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Alternatives to form tooling on a HMC

316head

Aluminum
Joined
Jul 27, 2008
Location
finland
My employer is looking for a solution that would add turning-like capabilities to a machining center. We manufacture parts which have cavities of various shapes and diameters, the main application range being from 1/4" to about 2". The machine procurement process has already begun and we need to know the best options available. Currently the two viable options are

a) a programmable boring bar system (such as Ta-tronic from D'Andrea)
+ Accurate
+ Can do cavities small in diameter
- Expensive
- Radio control, how reliable is it?
- Are there manufacturers other than D'Andrea?

b) conventional boring where X and Y axis are synchronized with the spindle which kind of oscillates (looks fancy; there is a name for it but I forgot what it is)
+ Cheaper
+ Easier to program
- Not so accurate
- Probably cannot do small cavities as the axes would need to move at a tremendous speed.

No one I know have any experience with either of these processes so we are going in blind. Does anyone have experience with either of these or some other that should be taken into consideration and would like to share some wisdom? Much appreciated!
 
Could you expand on what accuracies are needed, what surface finish, etc? If the geometries are not too exotic (and if I understand the need, which I may not), then could ball or woodruff cutters and axis interpolation do the job?

A more specific example of the shapes you wish to make would help with suggestions.
 
Could you expand on what accuracies are needed, what surface finish, etc? If the geometries are not too exotic (and if I understand the need, which I may not), then could ball or woodruff cutters and axis interpolation do the job?

A more specific example of the shapes you wish to make would help with suggestions.

Hi,

http://www.dandrea.com/public/jpg/25b.jpg <- The shapes on the upper row are very close to "our" shapes. Also this is to replace the need for cavity drills and reamers, such as 10-Size 3-Way Cartridge Cavities for HydraForce Hydraulic Valves

Material is martensitic, stainless and case-hardened steel, in soft and hard stage. We use CBN inserts for hard boring, up to 65 HRC. Surface finish is Ra0.8
 
In the USA we'd call those ports, and frequently there's specific tools designed to cut the shape in a plunge operation, like a drill. But when there's undercuts or diametric o-ring seals you can't do that.

The cutters I mentioned (ball and woodruff) might be able to make most of the shapes you'll need as long as surface finish is acceptable (if there's sealing requirements). That's a matter of good machine dynamics, programming, and proper tool use.

How good (accurate) are your machines? Could you put together a library of roughing and finishing tools that would cut the shapes you need?
 
Woodruff cutters (we call it T-slot here in Finland) are in daily use. There is no reason to replace them. But ball endmills are real productivity killers, especially when it comes to hard milling conical surfaces. It is however the best way to get the required surface finish and yes, the surface acts as a metal-against-metal seal that has to withstand tens of thousands of PSI.

I don't think these programmable boring NC heads are in very wide use worldwide, although on paper they sound very sweet.
 
Boring mills can use a quill actuated contouring tool holder.

ZX Facing & Contouring Heads | ZX Systems by Cogsdill

Many machine builders can incorporate a U axis into their machines. I bought a used Makino had a U axis setup for a total 6 controlled axes. Servo motor and gear head mounted alongside the spindle nose. A zero-backlash coupler transferred the rotary motion to the U axis head(s) which could be handled by the toolchanger. It was pretty slick, but we had no use for it so it was removed and the machine re-configured as just a 5 axis.
 
My employer is looking for a solution that would add turning-like capabilities to a machining center. We manufacture parts which have cavities of various shapes and diameters, the main application range being from 1/4" to about 2". The machine procurement process has already begun and we need to know the best options available. Currently the two viable options are

a) a programmable boring bar system (such as Ta-tronic from D'Andrea)
+ Accurate
+ Can do cavities small in diameter
- Expensive
- Radio control, how reliable is it?
- Are there manufacturers other than D'Andrea?

b) conventional boring where X and Y axis are synchronized with the spindle which kind of oscillates (looks fancy; there is a name for it but I forgot what it is)
+ Cheaper
+ Easier to program
- Not so accurate
- Probably cannot do small cavities as the axes would need to move at a tremendous speed.

No one I know have any experience with either of these processes so we are going in blind. Does anyone have experience with either of these or some other that should be taken into consideration and would like to share some wisdom? Much appreciated!


As far as the "radio controlled" heads go, I think that BIG has them too?
Could be the same unit - rebranded tho too?


I don't know how accurate those are, but the old skewl version is an HMC or VBM type machine with a "U" axis.
Your boring head plugs into 2 different spindles at the same time. The ones that I have seen had a Cat50 for the main spindle, and maybe a Cat40 for the secondary spindle. The secondary spindle actuates the in/out of the head to produce hour-glass type forms and whatnot with a single point tool, which will Shirley git'chew a better finish and lesser perishables costs in most materials. I am sure that the U axis mills are built to order tho.

Boy, a search isn't turning up any pics of the old skewl version... I saw them on a cpl of smaller HBM's and I think I have seen a Cinci Maxim for sale once that had that set-up.

I did see a plug-in unit from the same company that you mentioned that had a cabled head, and possibly that is more reliable? Or just an older version of the current?



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