[4technology]

Hi All,

New poster here, also entirely new to CNC. I am pushed into considering buying a machine as all the local shops are just too busy to fool with my small run, relatively simple but close tolerance parts (Bolt hole patterns to .003" true position, simple profiles and face to face tolerances of .003-.005" both over 6-8" envelope).

I came across a very low hours S2 Boss 6 in a shop that has very low hours. The machine has obviously seen very little use. The shop has had the machine since the mid 80's and are the original owners. The guy who was supposed to run it when they bought it left shortly thereafter, and except for one other one year stint, no one knew how to run it. It hasn't run at all for 6-7 years but was completely operable when last run. It wasn't advertised for sale, I saw it there and asked. It comes with all documentation.

My Questions:
1. Would this be a good machine to start CNC with on a limited budget?
Will it circular interpolate?
2. Can I tap with it, not solid of course but with a comp/ext holder?
3. If it truly is in this good of shape, (I looked in the control cabinet, very clean) might I be able to get pretty reliable service out of it for a couple of years under light part-time use? Reading the past forums make the machine sound rather problematic.

Very Important: My homemade 3 phase generator (the deceased builder was a bright guy but that is all I know of it) is based on a 7.5 hp motor (really big one) with a bank or 3-4 capacitors the size of 6 volt lantern batteries wire into the box that feeds it for the 3 phase. It works just fine on my manual machines. Will this machine run on this type of 3 phase setup? Is there any way to test the generator to see if it meets whatever criteria the machine may have?

I have heard old CNC machines "don't like" generated 3 phase... I am attaching photos.

TIA for all advice,

Bill

[Jaguar]

The phase converter will be problematic. If the machine costs anything at all it's too much. There are no parts available for the most part and this machine is notorious for blowing the servo drive transistors on a regular basis. Do what you want but it wouldn't be on my radar.

J.

[gus]

this is excellent iron. I think many guys still make money with them. I would want to see it run. Some things such as caps are age dependent and may blow despite low hours.

If the price is right and you have a little adventure in you, go for it.


As a side note, features in a single setup a pretty flogged VMC can hold your tolerances, but if repositioning you might see wander. Bolt hole circles are not really an accurate locating method, so perhaps the shops are trying to tell you something.

[4technology]

Gus,

Thank you for the reply. What are 'caps'? The bolt hole position of .003 is to a central bore used as a locator. Will it do that? Does anyone know if this machine will tap?

My concern is I tend to have a little too much adventure in me... For once I am going to try to thoroughly research something before I jump.

Bill

[gus]

It has no rigid tapping.

capacitors

[jreillycnc1]

Unless you have 3 others next to it for parts, this machine has no value. It is scrap Iron and if you spend money on it you will be sorry for it.

[ccoleman]

I've had the same machine and now have a Series I R2E3 and think they are just fantastic. Like Gus said, excellent iron. Both of them were converted to a modern control before doing anything else and that may be the most important element. I think we paid $500 for the S2 not working and then whatever the conversion cost. I paid $700 at auction for the S1, felt that was a little high but even so, I'll be under $2,000 for a completely retrofitted servo machine which actually fits in my garage (unlike most VMC's). The S2 paid for itself many, many times over. Of course, I'm not a machinist so my view of machines may be a little skewed.

[machintek]

As mentioned, great iron. Parts still available. If it has the correct voltage going to it, it can run for years without blowing a transistor. Yes I have had such machines in my territory.
BUT, it dates to the early 70s. Are you using a phone or computer from that time period?

George

[ad_bfl]

I have that exact same mill, kept the steppers, added some 203 drivers, smoothstepper, used the original limit switches, and rewired the front panel.

it works incredibly well, slow, but very accurate and repeatable.

The biggest expense was the oiling system, they tend to gun up over time, so I had to strip the oil system and rebuild it, same for the pneumatics.

However excellent iron.

[cncbpt]

I have a SII and if you dont want this one I will take it if close enough to Ohio.
You dont want to pass it up.
Guys go out and buy the BP clone machines for far too much money when there is these great machines setting around.
Some of the best iron you will find.
I ditched the control right away,just too much to program it and make it easily
productive.
There was a guy on here that went by Hillbilly that sold a simple to setup B.O.B that used the original drives and steppers and allowed it to run from Mach3 on a pc.
This is how I run mine and I love it.
Its amazing as too how well they cut and what you can do on it.
You will be happy with it

[polaraligned]

Great iron.
Buy it and put an AJAX setup on it and join the 21st century.