Fly Cutters

[saw]

This is very nice done, but I have to ask how have you made the surface? 

[Mayhem]

...Cheers Mayhem ,,,, I may do some drawings  ...

That would be greatly appreciated Rob and much less secretive than giving away the finish recipe!  Besides, a man of your skills could whip them up whilst having your morning cuppa 

[Rob.Wilson]

made a start on the cutter bar tonight , not too many photos .

The cutter bar is made from a lump of EN24 , needs to be tough , so here are just a few machining shots ,

fly cutter with TCT removing 1.5mm from said tough steel .


those intermittent cuts sure do make for a ruff finish 




still using the same tip in the cheap and cheerful fly cutter 


got most of the machining done ,






still a bit work to do around the tip area ,some reliving and a few rads here and there to tart it up.


Cheers Rob

 

[micktoon]

Rob, Only one problem here, I can not tell what is real and what is computer generated in your posts now lol................... I think the real one looks so much like the 3D version I just can not tell anymore    Saying that your 3D drawing looked very smart so that must mean the finished real one does too  ............. its reminding me of that film Tron, I think it was called ? 

   Another bit of tooling that is better than you can buy for your collection , Well done 

  Cheers Mick.

[doubleboost]

Just what i expected perfection
Mick
The ones with the tooling marks are the computer generated ones
John

[NickG]

Hi Rob,

Awesome work as usual, I just realised I missed a lot of the juicy bits on this thread, when looking on the iPhone I thought the photo of the real body was just a cad model and you hadn't machined it yet - must have skipped a page or something so just skimmed through on the computer!

I've been reading up a little on quenching and tempering as I need to make a couple of tommy bars, but then confused myself  So I want something tough, not brittle but not something that'll bend! I see you quenched at 800C then tempered at 240. From what I read on wikipedia (could easily be wrong!) you tempered at the sort of top end of a stress relief type temp , any higher goes into the TME range - or is that just for carbon steels? I don't have the ability to heat to 800C so can't really harden, but if I tempered mild steel without quenching would it make the material tougher or just anneal it? Or could I just try to get the things cherry red, quench then stick in the wifes oven at 220 or whatever to temper?!

On the carbide debate, I think partly like Norman said, for the model engineer it was probably in the past a no go due to small, low powered machines. The cutting forces are a lot higher with carbide and you need higher speeds to make it efficient and prevent the build up of swarf on the tip which can cause it to chip etc and give a crap finish.

My next question is, why do you need a super duper flycutter if the cheapo one gives you a finish like that on the parts of the new one?! Is it just because you want to put the collet thingys to good use or have you got a monster project in mind for it?!

[Meldonmech]

Hi Rob

                    Turned out well, a nice beefy and practical fly cutter, I hav'nt  got a carbide cutter, might make one for the 626.

                                                                                 Cheers David

[Rob.Wilson]

Thanks lads 

I've been reading up a little on quenching and tempering as I need to make a couple of tommy bars, but then confused myself   So I want something tough, not brittle but not something that'll bend! I see you quenched at 800C then tempered at 240. From what I read on wikipedia (could easily be wrong!) you tempered at the sort of top end of a stress relief type temp , any higher goes into the TME range - or is that just for carbon steels? I don't have the ability to heat to 800C so can't really harden, but if I tempered mild steel without quenching would it make the material tougher or just anneal it? Or could I just try to get the things cherry red, quench then stick in the wifes oven at 220 or whatever to temper?!

Hi Nick , I hardened the part at 800c and tempered at 240c  , 240c is at the low end of the tempering scale , the part is very tough but not brittle . I would not believe all you read on  wikipedia .

Not only dose the part need to be heated to the correct temp for hardening and tempering but it needs to be held at temp ,its no good just heating the part up to temp then quenching. Rule of thumb 1 HOUR PER INCH OF THICKNESS.

Forget mild steel ,hot rolled or BMS its has a low carbon content , and wont harden , it can be case hardened . So you would need to get hold of some steel with a higher carbon content . 

The house hold oven can be used to temper parts , have used it many times myself 

My next question is, why do you need a super duper flycutter if the cheapo one gives you a finish like that on the parts of the new one?! Is it just because you want to put the collet thingys to good use or have you got a monster project in mind for it?!

I wanted a no brainer quick project as my shop is still in a bit of a mess from all the upheaval of moving machines , also wanted to make use of an old arbour and at the end of it all have a  larger fly cutter for the new mill   , no plans for using the fly cutter yet ,but there has been many a time i could have done with a larger one , so its another job knocked off the list . 



Well its finished , being a lazy git I went for chamfers 



did the cutter bar relief .








Min about 5" dia cut


Max about 9" dia cut



Cheers Rob

[doubleboost]

The main body looks like a flying saucer against the black background with all the stars
It is out of this world
You will be able to use it to finish the 626 CNC 
John

[micktoon]

 Amazing how much better the bar looks than in the last shots of it not quite finished .......... good job your hand was in shot to give me a clue to what is real Rob lol . Top class job  :bow:and as you say another thing crossed off the to do list.

 Cheers Mick.

[Swarfing]

Rob i keep reading but can not see??????? How do you get that anodised finish look please 

[Brass_Machine]

Seriously? 

Sometimes I cannot tell what has been done in Autocad or what is real when Rob makes parts. That looks amazing Rob!

What did you do to get the finish? Looks like it was bead blasted? but what else?

Thanks
Eric

[awemawson]

I reckon Rob has bought a nickel mine and is experimenting with nickel plating 

[NickG]

Thanks Rob, amazing work there, looks like itll rip sime metal off that! what I meant was 240c for temper is low but if you'd have gone any higher you'd be into the TME "tempered martensite embrittlement" temp range where you actually lose ductility and make the steel more brittle? To get out if that range you'd need to go 370C. So your tempering at the low end will give a slight reduction in hardness / increase toughness but mainly be relieving internal stresses?

Thought I'd heard you need higher carbon content to harden, is that like EN8 or something? So heating with a blow torch would do no good as the heat has to soak through to the middle? Would it not even harden the surface? Guess that is case hardening to reduce wear on pins and such like, though for that you need some sort of powder?
Lol looks like I'll have to have bendy tommy bars then or make them from something tough in first place!

[Rob.Wilson]

Thanks Lads .

Just goes to show nobody bloody reads the post  ,,,,, I actually did said that I had gave the parts a satin Nickel finish 


Hi Nick

I get what your saying , I would not worry too much about martensite embrittlement .

What about using Chrome vanadium ?  cheep and easy to get if you no were , that would do the job .

Heating with a blow torch would be fine if you built a small furnace from a few fire bricks , you would need to use the mark one eye ball to judge the temp .

Rob

[NickG]

Ah good idea, maybe an bar from an old socket set or something. Could I machine it though!

[Rob.Wilson]

I was thinking a coil spring from a car /truck .

Ah good idea, maybe an bar from an old socket set or something. Could I machine it though!

Yes if you anneal it first ,

Rob

[NickG]

Nice 1, can but try. Cheers

[Brass_Machine]

...

Just goes to show nobody bloody reads the post  ,,,,, I actually did said that I had gave the parts a satin Nickel finish 
...

Read?? Who can read when they have been blinded by the brilliance of your parts! lol!!

[Swarfing]

Too right, sorry Rob totally missed it 

[NickG]

I read it Rob - seem to remember you wouldn't tell us how though ! 

[Swarfing]

Rob i bet your the sort of guy that does not polish his shoes? saves that for the bling in the workshop 

[Rob.Wilson]

  Cheers lads

I read it Rob - seem to remember you wouldn't tell us how though ! 

Correct    , got to have at least one secret ,,,,,,,,,,,,,,,,,,,, if it makes you feel any better I have not let  John DB or Micktoon into it either .  


Rob

[micktoon]

 He is telling the truth     and because I know Rob wont tell me I am pretending I dont want to know anyway  I bet John DB doing the same  .... as far as I am concerned there is nothing wrong with satin black spray can ...... or if the part is really special .....chrome look spray can 
   I think Rob should do some sort of raffle and the prize would be his secret recipies  
    Mick

[andyf]

Apparently, satin "nickel finish" rattle cans are available, too. But I'm sure Rob electroplated his, using an organic emulsifier in the electrolyte, like the professional platers do.

As for me, I can't even produce a finish that is worth plating...

Andy