Monarch 60

[rabler]

Dave,
Good to see the Monarch working. I did similar with my 12CK in terms of motor RPM, I'm using a vector rated Baldor with RPMs from 40-90Hz. The 612 is going to run off a RPC for now, but it has 32 speeds that go up to 1500RPM in factory configuration. After using both for a few years I have several things to address on each.

The Skyhook is a nice accessory. I find anything over about 6" chucks I want some sort of lifting mechanism to avoid damaging ways, and my back.

 

[Beckerkumm]

I worry about running the 60 as high as 90 hz. Are you concerned about the clutch wearing or the input side of the gear train at all? When you compare the headstock of the 612 to the CK, does it look like mainly the bearings are different to allow for the greater speed or are the gears also redesigned ? I've wondered if monarch just took the design of the CY and 60 ( both very similar ) and drastically changed it to step up the speed or if the old design can handle speeds over 1200 which seems to be the top end available before the 612.

I'm looking forward to a thread on the 612. I've seen some of your CK over at PM. Dave

 

[Beckerkumm]

I went into the headstock and removed the oil pump. The Model 60 has an opening in the casting to allow access so much easier than on the C series. Cleaned the filter and two screens, and tested all meters. They all pumped oil equally but I did replace the one going to the rear spindle bearing as that is the one that runs warm when overspeeding the spindle. The job was really quite simple except for the part where I dropped the wrench in the headstock and had to fish it out.

Dave

 

[rabler]

I worry about running the 60 as high as 90 hz. Are you concerned about the clutch wearing or the input side of the gear train at all? When you compare the headstock of the 612 to the CK, does it look like mainly the bearings are different to allow for the greater speed or are the gears also redesigned ? I've wondered if monarch just took the design of the CY and 60 ( both very similar ) and drastically changed it to step up the speed or if the old design can handle speeds over 1200 which seems to be the top end available before the 612.

I'm looking forward to a thread on the 612. I've seen some of your CK over at PM. Dave

Dave
I’m not really worried about the CK overspeed causing issues, especially at hobby use levels. My understanding is it was available with just over 1000 rpm as an option, and that’s my max in my configuration. I do tend to run it on the lower end of the VFD range and use gear selection for speeds unless I need the higher RPM. Motor rpm in addition to gear selection does make a difference on clutch action, I don’t like shocking the gear train with the clutch grabbing too quickly. The headstock seal around the end gear drive to the qcgb on the CK leaks badly so needs replacement.


I haven’t been into the headstock of the 612 yet. I strongly suspect it is a complete redesign as it uses a dial for most of the speed gear range selection, with one separate high/low lever. I’m currently building a bridge crane in my shop, in part to use on the 612. I previously pulled and reinstalled both the apron and QCGB on the 612 with various hoists but that was not easy.

 

[mksj]

This is the VFD control system for Dave's Monarch, we went with a Yaskawa GA500 VFD (56A output) to run the lathe 10Hp motor which is 25.4A, so some headroom should it be run on single phase at some future point. He will be using a PhasPerfect to power it. The VFD enclosure has a transparent front panel so one can check the status of the VFD, I did custom plug and socket shielded cabling so very easy to assemble. I went with #6 THHN internal wiring with an 63A rotary disconnect and 60A slow blow J class fusing. Since the lathe has a clutch system we went with a somewhat simpler implementation of a control system, so 3 wire control with IDEC 30 mm industrial switch gear. The wiring uses 2 separate circuits, one for VFD control and the other for 24VDC power to the control light circuit/tach, a single relay is part of the E-Stop system which disconnects the front panel signal controls and issues a VFD fast stop command. There is triple redundancy in the E-Stop system and double in the run circuit should the run switch fail closed. there are additional wiring for JOG and 2 stage braking should he want to add that at a later point. The Front control panel was sent out to Front Panel Express after designing, it is 5mm aluminum which is powdered coated.

The Tachulator is installed in a custom enclosure along with a 3-turn mil-spec. speed pot. The Tachulator is wired to use a magnetic sensor, something that is not available in their kits.

As usual, getting parts was a big issue, so took about a month to get all the parts, in the interim I worked on the control system design and programming, which I finished up today. Always seems to be a few bugs in the drive software for programming, but I eventually got it all worked out. I always like to say, I do not want to build another one of these VFD systems, I guess I get some memory loss with time of what a PTA it is to do these systems. Now to figure out how to get this all shipped...
Mark

Programming:


Control Panel and Tachulator/speed control:


E-Stop testing:


Wiring and Cables:

 

[Beckerkumm]

That is a work of art. I have some limited mechanical ability but Mark's work puts my old machines into another league and I appreciate the expertise and his willingness to put up with me. I have an old retired guy who works on my electric motors and he says when I show up I'll have something "weird " for him to do. I suspect Mark feels the same way.

Thanks, Dave

 

[tailstock4]

Nice job, Mark, on the VFD system. I use a taculator on a few of my machines and like them.

I do have some thoughts on speeding up these old lathes. While I believe it is true that a given lathe may use the same spindle bearings for several RPM ranges, I believe that it is also likely that they did not use the same preload. As speed increased, preloads would go down. An example might be my Pacemaker which has externally adjustable spindle bearings. This is a good thing if an experienced person is doing the adjusting - something that was probably a safer bet in the 1940’s and 1950’s. The Pacemaker had a top spindle speed of 1,000 to 2,000 RPM.

Another thing to keep an eye on might be the secondary shafting and bearings. In this class of machine, especially with helical gears, most of the shafts would be on tapered bearings. Although these are not preloaded in the same way as a spindle, they are set for clearance. On the Pacemaker they are adjustable so periodic monitoring of their temperature might be something to check on. Also, if you do decide to back off on the spindle bearings, remember that a little goes a long way. You would need to re-seat them and then run through your spindle deflection test and monitor surface finish.

But before doing all this you might want to consider something I did on the Rivett. The Rivett has a 3,500+ RPM headstock. It uses an ISO 150 which is a 40W gear oil in the headstock. I believe they did this to dampen the effect of the gearing on surface finish. But this heavy oil makes restricting flow to the bearings important to guard against excessive heat rise from over lubrication. But in a colder shop, the oil can take a considerable amount of time to reach the bearings on initial startup. My solution was to go to a synthetic oil (Mobile SHC) of the same viscosity. This greatly reduced the time it takes for oil to reach the bearings. It also reduces friction. The Rivett has at high speed some wrap around and aeration of the oil. It also helped with these.

Your 60 series might be a good candidate for this as it might reduce some friction in the bearings and increase the efficiency of the oil pump in terms of oil volume. It would also allow for quicker circulation of oil in the head stock, which would also help with heat reduction. But of course, like everything, there is at least one downside. The stuff is not cheap. But it might offer some help for a modest speed increase.

 

[Beckerkumm]

Good information. My set up increased the motor pulley so the speed chart is accurate at 40 ( 38.9 ) hz. I may overspeed the clutch pulley by 20 % but only rarely. I have noticed some warmth at 1000 rpm and a little more at 1100-1200 which I don't intend to run but wanted to see how they handled it. I believe prolonged running at 1200 would heat up the bearings beyond what i'd want to do for any period longer than 5-10 minutes but more testing needs to be done since I cleaned the pump and fittings. Warm is good, hot is bad. I will typically run at lower hz for a few minutes as I know it takes about a minute for the oil to get through the tubes and into the bearings. Your suggestion about Mobil SHC is interesting as I would have guessed that going from the ISO 68 recommended to a 46 might be in store if running above 700 for long. I know the 10ee used ISO 32 as does my Smart Brown but the idea of heavier oil with less friction wasn't on my radar screen.

Is the correct SHC the 626 circulating oil ?

I'm on to the clutch now and will follow up with that later.

Dave

 

[Beckerkumm]

Started going through the clutch tonight. It will be a few days before I can get back to it but I have new 6018 Explorer bearings for it. The pulley seems to run like it should but it won't take grease or expel the old so I need to see what is going on. I figure the bearings will be fine since i bought new because that is how it goes. I will need to extend the largest puller i have and wrap around the V groove un less someone has a better idea for removing the large sheave. As I've found with this machine, nothing seems to have been cobbled up and I'm not even sure the clutch has ever been removed. The springs are good and the rollers and disks look good.

I could use advice as to how to lubricate the rollers and springs that engage the cone. I'm wondering if something like Slick 50 or some other fairly dry lube might be better that grease. There wasn't any evidence of grease on them before cleaning.

Dave

 

[tailstock4]

As far as lubricating the rollers, I might suggest something like copper anti seize. I also keep quantities of Kluber grease in a container that I use to smear on components like these. Both will stay for a long time. They also won’t become a sticky residue when they do dry out. But whatever you use, I would make sure it is something that won’t migrate to someplace it shouldn’t over time like friction plates.

Regarding your question about if the correct SHC is the 626 circulating oil – the answer is yes. This is I believe the ISO 68 stuff. Although it has all the properties and then some of ISO 68 gear lube, it circulates and pumps like a grade lighter in conventional oil. I don’t know what it would cross reference to. It has been around many years, and I’ve used it for quite a few years on a few of my personal machines and in an industrial environment.

My thinking for deciding whether a machine is a good candidate for this oil is if a machine has wet clutches, brakes and pumps inside the gearbox and has no particular need for friction or temperature reduction then I usually consider the money spent on more frequent oil changes to be a better choice due to an increase in contamination from these additional components. However, a machine like the Rivett where I was trying to improve circulation and reduce friction with an absence of these other components means the possibility of longer drain intervals. This makes the SHC oil seem like a more attractive option.

Personally, for this application I would stick with Mobile if at all possible.