# Resurfacing a flywheel



## Aukai (Aug 26, 2017)

The automotive shops I worked at used a flywheel machine with stones. Can a flywheel be cut with a fly cutter, or does this cause some kind of dynamic that is undesirable? Thank you


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## Bob Korves (Aug 26, 2017)

I would not attempt to surface a flywheel for an automobile myself.  Too many things can go wrong leaving the results poor.  It is an expensive part to replace and cheap to have it surfaced commercially.  If I had to do it, I would turn it on a lathe.  Flywheels are ground commercially.


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## Wreck™Wreck (Aug 26, 2017)

It is likely a species of cast iron, some of these materials are very difficult to cut and are ground for this reason. You may not be able to achieve the desired surface finish with a single point tool without much trial and error.

There is only one way to find out so just do it and see if it works, if it doesn't buy a new one.


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## T Bredehoft (Aug 26, 2017)

Take it to a shop with a Blanchard Grinder. That's what they are made for.


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## tq60 (Aug 26, 2017)

Back in the day when we repaired things it was easy as many places had grinders for just this.

Now not si much but still there.

The surface must be flat and true and one could possibly do one with a fly cutter with carbide but time and effort much where one could drop it at an automotive machine shop and it is done correctly for reasonable cost.

Do NOT mess with it.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk


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## Billh50 (Aug 26, 2017)

yep....have done a few through the years on a blanchard grinder. best way to do them


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## benmychree (Aug 26, 2017)

Yes, the best way is the use of a machine designed for the work, likely in a shop that does automotive work; when I started my machine shop in 1973, there was not such a machine in town, so I got lots of flywheels to resurface, at first, I did them in the lathe with carbide tools; most grades of carbide are not hard enough to do the job on flywheels with hard spots caused by overheating from slippage, and common on truck and tractor flywheels; for this I reserved one tool that also had an extra long shank so that recessed flywheels could be handled, it had a Kennametal K6 bit silver soldered on its end.
After that, I bought a used flywheel grinder made by Van Norman; it used a disc type wheel normally, but could also use a cup wheel for recessed flywheels, and also was equipped with a tool bit for roughing.
Back to using carbide tools for resurfacing flywheels in the lathe, I mentioned it being necessary to use very hard grades of carbide with respect to hard spots; when using softer grades, the tool would cut through the hard spot, but leave a raised shiny spot that could be felt with the fingers and seen easily and detected by dial indicator; the K6 tool would cut the same spots without leaving a raised area.
Finally the automotive shop in town bought a flywheel grinder and that part of my business evaporated, except for big tractor flywheels and I sold the machine that I had.


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## Ulma Doctor (Aug 26, 2017)

when i was younger, i worked for a transmission shop for in high school . 
we had Elby's machine shop that handled our flywheel resurfacing.
i watched the wet horizontal grinder many times do it's work on flywheels. the surfaces were satin and beautiful to look at


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## Aukai (Aug 26, 2017)

The store I worked at had the Blanchard grinder. Cutting with a tool, and the hot spots makes sense, just trying to see what is possible, I'll take that one off the list. This is what I have for my hot rod.


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## Silverbullet (Aug 26, 2017)

The real reason there ground is the heat generated from use makes the material super hard and it tends to wrap when ground there flooded with coolant to reduce the reaction of more warping. At least that's how it was explained in vokie 45 years ago.


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## benmychree (Aug 26, 2017)

Silverbullet said:


> The real reason there ground is the heat generated from use makes the material super hard and it tends to wrap when ground there flooded with coolant to reduce the reaction of more warping. At least that's how it was explained in vokie 45 years ago.


The coolant also keeps the dust down, an important issue.


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## GoceKU (Aug 26, 2017)

I've resurfaced couple of flywheels on my lathe and is not too difficult if you have big enough chuck or and cut crank to bolt the flywheel to the only difficult i've experience is chatter when the cuter hits the bolt holes for the pressure plate, here is a link i've recently used an old flywheel to make an drilling table : http://www.hobby-machinist.com/threads/shop-made-homemade-drill-press.60639/page-2


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