steppers or servos ???????????

I am in the process of getting a series 2 bridgeport and then retrofitting it with a newer control.. The stepper systems are considerably cheaper. But what do you lose??? over the servo systems.

been looking at the ahha retrofit system and the centroid systems...
Anyone out there have either system ???
any comments or remarks appreciated.
thanks MR.BRIDGEPORT

we converted a series one ridged ram B/P cnc miller which had a "boss" 5 control to an ahha artisan pc system and use it in our shop on a regular basis,so I suppose we could make some constuctive comments based on that experience. You didn't say if the machine you want to pc is a cnc machine to begin with or a series II manual. If it is not cnc, forget the whole thing, period, If it is.. let us know and we can keep talkin'

regards
sas

sorry about that oversight.... yes it will have ballscrews allready. dont want to do that major of a retrofit!
I have a few prospects but i really want to pick a good one... hopefully
anyway just for reference I have run cnc equipment for 20 yrs and helped set up several new """large""" 6 axis machining centers for the company i work for and have ran many from OKUMAS,FANUC,BANDITS,HURCO,HAAS,WHITE SUNDSTRAND, and a few that i want to forget lol.... Mainly just looking for a comparison or info on the steppers!!!!
all i have run has been servo operated. AC or DC but all servos and i am wondering what you lose if anything?? with steppers.

hope that clears the air

John, Steppers are old technology and the only reason I can see to go that way is cost.(good reason) having said that,even though the newer systems are better,faster,quicker don't let anyone tell you steppers won't produce quality work! think about all of the aircraft/military hardware cut with steppers in 60's to early 80's. In the case of a B/P "Boss", the AHHA or similar systems make a lot of sense because those machines were not engineered to be a high speed machine in the first place.with the AHHA package you are able retain the exsisting motors and you gain in every respect over the original control.
If money is not a concern and you want to get the best performance out of the machine in a production type invironment then by all means select an Anilam or similar servo retro kit. We looked long and hard at this syst and would have prefered to go with it but for the 13thou price tag. Back to your original question "what do you lose" ? In reality I think just SPEED and, that you are using "old" technolgy. accuracy? nope,the condition of your machine is going to determine that issue. smoothness? to a small degree (in linear interpolations).Reliability? think there is a gain here because of the simplicty factor.Plus, I personally like the idea that since we did this conversion ourselves we actually understand how the damn thing works and don't need to hire the Fanuc guy to come around when it does't. Are we happy with the conversion? YOU BET! Would I rather have a new state of the art Fadal or such toolroom mill?..ah ,the cost factor again. The key to all of this IMHO is for you to figure out what you really want the machine to do for you and then go from there. If you decide to go with a stepper deal be sure and contact Bill Griffen at http://www.grifftek.com , very nice guy with lots of good info and support for those types of systems.

Be happy to email some photos if interested. regards,

sas

thank you so much !!!!!!!!!!
exactly what my machinists eye was telling me but all the "servo" ppl said oh man you dont want that................
having not actually ever seen a stepper system for axis controll i wasnt sure.
thanks again

Well, gotta put my 2 cents in here. The main differance between steppers and servo is open loop and close loop. Servos need a position feed back loop to see if they are were they are supposed to be, were as steppers just step what the control puts out and can get lost if they are bound up in an axis. Chips behind the saddle can do that. If you know what the control and drives are capable of, you can get excellent resualts out of both systems. I'm currentlly getting a machine shippped to my shop, Series 2, BOSS 6 with a AHAH retrofitt, bought it for 1500.00 When I get it up and running, I'll tell you more, but playing with it at the customers shop was cool. Looks like a cheap alternative to a complete control retofit. And that BPT series 2 iron is bulletproof as long as it has been lubricated well, Vactra # 2 being the only thing allowed in my machines. Thats a hint to people that think oil is oil. And remember, your RPM is limited to 4200, your not gonna do high speed maching here. For a cheep good solid machine, these series 2 with an updated control is the ticket. I worked at Bridgeport for 13 years, they were the best iron that ever came out of the plant. Hope this is of some help. Bill

Hay mr. B
that series gonna be for sale soon?????
I have been looking for one per your recomendations. tracked down a good one through a friend of a friend but by the time i got to the owner he had sold it becauese he needed the room.......AHHHHH
series 2 friend said mint condition working boss control...
price was 750.00
I about died.

hay sasbenson pictures would be great
send to [email protected] thanks man.