# Belt Slipping On 5400 Clausing Lathe Spindle (linked Belt)



## medic0079 (Jun 1, 2016)

Hey guys and thanks in advance for the advise. I picked up a 5400 series clausing lathe recently. It works well, but I'm having a problem with the spindle belts slipping. It has two very worn varispeed belts which I have ordered replacements for and 3 linked belts (never used them before) which look to be in good condition driving the spindle. The problem is they slip badly. They don't seem loose, but were oily. I cleaned them and the pulleys with brake cleaner to remove the oil and tightened the adjustment some, but they still slip. I have never used the linked belts but everyone seems to love them from what i have read on the internet. should I replace them with regular v belts? Is it possible that they are just saturated with oil? are linked belts prone to slipping? should I replace them with new linked belts? any other advise relating to the slipping. its not taking to much to make them slip. 10 thou pass on some cold rolled is causing the spindle to start slipping and slow 15 thou locks it up completely.


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## mmcmdl (Jun 1, 2016)

Try some belt dressing ! If that doesn't work , replace with the appropriate belts .


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## kd4gij (Jun 2, 2016)

A picture would be a big help. I use link belts on my lathe with no slipping. It could be that the belts are not the right for the pulleys.


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## wa5cab (Jun 3, 2016)

Link belts are prone to slippage in some applications.  The belt surface area actually in contact with the "V" of the pulley is around 1/3 that of the correct size V-belt.  If it works OK, fine, although it will eventually ruin the pulley (but maybe not in your lifetime).  If it slips, replace it with the proper V-belt quickly before it ruins the pulley.


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## John Hasler (Jun 3, 2016)

wa5cab said:


> The belt surface area actually in contact with the "V" of the pulley is around 1/3 that of the correct size V-belt.


Friction force is proportional to normal force times coefficient of friction.  It's largely independent of contact area.


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## wa5cab (Jun 4, 2016)

I know that's what the books say but there are more reports of belt slippage with link belts than with decent condition V-belts.  And they do tend to wear out pulleys.  But, different strokes...


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## medic0079 (Jun 4, 2016)

I will upload some pics I did the belt dressing which helped a little, but they still slip. I assume slipping belts will mess up my threading if I were to try? I haven't threaded anything with this lathe yet. I ordered some vari belts for it but haven't received them yet. I guess I will call clausing Monday and order the regular v belts for this as well. is there a better place than factory to order belts. I have no idea what size they are but I guess I could just measure the link belts.


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## John Hasler (Jun 4, 2016)

wa5cab said:


> I know that's what the books say but there are more reports of belt slippage with link belts than with decent condition V-belts.  And they do tend to wear out pulleys.  But, different strokes...


I imagine that if you load both kinds to failure that the link belt will slip first since due to the smaller area the shear stress will be higher.  I doubt that the link belt would slip at rated load for an equivalent v belt, though.  My Avey has link belts on it: from look of it they've been there for decades (they are a type with brass rivets).  The pulleys look fine.  So do the belts.


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## John Hasler (Jun 4, 2016)

medic0079 said:


> I will upload some pics I did the belt dressing which helped a little, but they still slip. I assume slipping belts will mess up my threading if I were to try? I haven't threaded anything with this lathe yet. I ordered some vari belts for it but haven't received them yet. I guess I will call clausing Monday and order the regular v belts for this as well. is there a better place than factory to order belts. I have no idea what size they are but I guess I could just measure the link belts.


Well, if they are soaked with oil they are going to slip.  I'd take them off and wash them and then make sure they are properly tensioned.

The slipping won't mess up threading.


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## medic0079 (Jun 5, 2016)

some pics


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## medic0079 (Jun 7, 2016)

well pulled the belts off, removed a link, and soaked them in simple green. flushed them off with water, now they are drying. if this doesn't work I will try and find new v belts. I called clausing they don't carry belts anymore for this machine. I did replace the varspeed belts which made a huge difference in how the machine sounds, and runs. much smoother now.


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## Randall Marx (Jun 9, 2016)

Are they installed the right direction? Link belts need to be oriented correctly to transmit power efficiently.


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