chance to buy j300

[cruzin]

Hello, I have a chance to buy a j300 which was a family members who was a lifelong tool and die man. It is cnc with everything right down to the pc. After he retired he had a small shop and used the mill to cut production wood parts for someone. He had the head rebuilt I think. I do not find much on line about the vintage of the j300. I am trying to put together a small home shop. my uncle passed away and at that time it was a working mill. The price on the j300 is 1250. Is there any reason for not going with this mill. Can someone direct me to good information on this mill. thanks.

[underthetire]

Since the later models are J310, J325,J425, I would assume that is an old system 10 control on a beige machine. If it is an old beige machine with a system control (newer ones were dynapath Delta) I would not pay over scrap price for it. System parts are getting hard to get and expensive.

[cruzin]

Originally Posted by underthetire Since the later models are J310, J325,J425, I would assume that is an old system 10 control on a beige machine. If it is an old beige machine with a system control (newer ones were dynapath Delta) I would not pay over scrap price for it. System parts are getting hard to get and expensive.

It is one of the beige models. thanks for the input

[ions82]

I'm guessing it has the old "System" control made by Bendix. About the only thing those old machines are good for is a retrofit. So, unless you're ready to take on a control retro project, I wouldn't buy it. I have a 330 sitting in my garage that needs a retrofit control. The iron is great, and it will make a great machine. However, the control that came on it (Dynapath System 10) was in a state of disrepair. It had been worked on before I bought it. I did a little more repair work on it. Then, the first time I went to run some parts, the proprietary power supply in the control took a dump. The crooks that deal with that stuff wanted $800 for a "rebuilt" PS. So, I decided to scrap the control and do a retrofit.

Anyway, like I said, I wouldn't buy a Pre-Delta machine without planning to install a new control. A retrofit can be a complicated undertaking, but the end result is like having a new/modern CNC machine.

[cruzin]

Sounds risky buying this unit. My uncle owned it and used it regular right up till he became ill and passed away. He used it as a cnc with bobcad.

I guess I will have to look at what it involved with a retrofit. And what those options are. I have never done anything like this and do not know what will be involved.

We have a series one and thought of making it cnc but that was over the cost I want to put out. This unit is 1250 and about 1/3 the cost that I was told to change the smaller bridgeport.

Thanks for the advice I appreciate it.

[ions82]

Well, it may not be a bad deal if it is running and has all of the tooling. However, it's inevitable that the control will take a dump at some point. Could be two weeks after you get it. Could be two years! A running machine (with tooling) at that price is a pretty good deal. But if that control ever crapped out on you, it would be time for a retrofit. Also, I wouldn't even consider retrofitting a machine that didn't already have ballscrews. So, the Tree would be a much better option than the B'port if a retro is in your future.

[sld4121]

The J300 certainly has some history - I learned on those at a shop in the 80's.
However, the ones we ran had an IIC control if I remember correctly.
I am pretty the Bendix control did not come out until the J310.
The iron was always pretty decent, and the heads are a breeze to rebuild since they used to scrape them in back then.
Way back when - someone on the west coast was rebuilding the boards, but who knows if anyone is now.
So, yes it is probably a matter of when the control will take a dump.
Might even have some old manuals laying around if I looked real hard.

[dmauch]

The J300 is a fine machine. They used SD servo amps in them. The one I have I bough on ebay that I knew had a bad control unit and retrrofitted mine to Gecko drives. I've had it for about 5 years. Once I fixed a few problems with it, it has been a fine machine. Really rigid. They have a 5 HP 6000 RPM spindle motor. If you buy it I have the manuals that I can email you

Dan mauch
Camtronics, inc. -- CNC with Dan Mauch
dmauch@camtronics-cnc.com
kits, custom and azssembled stepper and servo systems


low cost cases for gecko products.

Originally Posted by cruzin Sounds risky buying this unit. My uncle owned it and used it regular right up till he became ill and passed away. He used it as a cnc with bobcad. I guess I will have to look at what it involved with a retrofit. And what those options are. I have never done anything like this and do not know what will be involved. We have a series one and thought of making it cnc but that was over the cost I want to put out. This unit is 1250 and about 1/3 the cost that I was told to change the smaller bridgeport. Thanks for the advice I appreciate it.

[cruzin]

I do appreciate the reply. I think my uncle had the manuals for it. Can you tell me briefly what is involved with changing it over if the control unit goes out and the cost of such? thanks, Mark

Originally Posted by dmauch The J300 is a fine machine. They used SD servo amps in them. The one I have I bough on ebay that I knew had a bad control unit and retrrofitted mine to Gecko drives. I've had it for about 5 years. Once I fixed a few problems with it, it has been a fine machine. Really rigid. They have a 5 HP 6000 RPM spindle motor. If you buy it I have the manuals that I can email you Dan mauch Camtronics, inc. -- CNC with Dan Mauch dmauch@camtronics-cnc.com kits, custom and azssembled stepper and servo systems low cost cases for gecko products.