Author Topic: Can I machine sintered iron similar to cast?  (Read 3286 times)

Offline mp43sniper

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Can I machine sintered iron similar to cast?
« on: June 12, 2018, 04:41:04 PM »
I found some 3" sintered iron casters at Tractor Supply and was wondering if they'll machine into flywheels ok or if I should avoid them. Don't want to grenade anything, but also don't want to pass them up if it'll work. I haven't made my patterns yet to cast my own from iron or lead and I really want to get my first engine built.

Thanks,
Craig

Offline crueby

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Re: Can I machine sintered iron similar to cast?
« Reply #1 on: June 12, 2018, 05:06:39 PM »
How do you tell sintered iron from cast iron?

Online Jo

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Re: Can I machine sintered iron similar to cast?
« Reply #2 on: June 12, 2018, 05:10:20 PM »
They make gears out of sintered iron. However there are many variations as to its composition and manufacturing process (compacting, sintering, re-pressing, re-sintering etc) which change the properties of the sintered material.

There is a lot of difference between looking to make a flywheel to run on a 300 rpm engine and one for a 8000rpm engine. I would personally prefer to use material of a known grade for anything that was going to be subject to high stresses.

Jo
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Online Jo

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Re: Can I machine sintered iron similar to cast?
« Reply #3 on: June 12, 2018, 05:14:09 PM »
How do you tell sintered iron from cast iron?

Sintered Iron looks to be made of particles, machines different too - sort of gritty.

Jo
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Offline mp43sniper

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Re: Can I machine sintered iron similar to cast?
« Reply #4 on: June 12, 2018, 10:57:58 PM »
I am just looking for (very) low rpm flywheel for my first engine (flame eater). Wondered about the machinability of sintered vs cast iron.

Offline Ian S C

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Re: Can I machine sintered iron similar to cast?
« Reply #5 on: June 13, 2018, 03:43:38 AM »
I tried turning the side off a sintered iron gear, it broke up. It was quite hard, and had worked without wear on a large photo copier for many years.
Ian S C

Online Jo

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Re: Can I machine sintered iron similar to cast?
« Reply #6 on: June 13, 2018, 07:00:11 AM »
I am just looking for (very) low rpm flywheel for my first engine (flame eater). Wondered about the machinability of sintered vs cast iron.

If you are having to PAY for them  :facepalm: I would look to buy cast Iron instead.

If they were free  :) I would say try turning them and see.

Jo
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Offline derekwarner

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Re: Can I machine sintered iron similar to cast?
« Reply #7 on: June 13, 2018, 08:27:55 AM »
Craig......if these iron casters were some surplus materials, one could wonder on the age?

Could they be old sand cast components?......the most common item I can think of were the tapered cylindrical [prisim] sash counter weights used in casement window assemblies

These were mass produced from raw grey Pig Iron with very limited flux treatment, and poured into sand mould trees

The final product was never machined and had a sandy inclusion texture. When machined, the high carbon content is immediately apparent

Tipped tools are not recommended for this material....plain HSS being the only option

Derek
« Last Edit: June 14, 2018, 12:25:42 AM by derekwarner_decoy »
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Offline Zephyrin

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Re: Can I machine sintered iron similar to cast?
« Reply #8 on: June 13, 2018, 09:51:25 AM »
Quote
sash counter weights used in casement window assemblies

I do have a pair of such weights...as new !
I can't count the number of lathe tools I've ruined on those...I haven't tested mill bits, I'm not that dumb !

Offline Jasonb

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Online Jo

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Re: Can I machine sintered iron similar to cast?
« Reply #10 on: June 13, 2018, 11:19:11 AM »
It would be cheaper to by a similar sized cast Iron flywheel and there would be no question about the quality

Jo
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Offline Jasonb

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Re: Can I machine sintered iron similar to cast?
« Reply #11 on: June 13, 2018, 11:26:07 AM »
If you can find them for less, Martin Model want $20 for a 3" CI flywheel

Online Jo

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Re: Can I machine sintered iron similar to cast?
« Reply #12 on: June 13, 2018, 11:33:33 AM »
From £7.50 on Fleabay.

Jo
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Offline derekwarner

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Re: Can I machine sintered iron similar to cast?
« Reply #13 on: June 13, 2018, 12:12:47 PM »
American sales people are well known for using material descriptions beyond the limits of the imagination :facepalm:

I doubt any manufacturer would consider a Sintered Iron production method for such a [wheel]  item........sintered iron would require significant post manufacture heat treatment to attain any such impact rolling resistance

If the wheel was cheap $....my bet it would machine with characteristics similar to grey iron  :DrinkPint:

[Apart from this, the bore, OD and major face diameter have already been pre machined] so suggests the machinability of the iron  :ThumbsUp:

Derek

« Last Edit: June 13, 2018, 12:29:46 PM by derekwarner_decoy »
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Offline Jasonb

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Re: Can I machine sintered iron similar to cast?
« Reply #14 on: June 13, 2018, 12:23:48 PM »
From £7.50 on Fleabay.

Jo

And postage to the US?

The caster is also less than £7.50 ::)

Online Jo

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Re: Can I machine sintered iron similar to cast?
« Reply #15 on: June 13, 2018, 01:04:02 PM »
That was just an example. Normally castings are much cheaper in the US than in over taxed UK :facepalm:

Jo
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Offline bent

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Re: Can I machine sintered iron similar to cast?
« Reply #16 on: June 13, 2018, 07:17:03 PM »
I'm tending to agree with derek, any powder-metal part is going to have strength and brittleness issues, unless some time in a sintering furnace with impregnation/infiltration materials (copper, nickel) is done.  Furnace time is not cheap, nor are the infiltration metals.  I'd be willing to bet the caster is just grey iron, so for $10 why not try it.

Another minor problem, that caster likely has a fairly large i.d. bore to hold a pressed-in wheel bearing.  Not a big deal if you are ready to machine and press a tight fitting steel plug and remachine to your desired bore size.

I've been pondering buying a decent ladle to melt pewter (or zamak?) and cast my own flywheels.  Lead would work too, but I don't like poisoning myself.  Or making built-up spoked wheels from pipe, of which I have access to a lot of.


I have a couple of engine projects to work on, but I've been too tired lately, having to do a lot of real work (sorry for the curse word).  We're doing R+D on a large cast iron valve, requiring a number of build/rebuilds) which means moving heavy parts around and big wrenches and bolts and impact tools.  Then one of the hoist rings got a buggered screw from a poorly tapped hole in the casting, and needed a new bolt with a machined e-clip groove.  No biggy, grab a bolt from the bin and turn the groove on the lathe...until a stray chip came over the top of my reading glasses and into/onto my eye.  No  lasting damage done, but it gave me pause.  I need to find some decent safety glasses with about a 1.5 diopter lens on them...or buy or make myself some leather side and top shields to fit a pair of readers.

Offline Ian S C

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Re: Can I machine sintered iron similar to cast?
« Reply #17 on: June 14, 2018, 10:26:36 AM »
The retail engineering supp[y shop in Christchurch that I normally use has safety glasses in a number of magnifications to at lest 2.5, tinted and untinted, with side shields. You shouldn't have any problem finding some specs.

Offline Tennessee Whiskey

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Re: Can I machine sintered iron similar to cast?
« Reply #18 on: June 14, 2018, 03:27:50 PM »
Lowes carries safety readers also

Cletus

Offline bent

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Re: Can I machine sintered iron similar to cast?
« Reply #19 on: June 14, 2018, 04:27:14 PM »
Yeah, yeah.  You know the problem, though - I'll have to have a pair for work, a pair for home, and a spare pair in the car and another spare in the other car, then I'll lose track of all of them and buy another pair, only to find the missing ones atop my head....you know, just like regular glasses.
 :Lol:

Seriously, thanks Cletus, I'll have a look in the local hardware store today, I've been "getting away with it" with my regular readers for too long.


 

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