Unusual Machining Processes, feel free to share ones you are familiar with

[Rannsachair]

Probably a bit of nostalgia, I was thinking back to some of the more unusual processes we used to make Hydraulic components, Might be interesting to share some if you are familiar with any.

I should add that I was design and development, so not my specialism, though always fascinated me.

Ballizing

We used to press a precission ground tungesten ball through a slightlly undersize bore. This process finishes to size and gives an excellent surface finish, We were doing this back in the 80's/90's, not sure if still used much elsewhere.

Thermal deburring

We used to use a Bosch Thermal deburring Machine, parts are loaded onto a track, fed into the machine which has a combustion chamber. When in the combustion chamber a mixture of gas and oxygen is exploded and it removes all burrs etc in components, useful in cored castings with hard to reach galleries.

Precission Cylindrical grinding

Not so unusual, though we used Studer S20's in a temperature controlled room to grind steering valves to tolerances in microns. As in you had a ground sleeve that fitted over a shaft, if you disassembled and held one part in your hand for seconds they would not reassemble.

They were some of the processes I recall, we also did hard chroming.

 

[slim_boy_fat]

As in you had a ground sleeve that fitted over a shaft, if you disassembled and held one part in your hand for seconds they would not reassemble.

 

[hotponyshoes]

A chap I know still uses ballizing.
It's for a rotating shaft that fits into a closed end bush.
The bush is drilled nearly to size then the ball is pressed in to give the final surface finish and dimension.
The ball is then left in the bottom of the hole to act as a bearing to control the end float of the shaft.
His press is pretty funky as it's basically an adapted air chisle that drives the ball in. That leaves little ripples on the inside of the bush which help retain the shaft lubricant.

 

[Morrisman]

A chap I know still uses ballizing.
It's for a rotating shaft that fits into a closed end bush.
The bush is drilled nearly to size then the ball is pressed in to give the final surface finish and dimension.
The ball is then left in the bottom of the hole to act as a bearing to control the end float of the shaft.
His press is pretty funky as it's basically an adapted air chisle that drives the ball in. That leaves little ripples on the inside of the bush which help retain the shaft lubricant.

There's a kit for 'resleeving' valve guides on old Chevy motors. Basically a brass sleeve you put through then a ball bearing is forced through with a hammer and drift. Seems extremely flakey to me but seems to work.

 

[MetalMonkey]

Ballizing

I've been Ballzing up my machining attempts for many years....
But I think that's a slightly different technical process though.

 

[Seadog]

A classic way for sizing smallest bushes. Triumph/BSA certainly used that method.

 

[mtt.tr]

Hydraulic stuff mostly blows my mind, and orbital valves were designed by a wizard I believe

 

[Rannsachair]

Hydraulic stuff mostly blows my mind, and orbital valves were designed my a wizard I believe

When I worked for Eaton we actually had an ex NASA rocket scientist helping with mathematical computer modelling of hydraulic steering valves on articulated trucks, all the way to modelling the tyres and their influence. I used simpler modelling on Matlab, though at times it was best just to try something instrument the vehicle, test and just try gradual changes in the valving and priority valve.

 

[mtt.tr]

When I worked for Eaton we actually had an ex NASA rocket scientist helping with mathematical computer modelling of hydraulic steering valves on articulated trucks, all the way to modelling the tyres and their influence. I used simpler modelling on Matlab, though at times it was best just to try something instrument the vehicle, test and just try gradual changes in the valving and priority valve.

Had a good one, pressure sensing swash plate pump had been replaced at 4k, comes back in low pressure another 4k pump purchased still not working.
We get called, check LS pressure all good

"When you put the pump on did you set up the actuator"

"Erm the what"
"Where's your manual" show them the page they should have followed.

 

[Maker]

Thermal deburring sounds interesting, how do you deal with scale forming on the components?

EDIT: Just looked it up, it literally is an explosion, one bang and it's done, anything thicker than a burr probably barely even gets warm. Time for a DIY version...

 

[mtt.tr]

Thermal deburring sounds interesting, how do you deal with scale forming on the components?

EDIT: Just looked it up, it it literally is an explosion, one bang and it's done, anything thicker than a burr probably barely even gets warm. Time for a DIY version...

Suffolk man arrested after building a pipe bomb

 

[Rannsachair]

Thermal deburring sounds interesting, how do you deal with scale forming on the components?

EDIT: Just looked it up, it it literally is an explosion, one bang and it's done, anything thicker than a burr probably barely even gets warm. Time for a DIY version...

We used a large ultrasonic bath, not sure what chemical was in it.

Aye, you do wonder who was mad enough to think. lets put parts in an explosion and see how that deburrs them

 

[Maker]

Suffolk man arrested after building a pipe bomb

Yeah good point, maybe best to stick with vibratory tumbling in the home workshop.

 

[Misterg]

Not unusual, per-se, but definitely a bit niche:

Single Point Diamond Turning - mostly used to cut optical surfaces on plastic lenses or metal mirrors, but also used for machining precision air bearings and the like.

It's a turning operation on a lathe, but the tool is made out of a single, gem quality diamond, lapped to pretty much a perfect edge and the lathe has servo systems that can position to the order of 1 nanometer (one thousandth of a micron).

There are only a few videos about it on Youtube, and most don't really show the magic of the process. This one gives an idea (no connection to me):

I was involved with it in an R&D capacity when I first started work but then moved on to other things. In an odd twist of fate, I'm dabbling in it again.

These are the jog options I've got:



When you think that the wavelength of visible light is about 550nm (~0.5µm) ...

 

[MattF]

one bang and it's done

You'll become familiar with that, as you age.

 

[Wedg1e]

Yeah good point, maybe best to stick with vibratory tumbling in the home workshop.

Bloody youth. Keep it in yer trousers.