TOS FN20 Upgrade to CNC

[Ark1]

This is coming along nicely. Good work.

Have you contacted Machine Tools CZ? They deal in TOS machines and might be able to help you find the manuals.

Thank you for the Link, I didn't know of any company dealing with TOS FN20 machines. I will email them and hopefully they can supply a machine manual.

The TOS FN20 is a great machine, well built and accurate. Repeatablility is within .0003" on the CNC converstion, I am very suprised with the tests that I have been doing. I was hoping for .003" and obtained 1/10th of that.

More posts to follow when time permits.

Ark1

TonyK.

[Ark1]

With the power supply down waiting for parts the oppertunity to do some problem solving was now at hand. The TOS FN20 protects the ways with a fabric bellows. When I obtained my machine all of them were ripped except the Y axis as it was at the back of the machine away from the oil and chips presented in machining.

I have always liked the look of the stainless steel way covers so I set out measuring and forming a set of covers for the Z axis made from 18 guage Stainless Steel. Metal Supermarkets in Canada is a great soarce as they often have cut off sheets of stainless steel and also have shear to cut strips to size. For trimming I used my Plazma cutter and the cut was clean and quick to do.

Since I do not have a break that will form 18 gauge Stainless Steel I used a hard maple former. The former was made the size of the first section of the chip guard size to be made, clamped, then hammered to size. I then cut the former 3 x the thickness of the sheet smaller and formed the next section. This progressed untill all 4 sections were made. The same was done for the top but with 5 sections. The back is shown with the fingers that keep the sections from falling apart. Welding the fingers was done with my TIG welder at 35 amps DC. I used the TOS FN20 mounting strips for the Bellows to mount the top and bottom sections. Method of attachement , MIG Weld. I also formed a drive belt guard fo the X and Z axis to keep the chips from clogging the belt and possibly jumping a tooth.

A bit of electrical theory.

Supply to my house is single phase 120/240 volts 60 Hz. The single phase primary on the street (16.6KV) steps down the Utility line voltage with a transformer. The transformer secondary coil has a centre tap that is grounded and called the neutral tap. From the neutral tap in either direction 120 volts is presented. Across both windings 240 volts is present. I wired the Antek power supply up the same way, although connecting the neutral to the centre tap is not required this connection does not allow the primary of transformer to see more than 120 volts to ground. The inital set up used 2 electronic relays to switch the 8 amps of load on each primary coil to the power supply. I will also note that if only 1 coil is energized the power supply will still work, but will only work at half of it's current rating. Both windings are required to obtain the full out put of the power supply secondary voltage. The relays are picked up by the EPO circuit in Mach3. When the reset is pressed and is sustained the Sound Logic Break Out Board energizes relay #4, the normally open contacts now close and pick up 2 electronic relays the energize the Power Supply. This was my first encounter with electronic relays and I have now changed them out for an Allen Bradly 30 amp contactor. More about that in the next post.

Ark1

TonyK.

[RotarySMP]

Do those sliding way covers reduce the travel at all. You made a nice job of them.

[Ark1]

The travel on the top was reduced by about an 1", but the Quill travells down 4" so I really didn't loose anything. The bottom travels down as far as the machine did when it had the bellows. Removal on the top is only 2 screws and a snap fastener. The bottom uses the same snap fasteners as the bellows did and 2 screws as well.

I am pleased how clean the new chip guards came out. On larger machines the metal is .125" or thicker, however on this little machine 18 guage metal is strong enough for the task at hand.

Thanks for your comments.

Ark1

TonyK.

[diyengineer]

Great job with the covers. I am in need of making some covers for my rails/linear gear track in the future. I will for sure look into this method when i can cnc cut them out.

The travel on the top was reduced by about an 1", but the Quill travells down 4" so I really didn't loose anything. The bottom travels down as far as the machine did when it had the bellows. Removal on the top is only 2 screws and a snap fastener. The bottom uses the same snap fasteners as the bellows did and 2 screws as well.

I am pleased how clean the new chip guards came out. On larger machines the metal is .125" or thicker, however on this little machine 18 guage metal is strong enough for the task at hand.

Thanks for your comments.

Ark1

TonyK.

[RotarySMP]

Did you put sissor links on the back of the way covers?

Yesterday I was looking at used TOS mills on a Czech used machinery web site. I knew TOS was a big company, but was surprised at the large number and vareity of mills they made in the 70's and 80's. The FN40 looks tasty, similar to the FN20, but with a greater X travel.

[Ark1]

Tos is as big company and the machine I have is robust. Because of the embargo against communist countries held by the USA Tos was not sold in the USA, but was sold in Canada. In the machining community in Canada when I mention that I have a TOS milling machine people are impressed. Do a google search and you will find a lot of the FN20's around. There are lots of options for this machine, even a slotting head. The machine is horizontal as well. There is also and FN25 and FN 32 all just a bit bigger in size than the FN 20. The nice thing about this machine is that the table comes off and I can bolt the dividing head straight on the vertical table, I can then turn the indexing head straight up and have machined small fans for model helicopters. The CNC conversion will allow me to machine a blade all in one step before I rotate the fan blank. A very versitile machine.

As for your question about the way covers, on the top of each section on the inside is a tab that gets captured by a "C" shaped finger that is welded to the next upper segment. The tab is allowed to travel inside the "C" shaped finger of the next upper segment. When fully extended each segment is suspended by the "C" shaped finger.

If you need a better picture let me know I can remove the guard it is only held on with snaps and a few screws.

Thanks for asking.

Ark1

TonyK.

[Ark1]

With the power supply secondaries repaired I was ready to test the drives again. A month had passed. ( I sent the shorted rectifier bridges back to Antek with a copy of the emails, Antek did not respond ) The sound Logic board has an optional relay board that plugs into the Break Out Board. Relay #4 is used on the EPO circuit. When energized this relay picks up 1 primary winding on the power supply and electronic relay picks up the other primary winding. Both relays are rated at 250 volts and 25 amps. With great aprehention I hit the reset button in Mach3 and energized the power supply. No bang, no boom, no smoke. I then tested all three drives and motors as the Gecko drive manual recommends, no problems. Each motor held and jogged as instructed. It was now 3:00PM on a Sunday and I thought this is a good place to stop for the day. I hit the reset on Mach3 to drop out the EPO and power supply and noticed that the power supply was still energized. Not good. I traced the problem back to the electronic relay that was in the closed state. Removing the relay I took it apart with a screw driver and a HAMMER. The SCR was shorted. ( why me?) Lesson learned my first time using an electronic relay too, never use in a crittical circuit. The next day I stopped back a EMC in Hamilton and picked up an Allen Bradley 30 amp contactor. A bit of rewiring and success. Each time I modify my control circuit I up date my prints to have record of what is current for trouble shooting.

With the new contactor installed and wiring changes complete I now set about the task of Calculating motor steps per revolution. Done, but something was wrong way wrong. The travel wasn't an inch but only 1/4 of an inch. Back again to reading. Quadrature. The encoder pulse is times 4, more calculation.

With the gear reduction, belt reduction and Quadrature the following calculation provided these numbers for steps per inch.

X 15.593.90822
Y 30,720
Z 61,440

The kernal speed on the mill is 45K.
I was now at the point of testing motor Maximum speeds. I was getting somewhere.

Mach3 also instructs the following to be done for repeatability and testing axis.

F1000
G20 g90
M98 P1234 L50
M30
O1234
G1 X4
G1 X0
M99

Well since I only had a 3" guage block I changed the program to X3. Now I wasn't able to get this to work from the teach screen so I wrote it in the edit box of the Main Program.

I ran this on the X and found after 50 reps. the dial gage was out .002" in 3.00"

the Y and the Z have scales and graduated hand wheels and I found that each hand wheel came back to the Zero after 50 reps.

Because I wanted to face mill and machine a small alumium casting I purchased the Mach3 Mill Addons. For a person that has no idea of G Code this is a great starting point. It allows me to fill in the blanks, Just remember to hit enter to do so, I keep forgeting this step and Mach3 will write the G Code for you. You can the post the code and watch the simulation of the tool path to see if your program is correct for what you want done. I spent a fair bit of time editing, I plainly don't know what I am doing, but could play with the computer until I obtained the result I was looking for.

I ran a test with a wooden dowel rather than a tool, that way there was a problem wood hitting metal will not do any damage. So the first trial was ready, loaded and then the surprise. The rapids were slow, the feed was fast and the mill tool ( dowel ) moved away from the work instead of moving into it.

I had set the pins wrong as in my mind the table was moving positive, but the tool was moving negitive. Also the TOS FN20 Y axis moves, the table only moves in the X and Z direction. Still more learning to do.

So I shot 3 videos, one using a dowel for a tool. The next was with the Tungaloy face mill. Well again I am just learning here and wanted to shoot the video, the belt on the spindle was loose and you can see the mill head speed bleed off. I tried it again today and all was fine, but the video file got corrupted and I wasn't able to look at it or post it.

The last video is of the clean out to final dia. of the casting.

I did encounter a few more problems that I will disscuss in my next post.

[nomedia="http://www.youtube.com/watch?v=KTsQfGFr9sw"]YouTube - TOS FN20[/nomedia]



[nomedia="http://www.youtube.com/watch?v=-mLGDe3N_vs"]YouTube - TOS FN20 Milling Machine[/nomedia]




[nomedia="http://www.youtube.com/watch?v=1AkOQzZ9dbw"]YouTube - TOS FN20 Milling operation CNC conversion on Mach3 control[/nomedia]


Ark1

TonyK

[Ark1]

When setting up the Gecko 320x installing a jumper between the Error Reset terminal 5 to the + Terminal 7 allows the servo to be checked and tuned. When commisioning the drive and Servo the manual requests that the armature connections not be made and that the servo motor should be turned by hand with the encoder connected and energize to put the servo drive into alarm and fault. Alarm is any encoder count of less than 128, at greater than 128 the drive goes into fault. Seems simple enough and it worked flawlessly on the 31st of December 2010. The day here in Canada was +60 degrees and my shop was quite warm with everything working and tested I decieded to run a small facing program written by Mach3 addons and checked the speed of the axis and all worked very well. The drives did what the manual said they would with the base setting of PID at 11 oclock. A few days had passed, the temperature in the shop now about 40 degree I set up to run the facing progam, chucked a part in the vise, loaded the GCode program and hit cycle start. A few stops, starts and then the table headed for the stops as the cutter head was turning and the part was ruined. I lowered the table, and tried again to run the program and again the table ran to the stops.What had changed, temperature of the machine and friction. The TOS FN20 uses gibbs and ways with a film of oil between them. My shop was colder than when I set up the program to run.

What I learned. If the lost steps occure and are greater than 128 the Gecko 320x goes into fault. The drive now signals Mach3 to reset the axis to zero and then the program continues to run and accepts the new zero. Well if the machine has alread moved 8 inches on a 13" table and is told to move 8 more inches the table is heading for the stops at the feed rate written in the GCode for the part to machined program. Not good.

With this found and it took me a few hours to figure out what the hell was happening, I started this post.

Mach3 Fault when Drive faults. - CNCzone.com-The Largest Machinist Community on the net!

Many thanks for the responses and I was prepared to purchase a Gerc board. A quick email to Marcus Friemens at Gecko informed me that the drives I had could have all the Error Reset terminals connected together and this would hault the drives, I would then have to manually reset the drives to continue. Let us face a fact here that 129 steps out of 61,000 will not produce an error in the part that I will see. I could live with that. However more research led me to read about this product.

Page Title

An encoder board that will hault the machine and signal the offending drive.

I have now gone full circle as I had installed the Rodgers Board to use as DRO manual machine with Mach3 displaying the axis posistion when the need arises.
Currently that board is not connected to the encoders or the software loaded for it's use. It is on my to do list, which will require more hard wiring and print updates and more testing.

For now I will be completing the run of parts that I have on back order and then when time permits make the chances to use the Rodgers Board that will allow me to use the hand wheels to posistion the axis and keep the DRO in Mach3 alive and counting.

With only 1 Milling Machine I still have the need to turn a hand wheel from time to time.

I supose the Z axis could by reworked with a larger servo, power supply and drive to increase cold shop performance. For now I will work with what I have being mindful that a cold machine can cause problems with increased friction and loading of the servos and drives.


Ark1

TonyK.

[Ark1]

The trouble with building all of this is that at times an problem will crop up that was missed in the thought of design.

I was milling an 8" x 1/8" slot for an O ring seal to make a vacuum chamber for degasifing a mixed rubber compound. Using an 1/8" end mill and my spindle speed at 2500 rpm and 3" a minute feed and the slot was progressing well.

Then the spindle stopped but the X axis continued to travel and broke my new end mill. Missed that one. Interlock the spindle with Mach to stop travel. After a bit of trouble shooting it was apparent that I had burned out the 1.8Kw spindle motor. The shop was cold, the belts tight, the oil in the gear box thick and the overloads set just a bit on the high side to compensate for the 600 Volt dynamic Phase Converter inbalance. Where to go from here. I did not want to get the motor rewound, so I opted to purchase a new 3 phase 240 volt motor and VFD. The unit I purchased was from Transwave Converters in the UK. One of the problems was the limited amount of space for the Spindle motor. The frame was metric 90L. The VDF is a Jaguar Cub and I bumped the motor up to 3 Hp or 2.2Kw.

The motor is a universal foot mount unit that allows the feet on the motor to be placed on any side of the motor to allow for clearance of the Junction Box. I tried installing the motor with the JB on the top but was forced to remove the motor and remount on the mounting plate due to clearance issues.

When I ordered the VFD I also ordered a remote start stop station. I have incorperated this in the Mill Control station as I still want to be able to use the mill in manual mode for small jobs. By doing this the remote mill station comes with a relay on the Jog selector button that will allow me to use the dry contact on the Sound Logic Board and have Mach3 turn the spindle on and off. In run mode I can use the VFD station to start the spindle when I use the mill manually.

I have followed the IMO drive manual and have installed the VFD in the control cabinet of my Mill as instructed. I am hoping noise will not be an issue. Time will tell when I start the mill and run through the comissioning steps. The VFD also has a fault system that has a set of dry contacts that I will put in the Mach3 EPO circuit. If the drive faults it will signal Mach3 to stop the axis feed and hopfully not destroy a part in the process or break a tool.

I am sure glad I made prints as I wired up the mill as this change is simple now to do. Just review the prints, change the drawings, implement the changes and proceed to commissioning.

Here are the current pictures of where I am.

Just a mention here. Pete Moss of Transwave Converters was most helpful with this purchase and sent me links to review as well. Shipping from the UK to Canada was only a day! and cost $140 by DHL. Shipping weight was 60 pounds. DHL does not charge brokerage on items less the $1600 only a $7 handling fee to clear the package into Canada. My package left the UK at 3:00pm was in Cincinati by 6:00 AM the next morning and at my door in Grimsby Ontario Canada by 4:00 pm the same day. The drive package with remote station and motor was $637 CND.

Ark1

[diyengineer]

At least now you have a new motor One less thing to worry about failing later on haha. Loooks goood!

The trouble with building all of this is that at times an problem will crop up that was missed in the thought of design.

I was milling an 8" x 1/8" slot for an O ring seal to make a vacuum chamber for degasifing a mixed rubber compound. Using an 1/8" end mill and my spindle speed at 2500 rpm and 3" a minute feed and the slot was progressing well.

Then the spindle stopped but the X axis continued to travel and broke my new end mill. Missed that one. Interlock the spindle with Mach to stop travel. After a bit of trouble shooting it was apparent that I had burned out the 1.8Kw spindle motor. The shop was cold, the belts tight, the oil in the gear box thick and the overloads set just a bit on the high side to compensate for the 600 Volt dynamic Phase Converter inbalance. Where to go from here. I did not want to get the motor rewound, so I opted to purchase a new 3 phase 240 volt motor and VFD. The unit I purchased was from Transwave Converters in the UK. One of the problems was the limited amount of space for the Spindle motor. The frame was metric 90L. The VDF is a Jaguar Cub and I bumped the motor up to 3 Hp or 2.2Kw.

The motor is a universal foot mount unit that allows the feet on the motor to be placed on any side of the motor to allow for clearance of the Junction Box. I tried installing the motor with the JB on the top but was forced to remove the motor and remount on the mounting plate due to clearance issues.

When I ordered the VFD I also ordered a remote start stop station. I have incorperated this in the Mill Control station as I still want to be able to use the mill in manual mode for small jobs. By doing this the remote mill station comes with a relay on the Jog selector button that will allow me to use the dry contact on the Sound Logic Board and have Mach3 turn the spindle on and off. In run mode I can use the VFD station to start the spindle when I use the mill manually.

I have followed the IMO drive manual and have installed the VFD in the control cabinet of my Mill as instructed. I am hoping noise will not be an issue. Time will tell when I start the mill and run through the comissioning steps. The VFD also has a fault system that has a set of dry contacts that I will put in the Mach3 EPO circuit. If the drive faults it will signal Mach3 to stop the axis feed and hopfully not destroy a part in the process or break a tool.

I am sure glad I made prints as I wired up the mill as this change is simple now to do. Just review the prints, change the drawings, implement the changes and proceed to commissioning.

Here are the current pictures of where I am.

Just a mention here. Pete Moss of Transwave Converters was most helpful with this purchase and sent me links to review as well. Shipping from the UK to Canada was only a day! and cost $140 by DHL. DHL does not charge brokerage on items less the $1600 only a $7 handling fee to clear the package into Canada. My package left the UK at 3:00pm was in Cincinati by 6:00 AM the next morning and at my door in Grimsby Ontario Canada by 4:00 pm the same day. The drive package with remote station and motor was $637 CND.

Ark1

[Ark1]

Just a short post if you are looking for a manual for the TOS FN20 or other older machines check out these links.

http://www.lathes.co.uk/manuals

http://www.lathes.co.uk/catalogues

I stumbled upon it yesterday and have found a manual for my machine the TOS FN20. This vendor has hundreds of manuals for older machines and if you have a manual for an older machine contact Tony Giffiths as he is interested in obtaining manuals and blue prints for older machines.

Ark1.