Is this skim good ?

[W.olly]

Made a fly cutter last week. Happy with it but for some reason after seeing an engine block I had skimmed last year I wasn't thay happy then.

So I messed with speeds feeds and cutter and got it even better

But what should I be looking gat for a finish on a fly cutter?
This is a 155mm x 60 mild steel and took 8 mi s 40 secs to finish cut.

Very smooth. very little feel to the finger nail scratch test.

Got it within a thou over its length once I trammed the mill in aswell.

BTW. I am not going to be doing engine vlocks just want the best I csn get in a DIY Shed.

 

[Brad93]

is it flat, that's the factor if interest

 

[wyn]

That looks like it would probably bow a bit as you take material off.

 

[Seadog]

Try putting a small radius on the cutting edge. It looks rather pointy to me.

 

[W.olly]

is it flat, that's the factor if interest

That looks like it would probably bow a bit as you take material off.

Its flat to 1 thou. but only over the 155mm. doubt ill be doing anything much bigger as its only a Tom Senior mill. Used a DTI on it to check.

Try putting a small radius on the cutting edge. It looks rather pointy to me.

I did that before this ponity one and it was worse a finish. which i understand your comment on the radius on the point. Unless my sharpening was bad.

 

[mike 109444]

There you go

Surface Finish Gauges, Testers, Comparators, & Comparison Specimens - Rubert + Co Ltd

In cases where surface roughness needs to be measured with great precision, elaborate instruments must be used. These are expensive, and often unsuitable for workshop use, where roughness of machined surfaces can usually be assessed conveniently and with sufficient reliability using visual and...

www.rubert.co.uk

 

[brightspark]

Its flat to 1 thou. but only over the 155mm. doubt ill be doing anything much bigger as its only a Tom Senior mill. Used a DTI on it to check.




I did that before this ponity one and it was worse a finish. which i understand your comment on the radius on the point. Unless my sharpening was bad.

after sharpening the radius is very slight and can be done with an oilstone just to take the sharp edge off

 

[W.olly]

after sharpening the radius is very slight and can be done with an oilstone just to take the sharp edge off

thats probably it. i have a stone here, think it came with the wood chiseles i got ages ago, best i have, and no good.

Next investment then new stones

 

[brightspark]

thats probably it. i have a stone here, think it came with the wood chiseles i got ages ago, best i have, and no good.

Next investment then new stones

if your stones worn just rub it up on a concrete paving slab and it will be flat and good as new i have about 4 got them given and rubbed them, up

 

[W.olly]

mine is this type

https://www.ebay.co.uk/itm/16594785...kODSNoQzNwcYifebXyW92qJ/Lddl|tkp:BFBMjOnZv5lj

will that do. been told olive oil is good, got loads of that in the kitchen.

 

[brightspark]

mine is this type

https://www.ebay.co.uk/itm/165947859055?hash=item26a343606f:g:wQMAAOSwsLhj8qbr&amdata=enc:AQAIAAAA4D/Ta67luuD3QNcsDYHdU20cTcMTeqGEckh1tkF/Sk6fuAyZbCsiYKPh3HLzzIwsxfbZB+qjhYYP+50gH3MEGmnbfQSOLJ1EzF281x48Jbt+b1B3j9HZj0WRejow1xuwIxbtzR1ufh2z9GAF8paZP3GOhqJKc0Ei3vdhkLZdW0VRkKqV1RDpKx2xt4GMEsr5KBZFuKGtkki8bCWuvAQ1T/LxteUR2EcyuEGxpOEU3mEUv0p/KrsQvz37q/UrSrILt6QPzP6Wbi8AVb7lkODSNoQzNwcYifebXyW92qJ/Lddl|tkp:BFBMjOnZv5lj

will that do. been told olive oil is good, got loads of that in the kitchen.

it will do not my choice though pretty cheap i prefer the old quality carborundum ones second hand. if your feeling real flush buy an arcansas natrual stone one big £££

 

[Brad93]

Did you test the flatness on a surface plate.

 

[Brad93]

You want to lap the cutting edge and the relief faces super smooth and flat.

A nice india stone does a decent job, if you've got a diamond lap that's ideal.

 

[Erie Fred]

I'm not seeing any bounce.
Which is a good thing.

 

[Morrisman]

is it flat, that's the factor if interest

Theres no back cut showing, off the fly cutter, so it may be slightly concave.

 

[W.olly]

Thanks chaps, ill check it again properly for flatness tonight on my surface plate, although i dont know how flat that is. I can use a feeler gauge for that ?

And try again with newly sharpened tooling.

quit enjoying this just machining bits of metal, even though i am not actually making something.

 

[Brad93]

Thanks chaps, ill check it again properly for flatness tonight on my surface plate, although i dont know how flat that is. I can use a feeler gauge for that ?

And try again with newly sharpened tooling.

quit enjoying this just machining bits of metal, even though i am not actually making something.

blue the surface plate or use a dial indicator on a scribing block

 

[Wedg1e]

quit enjoying this just machining bits of metal, even though i am not actually making something.

Thing is, if you can see early on what can be achieved, you'll spot it quicker when it's not looking right in future.
A bit like when you think you can weld, then someone shows you how it's done

 

[W.olly]

Thing is, if you can see early on what can be achieved, you'll spot it quicker when it's not looking right in future.
A bit like when you think you can weld, then someone shows you how it's done

is that bit like me not having a bloody clue what your on about haha

 

[Chippie]

is that bit like me not having a bloody clue what your on about haha

W.olly, watch n learn, and most important, do….then you learn