By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Warco WM280V-F Gearbox

Replacing Gears

All Topics | Latest Posts

Search for:  in Thread Title in  
Brian G22/03/2020 11:52:37
701 forum posts
27 photos

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

Chester Gearbox.jpg

Barry Chamberlain 122/03/2020 12:25:37
18 forum posts
10 photos

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 Lewis22/03/2020 18:17:28
3289 forum posts
2 photos

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.30/06/2020 22:16:34
217 forum posts
37 photos

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.

#1.jpg

#2.jpg

#3.jpg

#4.jpg

Posed by Steve Larner for Barry

Dave Halford01/07/2020 10:35:51
761 forum posts
6 photos

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 101/07/2020 12:13:31
18 forum posts
10 photos

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 Halford01/07/2020 20:12:09
761 forum posts
6 photos

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.01/07/2020 21:16:52
217 forum posts
37 photos

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.

#5.jpg

#6.jpg

#7.jpg

#8.jpg

#9.jpg

#10.jpg

Posted for Barry by Steve.

S.D.L.02/07/2020 18:36:32
217 forum posts
37 photos

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

#11.jpg

#12.jpg

#13.jpg

#14.jpg

#15.jpg

Tony Pratt 102/07/2020 19:46:19
1130 forum posts
5 photos

I have a Warco lathe & sorry to say this type of thing is par for the course, a first year apprentice wouldn't do some of the things I have seen on my lathe.

As I have said before I'm generally pleased with the lathe & it's got a lot of good points but I could write a book on the poor practices which have gone into its manufacture & assembly but hey ho it's back to the old chestnut of old British iron or new Chinese, both have their problems.

Tony

S.D.L.03/07/2020 18:27:29
217 forum posts
37 photos
Posted by Tony Pratt 1 on 02/07/2020 19:46:19:

I have a Warco lathe & sorry to say this type of thing is par for the course, a first year apprentice wouldn't do some of the things I have seen on my lathe.

snip

Tony

Reminds me of the old 80/20 rule, get 80% of a broduct for 20% of the cost, its that detail that costs the money,

Steve

S.D.L.03/07/2020 18:29:29
217 forum posts
37 photos

Next Installment

Although I had read it elsewhere, I was surprised at just how ineffective the gearbox drain plug was. It is around 20mm ABOVE the level of the inner casting. This results in a large amount of residual oil cascading out when the front panel is removed. Someone had suggested adding a drain hole at a more appropriate position, so that formed part of my project. I decided to fit a magnetic drain plug and sourced one from eBay. It required an M12 x 1.5mm tapped hole. After some deliberation I drilled a pilot hole 19mm up from the bottom of the front cover in the mill. The panel was turned over and a 14mm mill, centred on the previously located pilot hole, used to produce a clearance for the M12 tap. The panel was again turned face up and a 10.5mm tapping hole drilled. The hole was then tapped perfectly square whilst still in the mill. The finish on the front panel although adequate for a panel face was not deemed good enough to guarantee a good tight fit when the magnetic drain plug crush washer was compressed, so a light skim with a 20mm end mill improved that area. I used a 20mm ‘Q’ cutter to produce the hole in the front aluminium cover plate, the centre of which had also been located using the pilot hole..

The last photo shows the reworked gear to the left on its keyway and the now smooth triple gear assembly on its shaft & keyway

#16.jpg

#17.jpg

#18.jpg

#19.jpg

#20.jpg

#21.jpg

#22.jpg

Posted by Steve for Barry

Howard Lewis03/07/2020 19:08:25
3289 forum posts
2 photos

So soon, you will be up and running again, and better than when the machine left then factory.

Good work!

Howard

S.D.L.04/07/2020 10:01:46
217 forum posts
37 photos
Posted by Howard Lewis on 03/07/2020 19:08:25:

So soon, you will be up and running again, and better than when the machine left then factory.

Good work!

Howard

Considering Barry did a conversion to three phase motor and vfd that was covered in MEW. Before this happened it will be a far better lathe than when new and shipped.

Steve

Samsaranda04/07/2020 10:53:23
avatar
934 forum posts
5 photos

I had problems with a Warco lathe gearbox, I bought a new Warco BV20 lathe some years ago now, no longer a current model, I purchased a geared lathe because at the time of purchase the electronic boards that governed speeds on non gear head lathes were considered to be somewhat prone to premature failure. My problem was excessive noise from the gears, on investigation I found that the running clearances of the gears was excessive leading to backlash noise from the gears. I mentioned the problem to Warco when on a visit to one of their open days and with no argument they exchanged the lathe. Unfortunately this did not cure the problem, the exchanged lathe was just as noisy, I checked the backlash of the gears and it was the same as the first lathe. Fortunately everything appeared to be in line so no problems there, I accepted that the gearbox was noisy due to backlash between the gears and that it was going to be noisy, Wearing ear defenders became the norm when the noise irritated me. I worked out that the cause of the backlash was due to the gears being cut undersize, it doesn’t take much of an error to make a significant difference to the mesh of the gears. Being that the lathe is a budget model intended for occasional use for hobby work the gears are basic and cut from inexpensive material, had it been an expensive lathe I would have expected ground and hardened gears with minimal backlash, the lathe has continued to function for many years now and the only other problem that has happened has been the failure of the NVR switch, easily rectified. All in all I consider that although my lathe was noisy it was fit for the purpose that I purchased it for and I am still glad that I chose a geared lathe rather than an electronic one.
Dave W

S.D.L.04/07/2020 17:29:32
217 forum posts
37 photos

Next Installment

Refitting the front panel. I had removed the three knobs to give them a good clean. Each knob has TWO balls, a spring and a tensioning grub screw so care must be taken not to lose any part. These were removed before driving out the roll pins securing the knobs to their shafts.

I used some M4 nuts and bolts in place of the roll pins to position the gear selectors such that the selector arms would line up with the gear trains. The selectors were very loose, so to keep them vertical I inserted some 15mm lengths of bamboo skewer and slightly compressed them against the front panel with bolts screwed by hand into the tensioning grub screw holes. This method worked well.

The technique I found worked was once the arms were vertical it eventually becomes possible to get the actuating cams to engage whilst pivoting the front panel against the bottom of the gearbox housing. Full engagement could be confirmed by looking in a mirror positioned behind the gearbox (as in the last photo) then moving the selector knobs in both directions. Once comfortable with the positioning it was a matter of applying gasket compound to the previously cleaned surface of the gearbox, repositioning it in front of the mirror and repeating the pivoting motion and confirming again that the selectors worked correctly before refitting and tightening the 5 front panel retaining bolts.

#23.jpg

#24.jpg

#25.jpg

Loaded by Steve for Barry

S.D.L.05/07/2020 18:33:40
217 forum posts
37 photos

And the last part of Barry's journey back to a working lathe.

After final confirmation that the gear selectors were engaged and working properlye gasket sealing compound was applied and the rear cover panel refitted. Where the missing screw had been (original hole filled with sealer) I managed to extend the tapped portion of what was left in the casting and fitted longer screws which gave some purchase.

Gearbox and shaft taper shear pins refitted. Note table used for changing gear wheels. Corner removed to allow door to open, override block top right engages with safety cut out switch for testing, and banjo rests on the extended piece when pivoted forward. Final photo shows everything panelled up and ready for testing.

#26.jpg

#27.jpg

#28.jpg

Posted by Steve for Barry

S.D.L.06/07/2020 20:58:08
217 forum posts
37 photos
Posted by JasonB on 15/03/2020 15:52:13:

Is there a Circlip missing from the groove?

circlip.jpg

One of the interesting things with Barrys stripdown of the gearbox was the the O ring grooves, as the dimensions were decidly odd Barry sent me the dimensions and asked for my view on the circlips to use.

The dimensions were:-

Shaft :19mm Groove 18.5mm Width 1.3mm old circlip 1.0mm thick
Shaft: 18mm Groove: 17.0mm Width 1.3mm old circlip 1.0mm thick
Shaft: 15.74mm Groove: 15.36mm Width 1.22mm old circlip 0.94mm thick

The only one that is std that I could see is the 18/17 and that was after checking the imperial ones as well.

In the end I sugested the following sizes and comments.

Well all I can say is what a dogs dinner

D1400-019
D1400-018
D1400-016

I would get 10 packs as they are only a bit more than 2

If they don't look as if they will stay In place make a tapered mandrel out of steel
and lap the ID of circling with valve grinding paste.

Hopfully now that everything is sliding properly the circlips will stay in place.

Steve

Dave Halford07/07/2020 16:24:58
761 forum posts
6 photos
Posted by S.D.L. on 04/07/2020 17:29:32:

Next Installment

Refitting the front panel. I had removed the three knobs to give them a good clean. Each knob has TWO balls, a spring and a tensioning grub screw so care must be taken not to lose any part. These were removed before driving out the roll pins securing the knobs to their shafts.

I used some M4 nuts and bolts in place of the roll pins to position the gear selectors such that the selector arms would line up with the gear trains. The selectors were very loose, so to keep them vertical I inserted some 15mm lengths of bamboo skewer and slightly compressed them against the front panel with bolts screwed by hand into the tensioning grub screw holes. This method worked well.

The technique I found worked was once the arms were vertical it eventually becomes possible to get the actuating cams to engage whilst pivoting the front panel against the bottom of the gearbox housing. Full engagement could be confirmed by looking in a mirror positioned behind the gearbox (as in the last photo) then moving the selector knobs in both directions. Once comfortable with the positioning it was a matter of applying gasket compound to the previously cleaned surface of the gearbox, repositioning it in front of the mirror and repeating the pivoting motion and confirming again that the selectors worked correctly before refitting and tightening the 5 front panel retaining bolts.

#23.jpg

#24.jpg

Loaded by Steve fo

The Centec has similar design fingers to shift the gears except they are bronze.

Barry Chamberlain 109/07/2020 21:26:01
18 forum posts
10 photos

In response to earlier queries, all I discovered inside the gearbox were these two broken teeth.

broken gear teeth.jpg

Photo uploaded by Barry - at last! Many thanks to Steve for earlier uploads!!

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Allendale Electronics
emcomachinetools
Eccentric July 5 2018
ChesterUK
cowells
Warco
EngineDIY
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest