Hello All,

I just recieved this machine and need to do a retro on it. I am including a link to the machine since I can not get the photos in here.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3852883566&ssPageName=ADME:B:EOAB:US:6

A aftermarket retro for the 3 axis' would be easy but I have no idea how to do the tool changer. Does anybody have any ideas on how to do this at home for a reasonble price? The servos and spindle motor are fine but the control lacks seriously. Please Help

Thanks Tony

You need a control that has machine control I/O capability, or it can be done with an external PLC with limited communication with the control.
Upper end systems, wether it be PC based that use a motion control card with built in PLC or motion card with separate PC based Digital I/O cards use this method.
Typically when the control tool-change M code is issued this is passed over to the PLC and the control will hang at that line until it receives a 'finish' signal from the tool changer that the tool function or M code has completed.
Al

Not to be negative but this will be a can of worms.
Reason is the way this machine changes tools. Besides a pile of switches to tell the control where the tool carosel is, when you command a tool change:
the quill goes up; the machine files air cylinders to go to low gear verified by a micro switch in the "shoebox'; Volkman drive turns spindle slowly; another cylinder fires and a bar runs along a scroll in the gear that also gives spindle speed and locks it into orient verified by a micro switch; then the tool changer starts moving. this is air over oil and has a pack of micro switches on top to tell the control what is going on because more cylinders fire to slide a plate across the spindle to hold it up while the drawbar fires at the exact moment to release the tool and grab another. The tool arm literally slaps a tool up there. If the carosel needs to move 1 station, it strobes the air solenoid to the air motor to move it slow. If you load up the tool carosel, it must be balanced and you need to adjust a air flow valve to compensate for the additional mass or it will not move correctly. The air over oil arm mechanism also has flow valves but if you change the speed, you will upset the timing of the dozen or so switches involved in a tool change. Most of the solenoids are run by the CPL board in the control. You MUST have the maintenance manual to keep this machine running. It was called a BOSS 7 and was the first BOSS machine to use servo motors instead of steppers and even has backlash comp.

George W.

It sounds like a mechanical nightmare and writing the logic would be the least of it. :rolleyes:
Does the spindle drive perform the spindle orient? or is this achieved with other mechanical means? Is there servo motors in the tool changer?
Al

The orient is actually achieved mechanically. A air cylinder pushes a piece of metal in a groove that gets deeper untill the end of the groove is found which is deeper still. At this point a microswitch tells the control that orient has been achieved. The Volkman spindle drive moves the spindle slowly to achieve orient. Just like a series one standard, there is a backgear but instaed of a lever there are two sets of air cylinders that push against the bull gear and springs. One set gets it to neutral, another set gets it to low gear. There is a cam with notches in it for each of the three gear positions. The control hunts (keeps firing) the specific air cylinders to try and gets the gears aligned. Each attempt includes a small air cylinder. paw, and switch that sees if the position has been achieved.
There are no servo motors associated with the tool changer. Lift the lid, it is hinged, and look in. There is a air over oil cylinder and a complex cam for tool arm motion. The air provides the force. The oil allows better regulation and consistancy of tool arm speed. The tool carosel has a air motor to turn it. A set of micro switches (later prox switches) tells the control were the tool carosel is at.

And yes, it is possible to write a ladder diagram to do all of this, but is it worth it? The drives are obsolete (NC400) and did fail often. The actual control works very similar to all the other BOSS machines. It is fairly reliable but needs a PC for loading programs and editing them. Because of the spindle drive, it can tap. If you still want to replace the control, consider getting rid of the tool changer.
Take it from someone who kept these machines running. There is a lot to go wrong or get out of timeing.

George W.

Sound like advice from the bpt maintance dept.

The orient is actually achieved mechanically. A air cylinder pushes a piece of metal in a groove that gets deeper untill the end of the groove is found which is deeper still. At this point a microswitch tells the control that orient has been achieved. The Volkman spindle drive moves the spindle slowly to achieve orient. Just like a series one standard, there is a backgear but instaed of a lever there are two sets of air cylinders that push against the bull gear and springs. One set gets it to neutral, another set gets it to low gear. There is a cam with notches in it for each of the three gear positions. The control hunts (keeps firing) the specific air cylinders to try and gets the gears aligned. Each attempt includes a small air cylinder. paw, and switch that sees if the position has been achieved.
There are no servo motors associated with the tool changer. Lift the lid, it is hinged, and look in. There is a air over oil cylinder and a complex cam for tool arm motion. The air provides the force. The oil allows better regulation and consistancy of tool arm speed. The tool carosel has a air motor to turn it. A set of micro switches (later prox switches) tells the control were the tool carosel is at.

And yes, it is possible to write a ladder diagram to do all of this, but is it worth it? The drives are obsolete (NC400) and did fail often. The actual control works very similar to all the other BOSS machines. It is fairly reliable but needs a PC for loading programs and editing them. Because of the spindle drive, it can tap. If you still want to replace the control, consider getting rid of the tool changer.
Take it from someone who kept these machines running. There is a lot to go wrong or get out of timeing.

George W.

Hello George could you please tell me on the BTC 1 what size taper in in the spindle if it is 30 int were the tools held by a pull stud if so are the any spare parts available to retorofit onto a Series 1 CNC bridgeport with a boss 5 and variable speed head if so can you give me an address for them as I would like to use this method with a air over oil cylinder on top like the Interact 4 toolchanger is . Thanks Colin

The BTC-1 used a 35 taper spindle nose with a pull stud. The internal spring stack up has a force of 2100 pounds. The BOSS machines had either a Universal Quick Switch 30 or the Erickson QC-30. The Erickson had a 1/2 X 13 tapped hole in the top. It would accept a Kurt power draw bar which is a air driven butterfly type air impact wrench with a draw bar for quickly swapping out a tool holder.

George

not sure what colin is asking, but the spindle parts are not interchangeable with any other machine, complete different head. Also toolholders have integral pull stud, and I don'[t know of any other machine that uses similar. 35 taper really sucks, much more chatter than kwik switch

Weather or not you decide to retro your BTC I think it would be worth the effort to keep the tool changer, we have two of these machines, we use them all the time, Machintek is right about them being a mechanical nightmare. But once you get the three main systems, tool changing, spindle orient and gear shifting figured out they really aren't that hard to keep going. The maintence manual is very thorough and is a must have. In my opinion its the tool changer that realy makes these BTC's productive machines, just remember they are about 25 years old!!!!!!!

I like to hear that Jonp, a bucket of encouragement for the guys who has BTC1. Mine is nolonger a nightmare but still has so much to tackle. Everything works except the tool changer.

Note that the switches for tool carosel position interface to the XTC board on K-9, pins 19,10,9,8, and 7. this is shown on page 7 of the machine wiring schematic. Although the discussion in the maintenance manual shows micro switches with little rollers, the schematic shows prox (hall effect) switches. I have seen both on a machine.
Note that carosel position 14 has all the switches made, and position 24 has all open.

George

Hello George the information that I was asking for was to see if I could use the same principal to hold the toolhoder in the spindle as the BTC 1 with a pull stud and the use a air over oil cylinder to press on the top of the pullstud actuator rod so as to eject the toolholder dont no if this would work or not also if the pull stud puller mechanism would be able to fit the head on my machine with some modification. Cheers Colin 1544

I am assuming your question relates to application to the BTC1 only. The air over oil was used for tool arm motion in a BTC1. There was a air over oil that was used for a brief period on the interact 4 for tool release. It was not reliable. Also this machine had a mechanism that turned off the Z axis drive, and used a paw that held the Z axis belt against the applied force. The BTC1 had a plate that held the spindle against the air operated drawbar actuator. This to prevent all this force working against the spindle bearing and preventing the Z axis from being forced down giving a positioning error. I mention this because you will need to make similar accomodations, either automatically or manually. Either keep the control as is or you will have to engineer whatever is necessary to achive your end desired.

George

I have a btc11 here scared the crap out of me the first time i got it to change tools
hiss arm fly out bang boom tool in . arm out bang boom tool out ....To get it to work
i had to replace all the hoses to the tool changer

A LOT is going on the change a tool and rapidly! It SLAPS a tool up to the spindle and the arm shoots in and out. The only part of the tool change that seems reserved is the spindle orient and the tool carosel turning.

George

I recently purchased a BTC-1 off Ebay Although I have run the Boss 5 controls in the early 80's I had never heard or seen of a BTC-1. After posting a HELP message on the NET Jonp was gracious to reply and assist in getting MY BTC-1 up and running. This machine is mechanically dependent on micro switches and prox switches for tool changes and what machine isn't. With Jons help my machine is running like a top, and like Jon states it is 25 yrs OLD. I would incourage anyone that has a BTC-1 to use the toolchanger and not be intimidated by the mechanical complexity. (This machines tool changer mechanism is much simpler than the OKUMA 3V of 84') and cost thousands less. I agree with Jonp that this machines ability to change tools makes it a more valuble machine than many CNC machines. Thank you Jon for all your Help!

When it is all working correctly, it is a sight to watch! I marvel that it works as well as it does considering the complexity and the tolerance of everything (these switches are not precise devices). If a video of a tool change could be posted, it would be worth while. I still do not believe one can appreciate how much is going on unseen.

George

looks like i stumbled into theright room! I just won a btc1 on ebay. seller claims its in top shape...found out that the thing had been sold before ( the story is that there was a discrepancy on travel size and original buyer needed more than the unit had...i guess i can buy that... see the link here ---

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7537278656&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26satitle%3D7537278656%26fvi%3D1

then i get to digging around tonight and i read this...
http://www.machinemanuals.net/web_pages/bridgeport_boss_7_btc.htm

im freaked out i may have gotten a POS!.... thoughts everyone?

I hope you have read the above. There are others that own these and keep them running. It may not be easy. You will have a hell of a learning curve. It would help to be a jack of all trades.

George

followed my gut and pulled the plug on this one. i really do appriciate the guys who called me to offer insight ( that pretty much drove me over the egde LOL ) better safe than sorry though! still looking meanwhile- THANKS ALL!

Don't let the oil jar on top of the tool arm get low if it does it becomes a tool treblej thus throwing the tool in the general direction of the spindel tool chater could be from broken bellvil washer's in the drawbar not holding the tool tight . Ive been making chip's with mine almost two year's now with most of it being good they don't deserve all the bad rap that machine manual's gives . I would like to hear from a bobcad user that has got a post for BTC . I also have and am looking for tool holder's The tooling manual shows TG100's but have yet to find any or any one who has any .PS I wouldent give up the tool changer.

Yaaa, Kevin, As we have disscussed the tool changer has REALLY been the least of the problems with this machine. I have been very happy with the tool changer and all the related mechanics. This machine has recieved some very bad and miss guided negitive information. The tool changer is very mechanical and relies on switches? but what tool changer does'nt! ( Note the company I work for has unfortunitly purchased the FADAL 104-D, This machine has torn off 3 buggets from the tool changer) So problem tool changers is not new problem!) I plan to use my machine as long as the control continues to work, if the control fails and the cost to repair is unreasonable
then I will consider retrofit. Bottom line, the BTC-1 is a good machine and with a little care can be a very proffitable additon to your equipment.

I'm amazed at the negativity and not the suggestions of how to make this machine better. If limit switches are too inprecise, then optics and/or better prox switches would solve the problem. It sounds like a good machine to do tweaking or retrofits on to get a great machine. No machine of it's age is going to be completely free of problems. I've spoken with many people which have or had BTC-1s, and the only complaint I've heard of that would cause me great concern is the slow rapid travel. That means you have to go to greater voltages (it's a servo system vs. stepper system as I understand it), which would translate to all new servo amps. Even that may not be that great of a concern, I just don't know.
I also know several other manufacturers use air over oil systems for tool changers, and I haven't heard any complaints about their changers.
I'll be letting you know when I get the one I just bought home and try it out.

See The BTC Clubhouse in the bpt section you will find what we have done with our's I'v been slow on finishing the encloser, the rapid's are fast enough for 18X12 X&Y tool change is quite fast enough for it also I beleve the rapid's are 300ipm X&Y and 200 in Z I know that there are new machines with .04sec chip to chipTC and 1500ipm rapid's but what do you expect for early 80's and a machine that can be had for $2000.00 up with tooling If you post on BTC Clubhouse please tell us where you are and give contact info we try to help each other out if we can Good luck Kevin