Author Topic: Pulling the shaft on an ST head?  (Read 7886 times)

dkwflight

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Pulling the shaft on an ST head?
« on: August 16, 2006, 02:42:04 AM »
Hi I've been thinking about putting an extra fly wheel on a st head.
If an extra long shaft were made for a st head the opposite side could carry some sort of fly wheel.
York has a 100 lb barbell weight that looks symetrical and could be machined for a tapered collar easily.
Dennis
« Last Edit: August 16, 2006, 02:46:39 AM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

Doug

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Re: Pulling the shaft on an ST head?
« Reply #1 on: August 16, 2006, 02:55:00 AM »
You probably would be better served to take the rotor to a good auto machine shop and ask them to cut and weld the shaft to length.

I did this years ago....
A standard electric motor T frame has a normal looking shaft. A JP pump motor has a longer odd looking shaft. My good ( retired ) machinist friend would cut bevle and subarc a new longer chunk of steel and remachine the new shaft to except the SS sleave and fit into the pump housing.

Result I made an expensive JP motor ( or JM did that too ) from a cheap T frame
And this would probaly bew the best thing for you. You might be able to press the shat out of the rotor, but I doubt you could do it without some damage ( possibly the not easily hacked kind )


Doug

Rtqii

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Re: Pulling the shaft on an ST head?
« Reply #2 on: August 16, 2006, 03:55:55 AM »
This can be done... Remember that a barbell is not speed rated for 1800 RPM however ;)  I would look at maybe bolting some steel auto/truck/tractor flywheels on.

As for shafting... Rather than pull and modify the rotor, just direct couple the end of the rotor to a jackshaft on its own bearings (pillow block bearings) and mount the drive pulley to the jackshaft instead of the ST shaft.

As far as costs: this depends on the shaft diameter (material cost), whether or not you need to have a custom coupler (say a 48 mm to 2") or whether it is cheaper to machine down the one end of the jackshaft to accept an off the shelf coupler (say 48 mm to 48 mm).

I got a quote back from Associated Steel today on a 2 inch shaft of hardened steel shaft (exceeds 1045) with some custom machining (one end necked to 48 mm to direct couple with an ST shaft and the other end drilled for a pilot bearing to mount a flywheel and clutch... $465.00  :o

mobile_bob

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Re: Pulling the shaft on an ST head?
« Reply #3 on: August 16, 2006, 06:36:15 AM »
you might try lookin into hd truck axle shaft,, some are up to and over 2"
you have to machine the ends anyway,,, so just have em run a pass down the length to the size you want..

not sure of the metallurgy but likely plenty good stuf, and a heck of alot cheaper

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

GuyFawkes

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Re: Pulling the shaft on an ST head?
« Reply #4 on: August 16, 2006, 08:42:14 AM »

York has a 100 lb barbell weight that looks symetrical and could be machined for a tapered collar easily.



spinning up barbells is an excercise is making a potential bomb.

(PS moving home so quiet over the next 3 weeks or so. No, not off grid)
--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

dkwflight

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Re: Pulling the shaft on an ST head?
« Reply #5 on: August 17, 2006, 12:33:53 AM »
Hi These are a quality american casting. They probably should be balanced and x-rayed too. A piece of heavy plate would work too.

As a related topic, the large circular saw blades used in saw mills have to be hammered into a slight cone shape so they will spin true. The center is slightly thinner than the rim. The centrifugal force stretches the blade to  larger diameter at operating rpm.
This situation is wel beyond what the cast flywheels on a Lister are experiecing. The forces are similar but lower magnatude.
Dennis
PS it would be extremely inforative to spin Lister-oid flywheels to distruction. Different  brands, foundrys, alloys etc.
« Last Edit: August 17, 2006, 12:39:18 AM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

mobile_bob

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Re: Pulling the shaft on an ST head?
« Reply #6 on: August 17, 2006, 08:30:51 AM »
"PS it would be extremely inforative to spin Lister-oid flywheels to distruction. Different  brands, foundrys, alloys etc."

what would be the purpose,, i doubt the indian metallurgy is exact enough to get any useful data.

if you tested 10 from a supplier and they all passed the next 10 might be better or worse,,

staying within the engines rpm parameters, i am unaware of any failures,, have you heard of one failing at the design rpm?

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

snail

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Re: Pulling the shaft on an ST head?
« Reply #7 on: August 17, 2006, 09:01:39 AM »
Quote
"PS it would be extremely inforative to spin Lister-oid flywheels to distruction. Different  brands, foundrys, alloys etc."

what would be the purpose,, i doubt the indian metallurgy is exact enough to get any useful data.

Be great fun though!! :o Count me in!!!

Brian

listeroidsusa

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Re: Pulling the shaft on an ST head?
« Reply #8 on: August 17, 2006, 12:46:58 PM »
If you want to add a flywheel to the ST the simplest, easiest, and most cost effective way is to incorporate it into your pulley, like the SOM pulleys. I build these but due to the price of metal, machining, ect. they tend to be expensive to build. Alternatives could be found that will work on the shaft as it is.

Mike

dkwflight

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Re: Pulling the shaft on an ST head?
« Reply #9 on: August 17, 2006, 02:46:16 PM »
Hi
I was just wondering.
Right now I don't seem to have flicker issues with the 28/2 and 20k head turning 800rpm. The 20k head is very massive and the rotating weight will smooth the rotational surges I am sure.
Listeroidusa's heavy pullys seem to be a good start. But having chose an "L" section pulley and belt those pulleys won't work for me, unless he can change pulley size and style easily.
Has any one reported flicker issues with twins?
Thanks
Dennis
« Last Edit: August 17, 2006, 02:51:05 PM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

artificer

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Re: Pulling the shaft on an ST head?
« Reply #10 on: September 02, 2006, 11:02:58 PM »

I got a quote back from Associated Steel today on a 2 inch shaft of hardened steel shaft (exceeds 1045) with some custom machining (one end necked to 48 mm to direct couple with an ST shaft and the other end drilled for a pilot bearing to mount a flywheel and clutch... $465.00  :o

Why are you going with a hardened shaft?  Is it going to be used as a bearing surface?  I guess I can't figure out why cold rolled wouldn't work, and be a lot cheaper.

bitsnpieces1

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Re: Pulling the shaft on an ST head?
« Reply #11 on: September 03, 2006, 05:51:55 PM »
 I think a jackshaft would be better, because, you would be able to support the extra weight on it's own bearings instead of possibly overloading the gen head ones and use whatever aount of weight you wanted.  The truck axle sounds good, proven tough for torque.  Get a broken one and it should be pretty cheap. 
Lister Petter AC1, Listeroid 12/1, Briggs & Stratton ZZ, various US Mil. surplus engines. Crosley (American) 4cyl marine engine(26hp).

dkwflight

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Re: Pulling the shaft on an ST head?
« Reply #12 on: September 03, 2006, 07:08:26 PM »
Hi A jackshaft is mechanicly the same as putting weight on the engine shaft, I think. The belt drive between the engine and the load. I may put extra weight on the engine shaft too.

I fired the gen set up and carried the house load for a couple of hours.
I do have some flicker. My first step is to purchase one of those heavy flywheel pulleys made by one of the venders.
Thanks
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

bitsnpieces1

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Re: Pulling the shaft on an ST head?
« Reply #13 on: September 03, 2006, 07:41:26 PM »
  Same mechanical advantage for surging yes.  Putting the extra flywheel on the engine crankshaft or the gen head adds that much weight to the bearings.  Question is: How long will they last that way?  The jackshaft allows you to use heavy flywheels supported on their own set of bearings.  Also gives you another spot to drive some accessories if you want too. 
Lister Petter AC1, Listeroid 12/1, Briggs & Stratton ZZ, various US Mil. surplus engines. Crosley (American) 4cyl marine engine(26hp).

Rtqii

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Re: Pulling the shaft on an ST head?
« Reply #14 on: September 06, 2006, 11:49:31 AM »
Why are you going with a hardened shaft?  Is it going to be used as a bearing surface?  I guess I can't figure out why cold rolled wouldn't work, and be a lot cheaper.

I am hard on equipment. I intend to load the shaft down with up to 350 lbs of flywheel mass in the center of the shaft spinning at 1800 RPM, and while I will do my best to balance the overall shaft, the individual flywheels will not be balanced for this application. Also, I intend to drive loads off the ends and that means there will be twist on the shaft with the applied torque...

When I say I am hard on equipment it means I may well ramp up the speed several hundred RPM in experimental applications where 60 hz is not a requirement but high peak power is... This means not only increased operating speed, but also increased torque and the resulting twist and flex in the shaft. Given that the shaft is going to be 3 feet long I simply feel better going with better material.

Cold rolled may work just fine... Are you going to replace it for me if I break it? What about cover the damages and medical bills?

Well... Since you are not willing to insure it... I will.

 ;)