Thread: Lathe stops when it's not supposed to

what are you using in the head stock for the drive?Spur drive?

Yes it's a spur drive.

What do you mean stops? Do you mean the motor stops or the drive spur looses it's "bite" and the piece stops spinning but the drive spur is still spinning?

How do you mount your pieces? Really you shouldn't OVER tighten the tailstock. It will put undue pressure on the bearings I've been told. You should mark the center on your blank on both ends then with a piece of wood or wooden mallet tap the tail center into the blank on one end and then do the same with the drive spur on the other end. Put the tail center and drive spur back on the lathe and mount the blank on the lathe with the tail center and drive spur in the indentations you just made. Hand tighten till secure. Make sure you get a deep bite with the drive spur otherwise when you go to cut the drive spur will tear the wood and continue to spin while your blank stops.

Having owned a H&F MC900 I'm a bit confused about your statement that the lathe stops.

What sort of mounting are you doing;
Timber
Diameter
Length
Mounting Method ( how are you mounting between centres - both ends)

Other than that my observation is that you probably need to drive the drive center home with a little more persuasion. If it's really hard wood cutting a lead in with the band saw or a tenon saw is necessary. In any event I always seat the drive dog home with a mallet off the lathe first.

FWIW

Barnsey,

The wood I was turning was about 70 by 70 Redgum, it was about 200 long. I do hammer the drive centre with a mallet before I put it into the headstock.
Can you explain what you mean by a "lead in" and how that is cut?

If your lathe is belt driven like mine, then it may be the pulleys slipping on the belt - like the fanbelt slipping in a car. If so, tighten the adjustor for more belt tension and a bit of talc on the belt will fix it.

Originally Posted by Tiger

Barnsey,

The wood I was turning was about 70 by 70 Redgum, it was about 200 long. I do hammer the drive centre with a mallet before I put it into the headstock.
Can you explain what you mean by a "lead in" and how that is cut?

Ok Tiger,

Redgum is often as hard as concrete and hammering the drive is a bit like trying to drive a nail in it. :eek:

Take to the drive end of the timber and once you are satisfied you have a center take the tenon saw and make a cut across the blank about 3-4mm deep. Then at right angles to that make another such cut. This will give the spur drive a lead in to get a solid grip (I'm assuming you are using a drive with 4 spurs here, if only two then the second cut is unnecessary.) Now when doing this just make sure that the drive seats well, the center may require a little easing with an awl just to make sure the point penetrates the concrete as well.

Turning the hard timbers we have here demands light cuts. It's good practice to take the corners off a square blank with the band saw, planer or hand plane if you must to reduce the loads when you are roughing to round.

Hope that helps.

Jamie

Sounds like a loose belt to me.

Hi, I am little confused as well as I also own a Hare & Forbes lathe.[WL20]
Its belt driven with a variable speed drive -- reeves type. eg two pulleys that change diameter in order to change ratios and this effects the speed.
I suspect that your belt is worn, its 0-625, O being cross section type and 625 being the length.
When I bougth mine the motor was loose and out of line as with the variable speed pulleys, this caused some advanced wear and consequently I have changed the belt. I put a A-670 belt and packed the motor out with a block of hard wood. I am using the 670's cos I had em on hand and they are doing fine although the guard no longer fits.
regards Hughie

Okay if the mounting of the timber is no longer a problem, then belt wear/slippage may be the thing however these variable speed mechanisms are usually very accommodating in that situation.

If you find that there is a lot of dust and gunk in the drive mechanisms this may be stopping the split V's from moving freely and placing tension on the belt. You need to clean it - instructions in the manual. If you've still got slippage then replace the belt. After that you perhaps need to check the alignment of the spindles parallel to each other.

If the unit is under warranty , talk to H&F - I found them quite prepared to help and stand by their product even after warranty.

I have another issue with the Hare and Forbes 900 b/w centres. As some of you have suggested, perhaps there is dirt buildup on shafts etc. I took off the cover and cleaned what I could, I wouldn't say it was real dirty, but it made little difference to the lathe. I may not have mentioned that sometimes when I turn on the lathe that the lathe does not turn, it makes a quiet noise (like it's about to start) and then when I spin the handwheel gently it then goes into action. This has become more prevalent and is really giving me the *****. I may have to spin the handwheel 20 or 30 times over a 2 hour period. It doesn't occur everytime I stop perhaps every second time. As if I don't have enough to worry about with learning to sharpen woodturning tools and making sure I don't have too many catches with the skew chisel, I need to worry about the poor quality machine that I've bought. I've had a look at the belt. It is only slightly frayed but there seems to be enough tension there for it to work. Can you tell by looking at the belt that it's gone? How do you increase tension on the belt, what do you adjust? How do you take the belt off? There is nothing in the booklet that came with the machine on these questions, it is useless. Judging from some of the threads I have seen on lathes, my questions may seem basic to some forum members, but I am no engineer, could you please explain in simple terms what I have to do. I am loathe to try and take it apart as I would be guessing and could render the whole bloody thing useless. I would really appreciate some help here.

Here's something to try... next time it needs a hand start, try spinning it the wrong way & see if it runs backwards.

If it does, the problem is with the start winding.
I could be the switch if it switch operated or a crook start cap if it has a capacitive coupling to the start winding.

WARNING! Don't spin it backwards if you have a right hand thread chuck on it that doesn't have alocking device, it may come undone.

yeh, what cliff says. Say its just the capacitor. Which is good news if it is. Quite easy to fix yourself. Just replace it. Often they are just in those bulgy cases on the outside of the motor.

Stating the obvious, but, pull the cord out of the wall before doing it. I'm not an electrician, but, thats most of what you have to really worry about, with basic electrical work.

Before I touch anything electrical must get in the habbit of ask oneself " is it on " ....cause, sometimes when your troubleshooting a problem, you may have put it back on and forgotten, and in your excitement in finally realising the problem (yippee!) you dash to fix it and ......zzzzapp !

Cliff and Apricot,

Tried to turn it in reverse, the mere touch is enough to get it to turn and it turns in the right direction so I guess we could rule out electrical problems?

Really in a quandary here, Help!