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When to fix old machines. (Brown and Sharpe Screw machines)

harjonmfg

Aluminum
Joined
May 26, 2015
I think this is a "Shop Management and Owner Issues" subject.
I would just like to hear people's thoughts on how to decide whether or not to put money into repairing old Brown and Sharpe screw machines or just old machines in general.

Here's my situation and opinion: all I have for production is 26 old Brown and Sharpes. They are all "G" machines (the ones they stopped making in the 50's). When I took over here in 2012, The machines were in a serious state of disrepair which made setup on the machines take much longer. It also made the machines less repeatable and much more prone to smashing up. Back then, most people told me that I should start switching over to CNC, or at the very least, start getting newer cam-drive machines. The way I saw it, most of the work I had could be produced on a Brownie with little or no secondary and I could probably repair all 26 machines for the cost of 1 new CNC machine and learn a lot about my machines in the process. That's that what I did and to make a long story short, I still wonder if I went in the right direction.

Are there any other Brown and Sharpe guys out there with an opinion?
 
Please excuse me if I'm out of line here, but I sure would like to tour your shop and see these treasures.
Stephen.
 
I'm not a Brown and Sharpe guy, but a spindle is a spindle a lot of the time. If you have real screw machine (x26) quantities of product, one whizbang swiss isn't going to outproduce all 26.

Fundamentally there's nothing wrong with cams or other hard tooling. Especially if you have a CNC and a CAM system banging out new profiles. It requires the right job, but that can be said for any piece of equipment.

For every paying 5 axis turbine impeller there are probably a thousand plates with eight holes and a million spacers.

Too many people go broke trying to chase sexy instead of dancing with the one what brung em.
 
Please excuse me if I'm out of line here, but I sure would like to tour your shop and see these treasures.
Stephen.

Haha. Come on down! There's actually quite a few screw machine shops like mine in the area. Not many left with exclusively such old machines though..
 
Not a Brown and Sharp guy, but I do have a few large (20+machines) Brown and Sharp shops as customers. Most are still using some G's. Quite a few Ultramatics, as well as servo-cams.

Several of them still don't own a single cnc. But they probably will soon. Others gradually started using cnc's to first do second op on parts that they couldn't drop complete. And eventually ramped up doing production on both.

Still None of them ever talk about getting rid of the Brownies to do only cnc work. But a couple have stepped up to at least the ultra's, while phasing out the older machines.

Whether or not you went in the right direction really depends on your circumstance's, but I'd say that repairing what you have was a good start!
 
I think this is a "Shop Management and Owner Issues" subject.
I would just like to hear people's thoughts on how to decide whether or not to put money into repairing old Brown and Sharpe screw machines or just old machines in general.

Here's my situation and opinion: all I have for production is 26 old Brown and Sharpes. They are all "G" machines (the ones they stopped making in the 50's). When I took over here in 2012, The machines were in a serious state of disrepair which made setup on the machines take much longer. It also made the machines less repeatable and much more prone to smashing up. Back then, most people told me that I should start switching over to CNC, or at the very least, start getting newer cam-drive machines. The way I saw it, most of the work I had could be produced on a Brownie with little or no secondary and I could probably repair all 26 machines for the cost of 1 new CNC machine and learn a lot about my machines in the process. That's that what I did and to make a long story short, I still wonder if I went in the right direction.

Are there any other Brown and Sharpe guys out there with an opinion?
You can make a lot of

parts on the G brownies with little overhead. A few years back you could buy for just above scrap.

Picked up a few just for parts. You go to an auction buy a machine and pay for it on the first job.

My biggest complaint was sorting through parts to pick out the last short part no good counter on

machine. We run a lot of long parts that we hand feed. One job 36" long knurl one end 5 parts a minute.

RD from Indiana.
 
My biggest complaint was sorting through parts to pick out the last short part no good counter on machine. We run a lot of long parts that we hand feed. One job 36" long knurl one end 5 parts a minute.

RD from Indiana.

Looking for the short part is a pain. Little known fact: the machines can do it for you! There is a lever on the machine called the "stopping lever" that is designed to stop the cycle when the finger passes over the end of the bar and the bar is too short to make another peice. The stopping lever is also convenient because you can tell from the other side of the shop that the bar has run out just by looking at the handwheel. Also, it stops the machine with the chuck open so that a bar can be inserted immediately. Most people use the stopping lever for secondary such that it stops the drive shaft with the chuck open every cycle so that a part can be inserted into the chuck by hand. I don't think that I've ever seen anyone use the stopping lever for its intended purpose.

This kind of thing is sortof what I was getting at in the OP. At first, none of the stopping levers worked. one by one I fixed most of them and now it helps alot with production.

And, if you make long parts like that, have you ever considered Lipe air feed?
 
Something to consider, if you are not familiar with the latest and greatest and all the hoops to jump through on the new cnc setup, it can get very time consuming up front to get where you want to be on one. I went out and bought an old machine that I knew really well as I spent 7 years on one because I knew for a fact that I could start making money on it as soon as I had it set and hooked up. I know I could have done fine on another make/model but for what I was doing I preferred to go with what I knew to start with.

I think that you should keep what you have in place and running and phase in a cnc. I know very little about screw machines, but I am guessing that a cnc could at least pay for itself and supplement the shop or even better become a big part of growing it. If all you know is these machines though a cnc could be quite a learning curve, but one well worth doing.
 
Harjon,

When going to school for engineering I spent one summer working in an old screw machine shop. The shop was half screw machines and half CNC lathes. The shop was owned by two cousins and originally had been started by their fathers. This was back in 2004 so I don't know if things have changed much but at the time a B&S was only worth a few $100 at auction as all the shops were closing down or going CNC. But this owner found his niche. He knew how to run the machines and told me there were a few critcal setups for them, he kept them different default positions and when the job came in he fired them up.

Apparently he said there was a sweetspot of part quantity between 2-10K parts where the guys with the CNC machines that cost $250K or so didn't want to touch them as they wanted to keep their CNC screw machines running on bigger jobs, so he said most of those jobs were winding up on CNC lathes where they weren't really optimal for. As a result his strategy was to quote the job as though it went on the CNC lathe and then multiply by some percentage (sometimes as high as 90%) and that was what he charged. He said usually he could steal the job from the CNC lathe guys and then make about $150-$300/hr on a machine that wasn't worth more than 1-5hrs of production!

I gather his real advantage was knowing how to bid the jobs and having the CNC helped him know what the parts cost. Now as for the B&S machines the thing I hated unlike anything else was all the secondary ops I used to run on the hand screw. We had these little pins like lock pins, maybe 1/16" dia brass they were about 1/2" long with a 3/8" depth hole in the backside. Then they were radiused on the front side. The B&S screw machine drilled and cut to length. Then I came in and ran them on the had screw where I raidiused the front end. After doing 10K of those by the end of the day your thumb looked like swiss cheese! There was a cutoff tit on them that you had to press into the collet with the machine running and it chewed the hell out of you fingers.

I wonder if the real savings of CNC is not having to do all the 2ndary ops on the backsides? Talk about boring work!

On a side note where in Bristol are you? I work in a building next door to the Otis tower.
 
I work in a building next door to the Otis tower.

Yes, working on the hand screws stinks. I personally don't understand why any one would do a secondary job on a hand screw if they have a brown and sharpe to put it on.

I'm in the old sessions clocks building in Forestville.
 
I worked for 6-1/2 years in a shop that had a dozen B&S of various age and sizes, a dozen small Tornos for watch/eyeglass parts, and a half dozen CNC screw machines. Every two years they would take out 2 or 3 cam machines and replace them with one CNC machine. The work done on the B&S machines was always big tolerance, finish don't matter kind of stuff.

As the CNC screw machines started taking over that work, the customers were so impressed with the better finishes, lower reject levels and overall netter finishes that they insisted upon getting the work done that way. That shop is down to three cam operated machines, and when those jobs they do stop coming in, the machines will be replaced with one more CNC screw machine.

It definitely is possible to get shorter cycle times on an old Tornos making tiny screws, though the people who know how to cut a cam and set up for the 4.7 second cycle times are all retiring. Only the newest Tornos machines with the integrated programming systems seem to be able to approach those cycle times, and they are quite expensive.

As long as you have work that is a fit for those machines and they put out more sellable parts than junk, stick with them. When they start failing, replace with your first CNC version and get accustomed to what they can and cannot do for you.
 
We sort of merged with a screw machine shop some years ago and had a few of those machines here.

The machine made money on the right jobs, with the right setup people...they spit out good parts a good deal faster then our CNC lathes with little overhead.

We got rid of them for scrap money as we could not find the right people who were dependable. I kept the jobs better fitting to CNC's and farm out the screw machine jobs.

If you can keep them running on the right jobs and don't mind being tied to the shop...that is unless you can find or train people...it can be a good living.
 
Yes, working on the hand screws stinks. I personally don't understand why any one would do a secondary job on a hand screw if they have a brown and sharpe to put it on.

I'm in the old sessions clocks building in Forestville.

So now you have me wondering here's what the part looked like and we made something like 10K at a time. The material was brass and the B&S would drill out and cut to length one side but then we would have a cutoff tit to deal with on the other. The hand screw would fix that and round the tip. Can this all be done 100% on a B&S both sides with a dual spindle or something?

Or would you be stuck using the hand screw?

part.JPG
 
So now you have me wondering here's what the part looked like and we made something like 10K at a time. The material was brass and the B&S would drill out and cut to length one side but then we would have a cutoff tit to deal with on the other. The hand screw would fix that and round the tip. Can this all be done 100% on a B&S both sides with a dual spindle or something?

Or would you be stuck using the hand screw?

View attachment 143161

There is a "rear end drilling" attachment available that could theoretically allow you to complete a part like this 100%. However, I don't think this part is a good candidate for that attachment considering the tiny deep drill. Better off drilling that hole on the main spindle like you're doing. ..But, that's not what I was talking about.

I was talking about doing the secondary on another automatic screw machine instead of doing it on a hand screw. The screw machine that you're using has a "secondary mode" where you can insert parts and do more work to them. There are a few different ways you can set this up but basically, you put what I call an "insert tool" in the turret and use a simple dwell cam for the turret slide. The insert tool just holds the part and inserts it into the open chuck. The operator hand-loads the part into the insert tool when it is in the 11 oclock or 1 oclock position. Then, the turret indexes to 9 oclock and inserts the part into the chuck. Then, the turret gets out of the way and a cross slide comes in on a cam to cut the radius. Also, its very common to put a spring loaded plunger in the back of the collet so that the machine ejects the part.

Advantages of doing secondary on an automatic:

you don't have to beat up your hands because your hands don't go near the chuck.
the radius form and finished length are more repeatable because they're on cams.
for this job, you could probably set the cycle time to 3 seconds. maybe less.

This gets back to the point of the OP. Aren't old machines cool?
 
I just started farming parts out to a screw machine shop. I cant believe how cheap those guys can make parts once the numbers get over 2000 pieces. I showed a friend of mine a knurled hand nut that was made on a brown and sharp and asked him what he would charge for it on his cnc lathe and he said he could do them for around 90 cents each on a run of a 1000. He is only in his 20s so he had no clue what a screw machine was but I told him the whole pile of parts in that box only cost 20 cents each. I redesigned so of my parts to have them made on screw machines it has lowered the cost by more than half. I do have insane amounts of inventory but it was cheap and I will use it but it will take years.
 
I think this is a "Shop Management and Owner Issues" subject.
I would just like to hear people's thoughts on how to decide whether or not to put money into repairing old Brown and Sharpe screw machines or just old machines in general.

Here's my situation and opinion: all I have for production is 26 old Brown and Sharpes. They are all "G" machines (the ones they stopped making in the 50's). When I took over here in 2012, The machines were in a serious state of disrepair which made setup on the machines take much longer. It also made the machines less repeatable and much more prone to smashing up. Back then, most people told me that I should start switching over to CNC, or at the very least, start getting newer cam-drive machines. The way I saw it, most of the work I had could be produced on a Brownie with little or no secondary and I could probably repair all 26 machines for the cost of 1 new CNC machine and learn a lot about my machines in the process. That's that what I did and to make a long story short, I still wonder if I went in the right direction.

Are there any other Brown and Sharpe guys out there with an opinion?

I know this is an old thread, and I am curious what you've decided since last pondering the question but I'll add my two cents anyways. If you want to know whether it's worth it or not you have to project the future cash flows of each option and its' expenses. You estimate the likelihood of these outcomes and discount them accordingly as well as discounting them against whatever else you may be able to invest in that provides a comparable return. If the returns are greater than what you discount them against or have "net present value" then go forth with repairing and maintaining them. If not, then abandon them.

It sounds like your screw machines have high expenses in the form of repairs and extended set-up times. As other people previously mentioned, screw machine experience is hard to come by ESPECIALLY those older kind of machines. That has the problem of causing a lot of down time and in turn, losing customers. On the other hand, CNC help is far more widely available and the machines (although slower than a lot of cam driven machines) are more science than art in my opinion.

I've worked with many kinds of screw machines as well as many other machines manual and CNC and although there is a very novel element to manual and cam driven machining, that doesn't convert into a premium that customers are willing to pay for. The technology has been around for so long now that the costs of acquiring a simple and older machine are significantly less than they once were.

Hope I was able to provide any insight if not at least fetch a response and see what amounted of your particular query
 
To me theres the basic costs, this applies to anything more advanced than a loo roll holder. IE you have to disconnect it, remove it, place new machine, connect new machine and then learn its quirks. All of those items have a cost. All of thoes items take time. Hence in my eyes spending a grand or even a few grand to fix a older machine thats still fundamentally profitable with your typical work can make far better sense.

Way way too many people baby cnc's - dont run them with any thought to realy pulling cycle time down. They don't use any of the old tricks like form tooling and are then surprised the parts take so damn long to run. Combine a form tool and a die head and you too can drop small threaded parts off a CNC in single digit seconds, just because you have a turret does not mean you have to have the bloody thing index the whole way around to complete a part.

To me at least a lot of the old style cam - mechanical machines whilst needing some serious skill to setup can let you make parts fast and economically. Way too many people these days look at ever turned item and consider it as a exercise in single point turning, when pre cnc people were using far faster approaches well over a century ago. Everyone seams to want a cnc so they can run it in the least imaginative slowest single point turning way.
 








 
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