Warco WM 250V power feed stuck/crash

[Brian WoodParticipant @brianwood45127]

As the rack will be soft, bent teeth can be straightened with due care by using a shaped brass punch to push them back into position, as long as the damage is not severe. In this case the degree of damage looks to be within recovery and the rack could be salvaged. It is a choice Bombadier may care to try before coughing up for a replacement, particularly as the circumstances which gave rise to the damage are not apparent 

The job is best done with the rack off the machine and held rigidly in a vice using protected jaws. The degree of success can be judged by rolling a correctly matching gear in the rack to test for any tight spots or lumpiness as the two components mesh together

Regards Brian

Edited By Brian Wood on 05/06/2022 13:00:47

Edited By Brian Wood on 05/06/2022 13:01:34

[Mick B1Participant @mickb1]

It's full of risk to speculate, but I think the tooth directly below the tubular location dowel in the photo has fractured and can't be recovered – trying to reform it would most likely result (IMO!!) in the top 2/3 breaking off. Several others are in a bad case too. I'd say the rack has to be replaced.

As for cause I'm wondering if a substantial piece of solid debris (which might still be there in the adjacent toothspace?) got into the meshing pinon and trapped between it and the rack.

I still think the leadscrew shearpin wants looking at, because it should've broken well before any such damage was caused. That's what it's for.

[HOWARDTParticipant @howardt]

To bend the rack teeth like that the saddle gear must have been forced down so all the force was on the gear tip. If the gear tooth was fully engaged you could only shear the teeth. Check that the saddle bolts are tight to the front plate, and the pinion shaft and teeth etc are ok.

[Howard LewisParticipant @howardlewis46836]

When I had my disaster, the gear/shaft was in stock, so obviously a frequent event and a good seller.

In view of the low strength component, I made a new shaft from 16mm Silver Steel, and cut my own gear to Loctite into it. This required a brass spacer to locate the shaft relative to the Apron, and was how i found errors in the chart for HV6 Rotary Table.

It won't happen again, as I ground off the first four teeth of the racxk, (Two were badly bruised anyway! )

The pinion comes out of mesh just before Saddle / Headstock contact, so occasionally needs to be pulled back into mesh.

Howard

[BombardierParticipant @bombardier]

The mighty WARCO have agreed to completely replace the lathe.

Although that is great news I now need to take the old one off the bench and put it back on its pallet, take delivery of the new one . load onto bench, clean and oil etc, oh what joy

Great customer service from WARCO though I have to say

[Brian WoodParticipant @brianwood45127]

That certainly is a good result, It saves Bombadier all the worry and concern about replacing the rack or doing anything to it as I suggested.

The cynic in me wonders if they have found a fault with this model and this is their way of applying good customer relations and hiding the problem rather than issuing a recall.

Brian

[BombardierParticipant @bombardier]

Posted by Brian Wood on 06/06/2022 15:16:08:

That certainly is a good result, It saves Bombadier all the worry and concern about replacing the rack or doing anything to it as I suggested.

The cynic in me wonders if they have found a fault with this model and this is their way of applying good customer relations and hiding the problem rather than issuing a recall.

Brian

Time will tell Brian however I am going to be more positive and hope that is not the case

[Mick B1Participant @mickb1]

It's a fair result in that it gives Bombardier a new machine and saves investigation of any other consequential damage.

I'm pretty sure the rack is toast, and I'm not sure how much skilled machine tool fitter resource they have, to be able to send one out to replace it on site – plus of course resolve the bent pinion shaft issues, and replace the shearpin with one that'll function as it should. It'd take a posh top-o'-the-range dealer to do it that way, and that would have to push up new sale prices too.

[BazyleParticipant @bazyle]

The red patch on the photo implies to me that the pinion hit the bed so I suspect that something like a circlip or grubscrew holding the gear shaft in the gearbox was missing and it worked its way outwards from the gearbox.

[Tony Pratt 1Participant @tonypratt1]

Posted by Bazyle on 06/06/2022 17:41:44:

The red patch on the photo implies to me that the pinion hit the bed so I suspect that something like a circlip or grubscrew holding the gear shaft in the gearbox was missing and it worked its way outwards from the gearbox.

That makes sense, also about 5 teeth damaged to various degrees.

Tony

Edited By Tony Pratt 1 on 06/06/2022 17:45:57

[Mick B1Participant @mickb1]

Posted by Bazyle on 06/06/2022 17:41:44:

The red patch on the photo implies to me that the pinion hit the bed so I suspect that something like a circlip or grubscrew holding the gear shaft in the gearbox was missing and it worked its way outwards from the gearbox.

Yes – highly plausible – or maybe an obstruction in a toothgap in the pinion deflected the pinion downward so the rotating tooth crowns scarred the bed whilst the intrusion mashed the rack teeth.

Again – why didn't the shearpin shear? Wish I'd kept mine now – I replaced it with brass but suspected the original might've been silver steel.

 

Edited By Mick B1 on 06/06/2022 21:47:22

[not done it yetParticipant @notdoneityet]

And all this started with a powered cross feed operation?

[BazyleParticipant @bazyle]

Posted by not done it yet on 06/06/2022 21:49:45:

And all this started with a powered cross feed operation?

Easy to get confused! We have two different lathes in discussion here. First was cross feed then picture posted by Bombardier was a different one.

[HopperParticipant @hopper]

Posted by Bazyle on 06/06/2022 17:41:44:

The red patch on the photo implies to me that the pinion hit the bed so I suspect that something like a circlip or grubscrew holding the gear shaft in the gearbox was missing and it worked its way outwards from the gearbox.

Indeed. I had assumed Bombardier applied the red mark to point out the are of damage. But it seems to have circular marks indicating the pinion impacted the bed when looked at closely. Shaft or gear obviously moved for some reason.

Good result getting a new lathe anyhow !

[BombardierParticipant @bombardier]

Well new lathe has been back on the bench for a few days all going great until today when I was doing a power fed facing cut and the whole cross slide jammed up, I had done at least three identical cuts with no issues prior. Any ideas what could have happened.

With me, if something could go wrong it usually does

[Howard LewisParticipant @howardlewis46836]

I take it that you were not exceeding the Cross Slide travel in either direction?

having been careless myself, I can probably say that you have either been unlucky, or like me, careless.

Either way, you need to find out how this happened a second time and find a way of preventing repetition.

Long shot

Is it possible that something inside the Apron is causing the jam up?

howard

[BombardierParticipant @bombardier]

I decided to walk out of my shop for today as I was pretty flustered about the situation, when I finish work tomorrow I will go take a closer look in a calmer state

I dont think I exceeded the cross slide direction but I have to assume it is possible?

If I have done so what would be the fix?

[Tony Pratt 1Participant @tonypratt1]

Posted by Bombardier on 21/06/2022 16:58:03:

Well new lathe has been back on the bench for a few days all going great until today when I was doing a power fed facing cut and the whole cross slide jammed up, I had done at least three identical cuts with no issues prior. Any ideas what could have happened.

With me, if something could go wrong it usually does

Hold on, so you were facing towards the middle & it jammed up, if your 250 is the same as my 290 if you travel the tool too far away from the operator doesn't the cross slide screw just come off the nut? Not sure if you have a DRO which might have jammed.

Tony

[BombardierParticipant @bombardier]

Hmmmm I would be interested if that is the case, will take a closer look tomorrow, just calming my nerves with a nice scotch. Thanks though I guess it could be as simple as that (hopefully)

[Mick B1Participant @mickb1]

On my 250V the nut doesn't wind off the end of the cross leadscrew – it comes to a hard stop with the crosslide table rear face about 111mm from the rear stop (the front face of the handwheel bearing housing). If you go beyond this it'll jam hard and the cross leadscrew shearpin should break. If it does the broken bit's highly likely to fall into the apron gearbox and jam that by lying along a toothspace.

If you've not overtravelled I suppose it's possible that an apron gear has picked up some other debris.

Can you disengage the power feed, and if so, can you then run the cross leadscrew easily by hand?

Obviously, if the shearpin's gone, the crossslide won't move.

Edited By Mick B1 on 21/06/2022 18:11:56

[BombardierParticipant @bombardier]

yes the power feed has disengaged but the lead screw will not move so I guess it is the shear pin right?

[Mick B1Participant @mickb1]

Posted by Bombardier on 21/06/2022 18:34:39:

yes the power feed has disengaged but the lead screw will not move so I guess it is the shear pin right?

If the pin broke, the handwheel might spin idly but won't turn the leadscrew. If the handwheel won't turn, then something's jammed the drive pinion and moving the lever to disngage the feed isn't disengaging it for some reason.

I can't remember how it was put together, but when I took it apart, I could see how it worked it at the time.

[Tony Pratt 1Participant @tonypratt1]

Again speaking of the 290v but the 250 will be similar, the parts diagram shows the feed gear attached to the end of the cross slide screw so I think if you do indeed over travel away from the operator the feed screw nut will hit the gear and lock up?

Tony

[JasonBModerator @jasonb]

Tony have you actually looked at how it goes together? On a 290/280 if you over feed then the nut will be the furthest from the gear, more likely the nut will hit the cap head screw at the bottom rear of the trough the screw runs in. Unless you are in the habit of feeding from the middle out.

The diagram may show the nut at the far end of the screw but it actually slides all the way on to where the woodruff key is located so the gear does not spin on the screw.and meshes with the gear coming up from the apron at the front.

 

 

Edited By JasonB on 21/06/2022 20:41:46

[Tony Pratt 1Participant @tonypratt1]

Sorry to say I haven’t actually looked at it’s operation so my post may be a red herring

Tony

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