Vee belt question, for Centec 2B

[Another JohnSParticipant @anotherjohns]

[Another JohnSParticipant @anotherjohns]

Time for Vee belt change on my Centec 2B with vertical head.

Two questions though; can someone shed some light here?

1) Motor to gearbox has 2 belts, in parallel, and they say "Gates Truflex 2680 Made in Canada X 3" Any idea what the "X 3" means?

I presume that if I purchase 2 at the same time that they should be the same length, or at least close enough for what I'm doing with my mill.

2) From my measurements, the gearbox to vertical head is 29 inches long standard vee belt, section "2" or "4L" (I assume the same, just different nomenclature). No writing on the belt.

As things are mail-order, or order-in-with-restocking-charge, I'd like to try and get this right first time.

John.

 

 

Edited By John Alexander Stewart on 20/11/2021 19:50:39

[Andrew TinsleyParticipant @andrewtinsley63637]

Look up Centec on Ebay. You will find that SE power transmissions have the belt you are looking for at £12. Looks a reasonable quality one too.

Andrew.

[noel shelleyParticipant @noelshelley55608]

You SHOULD ask for a matched pair, they will be much more expensive but 2 belts off the shelf are unlikely to be near enough to both tighten ! Good luck Noel.

[Ady1Participant @ady1]

Just use the link belting, all your belt problems, now and later, instantly solved

[bernard towersParticipant @bernardtowers37738]

2 available on our fav auction site £6.60 each.

[Another JohnSParticipant @anotherjohns]

Hi all – thanks for the responses – all great ideas. John.

[not done it yetParticipant @notdoneityet]

I don’t know whether it was original, but my motor is bolted to a steel plate which, in turn is supported (for belt adjustment) by two supports bolted to the stand. The belt pulleys diameters and centre distance can easily provide the approximate belt length for shortest and longest adjustment positions.

Purchasing a set of belts slightly shorter than the maximum would be sensible. Buying them close to the minimum would be better for lower quality belts (which may stretch). If too short, the motor can easily be raised a bit by inserting a further plate to raisebthe motor. I expect the supporting frames could be raised, or lowered, to accommodate other belt lengths, if necessary.

A motor change, to one with different feet, might well alter the centre distance, just as a change from single to 3 phase motor.

I buy my belts from my local stockist, so I can usually obtain a close-enough match by taking in the old belts.

I suggest asking the supplier, or Gates, for the meaning of that suffix. Best to get information ‘straight from the horse’s mouth’ as they say.

At one horse power, I doubt it needs anything particularly special with it using substantial twin-sheave pulleys.

[Michael GilliganParticipant @michaelgilligan61133]

Catalogue page 97 et seq. might help : **LINK**

https://www.gatesaustralia.com.au/~/media/files/gates-au/industrial/catalogues/industrial-pt-catalogue-aus-nz-2018.pdf

MichaelG.

[Clive FosterParticipant @clivefoster55965]

TruFlex seems to be the Gates name for light duty, low stretch belts designed for smooth power transmission during start-up. L series belts. Close to A size but skinner and, usually, sized by outside diameter in inches. Its an American thing. 2860 doesn't seem to come up on the search. I'd guess the 3 means its a 3L.

The X suffix generally means a cogged belt where the inner part is in small sections separated by V shape cut outs. The cogging lets the belt run round smaller pulleys without loosing wrap angle. It also lets it settle into the pulley grooves better as it engages and grips a small section at a time. Uncogged belts are influenced by the straight run before engagement so drive take up and rection to load changes isn't quite as smooth. Cogged belt banding is usually more flexible too. Cogged belts are in herently alittle more prone to stretch and wear so good quality makers take steps to alleviate this.

Clive

PS Micheals link doesn't work for me.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Clive Foster on 23/11/2021 10:16:59:

[…]

PS Micheals link doesn't work for me.

.

No idea why that might be, Clive … it still works for me

Dimensions there are in millimetres, and 2860 is a listed length..

MichaelG.

.

Edited By Michael Gilligan on 23/11/2021 10:44:46

[Dave HalfordParticipant @davehalford22513]

My Centec has A section pullies. running the narrower belts may let the belts 'bottom' in the pulley and promote slip.

[duncan webster 1Participant @duncanwebster1]

sent the vertical head belt to the supplier for replacement, he sent A26.5, but it was too long to allow the idler on the outside. I've now got AX26, which fits much more nicely, just as original. I got AX as they are a tad more flexible. It just needed light persuasion to get it on

[Howard LewisParticipant @howardlewis46836]

better to run withb the idler on the back of the belt.

1 It runs on a flat surface

2 The angle of wrap around the pulleys is greater,and tends to press the belt into the groove, rather than out of it, Meaning that, in extremis, more power can be transmitted.

Howard

[Another JohnSParticipant @anotherjohns]

Duncan – I like the inside belt – it does make things look neater.

Thanks for all the help with my Centec. I did get the 29 inch belt in place; on my machine, the top pulley is a bit "wonky" (it wobbles a bit, I think it needs re-bored or replaced – so far I've lived with it) – when I get around to it, I'll get the 26AX as you did.

By the way, my old belt that was on it, had a slightly domed top-side, from the look of it, it might have been even older than the machine.

John.

[Dave HalfordParticipant @davehalford22513]

Posted by Howard Lewis on 14/12/2021 16:04:42:

better to run withb the idler on the back of the belt.

1 It runs on a flat surface

2 The angle of wrap around the pulleys is greater,and tends to press the belt into the groove, rather than out of it, Meaning that, in extremis, more power can be transmitted.

Howard

Sometimes, Fenner belts used to have the name moulded with raised letters on the outside of the belt.

[duncan webster 1Participant @duncanwebster1]

Posted by John Alexander Stewart on 14/12/2021 19:23:25:

… the top pulley is a bit "wonky" (it wobbles a bit, I think it needs re-bored or replaced – so far I've lived with it) – …..

John.

If you do have the pulley off, drill a blind hole and bury a magnet in it, then you can have a pickup for a tacho, that rather nasty brown thing. It's crude but it works

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