Warco WM280V-F Gearbox

[JasonBModerator @jasonb]

Could be there in the first photo but possibly part way out of the groove.

[Dave HalfordParticipant @davehalford22513]

True, they can't make springs very well, I've got a beach cart where the circlips have been mangled by soft plastic

[Barry Chamberlain 1Participant @barrychamberlain1]

Update – I really have to apologise because I am totally unable to select and upload images for some reason. Perhaps Steve will put up my latest images which show the rearside of the removed gearbox. I have tried to select images on 2 PCs and also this, my smartphone, so seems to be an account problem.

I have been thinking about the various helpful comments that I have received so far and on reflection agree that I have been over enthusiastically changing direction before the machine has stopped. This would explain the damage to the mangled gears.

The original ( and continuing) problem of a stiff ABC selector appears to be down to the triple gear assembly not being free to slide along the shaft. By the look of things could well be debris below the shaft key which is restricting travel. Should become clearer when disassembled.

[S.D.L.Participant @s-d-l]

Posted by Barry Chamberlain 1 on 15/03/2020 23:02:17:

Update – I really have to apologise because I am totally unable to select and upload images for some reason. Perhaps Steve will put up my latest images which show the rearside of the removed gearbox. I have tried to select images on 2 PCs and also this, my smartphone, so seems to be an account problem.

I have been thinking about the various helpful comments that I have received so far and on reflection agree that I have been over enthusiastically changing direction before the machine has stopped. This would explain the damage to the mangled gears.

The original ( and continuing) problem of a stiff ABC selector appears to be down to the triple gear assembly not being free to slide along the shaft. By the look of things could well be debris below the shaft key which is restricting travel. Should become clearer when disassembled.

More pictures from Barry via his IT attachment support engineer (Ongoing joke with Barry as he keeps losing email attachments due to an antiquated email program he loves )

Barry is going to look and see if he can find circlip debris later today.

I expect he will be along with updates later.

Steve

[S.D.L.Participant @s-d-l]

I missed adding this photo

See damage to gears at bottom of photo.

Steve for Barry

[clogsParticipant @clogs]

is it me or does there seem to be a lot of problems with Warco lately….?

I was gonna buy one of their milling machine, little used……

begining think glad I didn't……..

now have a Bridgeport……

[SillyOldDufferModerator @sillyoldduffer]

For the purpose of elimination, would Barry explain how he changes gear please, both now and in the past? The symptoms could be explained by either forcing the box under power, or by a mechanical problem, or by a failed tooth due to earlier damage such as absently mindedly changing gear at high-speed.

Also, is it just the obvious missing tooth and other mangling in the red box, or is there a problem with the gear in green as well?

Lots of possibilities still:

• Operator error
• Faulty gear causing tooth to detach and get caught at speed
• Whatever caused stiff selecting broke and fell into the works.

Unless the gear was cracked during manufacture, it would take a fair amount of force to break a tooth and do the other damage. Only the lathe motor at speed plus centrifugal energy stored in the chuck would be powerful enough to do that much damage I guess? I don't think it would be possible for the operator to break teeth by turning the gear selector knob on his own. But maybe a damaged gear when the lathe was built has gradually worsened over time.

Would missing or damaged circlips or a faulty selector explain the damage? Maybe if the gear pair was run with only their very edges engaged, but wouldn't that damage both gears?

Where's Sam Spade when you need him?

Dave

[JasonBModerator @jasonb]

Posted by clogs on 16/03/2020 11:05:06:

is it me or does there seem to be a lot of problems with Warco lately….?

I was gonna buy one of their milling machine, little used……

begining think glad I didn't……..

now have a Bridgeport……

Maybe there is more of a problem with Warco users, the mill the other day was being overloaded and the OP in this thread just said

"reflection agree that I have been over enthusiastically changing direction before the machine has stopped. This would explain the damage to the mangled gears."

Sounds like it is operator error in many cases to me. 12 years use out of my 280 and no sign of worn gears and I do sometimes change with spindle running.

[S.D.L.Participant @s-d-l]

Message from Barry

The first of the two gears from Warco have arrived. The other one is on back order .

Steve

[ChrisBParticipant @chrisb35596]

On my Wm280, I can move all three knobs on the go at minimum speed – without any strange noises, in fact it's easier with the lathe turning than stationary. The warning on top of the knobs say not to change gears with the lathe in high speed, so the cause of the damage could have been that, but it sure is fine to change at 150rpm,

[Howard LewisParticipant @howardlewis46836]

With sliding mesh spur gears, changing whilst in motion is inadvisable.

In a vehicle, you can double declutch and use you fine control of engine speed to ensure that gears mesh at bthe correct speeds. Try changing gear, on the move, with an old tractor, truck, or bus and you will soon find the difference in technique!

With a machine tool, the prime mover is fixed speed, so you do not have the facility (or luxury)

Other than machines like the Herbert Preoptives, gears are changed with the machine stationary, with the motor stopped, or the clutch disengaged.

Unless you enjoy stripping and rebuilding gearboxes?

Howard

[ChrisBParticipant @chrisb35596]

Posted by Howard Lewis on 21/03/2020 15:57:29:

Other than machines like the Herbert Preoptives, gears are changed with the machine stationary, with the motor stopped, or the clutch disengaged.

Unless you enjoy stripping and rebuilding gearboxes?

Howard

If I can't hear any grinding sounds or any sort of similar noises, then no wear or stripping of teeth should be happening right?

[SillyOldDufferModerator @sillyoldduffer]

Posted by ChrisB on 21/03/2020 14:52:30:

On my Wm280, I can move all three knobs on the go at minimum speed – without any strange noises, in fact it's easier with the lathe turning than stationary. The warning on top of the knobs say not to change gears with the lathe in high speed, so the cause of the damage could have been that, but it sure is fine to change at 150rpm,

Not sure to safe to say it's fine exactly. Although I can change gear on mine most of the time with the motor at dead-slow, I get a mild crunch now and again. Any hint of increased speed makes the chance of a crunch much larger.

After a couple of careless gear whoopsies I made it a rule to only change gear with the lathe stopped, turning the chuck slowly by hand to get the teeth aligned. Wastes a little time but it's zero risk.

It may be some of these machines are more tolerant of gear-changing than others. The selectors on mine aren't spot on.

Dave

[ChrisBParticipant @chrisb35596]

Posted by SillyOldDuffer on 21/03/2020 18:47:19:

It may be some of these machines are more tolerant of gear-changing than others. The selectors on mine aren't spot on.

Dave

Could be as you say, mine changes gear happily while turning at minimum speed with little effort on the knobs, when stationary it's slightly more difficult to engage, sometimes it does straight away, sometimes it takes some turning of the chuck.

The OP said he changes gears before the lathe had stopped, but most probably he changing gears while the lathe was still at high speed.

I have not changed the oil in the gearbox since I got the lathe, so one of these days I'll change the oil and have a look inside.

[JasonBModerator @jasonb]

Depending on what feed gear train you have the input to the gearbox is probably only turning at 9-10rpm when the spindle is at 150.

I don't do it with the half nuts or feed lever engaged which also reduces the load that the gears will possibly be suddenly faced with, I also tend to pause briefly in the neutral positions before moving to the next, Chris looks to go straight from one to the other.

[ChrisBParticipant @chrisb35596]

With half nuts and autofeed engaged it's difficult to change gears – I tried and there's a notable increase in resistance on the selector knob, so I just don't do it.

I had not thought of pausing to neutral, good practice I will take up.

[Brian GParticipant @briang]

My son's Chester has a similar (identical) gearbox and the warning at the top left is enough to stop me trying to change gears when moving, especially as it is his machine and may have to last another 60 years. No problems changing gear when stationary as long as I turn the output coupling whilst moving the lever.

Brian G

[Barry Chamberlain 1Participant @barrychamberlain1]

Just to clarify – I have NEVER attempted to move ANY lever at high speed. Where that idea came from I don't know.

What I intended to convey by "over enthusiastically changing direction" was that I didn't necessarily wait for the drive to completely stop before moving the lever over. I shall obviously do so in future. I also agree that there is no clear instruction in the manual about moving the gearbox levers.

The ABC (triple gear) lever stiffness reported shortly after delivery in 2012 could NOT be overcome by rocking the chuck, which is why the machine was returned. Warco reported that the problem was due to swarf beneath the knob and all has been fine until quite recently. After 8 years of regular use I have no complaints whatsoever with either the machine or the service I have received from Warco who have always been extremely helpful.

Having removed the gearbox cover it is clear that the triple gear does not slide freely over the shaft key and jams when moving to the left. I suspect debris in the keyway.

I have not commented for a while as I am waiting for spares prior to stripping the gear box down. I still have no idea why I am unable to post jpg images, but will continue to add pictures via Steve.

Thank you to all who have made contributions thus far – much appreciated. To be continued …………..!!

[Howard LewisParticipant @howardlewis46836]

I like Jason effectively double declutching his lathe!

The only alternative is to snatch change; as we did,from 1st to 2nd, when starting away on a hill. Some gearboxes could not withstand this technique. The Land Rover was one!

"The quickness of the hand deceives the ear'ole" as a schoolmaster once said.

Howard

[S.D.L.Participant @s-d-l]

Hi

Barry has been busy stripping his gearbox down and repairing and this is the first in a series of posts showing the cause and the repair.

At last I’m able to finish this Gearbox strip and rebuild report. Although I had two gears from Warco (the double and triple gear assemblies) the third gear was on a 12 week back order from China. THEN lockdown arrived and things slowed considerably, so I decided to get as much done as possible prior to the third gear arriving. First surprise, on removing the Gearbox from the lathe body, was when I was removing the rear cover to gain access. After removing 7 of what should have been 10 screws I realise that there was NO screw fitted at the second location in from the left on the bottom row, and the hole had been filled with sealer! When the sealant was removed it was apparent that the hole had been drilled way off centre leaving little thread in the casting.

Inboard of the top row of holes there was a burn mark clearly visible on the rear cover plate. When released it was obvious that the inner face of the cover plate had been ground down – to give clearance between the cover plate and one of the gears! See photos showing the teeth of the larger gear clearly above the ground rear face of the casting…………!

I am still unable to post photos onto this Forum for some odd reason, so Steve has again kindly stepped in to post on my behalf.

Posed by Steve Larner for Barry

[Dave HalfordParticipant @davehalford22513]

Looking at the first photo it appears that the recess for the plate is slanted. Hopefully the shafts are parallel to the mounting surface and the two shafts are parallel to each other.

I'll leave the rest unsaid.

 

Apologies Barry, I assumed the worst on your gear shifting.

Edited By Dave Halford on 01/07/2020 10:40:01

[Barry Chamberlain 1Participant @barrychamberlain1]

Hi Dave. Thanks for your comments, I hadn't noticed the slant but looking at the photographs again you may well be right. Would explain the requirement to provide clearance for the gears by grinding the cover panel. I didn't check for parallelism of the shafts. The gear trains were easy to rotate by hand in all positions on re-assembly so no cause for concern.

[Dave HalfordParticipant @davehalford22513]

Hi Barry,

The issue I was thinking about is if the two shaft bores are diverging you may get enough clearance to hammer the righthand gears. I think you ought to talk to Warco and share those photos with them.

[S.D.L.Participant @s-d-l]

Hi

Next set of Photos and text from Barry

In order to disassemble the gear trains I manufactured a simple gear puller as shown for the roller bearings. It may be recalled that when I complained about the stiffness in the gearbox Warco (who had the lathe back for rectification under Warranty) attributed it to ‘swarf’ under the gear selector knob. As can be clearly seen that was NOT the case at all. Someone at the factory in China had obviously struggled to get the triple gear assembly to smoothly slide along the gear shaft and had resorted to agricultural means of persuasion in attempts at achieving free movement!

I was not impressed with this at all and will let the photographs tell the tale. It was obvious that the key had to be replaced. The original key was wedged in place so I had to mill it out. As can be seen in one photograph there were several nicks along the edge of the keyway itself which I dressed prior to fitting the new key. I purchased a 4mm square length of keyway bar from Simply Bearings, cut to length and ground the ends to suit. Fitting this was not straightforward and I sensed that the key slot itself was slightly offset and found the new triple gear assembly was binding along the shaft. I resolved this by lightly scraping the shaft either side of the key with the square end of a small flat file. Eventually this resulted in a smooth sliding action along the keyway.

Posted for Barry by Steve.

[S.D.L.Participant @s-d-l]

Making the missing gear

Whilst waiting for the outstanding gear to arrive it dawned on me that there was a perfectly serviceable gear on the old triple gear assembly with the correct number of teeth. It would require removal of two of the three gears from the shaft, boring and reaming the hole to 16mm diameter then milling to the correct overall width. The lathe was perfectly useable without the gear box, but I did miss the power fed when boring the hole out. These stages are shown in the photographs. Although it looks otherwise, the shot where the gear is being milled is actually ‘finger nail’ smooth and not scored across the diameter.

There only remained the lack of a keyway …. At last, an opportunity to use a broaching tool inherited from a former club member’s workshop for the first time. After a bit of research I found Michael Cox’s article on making a simple internal keyway broach (MEW Issue 184, page 47) and set about modifying a length of 16mm silver steel. The broaching tool travel was pretty limited so the tool had to be customised. I milled a 4mm slot into which I set a length of 4mm square HSS tool steel. I didn’t grind the end, but used it as purchased. An M3 grub screw approximately 20mm from the end of the tool steel is used to progressively advance the cutter into the work in minute increments. After a considerable amount of time, copious amounts of cutting fluid and two blisters, the task was completed. It was slow, hard work but well worth the effort in the end.

Posted by steve for Barry

[Author]

Posts