ELB Surface Grinder Stuck Axis

[PANAGIOTIS EVRIPIOTISParticipant @panagiotisevripiotis95835]

Hello everyone,

I have an older model of an ELB Werkzeug SW 4/5 German surface grinder and as I was working on it, managed to get an axis stuck and unresponsive.

To be more precise, after I finished some grinding I started moving the Y axis further from me in order to inspect and remove the parts from the magnet. I was doing it slowly and towards the end I felt a bit of resistance and thought that the end of the leadscrew is there so I stopped and did not force anything. Now, the handle turns only a few degrees and it feels as that it is free spinning for those few degrees without actually doing anything. In the beginning I thought that maybe some part got off the ways or something so I had a friend push the column towards me (the operator) and tried again to turn the dial but with no result.

I have no idea how and why this happened and wanted to summon the collective experience in here before I start disassembling things.

Thanks in advance for any information

[Pete RimmerParticipant @peterimmer30576]

If the wheel is turning freely then it’s probably nothing more than you have wound the nut off the end of the screw. Since you have already tried pushing the slide back with no success what I would do is get a plastic mallet and knock it back towards the screw until you can engage the screw in the nut.

 

[PANAGIOTIS EVRIPIOTISParticipant @panagiotisevripiotis95835]

When you say wheel I am assuming you mean the handwheel. It turns only a few degrees and gives the feeling that for those few degrees it turns freely without affecting anything.

Regarding the nut are you implying that I reached (probably with some force) and the threads in the nut got damaged?

Knock the nut back towards the leadscrew? I don’t think there is any visibility to do that, but even if there was, want that damage the nut threads even more when banging it towards a hardened lead screw? Maybe I did not understand something in you message

[not done it yetParticipant @notdoneityet]

If Pete’s solution does not solve the problem, it is likely a simple case of removing the table and perusing the problem beneath.  Likely just a matter of aligning the two threads to enable them to screw together.

[Pete RimmerParticipant @peterimmer30576]

Ok so if the slide is not moving and the handwheel only turns a few degrees then the slide is stuck on the ways. if it has a tapered gib then it could be that there is some slack in the gib adjustment and it;s caused the gib to jam. orit could be simply that the ways are a bit worn in the middle and sticking at the end of travel.

Can you tell what kind of gibs the machine uses? if it’s a tapered gib then you might need to drift he gib back a bit to free it up. if not then you might need to loosen the straight gib adjusting screws to gain some clearance and allow the slide to move.

[PANAGIOTIS EVRIPIOTISParticipant @panagiotisevripiotis95835]

Thanks for the ideas guys, I will try all of the above and get back here with results

[John PParticipant @johnp77052]

Hi,

Have a look in Lathes.uk  in grinding section ELB Grinders Germany  Types  VA, SW, BDZ, W and Accessories shows  section of cross slide  and square  guide gibs  ,if this is the same machine  it looks unlikely  that the leadscrew  would  have become disengaged.

[PANAGIOTIS EVRIPIOTISParticipant @panagiotisevripiotis95835]

Hi John, I checked lathes.co.uk as you suggested. Even without seeing that I am assuming that if the leadscrew was disengaged it would freely spin since nothing would prevent her from rotating.

[John PParticipant @johnp77052]

Hi  Panagiotis

I was refering to an earlier post where the contributor had suggested that the leadscrew
had screwed clear of the nut.Seeing the cross section of this machine that would have been
unlikely as the pulley and motor drive is at the far end.
Assuming that the machine has this power cross feed will the slide move under this
power.

———————————————
The situation as in your original posting.
“Now, the handle turns only a few degrees and it feels as that it is free spinning for those few degrees without actually doing anything”

Further down on the first page in Lathes . uk is this below
item 2 sort of describes the situation as in your original posting.

“The handwheel cannot, therefore, rotate when mechanical traverse is engaged.”

I suppose  that the  position of the  sliding  knob  has not been accidentally  moved.

Cross Feed
Three methods of grinding column transverse feed are provided:
1. Manual cross feed via handwheel with fine setting knob. The planetary gear incorporated in the handwheel permits fine in-feed via
the fine setting knob down to 0.01 mm (.0004″). Manual cross feed is possible only when the sliding knob in the centre of the handwheel
is fully pushed in.

2. Automatic rapid cross traverse through electric motor driving the cross feed via Veebelts. The cross feed distance is set in accordance
with workpiece requirements by adjustable limit stops, situated at the front panel. The cross feed motor can only be engaged
when the handwheel sliding knob is pulled out. The handwheel cannot, therefore, rotate when mechanical traverse is engaged.

3. Automatic intermittent cross feed is steplessly variable via potentiometer and time relay imparting starting impulses of varying length
to the cross feed motor. Cross feed per table stroke can be set to occur automatically in increments up to full grinding wheel width.
Actuating a selector switch at the control panel permits instantaneous change-over from intermittent to continuous, and vice versa,
at any time.

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