dry ice deburing Delrin

[Crawling Calvin]

Anyone tried this before? I know the principle behind it is really simple, the dry ice freezes the burrs and then when they get hit by a non-abrasive media they get knocked off and hey-presto your parts are done

Ok that's the theory, does it work or is it just a good excuse to look like a mad scientist and put on your dorky laugh. Reason why I ask is I hate de-burring my rims due to all the tight spots on them and the burrs that seem to run forever! yes I have used the "scrape along the edge" trick and that's great till you get into the tight spots and your stuck!

I would be using a vibratory tumbler from Harbor Freight and prob some crushed walnut shells in there to act as the media along with some dry ice crushed up from the local grocery store

[crawl rookie]

Sharp polished tools seem to help me often

Edit: I realy don't think it would work, sorry

[losikid]

Liquid Nitrogen

[reddevildemo]

Seems like overkill to me. I use one of these http://www.spear-and-jackson.com/pro...ng-tool-blades

Works great for all materials.

[SMR 510RR]

I like to use a regular exacto on delrin. Try using a scraper or exacto and turn it 90 deg to the area you are deburring basically perpendicular and then just drag it along the edge. It will leave a nice sharp edge with a tiny chamfer, if you want all the edgeds to be chamfered then the best way is to chamfer them in the mill.

[Crawling Calvin]

This is what im up against I am cool de-burring thin sheet parts, that's easy as heck... if I could chamfer them I would program that into Gibbs but it isn't to easy as you can see...

[rmdesignworks]

Originally Posted by reddevildemo

Seems like overkill to me. I use one of these http://www.spear-and-jackson.com/pro...ng-tool-blades

Works great for all materials.

Thats similar to what I use on plastics and 6061...if the plastic burrs are really small try a disposable razor...

[Crawling Calvin]

I forgot to mention I have one of those things also. Works good except for the really small spaces down inside the rim. I guess I should get my self one of those tiny 3-bladed deburing knives and give it a shot with that?

[tom@vp]

id use a fresh exacto

[Eritex Inc.]

Try a Dremel tool and a buffing wheel or the nylon brush. After um-teen thousand delrin wheels I have found those work the best and the quickest.

Good luck

[Crawling Calvin]

Originally Posted by Eritex Inc.

Try a Dremel tool and a buffing wheel or the nylon brush. After um-teen thousand delrin wheels I have found those work the best and the quickest.

Good luck

Thanks Its the time involved de-burring Delrin parts like the rims that kills me. If I do get some dry ice I will give the idea a try and report back on it. Hey in the worst case scenario we got a nice excuse to fog the garage up

[Eritex Inc.]

Originally Posted by Crawling Calvin

Thanks Its the time involved de-burring Delrin parts like the rims that kills me. If I do get some dry ice I will give the idea a try and report back on it. Hey in the worst case scenario we got a nice excuse to fog the garage up

Another thing to look at is switching up your machining processes in order to minimize burrs.

[Crawling Calvin]

Originally Posted by Eritex Inc.

Another thing to look at is switching up your machining processes in order to minimize burrs.

Right, nothing makes burrs like dull tools! I just grabbed whatever end-mills we had kicking around but I can say this, they are nowhere near as sharp as my 3/16 3-flute Niagra aluminum cutting TICN coated end mill... that thing is sharp I think its time to invest in some of my own tools for plastic and let no one on them. Any tips on good end-mills. I was looking into 1-flutes but the price drove me away slightly. ive used up to 3-flutes {1/8" dia} in slot cutting just fine with a compressed air blast to keep the chips out with very minimal burring.

[tom@vp]

Originally Posted by Crawling Calvin

3/16 3-flute Niagra aluminum cutting TICN coated end mill... that thing is sharp

love those

[Crawling Calvin]

Originally Posted by tom@vp

love those

I was cutting some .090" thick 6061 aluminum today at 6,000 RPM and just about 36 IPM feed. I was shocked! I backed it down slightly so I wouldn't nuke it but the finish was still amazing considering it was an older Fadal mill. Something to be said about good tools and coatings! I noticed it used less HP {audibly} on my Sherline mill also. Hmm time to buy more of em

[tom@vp]

i dont think ive ever seen a better HSS em than niagra

[Crawling Calvin]

Originally Posted by tom@vp

i dont think ive ever seen a better HSS em than niagra

Ive tried:
some cheap import end mills {terrible... they were only $3 at Enco but in the greater scheme of life they were BAD!}

Accupro 1/8" ZrN coated Carbide end mills... made for aluminum, were OK but somehow they still managed to pack really easily, the only one I got now is on plastics duty till I get rid of him

then someone got smart and got the Niagra... I think I know who's getting my next tool order for some more 3/16" and 1/8" end mills.

Any faves that you want to share or that's a secret

[Dynamic Concepts]

I have had good luck using a short 1/8" 2 Flute Carbide end mill for machining both 1/8" 6061-T6 Al and 1/8" Delrin. I'm using a machining center, so i use flood coolant to wash away chips and keep the material and cutter cool.

The challenge for me it seems, is to be able to machine parts in a web quickly with minimal vibration, but keep the holding tabs to a minimum size and number. Then there is less deburring to do after the parts are torn off the machine.

[Crawling Calvin]

Originally Posted by Dynamic Concepts

I have had good luck using a short 1/8" 2 Flute Carbide end mill for machining both 1/8" 6061-T6 Al and 1/8" Delrin. I'm using a machining center, so i use flood coolant to wash away chips and keep the material and cutter cool.

The challenge for me it seems, is to be able to machine parts in a web quickly with minimal vibration, but keep the holding tabs to a minimum size and number. Then there is less deburring to do after the parts are torn off the machine.

I like using air, and only air for plastics {Delrin} but that's me. Anyone else feel free to chime in As for holding stuff down I have a custom plate for when I make my "Rocker" chassis. Ive found I can effectively hold a piece of .090" 6061 with 3 screws... while 4+ is good there's no WAY you can do Delrin with that few screws, it would chatter and leave a nasty finish.

At home I have a small Sherline mill with the 10,000 RPM spindle head on it and at the machine shop class I am in I normally steal our older model Fadal with a 7500 RPM max spindle. Sure its slower than the Sherline but lets face it, its got a ton more power

For now I am sticking with HSS and aluminum. The cost is pretty good and they take abuse so much better than carbide does. And when a friend drops your end mill it isn't AS big of an issue

[Dynamic Concepts]

Do you drill holes in the same machining process? I find I have to babysit the machine during the drilling process, so the Delrin doesn't build up on the cutter. I will have to try blowing air on it to see if there is a difference.

For your Fadal, are you using a G8 in your post while contouring? This eliminates acceleration, and deceleration. It's really noticeable in 3D machining on Fadals. They are great workhorses, but don't read arcs. I am referring to ones with the old FANUC controls.