Thread: CNC replacement for a Davenport screw machine

Our ASM department currently has 6 Davenport screw machines with 3 men setting up & operating them. Coming up real quick is the retirement of two of these men. We are facing the fact that there is not available in our area anybody skilled with Davenports that could be hired and also a profound lack of anybody willing or able to learn the machine.

We are looking at getting in some new technology to replace the screw machines but really have no experience in which direction to go.
Our jobs are quite simple. Brass under 3/4 diameter. Mostly rough form, finish shave, drill, knurl, thread roll and cut-off. Some cross drilling and back work needed on six parts. Part quantities are generally low, around 1,000 pieces per month but we do have several that are at the 10,000 piece per month level.

We would like to keep cycle times close to the Davenports, around 10 to 15 seconds. We hope to justify most of the cost of a new machine by set-up time reduction. Our current Davenport set-up time is 4-6 hours (down from 8-12 hours) but is still too long. We would need a machine that could be changed over in 30 minutes or less. This would enable us to run smaller lot sizes more frequently to reduce inventory.

I am assuming some kind of swiss machine would be a likely candidate. If anyone cares to post a few names of machine builders to investigate, it would be greatly appreciated.

Thanks...Blaine

Get hold of Dan Murphy at REM Sales - Posts here as SwissPro. He'll steer you right, and he's a damn fine fellow to boot. REM carries the Tsugami line of swiss machines.

Member here = Milacron has (last I knew) a "CNC Davenport" for sale.

Yep - here it is = ***Link Here***

I never was quite up to speed as to what part of this machine is CNC, and so I don't know how that will help your change-over times. ??? It may be a decent compromise between where you are and the single spindle option. ???

Also - another option is to advertise for replacement help in S Michigan, N Ohio, and N Indiana. There are many out of work Davenport operators here looking to relocate.

Of course the small CNC lathe is an option as well. If you don't require long skinny lengths (you are currently running Davenports) then you may want to check out the EMCO 425 (420) CNC lathes as well. They will run two identical parts on the same machine at the same time via two main and two sub-spindles. Capacity to 1". Not sure if they offer any live tooling or not?


Learned new today = the meaning of procyon. (dang star gazing hippys )


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They're closing down the textile mill across the railroad tracks
Foreman says these jobs are going boys and they ain't coming back
Ox

I don't think you will be seeing those 10-15 second cylce times. Just guessing, your cycle time woud have to at least double if not triple on a cnc lathe with the operations you listed. But with brass you could easily run lights out with a bar feeder. The Emco's Ox mentioned woud be a slick or a gang style cnc lathe. Just swap out the tooling plates from job to job. Change over would be minutes.
http://www.hardingeus.com/index.asp?...rodID=28#SPECS

Originally Posted by Ox

Member here = Milacron has (last I knew) a "CNC Davenport" for sale.

Yep - here it is = ***Link Here***

Is that the one I saw on ebay with a pretty lady for the thumbnail pic? That must have been better than a year ago, maybe longer.

Tim

While it can be a challenge to get those cycle times, it's not impossible at all. The right machine can put up to 4 tools in the cut at once. Other machine configurations offer more tooling stations which would afford keeping multiple jobs set up. There are some form tools available for CNC Swissturn machines, but the primary feature of them is to add flexibility by using programmed toolpaths and standard tooling to make forms rather then using special tools and cams.

Look at a Star SR20-RIII machine for it's fast cycle times using program optimization and extremely tight tolerance holding. It can't put a drill in the front while turining and O.D. though. A Maier ML-20D can though, and that helps a lot with cycle time. I used to program both and preferred the Maier for it's cool 3-channel programming and synchronized drilling/boring while turning or even threading an O.D. Very cool. Those are sold out of Massachusetts, not far from you. I can connect you with the right people to see one in action.

One caution is that running brass in a guide bushing machine requires tight-tolerance stock or centerless ground material. Do you currently grind your brass for the Davenports? If the budget is generous and those cycle times are critical, look at a CNC multispindle such as an Index. Big bucks though.

Thanks to all for the quick replies.
Got some good info here. Will check out
the recommendations.

PixMan- we do not run ground / precision brass. We would like to keep it that way. As far as a budget goes, could we get something in-house for less than 200K?

Originally Posted by Ox

Member here = Milacron has (last I knew) a "CNC Davenport" for sale.

I never was quite up to speed as to what part of this machine is CNC, and so I don't know how that will help your change-over times. ??? It may be a decent compromise between where you are and the single spindle option. ???

Never knew quite how that thing worked either, but here's a pretty good explanation on the exact machine Don has for sale. http://www.mmsonline.com/articles/ca...your-shop.aspx

Originally Posted by newg3

Thanks to all for the quick replies.
Got some good info here. Will check out
the recommendations.

PixMan- we do not run ground / precision brass. We would like to keep it that way. As far as a budget goes, could we get something in-house for less than 200K?

If you don't run ground stock, no problem but you will want a slightly different kind of machine. Both Maier and Tsugami have "non-guidebushing" Swiss machines. They're recommended only for making parts of about 1x to 2x L-to-D ratio though. You can get away with longer parts as long as they don't get too long & thin. The machines will still use magazine bar loaders, and are FAST.

You should be able to get a very good piece of kit for under $200K.

The Maier Series MLK is a non-guidebushing variation, and can get very near a multi in cycle times with intelligent programming. I don't see mention of the MLK "Hybrid" variation on their website, but it's much like the "D".

http://www.maierusa.us/series_d.htm

The Tsugami line also has many models that can be run in either mode. I'm sure SwissPro (Dan Murphy) can explain which models would work best for your applications.

I have a customer with a early 80s Index with live tooling, IIRC it is a 50mm but certainly at least 25 mm, big machine, he bought it a few years ago and set it up but never found work for it so I suspect he whould be happy to sell it. Old machine but it came out of a medical parts maker and probably only ran brass all its life.
Let me know if you want me to check it out. Remember I said early 80s

Originally Posted by surplusjohn

I have a customer with a early 80s Index with live tooling, IIRC it is a 50mm but certainly at least 25 mm, big machine, he bought it a few years ago and set it up but never found work for it so I suspect he whould be happy to sell it. Old machine but it came out of a medical parts maker and probably only ran brass all its life.
Let me know if you want me to check it out. Remember I said early 80s

Brass all its life? Sounds like a used car guy with a 1988 Buick that "a little old lady only drove it to church on Sundays". Most medical parts I've made were stainless steel, titanium alloys or cobalt chrome. All a tiny but harder on a machine than brass. I think.

Welch Allen, exam instruments, all plated brass. Lots of tube, bell nuts, knurling, basically very nice flash lights

Funny - it was posed to me yrs ago jist the opposite.

Had a local guy tell me about a B&S that he got. It was SWEET! Had ran nothin' but stainless all it;s life!

In this sence - the spindle has never been spun up, the index had clicked over many less times per hr as it would have with alum/brass. Don't have all those brass slivers up into every nook and cranny that even B&S didn't realize the machine has. etc....

A brass or alum machine has had the piss ran out of it! Maybe not much torque on the tools, but otherwise it will be MUCH more shot than the slow/tough materials would have left it.


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Think Snow Eh!
Ox

http://www.miyano-usa.com/products.a...0%202-3%20Axis

These miyanos ain't too bad, but you'll never get the pph or tool life on them as you will a Davenport.

You could check out the Davenport HP.
http://www.davenportmachine.com/prod...y.asp?prodid=1

Too bad it's a long drive or, I'd be happy to entertain the thought of keeping those machines running for you.

Originally Posted by metlmunchr

Never knew quite how that thing worked either, but here's a pretty good explanation on the exact machine Don has for sale. http://www.mmsonline.com/articles/ca...your-shop.aspx

FWIW, my LS 522 never ran anything but brass...company made small pneumatic and water connectors. Looks pretty much like new on the inside as well as the outside. Vidmar cabinet with lots of tooling goes with it too.

Originally Posted by Ox

A brass or alum machine has had the piss ran out of it! Maybe not much torque on the tools, but otherwise it will be MUCH more shot than the slow/tough materials would have left it.

I suppose that's true sometimes, but not in the case of mine. I know this from conversations with ex employees who ran it, and just the way it looks inside.

Well Davenports run brass 24/7 for yrs on end anyway. Yours is so new that it hasn't had the chance to be anything but worn "in" at this point.


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Think Snow Eh!
Ox

Originally Posted by Milacron

I suppose that's true sometimes, but not in the case of mine. I know this from conversations with ex employees who ran it, and just the way it looks inside.

Hex Brass at high RPM is new every 2. You should be looking at your spindle bushings every 2 years.

12L14 hex any RPM is new every 2. for your spindle bushings.

Round stock you should get away with 3-5 years.

These are considering 50 - 60 hr weeks at 90 to 96% up time.

Check turnbuckle ends and pins for slop every 6 months no matter.

There is much more, but I'll not bore you.

Thats just my personal guide on maintenance checks for these machines if it helps.

Back to the original question, there's a company just outside Hartford, CT called Nowalk (I believe) that makes a retrofit for Davenports - exactly what is retrofitted my memory is a bit hazy on.
No connection, except I bought my horiz mill from them.
I may, possibly, still have their contact info - if needed I'll check.

Anyone that runs Davenports should be very familier with Nowalk. ???

I even have some of their chucks on a 2" Acme. They will last longer than I will, but they like to stick a bit when first cycled from sitting for a cpl days or more untill they have a a cpl 100,000 cycles on them each, then they seem to not be so much an issue.


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Think Snow Eh!
Ox