[xlojon]

Greetings,

I have an Excello Model 602 vari speed 2hp turret ram vertical mill w/NMTB40.

I have been trying to remove the lower half of the variable speed pulley to service the brake without any luck. I have the top pulley half off and I removed the motor housing from the mill head. It looks like there is a spanner type nut that holds the lower pulley half down on the main shaft. I cannot for the life of me figure out how to get that nut off (direction) or special process. I have broken two spanner tools and I have not budged the nut. I need to get to the brake to replace the shoe, the oil seal and the main shaft. The shaft with the keyway is worn and was binding on the bronze sleeve of the moving upper half of the variable pulley.

Does anyone know how to get this apart?

I also need to replace the micro quill reverse/forward button and shaft that is in the center of the micro quill wheel. Has anyone serviced that area of the mill head??

Thank you!

I was able to locate a service/owner manual in PDF from a member on this site. I then located the OEM parts supplier for the Excello line. They are MAG Maintenance Technologies.

[Al_The_Man]

Did you get the lower half pulley off, IIRC, I believe it has a ring nut that I had to remove with a pin-punch, give it a good jar with a hammer to unscrew.
Al.

[xlojon]

Al,

I have yet to get that spindle nut off. I am building a long socket to engage the spanner holes and then hit it with an impact.

I managed to disassemble the entire mill for cleaning and inspection. The micro quill drive engagement pin was easily repaired with a larger shaft and a bigger roll pin.

I am ordering a new quill return spring and new wiper seals.

I am glad I disassembled the entire mill -- the spindle bearings in the quill are shot! They are NOT sealed like XLO claims. Looks like the bearings are big$$ SKF7010, 7008, 7006 are the three bearings in the quill.

I also found some galling on the x and y axis. Does anyone know how to address minor galling? Grind the bad area? Grind and fill the bad area? Any particular grease better for reassembly?

Last ---- Has anyone sent in a mill table to have the surface reground??

[Al_The_Man]

I also found some galling on the x and y axis. Does anyone know how to address minor galling? Grind the bad area? Grind and fill the bad area? Any particular grease better for reassembly?

A freind of mine uses Tercite, I have not used this method personally, but he swears by it.
You need to change the metering devices at the end of every lube line, and remove the automatic oiler and flush it and clean it out, re-fill with way-lube oil, Vactra etc.
Al.

[xlojon]

I finally got the retaining nut removed. My custom spanner socket and impact did the trick. I found it very interesting that there was no oil seal to keep oil out of the brake or dirt out of the 2 speed box. That is being changed.

Al, After considering the cost of repairing the stock variable speed reeves belt drive, I have decided to go the VFD route.

The Gates website has the program to help select the correct belt and pulleys BUT I have yet to find any info on the motor, etc. I have a 2 hp Baldor VFD that is new in the box. Did you use the stock GE TriClad 2hp motor with a VFD?

[Al_The_Man]

I have a 2 hp Baldor VFD that is new in the box. Did you use the stock GE TriClad 2hp motor with a VFD?

Yes.
The motor is 4 pole which I use up to 120Hz so it essentially doubles the speed of the motor, I have had no problems, if it was a 2 pole motor, it would run at this rpm anyway.
The Mitsubishi VFD I used has auto tuning, very fast accel/decel rate, it pretty much stop on a dime.
BTW, XLO went over to recommending/using Transmission fluid oil in the gear box.
Al.

[usfwalden]

I have a spindle wizard vmc built on the ex-cello-o 602 base which I am retrofitting right now. I'm just finishing repairing all the broken stuff and switcing to installing the new control. My varispeed housing is probably different than yours but I also have the national 40 tool holders and had looked up the bearings in case the spindle proved bad--thankfully it seems good. The price on those bearings can vary widely so I suggest you shop carefully. I got quoted 280'ish and 300'ish per pair from my supplier of choice (for fafnir) and 520'ish and 380'ish per pair from miller bearing. There's a big difference between $600 vs $1000 to redo your spindle.

I'm going to keep with my varispeed since I have fancy spindle wizard control of the varispeed working but I am also using a 2hp vfd for my 2hp ge motor(easiest way to get 3 phase) and it seems to work well. The vfd unit I'm using is a WEG.

[torinwalker]

As usualy, when one works with ancient machinery... ask the guys who've been around.

I read earlier in this thread that you guys were using a 2HP GE Triclad motor. I've been lookup up contactors to see if this motor has one. It's not evident from simply looking at the motor since the junction box is just that - a junction box. No electromechanical relay to speak of. This leads me to wonder if there isn't some temperature-sensitive or centripetal mechanism that engages/disengages some secondary wiring (or some such device) to handle the inrush of current. My instinct tells me no, but it has been wrong before, and I'd rather not risk it with the VFD not being crazy about contactors. I have no other means to test this motor, otherwise I'd hook it up to 3ph power and just listen for the click.

Secondly, is it true that a 1750 motor would have been run at 3400 RPM if wired with 2-pole? Previous converstations have had me learn that everything is done for a reason, and if a motor was meant to run at 3400 RPM, it would have been wired (or at least balanced) appropriately.

And while we're talking about max RPM, I've looked for MAX spindle RPM on the Excello line of CNCs and have also turned up bupkis. The max spindle with the infinite transmission is shown on the front of the machine as 4500, which is a very respectable spindle speed (I should probably leave well enough alone), but I wonder what the actual safe maximum would be. For example, was 4500 the max because of the complexity of the transmission? Or was it a combination of other factors including the vibration of the spindle, etc?


Torin...

[Al_The_Man]

My 602 was a max of 3800rpm with the old Vari-speed transmission set up.
It is not possible to connect a 1750 (4 pole) motor as 2 pole as this is dependent on the way it is wound.
It should be OK to run a 4 pole motor at 2 pole rpm using a VFD, I run mine up to around 3600.
Originally there should have been a 3 phase contactor to control the motor, this is best left in place and disconnect the single or three phase supply to the VFD to allow disconnect in the case of an E-stop condition.
Al.

[slipclutchms]

Hello!
I just got a 602 as well! I can't find where to get any parts for this thing! I need the top most bearing and the shaft that that bearing rides on....the keyway is shot and it sounds like crap. If I decide to convert to VFD will my 1.5 hp motor work? Just get two timing belt pulleys 1:1 ratio? What have people used for tensioners? Would it be ok to just put the pulley over that worn shaft? i.e. leave the bottom of that spindle pulley in place? Is there enough support there to not bend that shaft? That collar once the top half of the pulley is off seems to have a set screw in one hole, and two holes do not....so that is a spanner nut? Sorry for all the questions!


Thanks,
Dylan

[Al_The_Man]

There is a previous post with a photo of the conversion I did, I have a phone number for Excello parts but I don't know if it is still valid.
810-722-1043 [email protected]
Al.

[slipclutchms]

Thank you!
I searched but I couldn't find a picture of the conversion you did......if I ask you reallllllllly kindly could you post up some pics for me??


Thank you so kindly!
Dylan

[Al_The_Man]

I can't seem to find the original jpg's, I will keep searching.
Al.

[Al_The_Man]

Found it, post #4.
http://www.cnczone.com/forums/bridge...ari-speed.html
Al.

[slipclutchms]

Al you are in fact THE MAN! Thank you! I got that ring nut off, but it cracked through....How do I get that big bearing out from under the brake? And how far should I keep digging into this thing? How hard are spindle bearings to replace?



Thanks!
Dylan

[Al_The_Man]

It is easier to remove the ring at the bottom of the quill and the bearings come out with the drive shaft, it has been a while since I did it.
Do you have the manual? I have it in PDF if you don't.
Al.

[slipclutchms]

I do have a manual, however it is a crapy printed copy and I can't make out any of the part numbers or drawings for that matter. If you could send along a PDF that would be fantastic! [email protected] is my email!

I am going to try to take that ring off the bottom of the quill like you said and go from there. The whole shaft should just pop out and up?


Thanks!
Dylan

[Al_The_Man]

Everything drops out of the bottom,IIRC.
Al.

[slipclutchms]

Thanks for the help! I got the quill out (through the bottom) and also removed the shaft the connects to it above it from the "back gear box". So Now it looks like I have to make a spanner nut wrench tomorrow to get the actual shaft out of the quill......and also how do I split the other shaft in two to replace that bearing? Other than that the tear down is going great !!! Last pic is just of the mill hanging out waiting for her new vector drive!

Thanks!!!!
Dylan

[Al_The_Man]

It's been so long I've forgotten, I know it was tricky.
I should have taken photo's at the time.
Al.