after I had pushed on the drive drum. Then found it was on too far.

Then went back inside and downloaded the instructions. There is a flanged washer (as you get with a new bench grinder) and a thick 16mm flat washer.

I mis spoke saying that"screwing the pulley/drive wheel off" More correctly I wound it around and around on the smooth spindle shaft while trying to hold the other end of the grinder - still with the guard and original stone on it- and still it won't move out wards. I am going to retap the 3 holes and make a puller and pull the drum.

[Grahame Collins]

Hi guys,

I have had a reply back from PA the makers of the Multitool. They say its a self tapper so it looks like a job to re tap to a machine thread,

Do you think M6 x 1 is a robust enough thread pitch to use with a puller or go coarser like 1/4"Whitworth?

Thanks

Grahame

[BobL]

Grahame, I tried it out this morning and I was able to get puller feet over the rim of the drum quite easily - wouldn't this be easier?

[Grahame Collins]

Grahame, I tried it out this morning and I was able to get puller feet over the rim of the drum quite easily - wouldn't this be easier?
Hi Bob
It would be easy if I were to own a 2 or 3 legged puller. Those type pullers are real pricy - up to $100 or so. As it is, I have spun up a disc and tapped it for 10mm ,tapered the screw bolt ( pusher) end and it is ready for use once I settle upon a tapping size for the 3 holes in the drive drum.

I will tap out the original holes to Whitworth. It is not like I need to use those holes for any other purpose.I need to hunt up some local 1/4 Whit screws.The way it works locally, if I were to tap first they are nearly guaranteed not to have any stock, I have been caught before.

[Combustor]

Hello Grahame,
I have found that many of the cheap mild steel zinc plated hex bolts ( builders bolts) in the big hardware stores are for some reason still Whitworth. They have saved the day for me a few times on old machinery restorations by grinding or machining off the Chinese headstamp and buffing off the plating on the wire wheel, then a light oil blue job if disguise is needed. The big green shed may have what you need.
Combustor.

[BobL]

Hi Bob
It would be easy if I were to own a 2 or 3 legged puller. Those type pullers are real pricy - up to $100 or so. As it is, I have spun up a disc and tapped it for 10mm ,tapered the screw bolt ( pusher) end and it is ready for use once I settle upon a tapping size for the 3 holes in the drive drum.

I will tap out the original holes to Whitworth. It is not like I need to use those holes for any other purpose.I need to hunt up some local 1/4 Whit screws.The way it works locally, if I were to tap first they are nearly guaranteed not to have any stock, I have been caught before.


I made several (dodgy) 2 and 3 legged puller before realising that supercheapauto and others were selling them for about $30 - 40. They're not crappy ones either, the legs are drop forged chrome vanadium steel and threaded part is also suitably hardened.

Anyway I'm glad to hear you have a plan.

[Grahame Collins]

Hi everyone,
I was able to pull the drum wheel using self tappers and a very lightweight puller.

Being an older model all the threads were imperial-

Heads up for anyone with unresolved tracking problems. The little clip that retains the spring tube under tension during belt changes. Don.t let the space beteen the plates and bolts and nuts get too big.Too much clearance allows tube rotation and tracking will suffer. Just keeps bolts nipped tight enough to allow vertical movement of clip.

Here s some pics for Bob.

And the result which I am very pleased with

[chambezio]

Grahame, the business end of the linisher, is it your own manufacture? How does it perform?
I like the design of that Australian fella's. his can utilise 3 differ diameters to sand against. The price of his put me out of anything but dreaming about having one.
My linisher would have to be 25 plus years. Its a great machine to have at hand being able to handle steel or timber (or plastic and some aluminuim). To duplicate your set up would enhance its performance I'm sure.

[Ueee]

Rod that Australian fellow is John Price. Before the Radius Master he designed and manufactured the multitool, before selling the rights to the now owners of PA products who now make the multitool off shore.

The Flat platen and PU idlers at the front end of the multitool are designed and manufactured by myself, aimed at the knifemaking community.

[Grahame Collins]

The Flat platen and PU idlers at the front end of the multitool are designed and manufactured by myself, aimed at the knifemaking community.

A bloody good job too, I'll say.:U

And does'nt this unit make a huge difference to the standard Multitool machine.

If you already thought you could do a big variety of work on the Multitool, this addition takes it to another level. Add to this its much quieter than the old set up and much smoother. I have already sharpened twist drills and dressed some countersinks with it. Love it ! :2tsup: :2tsup:

[Grahame Collins]

Its a great machine to have at hand being able to handle steel or timber (or plastic and some aluminuim). To duplicate your set up would enhance its performance I'm sure.

Uee's answered most of your post but I would point this out.

Unless you get a variable speed drive it's way too fast for timber.It burns ,especially on end grain.

[chambezio]

Thanks Grahame and Ueee. I have been happy with the linisher but I reckon that the modification would be as you say a beneficial thing. I have shot off a PM to Ueee