Advice on machinery choices

[skyler olsen]

Hi all,

I am new to the forum. I am a mechanical engineer in the non-destructive testing industry. The company I work for is wanting to evaluate options for a full fledged machine shop. This would include renovating all older machines (2 Bridgeport mills and a Cadillac lathe) and possibly selling them, as well as looking for CNC lathes and mills. We do a lot of machining and outsource most of the parts. We would like to move to a in-house system with capability to do outside work. We spent a total of $600,000 in machining bills (including material, mostly delrin and aluminum) in the last 30 months. I would like to know what the experts here think about this situation and what is the best plan of action. Thanks everyone for your input.

[DouglasR]

There are alot of variables that you haven't addressed. Part quantities. Tolerances. Complexities.

[skyler olsen]

DouglasR,

Thanks for the reply. I apologize for the ambiguity. Some details regarding our uses include:

• small batches (10-30) of small parts that would fit within a 5"x5"x5" envelope
• small batches (1-10) of larger plates (lets say 15"x15"x5" thick)
• all tolerances are within a few thousandths to one thousandths of an inch
• complexities of the parts vary
• materials include aluminum (mostly 6061 and 7075), delrin, stainless, carbon fiber, high carbon steel
• machining is done 3-5 days a week in these types of numbers with some periods where for three weeks the machines are run all day

Although this accurately represents our current situation, this doesn't necessarily represent what we are looking to accomplish in the long run. We are looking for machines that give us good tolerances for our short runs as well as the ability to turn up the use and get some local machining contracts for longer runs.

I am looking for your opinions on what machine(s) have/has these qualities (I am sure there are many) based upon your experience. I have a strong feeling that the money we have spent in the last 30 months would have paid for a machine three times over.

I hope this makes sense and again I appreciate your responses.

[DouglasR]

Skyler:

Hi! For what was spent on your machine bills, you probably could have bought at least two very high end CNC's. This is kinda like cars, ask the Ford guy and the Chevy guy and you'll get two different answers that both would serve you well.

For what you're doing and what you've spent, a mid-range machine like a Haas would probably get the job done and save you money. If you really wanted to go 1st class, a Mori (my preferred brand) or an Okuma would really bang out the work and have the added benefit of high resale value and support.

I have both a Mori and Okuma and even though they are both mid 80s machines (I've had them both since new) and they are just fabulous machines. They are super machines that are still supported by their respective manufacturers and still punch out superior work. They hold tolerance, and function now every bit as good as they did when new.

To be fair, I do not beat up on them nor do I neglect them. They are treated carefully and receive proper maintenance when needed. They reward me with years of service.

Hope this helps.

I also strongly recommend a Cad/Cam system, and begin learning this stuff now, while your other machines are still running. This way there is less pressure to get things out the door while you are learning. I also recommend using machinable wax or delrin/plastic for your prove out on the CNC's, as this will reduce the potential for damage until you become more familiar with the machines. I used to do training and did this for all the newbies until they got familiar with the controls.

[skyler olsen]

DouglasR,

Thanks for your response. I have looked briefly at the manufacturers you mentioned and feel as though they could do a great job. Thanks again for your input, it is greatly appreciated.

Skyler