Bench Machine or Full sized, CNC or not?

[Compufobia]

I appologize for my newness in this but I'm attempting to break into the manufacturing industry with my business, and in doing that I have a handfull of parts that I want to make of machined Alu. 1/4 plate. What I'm hoping to get some advise on is what is the minimum machine that I can purchase to make these parts? Ive got a cut out of a portion of the Bluprints that I will Post here as well. I'm certain that the mostly direct cuts will be no problem but its the curves that worry me. There is a full CNC shop nearby but Id like to be able to do as much of work as possible in my own shop.

[aus-newb]

All depends on tolerances and quantities. However I would consider getting it water cut and then just drilling the threaded holes.

Craig

[Verfur]

how many difrent parts and quanitys of said parts?

Oh whats the radi of the curves?

John

[Compufobia]

wouldnt a water cutting table be expensive? I have no doubt that I will need a milling machine for some of the other parts that I am making so I'm hoping to get away with just purchasing one machine to do the whole operation with. the tolerances need to be fairly close but the part does need to be pretty when finished, it is ging to be highly visable. Oh and I guess I'm not certain on the radi of the curves, they are really just for appearances. there are 9 parts in total ranging from simple straps and a plate with slots and pass-through holes to a single part that is almost certainly going to have to be CNC as it is made of 1/2 aluminum and is a ver 3d sort of thing, I dont have the bluprint for it yet so i cant post it yet, but I just want to be able to do as much as cheaply as possible. I hope to make many of these, but it all depends on how many I can sell I suppose. I will start off small and as I grow make more, Id say its comfortable to be able to make batches of 10-20 a month for the next year or so at best.

[ViperTX]

You don't show a radius for the larger curves.

Basically, CNC is the best way to go it would be much faster.

You could use a manual mill (even a mill drill that had greater then 8 inches on the y-axis. On a manual mill you would cut the larger curves by using a boring head or a fly-cutter.

Also most of your dimensions are 3 decimal places so I'm guessing that you need +- 0.001, so at a minimun you'll need a manual mill with a DRO.

[Verfur]

looks to be about three ops with mutiple tools, so I would sugest that you have a machine that would change its own tools.

Personly I have acsess to a waterjet machine and that is the way i would do it.

Then use a standard mill (bridgport) to put in the screw holes. Just show you what your up against in the feild it would take about eight minutes towater jet cut and just a few minutes an a mill.

But the hole part could be made on just a standard bridgport mill with a rotory table.


hope this helps

John

[Compufobia]

How much would a water jet machine cost that would do that sort of work? what sort of finish would that leave on the cuts on aluminum?

[Verfur]

new i would guess in the $100,000 check out Omax water jet small machine. I seen a small used one go for $50,000. as far as finish it I would say around 50u'aa with no heat distortion. i would drop in a vibratoy machine and smouth it up or use some sadpaper on the sides. And yes you could leave I higher finish with a good cnc mill.
And after the intial tooling,fixturing the mill would be as fast or faster. the set up is for small number of parts and cutting hard to cut alloys (inconel, tool steel exct.) is where the water jet realy makes good money.

John

[Ken_Shea]

Not sure if there are any specific answers for you at this point, there are just too many variables not mentioned.


Some things to consider:
It does not take a particularly heavy machine to machine aluminum, this particular part is not complicated, however, to machine accurately and quickly you need a rigid, accurate machine with good tooling and the ability to use it and cad/cam software. The problem here is that we all have constraints in regards to time, money, ability, commitments and room to put and operate larger machines. Humans have a great capacity to turn a want into a need, I know from personal experience so, you need to ask your self, in all honesty, is this really the time to build or purchase a machine and all the other necessary related items or would I be better served at this point to just pay someone to do these and work towards getting a machine at a later date. I am not sure if the "handful of parts" is the total quantity to make or describes the quantity of parts to make many of. In house manufacturing usually works out for the best but not always. It takes time to learn to use equipment as well as learning to use Cad/Cam software. There is software out there that makes the learning curve shorter and print to part time shorter but it can be expensive. Other things, perhaps more important to your business can suffer when time is diverted to using the new equipment.

The curves are not a problem with a CNC mill, this part could be done on a manual machine, of course it would take much longer.

Ken

[Compufobia]

Yes its 9 diffrent parts in a set but some of the parts are repeated up to 4 times in a set, they are for computer cases that I'm making. at this point I really dont know how many I will be able to sell. I do have access to a non-cnc digital milling machine and i have a handful of friends willing to help me in learning how to use it and such, but at the end of the day i would like to be able to have my own equipment and I'd like to keep costs down as much as possible. I'm thinking that I should be able to machine out the parts as much as possible then any sections of those parts that I can not do I will take to a CNC shop to have finished.

[Compufobia]

the radius on that curve is 4.5 BTW. talked with the guy that is doin my drawings for me here.

[Verfur]

For the time being I would buy a used or inexspinsive manual machine and make my parts for the moment with the intent to convert it to a cnc retrofit or find a used EZ_Track cnc mill (factory cnc converson) but you still have to change the tools out by hand. To me this sounds like it mite be an option or the safest play would be to pay afew dollors and have the proto typs made and sold.


If you want just RFQ the Zone and alot of guys would quote it for you right here.

Thats realy cool no walking no phone calls and much cheaper than a walk in job shop i am way sure of that.


Good luck

John