Churchill Cylindrical Grinder

[shedhappens]

This thread has spawned from here http://metalworkforums.com/f223/t199629-churchill-cylindrical-grinder-free-home

The grinder arrived at my place on Saturday morning but the driver wasn't game to tackle my gravel driveway down to the shed.
Didn't think he could make the corner around the house......no worries I have a chainsaw and the fence is stuffed anyway :D
Nah !...:? still no good coz he had a duel axle truck, with only one axle drive he reckoned he would get stuck, maybe he would have ? I know those trucks do get stuck pretty easily. So let the tyres down on the lazy axle ? Nah !
So I ended up with a new garden ornament, personally I thought it looked just lovely but the Mrs wasn't overwhelmed :oo:

[shedhappens]

I had quite a bit of trouble finding someone to move the grinder the last 40 mtrs to it's new home, there are a lot of pussy's out there and hiring a telehandler or a rough terrain
fork wasn't going to be cheap.
Anyway I rang a mate and he put me onto Karl at Garner & Wheeler, this bloke was a beauty and had that machine down into my shed without a hassle and helped me get it into its new spot.
We sat the grinder on the fork tynes on blocks and gently skidded it into place :D
We got yacking and it turned out that we had mutual mates from years ago, he charged me 200 bucks and refused to take anymore, good operator and a good bloke.
The other bloke charged me 500 and I thought that was pretty fair also, so for 700 bucks I have a really cool Churchill grinder sitting in my shed.
Thank you again Phil :2tsup:
As a matter of interest the first truck driver reckoned that the grinder weighed closer to 4 ton than 3, the Franna man said it weighs 3.7 ton.

I still have not had a good look at the thing yet, when it first arrived I gave it a bit of a squirt with wd40 and covered it up as it was about to rain and then I got visitors just as it was deposited into the shed.

So here is some action shots and no doubt more pic's and questions on how to drive the thing are yet to come.

cheers, shed

[shedhappens]

Hi fella's, I decided to have a look at this toy, yeah I know it has only been sitting here for nearly 3 years.:oo:

I have started to clean it and I flushed and changed the oil in the spindle head, repaired the leaking oil level sight glass and drain plug.

I fired it up and it sounds and runs sweet as a bun :D

It needs belts and maybe some bearings in a couple of the motors but now that I have run it I will
buy belts and do the hydraulic oil......if i can find a drain plug....

If anyone can enlighten me on the usage of the dwell function I would appreciate it, about the only thing that I know about dwell is that it is for finishing.
The generator on the back of the grinder powers the electrical side of the dwell function, it is missing a sprocket and the chain so at this stage it is not working, but looking at the trouble that they have gone to to fit all the components for this I'll try to get it working again.

I have emailed Churchill to see if they could arrange manuals ect and they will contact me again next week when
the senior engineer returns to the office.
What I was told is that the grinder was built in November 1946 and sold to Vauxhall Motors.

You can have a stickybeak here https://www.youtube.com/watch?v=42pAZJCUl_U&feature=youtu.be

cheers, shed (https://www.youtube.com/watch?v=42pAZJCUl_U&feature=youtu.be)

[Steamwhisperer]

Hi John
the dwell is the pause at the end of each stroke.

Phil

[shedhappens]

Hi John
the dwell is the pause at the end of each stroke.
Phil

Ok thanks Phil, so why does it need to do that ?

Then the sizing gauge switch would be for finishing?

Or am I wrong again, is that to set it to grind to a dia for production work?

cheers, shed

[Steamwhisperer]

Hi John
the dwell is used for 'sparking out' at the end of the stroke. Normally you extend approx. half the wheel width past the shaft length never going completely past as it will tend to grind a taper on the shaft end. If you are grinding up to a shoulder the dwell comes into play a bit more.
Gauging I have never heard of or seen before but then I have only used a TOS and a Cincinnati.

Phil

If I am wrong on this please anyone feel free to chime in.

[shedhappens]

Thanks Phil, I will get the dwell/sizing gauge system working and take measurements of the wheel head movements.

Fingers crossed Churchill has some info to shed light on this.

cheers, shed

[jatt]

$200 for a Franna back in 2016 aint bad. From memory cost me $300 to move a truck body next to the workshop at about the same time. Needed the storage space and the body (already on site) cost me zip, so no complaints.

2 days with a 3 tonne Tele was over $500 (forks and bucket) delivered to site about 18 months ago. Had dirt to shift and a couple of presses to get off a truck, so seemed a good choice for me at the time.

Your grinder at 3.7 T -- the Franna was definitely a wise move.

[shedhappens]

I have had a bit of a look at how the hydraulics for the infeed works, when the infeed lever is pulled toward the operator the valve directs the oil to the hydraulic cylinder, this has a gear rack cut into the cylinder rod that engauges with a segment gear that is incorporated into a crankshaft that rotates and pushes on a connecting rod
that appears to be connected the Y axis nut and moves the head/grinding wheel forward about 40mm (at a guess).

When the head moves forward this 40mm distance the end of the rack presses against the servo rod, the movement of the rack is now restricted by the servo, the oil in the servo is now under pressure and as there is a check valve
(non return valve) in its oil supply line the oil is forced under pressure to the needle valve control on the front of the machine, this needle valve seems to be the control for the infeed speed while grinding by restricting the speed that the grinding wheel can move towards the job. The needle valve is screwed in tight at the mo and might require some work, oil pressure is leaking off somewhere because the needle valve is closed firmly and in operation the head moves forward 130 thou in about a minute and half when the end of the rack contacts the servo rod.

Electrical...... well um.....sure beats me :rolleyes:
Have a look at the pictures and be amazed at the high tech ingenuity employed here in a time before semiconductors diodes and so forth.

I have a PDF manual for the grinder that should be squishing is way down the wire into my poota tonight, supposedly there is a wiring diagram so here's hoping.
I removed the 110 volt DC generator from the machine and I temporarily connected a 240 - 110 v transformer to the input wiring, via a bridge rectifier. Yup, as as suspected nothing happened, I didn't even get boot. The only joyful moment was when I put a screwdriver across the dwell switch contacts and the dwell light illuminated.

Here are some pics for you.

[caskwarrior]

Wow that's some crazy stuff. Love seeing annotations like 'mystery lever'. Is anything obviously wrong with the DC Genset?

[shedhappens]

Is anything obviously wrong with the DC Genset?

Nothing obvious, probably brgs, brushes and clean the commie.

cheers, shed

[Ropetangler]

My knowledge is meagre here to say the least John, but just wondering if the proposed second check valve in photo 3 isn't a pilot valve, ( a hydraulic relay), and for what its worth the little globe looks like it may be a neon, although it certainly looks different to any neon I am familiar with. If so it may be some kind of voltage regulator, if not an indicator. She was certainly a sophisticated lady in her day, and a very expensive one too no doubt.

[BaronJ]

Hi Guys,

Definitely a complex machine !

The little globe is a neon indicator bulb. Very common on old equipment. I remember them on teleprinter systems years ago. In fact I've just resurrected a teleprinter motor in the hope that it might be useful.

[shedhappens]

Churchill have sent me a scanned copy of a manual for this grinder in PDF format, it is 27 pages and has some good information but is fairly meagre, it has no information for the 110 volt wiring or circuitry that controls the hydraulic infeed, it has no oil quantities or info how to change the oil, it states that the oil should be changed every 18 months to 2 years or more often if in constant use, no mention of an oil filter other than the fly catchers at the ends of the ways.

The hydraulic oil change is probably going have to wait until I get a bit fitter so that I can rob a bank, I tipped in about 14 ltrs and the oil level came up about an inch.
It is filthy in the oil reservoir so it also looks like I may even enroll in the Gymnastic School of Arts so that I will be able to contort my decrepit carcass into the unimaginable postures that will be required to clean the muck out.



My knowledge is meagre here to say the least John, but just wondering if the proposed second check valve in photo 3 isn't a pilot valve, ( a hydraulic relay), and for what its worth the little globe looks like it may be a neon, although it certainly looks different to any neon I am familiar with. If so it may be some kind of voltage regulator, if not an indicator. She was certainly a sophisticated lady in her day, and a very expensive one too no doubt.

I am sure you are correct Rob, I guess it is to reduce the flow and pressure to the valve and give better (slower) flow control, that valve is not shown in the diagram that I now have, a non return valve is shown situated close to the pump and none shown on the back of the machine as shown in the picture up thread.


Hi Guys,

Definitely a complex machine !

The little globe is a neon indicator bulb. Very common on old equipment. I remember them on teleprinter systems years ago. In fact I've just resurrected a teleprinter motor in the hope that it might be useful.

Hi John, I don't think that it is an indicator bulb, it is hidden unseen inside the control box and there is an indicator light up on the spindle hsg. I think that it must be something to do with voltage regulation or switching but I need to do a bit more homework here. A bit of info about this here https://en.wikipedia.org/wiki/Neon_lamp#Voltage_regulation

I think that I am going to pull the control panel out to have look behind it and trace all of the wiring to and from the various switches and draw an electrical diagram, from that I will have a better chance of repairing or maybe even upgrading the electricals.

There is a mercury tilt switch pictured below, it is tilted by a linkage connected to the solenoid/relay below it, I was thinking that it might be to switch the solenoid that operates the valve lever, that solenoid is a whopper and would throw a decent spark when switched off, I don't see any capacitors to stop or reduce arcing.

cheers, shed

[BaronJ]

Hi John, Guys,

Yes that bulb is definitely a neon one. It was very common to use them as voltage regulators. They strike at about 85 to 90 volts and consume 10 milliampere or so. Some actually have a current limiting resistor fitted in the base cap. Often you would see two or three in series being used to regulate higher voltages. In fact any multiple of 90 volts.

The technique was to use them to control the grid of a large (tube (American), (Valve (English) that could supply the required current, often at voltages far higher than could be regulated any other way.

That mercury switch is a whopper !

[shedhappens]

Hi fella's, the 110 volt DC generator that powers the electrical circuit for the hydraulics for the grinding dwell control is a goer.

If anyone is interested in the timer control board you can see it here https://metalworkforums.com/f309/t203783-resistors-neon-suggestions-please

Ok.... firstly don't be lazy, like me, don't use a CCMT insert to cut copper.
Yeah it works sorta but not as good as HSS, as can be seen in the photo below it cut pretty rough and smudged into the gap between the segments. No biggie as I needed to undercut the commutator anyway.
After undercutting I finished with wd40 and 400 wet and dry on a lathe file.

I made a rotary grinding tool to dress the damaged/worn brushes, with the emery glued on it was pretty close to the same diameter as the commutator, as you can see it clogged the emery but still did the job.

So now I need to make some pulley's, with the generator spinning at 1150 rpm it puts out 110 volts so I will need to make the ratio to suit that. The oil pump drive motor also drives the generator and has a double row sprocket on the shaft for the generator and nothing on the generator shaft, I will remove the sprocket and fit a pulley's and a belt.
Both the oil pump drive motor and the generator have virtually no adjustment, maybe half a bolt diameter of adjustment, so I think that it will end up with a spring loaded idler pulley.

cheers, shed

[shedhappens]

I found some pulley's to drive the generator, I made a drive pulley out of an old howard bantam pulley and bored it to suit the shaft on the test motor pictured in the previous post.
I then cleaned up an old alloy pulley to about the size i needed and fitted it on the generator and fitted a belt, i adjusted the motor rpm with the vfd to exactly the same rpm that the drive motor on the grinder runs at and measured the generator voltage.
I removed and machined the pulley 3 or 4 times until the generator was running at the speed required and putting out 110 volts.
Then rebored the cast pulley to suit the motor on the grinder and gave it a keyway.
I put the gen back on the machine and made a idler pulley bracket and tidied up another pulley, bored it and fitted a couple of brgs.

Test run :2tsup:

[shedhappens]

I noticed that when the grinding wheel was running that I could see the work head vibrating, it wasn't much of a vibration tho and it felt only slight...... but...

There was no weights in the bucket of rust that came with the machine nor was there any in the spare wheel flange, i guess the pics should tell the story here, both of the wheel flange dovetails needed re machining and as you will see the balance weights are not quite finished but well on the way.

cheers, shed

[BaronJ]

Hi John,

How are the weights secured, or are they loose like those on CD drives ?

[shedhappens]

Hi John,

How are the weights secured, or are they loose like those on CD drives ?

Hi John, there will be a grub screw at the centre line of the 2 halfs.
With a bit of luck i will get the threaded holes done in the next day or so..... actually... it might be a little longer because i am thinking that i would like all the threaded holes to have the threads start at the same point so that all the weights (inner and outer) are interchangeable with each other, if that makes sense:rolleyes:

cheers, shed

[BaronJ]

Hi John,

Yes that makes perfect sense. :2tsup:

I must admit I did struggle to try and work out how you would secure them where you needed them. Very nice work making them as well.

Thanks for the explanation.

[simonl]

That's a nice job with the balancing weights shed.

My surface grinder uses similar weights as well.

Simon

Sent from my SM-G970F using Tapatalk

[shedhappens]

Here are the finished weights, the longer weight is a spare, when i say spare i mean that if it is needed it gives me the option of using it as is or cutting it in half and having 2 smaller weights.

I drilled the first hole a bit south of where i was planning, i wanted all the weights to be interchangeable with each other so i went
with that hole placement for all of them.

To get all the threads to start in the same place i drilled through the fixture with the 5.5mm tapping drill then put a 1/4" drill through the back of that hole and leaving about 12mm of the 5.5mm hole, then came in from the back and tapped the remaining 12mm of the 5.5mm hole to 1/4 unf.

With the weights clamped into the fixture i then tapped them from the back using the thread in the fixture as a thread starting and following guide.

For a grub screw effectiveness test i fitted all the weights into one of the flanges and set that up in the lathe and faced the weights,
none moved so i called that job done :2tsup:

Next up is a balancing gizmo, bit of a problem is there is no through hole in the outer wheel flange for a shaft to pass through.

cheers, shed

[shedhappens]

I still have a couple of other things to do to the grinder so i have not tried it yet.

The spindle parts are pressed together and turned to within a beez from the finished size then ground to size and i skimmed the flange
front and back while it was in the t&c grinder.

The spindle tube is an aftermarket m/c fork slider with a slug pressed into each end and turned for the brg's.

The brgs are ceramic brgs bought off ebay, they seemed a little gritty when i got them so i washed and blew them out and they are
much better. The shaft spins very freely and i think it should work ok for balancing this size grinding wheel.

I knocked up a frame and SHEZZZAM there is a wheel balancer on the bench :D

cheers, shed

[BaronJ]

Hi John,

Thats a lovely job :2tsup:

[shedhappens]

I weighed the 8 flange and mounting bolts, they were up to 1 gram different in weight, i took a bit off the ends with a flap disc
to get them all the same. Then i dressed the wheel before putting it on the gizmo.
The ceramic brgs did not work that fantastic, i washed the oil out of them and they might of worked a bit better.
So with a bit of guestamation and nearly falling off the chair a few times from getting dizzy watching that rock spinning around i think that i got it fairly close to balanced, i will soon know when i grind something.
The vibration that i could previously feel on the workhead has gone so that is promising, just for entertainment i did the 2 bob trick with all 4 motors running.

cheers, shed

[shedhappens]

Another little job ticked off the list.
I took some measurements and I found a suitable CV boot in a specials box that I had seen at an auto shop.
It works like a little beauty :D

cheers, shed

[shedhappens]

As you would expect the coolant tank was a swamp, or maybe it was a black lagoon.
I shoveled it out and cleaned it with hot water and degreaser, cleaned the all the pipe fittings ect and fitted new clear pipe.
I poured in 88 ltrs of water and 4 1/2 ltrs of coolant, I reckon it probably wants about 100 ltrs all up
One problem that needed attention was the wheel cover, the cover bowed out at the bottom and the coolant poured out of the crack
and straight into the coolant reservoir and by taking this shortcut it avoided the settlement tank.
So I made a poor copy of the existing cover clamp and fitted some grinder guard sealing strip.
Sparks soooon......

cheers, shed

[KBs PensNmore]

Do you think the grinder guard sealing will hold up for any length of time???
Kryn

[shedhappens]

Do you think the grinder guard sealing will hold up for any length of time???
Kryn

Hi Kryn, "will it hold up"....... i pondered that very question myself, I thought about all the foam air cleaners and precleaners that i have cleaned and oiled over the years..... and given that it was in my hand and i didn't have to go for an hrs drive to find something else the answer to the qwestion "will it hold up" was .....suck it and see man... :D

cheers, shed

[BaronJ]

Hi Guys,

I think that I would have extended the sealing strip to go right around that lip. You have effectively created a gap above where coolant can get between the two lips above the strip and run between them.

A trick that I've done in the past to create a seal when I didn't have a suitable gasket was to use hot melt adhesive !

The application at the time was a washing machine water pump. It had a cast monkey metal support for the motor and a Bakelite cover that was held on by three spring clips round the edge. I greased the pump cover edges and heated the casting with a cooks torch, then ran a bead of hot melt around where the gasket would have been. I fastened the two parts together whilst still hot and trimmed the flash off with a Stanley knife when it had cooled.

The grease stopped the hot melt from sticking to the cover and allowed it to be removed without disturbing the hot melt. That pump was still in use nearly eight or nine years later without leaking when it got scrapped due to drum failure.

I still have the replacement seal for the pump, but it was never fitted. I also still have the motor and controller from the washer ! Waiting to be used for something or other useful. :o

[shedhappens]

Hi Guys,
I think that I would have extended the sealing strip to go right around that lip. You have effectively created a gap above where coolant can get between the two lips above the strip and run between them.


Hi John, I had a pretty good look where it was and wasn't leaking and it is not leaking now so i will just keep an eye on it, the clamp
and the seal seems to have done the trick and if it does leak again i will have another go at it.

I think the coolant is pretty much flung off the wheel before it gets to the second baffle.

Here is a pic showing how churchill has dealt with returning the coolant from the wheel guard.

cheers, shed

[BaronJ]

Thanks John,

I had no idea that there were baffles in there ! Your picture helped make it clear to me why you only put the sealing strip where you did.

Looking good :2tsup: I'm watching and learning :)

[shedhappens]

I wanted a better/quicker and accurate way to adjust the table and also a way to accurately know how much I am grinding (DOC) and more accurate finishing so I have added a couple of indicators.

The Syvac, I fitted a rubber dust boot to the plunger and I bored a bit of aluminum and slid it on the other end to protect the outer end of the plunger.
The mounting bracket is made out of 50mm SHS and clamps on to the cast iron splash tray, the indicator is fitted to a spring loaded swing away mounting and this also has a micro switch that retracts the grinding head almost instantaneously should the adjustable rod give it a shove in a moment of brain fade on my behalf.
I thought that the indicator reading would bounce around a bit when the machine was running but it gives a very steady reading.

The adjustable rod is adjusted to suit the diameter of the job to be ground and also has enough length to accommodate for wheel wear and new full dia wheels.
For an anvil it has a short length of HHS pressed into a bored hole in the end of the rod and then ground to finish it.

The adjustable arm and the indicators for checking the job and adjusting the table are removed after use and put away before grinding.

cheers, shed

[Ropetangler]

That looks really nice Shed, well thought out and nicely executed. Like John (Barron) I am watching and learning too.