Resurfacing a manifold using an angle grinder - GIF

[Altair]

Resurfacing a manifold using an angle grinder.




Previously:

Flycutter resurfacing a motorcycle engine part - GIF
Fly cutting a cylinder head - GIF
Resurfacing an engine block - GIF
Laser removing oil from engine block - GIF

[mdhatter3]

How does he make it smooth and flat with no grooves from the grinding?

[Frank S]

How does he make it smooth and flat with no grooves from the grinding?

If you expand it to full screen and slow the playback speed to .25 you will see it is really a poor-quality grind advancing the Y plane too much each pass and taking too deep a cut in the Z axis, but this could be just a rough grind to level out any warpage, the finish grind may come later

[mdhatter3]

Thanks Frank. That’s possible.

[Hill Top Machine Works]

If you are going to go through all that trouble to build a fixture for the grinder, why not just mount a grinding cup wheel and go at it. Much easier and better finish?

[Toolmaker51]

Getting decent surface with either cup wheel or periphery of a disc unlikely in that set-up. Fault not so much in the wheel, its the interrupted cut amplified by lack of dampening/ rigidity. Only the ends have any apparent degree of clamping, in same plane as cutting action. Each exhaust port (thinner cross section) and section of tubing are creating un-dampened harmonics. It's visible right in the toolmarks.
A simple remedy would add slotted fixture plate with sacrificial screws and nuts.
There are assuredly issues in the angle grinder's head bearings, depth of cut, wheel balance and true round diameter as well.

Real slap-dash hasty work, no sheathing over mill ways or lead screw. Anyone using rags probably also thinks facemasks work.
Instead, drape oil wetted newsprint or food wrap, using way lube as 'adhesive'. When done, roll up from outer edges to not spill detritus onto what was covered.

[meyer77]

Wouldn't the grinding wheel change diameter as it wears down, producing a out of flat surface?

[Toolmaker51]

Wouldn't the grinding wheel change diameter as it wears down, producing a out of flat surface?

Yes. Grinding wheels differ by grit size of course, angle grinder types are serious removal and shaping tools. Facing an object targets high spots and minimal contact with lowest areas, about 1/3 grit size bonded to release with less generation of heat that breaks down any wheel. Sure, there is an operation called form or plunge grinding using a profiled wheel, across thin sections. It's very predictable on a surface grinder. Reading the surface tells you when to redress the wheel, exposing fresh grains and restores roundness. An easy way to monitor it, simply a little cross hatching with a felt pen.

Can't think of any instance that occurs when someone other than Tuomas (here at HMT.net) is profiling to accurate layout lines with an angle grinder.