Filing buttons

[Sshire]

Many works in progress mention filing buttons. They look very useful for rounding the ends of con rods, etc.
Can someone explain how they are made, sized, mounted, etc. and how to use them.
Thanks
Stan

 

[smfr]

Here's an example of filing buttons in use:



Normally you make them the same diameter as the curve you want on the part.

I made these out of drill rod (which was already the right diameter). They are about 1/4" thick, and have a 1/8" hole drilled in the middle, but you can alter these dimensions to suit your part (for example, you probably want the center to match the diameter of an existing hole in the part).

You can harden them if you like, via heat treatment (I haven't done that, so won't give details).

Then you make a spindle to hold everything together from bit of scrap; threading the ends to hold nuts is one way to keep things together.

Once all this is place, you can happily file away knowing that your file will stop at the nut before it chews away too much of the part (at least for the radius!).

What I'm not sure about is whether people generally file across the part, or along the part.

 

[tel]

What I'm not sure about is whether people generally file across the part, or along the part.

Either or both - whatever it takes.

 

[bezalel2000]

In the case where you are using unhardened buttons, the most effective direction to file is at 90o to the axal.

otherwise you get flat spots on the buttons because they don't roll when the file hits them.

but if they are hard enough - as Tel says - it don't matter

Bez

 

[modeng2000]

Do the hard buttons harm the file teeth?

John

 

[tel]

More'n likely - I never harden 'em, use them more as a visual guide than a mechanical one.

 

[don-tucker]

I usually turn them to the radius needed then turn a small spigot to fit the hole,once in the vise they won't go anywhere.
Don

 

[ShedBoy]

I have made a few sets now, never hardened any yet, as Tel says I just use them as a guide. Dam handy thing to have around and knocked up in no time.

Brock

 

[tel]

Oh yar! Use 'em once you'll use 'em forever. Here's a variation on the theme - single sided (one button) that screws to the workpiece.

 

[Sshire]

That is great! Thanks so much. I'm going down to the shop tonight to make the ones I need for now. Looks like a collection built as needed will be very useful in the future.

Couldn't figure out how to hold them to workpiece. All is clear now.

I'll be using drill rod. If I decide to harden them, do I just heat them to red and air cool?

Thanks again
Stan

 

[bearcar1]

Here's a variation to a theme of what Tel was illustrating. Using this method sure made the shaping of these pipe flanges a breeze.

BC1
Jim

 

[portlandron]

I have re-purposed ball bearings used as guides for router bits to filing buttons. After their useful life life as guides they will work just fine for that. They have small 1/8" center holes so I have made arbors with the outer ends sized for the bearing center hole and the center section turned to 1/4", 3/8" or 1/2" which seems to cover most of the work I am doing.

 

[peatoluser]

I used to use screws to hold filing buttons in place, but following a tip posted on this site by Dr Jo, I now turn a spigot and superglue them in place. works a treat and no fiddly nuts and screws to mess with.

 

[tel]

Here's some bigger ones in play

 

[Sshire]

Thanks again. Looks a lot faster than setting up the rotary table for one or two pieces. Looks like I have yet another small detour between engine parts. But, it seems like I always have a small detour between engine parts
Stan

 

[Ned Ludd]

Hi Stan,
Boiled carrot colour, then quench in oil or water, hardness not is not that critical. All you want is for them to be harder than the material you are filing. There should be no need for tempering, unless you are over zealous in your clamping arrangements.

They should not damage the file, as it will merely ride over the smooth hard surface, unless great force is used.
Ned

 

[ChooChooMike]

Cool !! Had never heard of this technique before. Once you look at it, it makes perfect sense. Simple and very handy !!

Mike

 

[mklotz]

Mike,

If this technique is new to you, you may want to read about filing rests and their use. A good start would be Steamer's thread...

http://www.homemodelenginemachinist.com/index.php?topic=16348.msg166531#msg166531

 

[ChooChooMike]

Thanks Marv, that filing rest from Steamer is pretty clever !