V4 Oscillator Motor

[Ken I]

V4 Wobbler - double acting - magnetically held (no springs)
2D ACAD *.dwg & *.dxf plus *.doc build notes
?

View attachment V4WOBBLE.zip

 

[Richard Hed]

V4 Wobbler - double acting - magnetically held (no springs)
2D ACAD *.dwg & *.dxf plus *.doc build notes
?

View attachment 97833

View attachment 97832

Do you have a movie of this running?

 

[Ken I]

Richard, I added it to my response to your thread - you were too quick we've crossed.



Regards, Ken

 

[Richard Hed]

Richard, I added it to my response to your thread - you were too quick we've crossed.



Regards, Ken

I'll have to study that more closely at a later date. Thanx for the .dwg.

 

[Steamchick]

Nice to see another sweet little model. I am curious to know how much pressure it takes before the magnets are overcome by the air pressure at the inlet ports? - That being the limiting factor (as I understand?) for oscillators? I think the full sized oscillators used shaft porting and sealed better that way with higher pressure steam, without being so prone to "inlet valve leaks? - But I have never heard of anyone using "magnetic" sealing before - so well done!!! I am curious to know your magnet arrangement - if you have a schematic?
Thanks,
K2

 

[Ken I]

Richard, This is how the magnet sits between the cylinder trunnions.

The magnet is a press fit in the bronze bush and the trunnions - which the cylinders oscillate on within the bush - are almost touching the magnets.
This provides a surprisingly large hold down force - I had to skim the trunnions back from 0.1mm clearance to 0.5mm clearance as they were too strong.

So its simple to adjust the "spring".

The magnets a 8mm diameter x 5mm long - available from any magnet supplier.

Regards, Ken

 

[Steamchick]

Excellent design! - Love it! - I have a Single acting twin - with a pair of external springs - needs lots of attention as the bores and crank are well worn. But while I'm doing that, it may get the Magnetic conversion!
Will your engine take 20~30psi? - My engine is to run on steam and drive a generator...?
K2

 

[Ken I]

I don't know why but I never made a video of the single cylinder version - so here it is :-



The poor thing hasn't been run in 2 years.

I open the voiceover stating it to be a single acting - I meant to say a single cylinder version of my V4.

The magnet is capable of outperforming a spring - I run it at 100 psi in the video - I have under test previously run it at 120 psi.

This motor is entirely metal to metal - there is no rod gland or piston ring.

Regards, Ken

 

[ACHiPo]

Both of these are very cool! Love it!

Other than the number of parts, is there any reason the V-4 is more challenging to a noob than the single?

 

[Ken I]

The V4 is a little more challenging because of the complex of Ø2.0 & Ø2.5 deep drilled holes - requires a long series drill and careful planning and care at the intersects - if you break a drill off down there you are going to be in trouble - the build notes cover this.
Making 4 sets of cylinder parts is not that much work as you go into "production" mode.
Drill the deepest holes first and all the "breakthrough" holes on the shorter legs. Use a Vernier stop at the breakthrough to stop "snatching".

The V4 drawings have a version (above) without the "afterthought" throttle parked on top - designed into the body - in the middle of the "V"

Regards, Ken

 

[ACHiPo]

The V4 is a little more challenging because of the complex of Ø2.0 & Ø2.5 deep drilled holes - requires a long series drill and careful planning and care at the intersects - if you break a drill off down there you are going to be in trouble - the build notes cover this.
Making 4 sets of cylinder parts is not that much work as you go into "production" mode.
Drill the deepest holes first and all the "breakthrough" holes on the shorter legs. Use a Vernier stop at the breakthrough to stop "snatching".
View attachment 121106
The V4 drawings have a version (above) without the "afterthought" throttle parked on top - designed into the body - in the middle of the "V"

Regards, Ken

Ken,
Thank you. One other question--what would be the effect on operation if the holes were a bit larger diameter? I'm mostly set up for imperial drills, especially my longer drills, although I don't think I have a 2.5" long #39 drill so may need to order a couple specially for this project.

Evan

 

[Ken I]

The holes sizes are not critical - however the Ø2.0 porting holes in the face of the cylinders and block will eventually overlap at Ø2.74 so a Ø3/32" would still be fine.

A quick look at the drawing tells me you can go up to 25% bigger without problems.

Feel free to check with me on any aspect if you do go ahead.

Regards, Ken

 

[ACHiPo]

Thanks!

 

[minh-thanh]

Ken I !
" The magnet is "like" a spring "
A Great Idea !
Thanks for sharing.

 

[lathe nut]

Ken, that is cute and if fun to watch, great workmanship there, would it be possible to get that drawing in a PDF, I would surely appreciate it, love your work, thanks for sharing, Joe

 

[Ken I]

Lathe Nut - attached - dirty great big A0 sheet
Regards, Ken

 

[johnmcc69]

Pretty cool Ken!

John

 

[Ken I]

John, I posted these plans 8 years ago - and suddenly - nothing happened !

But since Richard's query has come to the fore again.

The zip file (post #1) contains all the ACAD dwg & dxf files + build notes

Regards, Ken

 

[johnmcc69]

I saw that, it's an oldie but a goody! Not sure how I missed it back then.

Maybe there will be some new builds of it now.

As always, great drawings & documentation!

John

 

[ACHiPo]

I've started looking for material and am getting sticker shock for aluminum bronze and other copper-containing alloys. I've found Al-bronze at 5/8 for a reasonable price on eBay, but the larger 7/8" stock needed for the plans seem quite a bit more expensive. If I have to spend $50 for stock, would Al-Si-bronze work as it machines easier than straight Al-bronze I think?