Denford Software & Machines

Right
I ran the lathe over the weekend and when I selected auto traverse longitudinally it worked ok for a few seconds, then I noticed the lower spindle under the leadscrew, the one with a slot running lengthwise, the collet mounted on this spindle which sits adjacent to the gearbox was moving in and out by about an inch, and the lathe seemed to be jumping or sticking, then it stopped traversing altogether. I opened the gearwheel door and held in the limit switch and switched it on again. The smaller cog attached to the lead screw was spinning freely but had stripped the teeth off the larger cog. I now have no auto drive either longitudinally or on the cross slide. You still need a lot of effort to operate the slide using the handwheel.
Anyone know if it is possible to disconnect the cross slide completely from the auto drive system and as such use the lathe manually and also would this free up[ the apron handwheel??? if so does anyone know how do I remove the leadscrew spindle and the lower drive spindle as this must have been damaged or bent when the lathe fell over it doesn't look damaged but somethings clearly not right. also how do I get the saddle off the apron, ideally an idiots guide would help.
Or should I just cut my losses and scrap the effing thing??

Answers please gents

Hi Steve,

I'm a bit baffled by your problems.
Don't scrap it, that would be a shame.
Of course the saddle should be free to move manually when the half nuts are disengaged and the lock is free.
Any chance of some pictures ?
I wonder if you have managed to bend the leadscrew or feedscrew ?
Are you in Scotland ?

Les.T.

As Les T suggests, some pictures would help.

The feed shaft (below the leadscrew, with the slot) is meant to move along its axis - this is the auto-cut-off. You slide the collar along and lock it using the grubscrew. When the apron pushes against it, it slides left and disengages the dog-clutch in the gearbox. If it is moving easily longitudinally, it suggests that the spring has become disengaged or broken.

As long as the leadscrew nuts are not engaged, the apron should move. The cross-slide power feed would only be engaged if the relevant lever is engaged. But possibly the interlock (that prevents power feed and screwcutting being selected at the same time) was damaged when the lathe had its accident?

Dazz included some pictures and description of removing the apron here - viewtopic.php?f=14&t=450

You should be able to stop the feedshaft and leadscrew from rotating by simply putting the tumbler gear in its mid position - as shown in the manual.

Andy

edit - P.S. You have my full sympathy - you can see what happened to my 280 in transit here - viewtopic.php?f=14&t=2268. It took some time to get the insurance on mine, but I did, finally.

Morning Gents.
Andy
Thanks for that description, obviously I am a novice with this, and I don't really want to scrap it.
The collet as I described on the feed shaft, I now totally understand what that is meant to do, I didn't realise that this was an adjustable piece of kit and after reading your description I get the gist now, so maybe that was just loose and obviously why it was moving about.
So to recap the feed shaft is operating freely and the small cog attached to the left hand side of the gearbox is also spinning freely, it is this wheel which stripped the teeth from the larger gear wheel attached to it.
As long as the leadscrew nuts are not engaged, the apron should move. The cross-slide power feed would only be engaged if the relevant lever is engaged. But possibly the interlock (that prevents power feed and screwcutting being selected at the same time) was damaged when the lathe had its accident?

After reading this Andy I am getting more of an idea, so once again I thank you, as I think this is where all my problems lie.

I am assuming that It is this section of the lathe that took the full impact as it hit the floor, as the apron handwheel was completely smashed, so I think the spindle that the hand wheel is attached to has been forced inwards, and in doing so has broken something internally possibly causing the leadscrew nuts to become fully engaged at all times, and if I am right this would make the hand wheel almost impossible to turn. I can turn it but with a lot of force, so I need to get access to the leadscrew nuts to see what damage has been done there.
The cross slide works freely and did energise when I lifted the lever under it to engage the feed, but again that stopped once the gear wheel shedded its teeth.

In answer to Les T, I actually work in Aberdeen through the week and return home to Wigan at the weekend.

I will take a number of photographs and will post them on here.

I will have a go at trying to remove the top slide off the apron, thanks for your photos.

To date I have repaired the tailstock, and that is now locking into position. I need to repair the gear guard door and refit that, as that also took a clout when it hit the floor.
I don't think this was ever attached properly by the previous owner but I have a solution to remedy this.

Also the chuck only spins anti clockwise, irrespective of the selector switch position, I have stripped down the controls unit and disconnected and removed the cumbersome 240/24 transformer and also removed the now broken anglepoise light.
I have checked the wiring against the denford wiring diagram and it appears correct, the selector switch operates correctly and shuts off the power in the central position.
Am I right in thinking that the four wires going to the motor X Y B A where A is the neutral and X Y B are to the poles, and if I try swapping two of them over it should operate forward and reverse? as the way it was wired it just ran counterclockwise.

Finally I will take a shot of the stripped gear wheel and count the number of teeth it originally had as I will need to source a replacement for this, any ideas where I might find one ?

Sorry for the long message, I am not going to give up on it, its lasted 40 years or so and deserves to be sorted

Thanks again in advance chaps

steve1963 wrote:Morning Gents.
I have checked the wiring against the denford wiring diagram and it appears correct, the selector switch operates correctly and shuts off the power in the central position.
Am I right in thinking that the four wires going to the motor X Y B A where A is the neutral and X Y B are to the poles, and if I try swapping two of them over it should operate forward and reverse? as the way it was wired it just ran counterclockwise.

Is the motor single phase or 3 phase? From your description of the labels (XYAB), it sounds like single phase. If so, you must only swap XY or AB.
Either way, this will only prove that the motor will run in reverse. It sounds to me like the wiring in the control box is wrong. Again, a photo would probably help.
Andy

Yeah Andy the motor is definitely single phase.

The wiring from the contactor to the selector switch appears as though its never been touched, and the way it was wired only allowed the chuck to operate Anti clockwise which ever way you had the selector switch it still ran counter clockwise.

I didn't remove the switch from the backplate to confirm if the wiring is exactly as per Denfords drawing. I will strip that down further and investigate and will take photos as well.

Will post them Monday with an update on how I get on with the Apron Hand Wheel Scenario

Thanks again for your help