Use Machine Shop vs. Buying Machine

[imp22b]

I work in the maintenance department of a "paper processing" company with 120+ employees. Currently we send any machine work we need done out to a local machine shop. This is usually 2-4 (sometime more) pieces a month. Most of the work is modifying an existing metal block or making a spacer etc... Most of the the work is fairly simple.

I am trying to find out if it would be worth it to buy a mill or etc.. or keep using a machine shop. Currently the only things we have in our shop is a junk Jet drill press, a vertical ban saw, a horizontal ban saw, welders, and plasma cutter. We would still send out the "big jobs" but for emergency repairs and making spacers and the little things. I don't think its worth the trouble of having to drive 10 min to a machine shop then having to drive back a few hours later to pick a part up.

What are your thoughts on this?

I'm new to machining and don't really know how much they change per hour to do work. I have been told the main reason we don't get a mill is the cost of tooling (bits and etc..) and that our time (the maintenance dept's) is worth more. I don't believe that... Hell, I work 3rd shift and sit around the shop 1/3 of the time anyways, might as well get some machining done.

[Caprirs]

A point not mentioned often times is farming out the work also farms out the liabilty of screwing up. If your company buys a mill and you make a mistake while using it, your company will pay you twice to make one part. If the outside vendor errs, your company still only pays once.

Tools, tool holders, and work holding can accumulate in a hurry also. I have 45 tool holders originally purchased for average $100 each including retention knobs. I also have 7 vises which were $350 each. This does not include actual cutting tools. Then there's the coolant and way lube. The related compressed air plumbing and wiring. So, the related stuff to make a machine usable is not insignificant.

[Zumba]

With such a low quantity of parts, it's going to take years to pay off the investment. Estimate $8K alone for a decent mill setup.

I find that a lathe is just as important as mill, so double that.

[cdlenterprises]

Don't forget the cost of the learning curve. If you don't have any one that has machining experience you can expect more than your fair share of broken cutters(pronounced machine repairs) and scrap parts.

[Geof]

I think you need to read between the lines; or at least read the last line: "I work 3rd shift and sit around the shop 1/3 of the time anyways, might as well get some machining done." I think what imp22b is looking for are some good arguments to present to the bean-counters to justify getting a machine to play with during the quiet of the 3rd shift. You-all are not helping coming up with reasons why it is not a good idea; whose side are you on? The Bean-Counters!!!

[Zumba]

Actually I'm on his side.

I know what these bean counters are like. They're always hesitant to invest in new ideas, and when they do, they expect an immediate return. If imp22b requires $10K down, he'd better figure out a way to make all that money back in 4 months. Too much pressure if you ask me.

It's a job. Sitting around is a good thing.

[excelerate]

Hi I'm in a situation not too unlike this one. It's all in the pros and cons; if you get enough machine time, in a few months you will be able to compete with the outsourced guys on the small easy stuff, but with a greater turn around. I also point out that to pay a contractor you must add on the taxes. You need to earn $1.50 to pay $1.00 (depends on tax rate) and office costs too often left out. Basic tooling is not a big deal. If a production machine is down for something simple; organising, driving, pick up and fitting costs heaps. If you can do it yourself, minutes, I've had machines for something as simple as a washer or small shaft, down for a long time; sometimes contractors cannot just drop what they are doing. I am now logging all my work to put a proposel for a cnc machine. We are all manual at the moment. it's not just now, I'm looking to the future, more capability will mean better performance with less. But if we don't start now we won't have the skills to move forward; so even if it's not justified now it may change a lot sooner to be the best thing you have done!

Look for another thread asking which cnc machine should I buy in the near future. :-)

[RGeo]

I feel that there are benefits of machining in house that are far less obvious, such as: When you have the ability to manufacture your own parts, you not only gain control of many downtime situations, but you suddenly become aware of improvements to processes that you would have otherwise overlooked previously.

I find this to be true concerning electrical controls as well. A few well placed rungs of ladder logic can represent seconds or even minuets of reduced cycle time. Of course initial productivity is not the only benefit of upgrades; safety, ergonomics, reduced rework, uniformity, and many other areas can be improved upon when maintenance personnel take a more active roll in the manufacturing process.

[widgitmaster]

My vote is get yourself a fully equipt mavhine shop in house!
If the business uses extensive machinery to produce their products full time, then those machines will breakdown over time, when not running, they are not making money!

A shop can be acquired a little at a time, and the most expensive items should be obtained first! Like a lathe proportionate to the machines you are using, and a bridgeport mill. All the accessories and attachments can be obtained as used items on eBay for much less than new!

As stated earlier, the current processes being used can be improved upon by making things a little better as they are repaired! In time, the machine shop will be vital part of the business!

[RGeo]

I would say skip the bridgeport and go straight for a small used CNC.

By the time you buy boring heads and all the tooling to make a conventional bridgeport worthy enough to produce the specialty parts that may break, you could justify a CNC.

Additionally the part programs can be saved, for future runs or improvement modifications. Go with a CNC mill, you can usually start off with a conventional lathe and make a judgment call on that issue later.

[excelerate]

I have just been to a trade show here in melboure australia. I was ammased at the ammount of cheap mannual machines that was on offer. a reasonable size lathe and mill can be had for arround $10 000 ea brand new. basic tooling wasnt that expensive, for a reasonable sized company we are not talking big dollars it wont take huge cuts and live to long but with care they wont fall apart. I have not had nc exp but most jobbing shop still have manuals too. i think these would be a exelent place to start.

BTW..... have some great glossy mags to show the boss
Mmmmmmmm cnc lathe look what i could do with this boss!!!!
can i have one can i can i pleeeeeese!
(probably tell me to bugger off and stop dreaming)

[RGeo]

I've heard that you can pick up new Fadal vertical machine center w/o covers for around $20k. I would imagine you could pick one up used for less.

Try cutting a piece with a bolt pattern on a manual mill, okay. Try cutting an odd pocket or a groove for a gasket seal and your going to likely take two days, so much for reducing down time. Try to thread mill an odd diameter hole like many mfg’s will use, or a cam………. I could go on and on.

You can do a lot with a properly tooled manual mill and an ace machinist. There are many other things that arise you can’t. Having a CNC wont preclude the need for skills by any means, but if you screw up a part on the last operation, you will fix the program, reload a new billet and press go. If you trash the manually made part, you will start over completely.

Get a CNC VMV!