Kondia FV-1 x-feed gearbox questions

[stevec]

OK, so now the only thing I can think of is making an eccentric stud.
It looks a lot like my "Tree" cross feed set up. I have experienced the
"click, click, thing when theres a jam.

[Mayhem]

(05-17-2012, 11:08 PM)f350ca Wrote: Is forward reverse mechanical or done by reversing the motor? If its mechanical try reversing the motor...

I reversed the motor and the idler engages and stays engaged. The table now travels in the opposite direction to that specified in the manual but I can live with that. The box operates smoothly and quietly.

Thanks for the suggestion Greg.

[stevec]

Good solution! does the lever now have to be moved OPPOSITE to the table direction selected? I only ask because I KNOW it would befuddle me.

[Mayhem]

It does Steve but as this is the first mill I have used/owned, I know no difference. Pull the lever to the left and the table moves to the right. Like reversing a trailer or steering an outboard!

[f350ca]

Glad that fixed the problem. Somewhere I remembered a similar situation, just don't remember where. I'll have to check my mill, you get familiar with something and don't think about it, but the lever on mine might be backwards too.
Greg

[DaveH]

That was a clever solution


DaveH

[Mayhem]

I have the same thread running on another site and posted this recommendation by Greg as a solution that has worked.

It was pointed out that whilst it will work, I may cause problems in certain situations, some of which could be catastrophic! Here is the key part of the reply:

1. The reason the gears push the selector away is a kind of a final overload clutch, if something binds the little pin will bend and the gears will skip, if you run it backwards, the pin doesn't take the load the gears bite harder and harder as the power loads up, until either the motor stalls or at very low gearing the case splits or the shafts bend or break
   
2. The other is that depending on design, if the shaft is feeding in the wrong direction sometimes the stops don't work properly leading the table to bind at the extreme end of the table's travel, then... see point number one.
   

The good thing is that reversing the motor has eliminated some of the possible issues and narrowed down the possibilities to a worn selector pin. One thing I did note was when the high speed was selected, it tried to pull the gear in too far and it was a little difficult to disengage it to change gears.

Oh well a little more work to do but I am sure I will get there.

[f350ca]

Its best if you can narrow down the real problem but as for the gear not being able to disengage under overload, I doubt if that was part of the original design. The slip clutch you repaired is there to handle overloads. Most transmissions with sliding gears are designed so that the angle of the bevel gears pull the gear into position. If they relied on that for overload protection you'd never keep a tractor transmission in gear. The detent on second gear in my old Willies jeep got weak, every time you'd come off the throttle it would pop it into neutral when the load got reversed on the bevel gear. Most trannies now are constant mesh I think with the syncros only engaging a dog clutch type arrangement.
As for the limit stops, you could be right, they may need to be reversed.
Will have to look at the quick change gear box on the Colchester lathe, I think its the same setup as your power feed. If so they run in both directions for carriage and cross feed travel.
Greg

[Mayhem]

Well I decided to see if I could get the issue sorted out, so that the gears would not slip when in the normal direction of rotation. As the issue is with the selector pin, I removed the gearbox and motor assembly from the mill and took it to my other workshop, where my lathe lives.

To make life easier, I welded up a quick and dirty stand:
   
   

With the selector lever removed and disassembled, the wear on the pin and the bore was evident:

   
   

I turned up a new pin, so that it was a close fit inside the bore. I also increased the size of the head, as the holes the pin engages were also worn:

   

Once I was happy with the fit, I put it all back together and wired the motor up. Flicked the switch and the gears stay engaged. A much simpler fix than I had imagined!

Sorry for the poor quality pics. The lighting was bad and the flash just washed out the pics. Pity, as I was really happy with the finish on the pin. Also, the battery died, so no pic of the freshly polished brass handles either

[DaveH]

Nice job Mayhem

Let's hope that's all the problem was.

DaveH