Sintered Bronze ??

[Die Judicii]

I have a piece of machinery that has White Metal bushes that are flogged out.

I was going to turn up 2 new ones out of a suitable bearing type plastic, but the supplier tells me they only sell it in 1 metre lengths.

1 metre = $154 I think he said, but was definately over the $100 mark.

Considering I need only 2 bushes that are 20 mm long I find the above pretty uneconomical.

I thought about using sintered bronze,,,, but I can't find anywhere that stocks or uses the stuff.

Can anyone point me in the right direction or supply what I need.
I would need approx 100 mm of 30mm diam shaft. (2 lots of 20mm plus enough for the chuck to grab hold of)

Cheers,,,

[Member-Deleted]

DJ it depends what sort of thrust or pressure is on the bearing face when the machine is running
Turbines run a mixture of alloy and tin for bearings on a floating shaft @4000 rpm
If there wasn't a lot of down pressure then some of the softer metals like alloys can be very cheap and easy to turn
I used to buy bronze by the 2m length for the workshop its not very dear at all or at least up here it wasn't some thing like
$75 /mtr I used to buy the softer bronze for the bearing or bush because the harder types tend to chip slightly if side movement
with slap occurs around the journal areas
Most of the engineering tool suppliers should carry most of the bearing metals in short lengths or off cuts even the engineering work
shops would have tins of off cuts I did when I had the workshop you can't help but have off cuts it goes with the territory in machining

[Member-Deleted]

By the way hollow bronze is slightly cheaper than solid bronze it comes with OD of 32mm and an ID of I think13MM
You'd be able to skim that to the size you require quiet easily

[Chronos]

Sintered bronze bushes can't be machined from memory, they are kinda moulded and turning them seals up all the pores.

Lots of people use Delrin and may have offcuts. We turned sheaves from it when I was building masts in the marine industry.

Chronos

[Die Judicii]

DJ it depends what sort of thrust or pressure is on the bearing face when the machine is running
Turbines run a mixture of alloy and tin for bearings on a floating shaft @4000 rpm
If there wasn't a lot of down pressure then some of the softer metals like alloys can be very cheap and easy to turn
I used to buy bronze by the 2m length for the workshop its not very dear at all or at least up here it wasn't some thing like
$75 /mtr I used to buy the softer bronze for the bearing or bush because the harder types tend to chip slightly if side movement
with slap occurs around the journal areas
Most of the engineering tool suppliers should carry most of the bearing metals in short lengths or off cuts even the engineering work
shops would have tins of off cuts I did when I had the workshop you can't help but have off cuts it goes with the territory in machining

Thanks Grand Dad,
Thinking along the lines of turbines is far in excess of this little problem of mine.
I didn't say in the 1st post, but it is a cement mixer, at typical cement mixer speed.

I will try some more fitting and machining places for an offcut of the softer variety of Bronze HB,,, or offcut of Ertalloy.

Where I used to live (and work in the trade) I had materials, friends, tradespeople, and contacts by the dozens.
I don't have that anymore and sometimes struggle with what is a simple task because of it.

It's amazing when you walk into a workshop where no-one knows you and they automatically presume you are an idiot and know nothing.
Some try to sell you stuff that you know is wrong,, and others try to simply rip you off.

Cheers Mate

[Die Judicii]

My 1924 windmill has White Metal main bearings for the fan. They however are pored in place around the main shaft. Not sure but yours could be similar. To replace those bearings in a windmill is a huge job. The whole fan needs to be disassembled the tail taken off then the gearbox lifted up out of its thrust bearings after of course removing pump and pump rod. The gearbox weighs 100kg+ and needs to be lifted over a meter to get out. I cringe and hide at the very thought of it. The cost would be exorbitant.

Hey there Sungazer,
I've spent quite a bit of time working on windmill stuff (mostly the Varcoe brand) and if your interested I can supply you with plans on how to build a gadget that makes lifting the head out of the tower much simpler, and easier.

You can also use the same gadget to lift/lower the tail and wheel.

PM me if your interested.

[Member-Deleted]

Yeah I get that a lot to DJ the old two year treatment without knowing your back ground if only they knew in some cases don't know the design of your mixer but a mate of mine bought some heavy wall pipe and machined it to size and its lasted for years

[Die Judicii]

Sintered bronze bushes can't be machined from memory, they are kinda moulded and turning them seals up all the pores.

Lots of people use Delrin and may have offcuts. We turned sheaves from it when I was building masts in the marine industry.

Chronos

Hi Chronos,
Thanks for that.
Done a little research on it and it seems that the White Acetal Delrin POMc is the one for me, and I have found a supplier.
Much cheaper than going down the bronze path and a whole lot better.

Can you tell me, how it turns, as in speed, and do you use HSS tool bits,,,, or,,,,, carbide ?

Any other helpful tid bits of info would be welcome.

[Oldbloke]

https://en.m.wikipedia.org/wiki/White_metal

Mainly just tin & lead.

[Chronos]

Sintered bronze bushes can't be machined from memory, they are kinda moulded and turning them seals up all the pores.

Lots of people use Delrin and may have offcuts. We turned sheaves from it when I was building masts in the marine industry.

Chronos

Hi Chronos,
Thanks for that.
Done a little research on it and it seems that the White Acetal Delrin POMc is the one for me, and I have found a supplier.
Much cheaper than going down the bronze path and a whole lot better.

Can you tell me, how it turns, as in speed, and do you use HSS tool bits,,,, or,,,,, carbide ?

Any other helpful tid bits of info would be welcome.

Turns pretty nicely. Use sharp HSS tools and don't get it too hot

Chronos

[Die Judicii]

Turns pretty nicely. Use sharp HSS tools and don't get it too hot

Chronos

Thanks Chronos,,,,,,,,, appreciated.

[Die Judicii]

Lots of people use Delrin and may have offcuts. We turned sheaves from it when I was building masts in the marine industry.

Chronos

Got the job done (Sunday) by using some black Delrin that was kindly given to me free of charge.

Also did some homework on the machining of it.
Apparently unless you have a really sharp tool, with depth of cut and feed rates just right,, it can bee a real problem.

It can over heat easily, and then burst into flames. Then comes it's nasty side.

It burns with a clear and invisible flame.
But the really dark and sinister side of it, is, that when it burns it produces Phosgene.
The same gas used in WW1, and the same gas as developed by the rabbit fumigant gas pellets that are thrown into burrows, and then sealed.

Not to be treated lightly or by fool hardy people.

[MalleeFarmer]

DJ i had to replace some bushes on my sprayer 1” ID last year they were bronze i believe and were only about $2 each i had to do 8 i think. If you shop around you should be able to find something adequate at a fair price. Other option is to just drill and tap and insert a grease zerk and just grease it before every use.