P/T woes

[MorrisWoodman12]

I have an old Record DMP106 planer/thicknesser that has just given it's thicknesser drive belt leave to go on holiday. Every time I go to use it the drive belt comes off the pulley so the thicknesser feed bars stop rotating. The DMP106 looks to be identical to the Record PT260 and the Elektra Beckum HC260. Everything under the cover looks to be in reasonable condition especially considering the machine was made in 1989. The bearings of the pulley and the cutter block appear to be OK with only minimal play and the belt isn't slack - it needs a bit of persuasion to go back on. Does anyone have any suggestions as to the likely cause please?
Regards. Martin

 

[Spectric]

A belt will normally only come off if it is loose or there is significant misalignment. Looking edge on o the belt and pulleys do they look to be in alignment, try and use a steel rule or straight edge to check.

 

[clogs]

the plastic pulley should have a def crown.....the belt will ride up on top of the crown.....
are u sure there's no play in the main shaft....?
cant really see the condition of the belts inside surface.....
lastly if the belt is off, does the black pulley spin without any wobble....?
have known the webs to be cracked at the center....

 

[MorrisWoodman12]

A belt will normally only come off if it is loose or there is significant misalignment. Looking edge on o the belt and pulleys do they look to be in alignment, try and use a steel rule or straight edge to check.

The end of the cutter block shaft providing the drive is a plain shaft so there is no alignment as such. I assume the belt will find it's own alignment as the pulley is crowned.

the plastic pulley should have a def crown.....the belt will ride up on top of the crown.....
are u sure there's no play in the main shaft....?
cant really see the condition of the belts inside surface.....
lastly if the belt is off, does the black pulley spin without any wobble....?
have known the webs to be cracked at the center....

Yes the plastic pulley does have a crown. I'm virtually certain there is appreciable play in the main shaft bearings. I would think much less than 0.5mm and more likely 0.2mm but I'm only guessing.
The inside surface of the belt is undamaged in any way though is quite smooth. I tried turning the belt inside out as the outer surface is matte rather than 'polished' like the inner surface. It made no difference. I did notice that the belt has taken up the curve of the crowned pulley.
I can't see any appreciable wobble as the pulley wobbles. I cleaned the mechanism after the belt came off the first time including the pulley. I didn't notice any cracks nor any play in the bearing or wobbling in the pulley due to cracks but I will have a better look again tomorrow.

Thank you both for your help.
Martin

 

[SkyBlue63]

I have the Metabo HC260c and have just had to purchase a new belt (about £25 incl P+P). When comparing the two belts I thought I'd been sent the wrong replacement. But went ahead and fitted replacement, wow.
I did ask Metabo if there is adjustment on this belt and there isn't ?
I think I bought new belt from Powertoolspares.
Hope this helps
Geoff

 

[MorrisWoodman12]

Thanks Geoff @SkyBlue63 . I was on the point of ordering a new belt this evening from Powertoolspares in fact, had I no more replies. I guess your comment about being sent the wrong belt means it appears a lot smaller than the existing one and therefore is quite a tight fit over the pulleys.

 

[Fergie 307]

Had a similar problem with a kity. The bearings were on the way out so on changing them I took the opportunity to convert to poly vee. I found a suitable pulley for the motor on e bay. Actually a PV car power steering pump pulley but the same diameter, £10. Then made a new driven pulley on the lathe, and turned down the original motor pulley to make a hub for the new one. Whole conversion cost less than 30 quid and now runs sweeter than ever before.

 

[Fergie 307]

Had a similar problem with a kity. The bearings were on the way out so on changing them I took the opportunity to convert to poly vee. I found a suitable pulley for the motor on e bay. Actually a PV car power steering pump pulley but the same diameter, £10. Then made a new driven pulley on the lathe, and turned down the original motor pulley to make a hub for the new one. Whole conversion cost less than 30 quid and now runs sweeter than ever before.

Sorry should have said, the machine ought to have provision for tilting the pulleys relative to one another to centre the belt, in the same way as you centre the blade on a bandsaw. On mine the problem was largely due to the crown on the alloy motor pulley having worn pretty much flat, so no amount of adjustment would keep it on for more than a few minutes.

 

[Fergie 307]

Thanks Geoff @SkyBlue63 . I was on the point of ordering a new belt this evening from Powertoolspares in fact, had I no more replies. I guess your comment about being sent the wrong belt means it appears a lot smaller than the existing one and therefore is quite a tight fit over the pulleys.

Always worth checking commercial drive belt suppliers, rather that buying from the manufacturer or a machine specialist. If your belt is a regular size, and they usually are, they will be a fraction of the cost. Gates PV belt for my Kity was less than £10, dread to think what Record charge for a belt for a similar sized machine.

 

[MorrisWoodman12]

@clogs I have now inspected my pulley: no apparent cracks or other problems with it.
@Fergie 307 Good idea but impractical on theRecord/Elecktra Beckum as the pulley has a pinion moulded into the back of it - see photos - and the drive 'pulley' is the plain shaft of the cutter block. The bearings is good + I could only sleeve it if it wasn't.
Also yes a commercial belt supplier would be cheaper but what is the correct belt size? I assume the belt I have has stretched. I'll note the length when the one I've ordered arrives.
Thanks everyone for your helpful comments.
Martin

 

[sometimewoodworker]

Also yes a commercial belt supplier would be cheaper but what is the correct belt size?

every belt I’ve seen has the size and often the profile listed on it. I’ve just looked at the belts for my 50 year old Dewalt and they are there, cost from a belt supplier about £3.50 + VAT + shipping each.

if the size information has worn off then width and approximate length will get you a belt that will be ok from someone like Flat Belt

 

[MorrisWoodman12]

Thanks everyone for your helpful comments. I have fitted a new belt (~£27 eek!) and the P/T is now thicknessing again.
@sometimewoodworker I must have the two ba$^£ds of belts. The original clearly has Elecktra marked on it several times but no size info. The replacement from Powertoolspares has no markings at all.
Just for posterity here is a photo of the two belts. The outer one is the original.The old one is about 17 x 3.3 x 610, the new one is 18 x 2.5 x 550

 

[sometimewoodworker]

Thanks everyone for your helpful comments. I have fitted a new belt (~£27 eek!) and the P/T is now thicknessing again.
@sometimewoodworker I must have the two ba$^£ds of belts. The original clearly has Elecktra marked on it several times but no size info. The replacement from Powertoolspares has no markings at all.
Just for posterity here is a photo of the two belts. The outer one is the original.The old one is about 17 x 3.3 x 610, the new one is 18 x 2.5 x 550
View attachment 102766

The prices are really quite high, it’s almost certain that a 15mm belt will work. There are a variety of lengths in about 10mm increments

 

[MorrisWoodman12]

Yes comparatively horrendous but without knowing the original length I'd end up buying two or three which is why I have posted the details above so hopefully others may be able to buy the less expensive option if their belt needs replacing.