rotating shaft connection?

[knighty]

as above... I need to make a 'pusher' rod is acme threaded rod, it'll screw through a nut to push the plate on the end of it forwards... to separate some parts of a machine

I need a decent way to mount that so plate doesn’t rotate (doesn’t matter if does rotate, but friction will fight it)

can't remember the rod size I bought... it's 18mm ish

there'll be a fair bit of pressure on it,


any ideas for an off the shelf link/swivel I can buy?

 

[sako243]

Can you just mount a thrust bearing on the end of the rod? Or have I misunderstood the requirements?

 

[knighty]

Can you just mount a thrust bearing on the end of the rod? Or have I misunderstood the requirements?

yes... problem is they need to be stuck together pretty well... and easy to clean - it's pushing some plastic parts out of a flow divider on a meat portioning machine

I've got my fingers crossed I can get something off the shelf without having to do a load of machining.... my lathe is buried right now, It'll be a full days work to get to it :-o

 

[sako243]

Piece of delrin or HDPE drilled out to sit over the rod? HDPE is pretty slippy so should hopefully just let it rotate?

 

[knighty]

I'd need it to be able to pull as well as push... shouldn't be any real pull force on it but don't want it falling off if someone retracts it :-o

 

[knighty]

p.s. I got a quote from the machine manufacturer for this.... £1200.00 :-o

 

[sako243]

Can you bolt through the plate? Just a holy into the end of a threaded rod with thrust bearings either side.

 

[Dapph2]

1 to 3 inch thick Delrin piston ..... step the rod and thread it , drill the Delrin to take the stepped rod and from the other end drill a hole to take the nyloc nut that secures the rod . Make a tight push fit blanking plate out of Delrin to blank over the nut hole & use super glue to ensure it stays in place.
If you use a thicker Delrin piston add thrust bearings on either side of the hole in the Delrin

 

[sako243]

@knighty if you want I've got a piece of I think it's Delrin, probably about 30mm diameter (about a metre of it) if you ping me a drawing I don't mind chucking it in the lathe and machining up something for you and bunging it in the post.

 

[8ob]

Why not fix the acme thread to the piston and have a deep internally threaded acme driven shaft.

Bob

 

[knighty]

Why not fix the acme thread to the piston and have a deep internally threaded acme driven shaft.

Bob

I don't want the piston on the end to turn / it doesen't really matter if it does turn... but there’ll be a lot of friction / make it too hard to turn

 

[knighty]

@knighty if you want I've got a piece of I think it's Delrin, probably about 30mm diameter (about a metre of it) if you ping me a drawing I don't mind chucking it in the lathe and machining up something for you and bunging it in the post.

that would be fantastic

could you cut a bit off about 50mm long?

I'll drill it out so it fits onto the rod tight then drill through at 90' and put a big split pin through

I'll try it like just that first and see if I can get away without the steel plate on the end - I should have thought to try this sooner, the picture of your bit on the end of the rod made me think of it just now :-o

 

[Agroshield]

I don't want the piston on the end to turn...

I think he is suggesting making a rigid connection between piston and threaded rod and rotating the nut to cause the linear movement.

The piston/rod connection would be easy to clean. Any gap at this end which allows rotation is also a place for bacteria and other nasties to hide. Not good in a food environment.

The other end (which would need a captive nut for push-pull operation) easy to fabricate from off-the-shelf parts, with no machining needed.

 

[8ob]

I think he is suggesting making a rigid connection between piston and threaded rod and rotating the nut to cause the linear movement.

The piston/rod connection would be easy to clean. Any gap at this end which allows rotation is also a place for bacteria and other nasties to hide. Not good in a food environment.

The other end (which would need a captive nut for push-pull operation) easy to fabricate from off-the-shelf parts, with no machining needed.

Better put than me but yes, rotate a nut rather than the screw. Other thing that may do the job is a hydraulic gate ram, all in one unit with its own reservoir and pump, pressure can be adjusted and there would be a chrome rod pushing on the piston which would be even easier to clean.

Bob

 

[knighty]

Ah, I didn't think of that, that could work well

Hydraulic is a bit overkill, I thought could use an air powered ram... but a bit worried it would shoot out too fast... maybe could have little oil tank and pressurise it woth airborne push the oil out....

But fingers crossed that's all overkill, the manufacturer just has an acme rod to push it out so ill try that first

It should have come with thstvehwn I bought it, it was pretty expensive for what it is... but low volume sales custom thing so I expect that.... but £1200 for a bit of rod and a couple of steel plates rubs me the wrong way

 

[bricol]

Thing is, does the 1200 quid option work, first time, every time?

By the time you've made something, invested time and money, revised it . . . If your time is worth nothing though . . .

 

[knighty]

No idea how well the £1200 option works... but we've been running fine without one for a good few months now

Making something would just make life easier for the lads cleaning it on a night

If it was a must have I'd have ordered one the first day we used the machine