[popspipes]

I am looking for 2" or 1.5 aluminum discs suitable for engraving, I can find 2" stampings but I dont think those are dead flat suitable for engraving etc.

I was wondering if someone on the forum has researched this or has any ideas as to what I could use? These are for my daughters special ed class students, name on one side and the school logo on the other.
most of the ones I have found are .020 thick, and I would like something .063 or .125 thick.

any ideas or insight appreciated

thanks

[Steve Seebold]

I would use .125 plate, double back tape it down, profile the shape and engrave it then peel the tale off. Or, profile it, anodize it then engrave it.

[MichaelHenry]

McMaster seels engraving blanks that might come close to what you want:

McMaster-Carr

though they are probably stamped too. They are pretty good about selling non-standard parts so it might be a good idea to call them, give them your requirements and see if they can meet them.

[popspipes]

Steve,
That would work, I have a soft jaw setup for the discs, I currently cut them from scrap ends of 2" round and engrave them for the kids etc, I just thought this would be faster if I need several.

Mike,
Thanks for the tip! Usually Mc Master is a bit high but on those 2" discs, they are only 12.65 for 50 of them .040 thick, I think its a typo but we will see.

thanks

[tmarks11]

Cutting the 2" round stock with a bandsaw, and than facing 0.050" off each side to clean up the cut edges seems like it would be the quickest and minimize wasted material.

[popspipes]

Cutting the 2" round stock with a bandsaw, and than facing 0.050" off each side to clean up the cut edges seems like it would be the quickest and minimize wasted material.

That is what I am doing now, I engrave one side then cut it off in the bandsaw, then carpet tape it to a a piece of faced stock, face the sawn side and engrave that side holding it in a soft jaw setup.
I think I will order some of the discs from Mcmaster , engrave one side, flip it over and do the other side in my soft jaw setup.

[AUSTINMACHINING]

I use the spring loaded engraver from Tormach, so the part doesn't have to be flat. you can buy pre anodized discs of various sizes off the web.

[Don Clement]

I would part the 0.063" discs off in the lathe from 2" aluminum rounds using Iscar DoGrip insert parting tool. I part thin aluminum discs all the time from round stock with excellent results. Below is shown parting off a 3.8" diameter disc.

I would hold the parted off 2"diameter x 0.063" disc in a 5C pot chuck that has a 0.05 lip. Shown below is a pot chuck I used to hold a 1.5" diameter part using only 0.05" lip. Held in the 5C pot chuck the part can be faced off in the lathe and then be held in an Eaglerock 5C fixture for machining in the mill. The following video shows a slitting saw operation with the part held on by the 5C pot chuck 0.05" lip. http://vid72.photobucket.com/albums/...f/100_3185.mp4

Don C.

Parting off a 3.8" diameter aluminum part


5C pot chuck with 0.05" lip

[CadRhino]

Very nice Don
The only part I don't fully get is the pot chuck. Did you make a custom 5c insert that acts as the chuck?

I would part the 0.063" discs off in the lathe from 2" aluminum rounds using Iscar DoGrip insert parting tool. I part thin aluminum discs all the time from round stock with excellent results. Below is shown parting off a 3.8" diameter disc.

I would hold the parted off 2"diameter x 0.063" disc in a 5C pot chuck that has a 0.05 lip. Shown below is a pot chuck I used to hold a 1.5" diameter part using only 0.05" lip. Held in the 5C pot chuck the part can be faced off in the lathe and then be held in an Eaglerock 5C fixture for machining in the mill. The following video shows a slitting saw operation with the part held on by the 5C pot chuck 0.05" lip. http://vid72.photobucket.com/albums/...f/100_3185.mp4

Don C.

Parting off a 3.8" diameter aluminum part


5C pot chuck with 0.05" lip

[ErnieD]

I would be wary of the McMaster blanks. I bought some brass ones and they were .03 - .04 convex/concave. When I called to complain I told the guy at McMaster that the blanks were concave and he told me to engrave on the other side. Very funny. I sort of fixed them by heating them with a propane torch and quickly dropping them into my mill vise and clamping as tight as I could til they were cold.

Ernie

[popspipes]

I would be wary of the McMaster blanks. I bought some brass ones and they were .03 - .04 convex/concave. When I called to complain I told the guy at McMaster that the blanks were concave and he told me to engrave on the other side. Very funny. I sort of fixed them by heating them with a propane torch and quickly dropping them into my mill vise and clamping as tight as I could til they were cold.

Ernie

Ernie,
That was my concern about the blanks they have, most stampings I am familiar with have the convex/concave shape to them, I have seen flat stampings with just a radiused edge but they arent as common.

[Don Clement]

Very nice Don
The only part I don't fully get is the pot chuck. Did you make a custom 5c insert that acts as the chuck?

Yes a pot chuck or step collet is machined in place to fit the diameter or shape of the work with either three 1/8" pins or a central pin in place. The pin or pins are removed after machining.

Royal Products

Pot Chucks for 5C Collet Systems - CNCCookbook CNCCookbook


http://hardingeus.com/usr/pdf/collet/2349.pdf

Don Clement

[SCzEngrgGroup]

Buy some 6061 sheet - the good stuff will come with a plastic protector sheet on one side, and that side will have a very nice brushed finish. It is also quite flat. Use double-sided carpet tape to stick a large piece to a flat plate or board, then mill out your discs (or whatever shape you need) - you'll have a couple dozen of them in a few minutes, for very low cost (4 sq. ft for about $25). Peel off the plastic, and do your engraving.

You can also buy pre-anodized sheets: 063 1 16" Dark Bronze Anodized Aluminum Sheet 5005 12" x 24" | eBay

Regards,
Ray L.

[vertcnc]

Yes a pot chuck or step collet is machined in place to fit the diameter or shape of the work with either three 1/8" pins or a central pin in place. The pin or pins are removed after machining.

Royal Products

Pot Chucks for 5C Collet Systems - CNCCookbook CNCCookbook


http://hardingeus.com/usr/pdf/collet/2349.pdf

Don Clement

Don.

Thanks for sharing, learned something new today.

[CadRhino]

Great
Thanks

Yes a pot chuck or step collet is machined in place to fit the diameter or shape of the work with either three 1/8" pins or a central pin in place. The pin or pins are removed after machining.

Royal Products

Pot Chucks for 5C Collet Systems - CNCCookbook CNCCookbook


http://hardingeus.com/usr/pdf/collet/2349.pdf

Don Clement

[Steve Seebold]

Mitee Bite has some stuff that would probably work for what you're trying to do.

Mitee-Bite Products Co. - Mitee Grip

It's a little on the pricey side if you're not doing a butt load of parts, but it will work.

[CadRhino]

Good idea. I didn't know about the pre anodized sheets.
After taping down wouldn't you do the engraving ops then cut them out saving another setup?

Buy some 6061 sheet - the good stuff will come with a plastic protector sheet on one side, and that side will have a very nice brushed finish. It is also quite flat. Use double-sided carpet tape to stick a large piece to a flat plate or board, then mill out your discs (or whatever shape you need) - you'll have a couple dozen of them in a few minutes, for very low cost (4 sq. ft for about $25). Peel off the plastic, and do your engraving.

You can also buy pre-anodized sheets: 063 1 16" Dark Bronze Anodized Aluminum Sheet 5005 12" x 24" | eBay

Regards,
Ray L.

[SCzEngrgGroup]

Good idea. I didn't know about the pre anodized sheets.
After taping down wouldn't you do the engraving ops then cut them out saving another setup?

You can engrave, then cut out, or cut out, then engrave. Either way, it's only a single setup.

Regards,
Ray L.

[CadRhino]

Ok got it. You keep them taped down the whole time.

You can engrave, then cut out, or cut out, then engrave. Either way, it's only a single setup.

Regards,
Ray L.

[Don Clement]

Good idea Ray to use double sticky tape and machine a pre-anodized aluminum sheet in a single fixturing.
I have a similar conundrum in making the flexures from 0.01" thick full hard 301 SS. Presently I cut 3/4" wide 0.01" 301SS strips using a paper cutter from 3/4" roll and stack 20 cut strips in a fixture to be drilled. I use a solid carbide drill. I have been experimenting using chemical milling with resist mask on both sides. I was thinking of using double sticky tape or a vacuum fixture to machine on the Tormach the flexures from a single sheet of 301 SS. I haven't machined full hard tempered 301 SS other than drilling. Anyone have experience machining 301 full hard tempered SS on the Tormach?

Don C.