surely it must be quicker and easier to part them off.

The bearings do wear, unsurprisingly, that allows things to move off line. The one we had in or little local section trials prep workshop at RARDE had noticeable rock but the saw still cut adequately. Albeit less square than we'd ideally have liked.

Modern plastic faced belts are potential issue as there tend to need both more tension and a higher surface speed to transmit useful power. The saw was designed and developed to use a leather or leather faced fibre backed belt.

if I had to replace the belt on one I'd change the motor pulley to poly-Vee and keep the standard flat pulley. The soft Vee side running on the big pulley will transmit enough power just fine at surprisingly low tension.

Doesn't help that power transmission nis inherently a bit on the marginal side to so the drive slips if the blade jams up rather than break. They were designed for site work where a certain degree of careless handling is inevitable.

Clive

This is just for belt slipping if you get further problems

Have you got the instruction booklet for it and how are you fitting the belt? You may have to loosen the two bolts near the front and pull it forward and tighten it, then put the belt on the motor pulley and then start feeding it on the big pulley and turn it as it forces the belt to follow. it will then try to move off the motor pulley so tap with a soft hammer and continue forcing the belt on, that's what the instructions say.

I can scan the instructions if you haven't got one

Edited By vic newey on 08/08/2023 17:50:32

I believe that the belt on the Hexacut was flat, Howard … Hence Clive Foster’s excellent suggestion.

MichaelG.

.

Ref. __ http://www.lathes.co.uk/taylor/page2.html

Edited By Michael Gilligan on 08/08/2023 19:19:58

I recently acquired a Kennedy 60 and one of the things I have wanted to do with it is replace the rather aging drive belt.

I have just drawn up the pulleys and pulley centres. The belt comes out at 535 mm and the nearest to this is 533 mm or 21" , belt number 210J10. I will be placing an order shortly for this and a few other things so I will let you know how I get on.

Regards

Gray,

Unwanted graphics

Edited By Graham Meek on 11/08/2023 15:53:58

Edited By Graham Meek on 11/08/2023 15:54:47

Edited By Graham Meek on 11/08/2023 15:55:21

I intend to use the Poly V on a grooved pulley on the motor, but with the ribs running on the larger pulley with no grooves. The large angle of lap should more than compensate for the lack of grooves. Further my current lathe will not swing this size of pulley.

The ultimate aim is to reduce the loading on the Saw bearings which wear quite considerably when using the current set-up. The other plus point is it should stop the smaller pulley from slipping. As well as stopping the belt from running off this pulley due to the above shaft mis-alignment.

It is possible using the Grooved motor pulley to go slightly smaller, as the minimum pulley size for this belt is 18 mm diameter. This however would mean a smaller belt and a reduced number of cutting strokes per minute.

The cost of this conversion as well as new Oilite bushes comes in a good deal cheaper than the replacement flat belt.

Regards

Gray,

.

Very common practice on Tumble Driers … for obvious Production-Engineering reasons

MichaelG.

Last night just before I turned in for the night. I had a sinking feeling that the new larger pulley would not fit inside the existing Kennedy Belt Guard. A quick look this morning allayed my fears. During today I have managed to manufacture and fit the new pulley and belt.

I chose steel for the pulley, but with hindsight aluminium would have been better. As the Compact 5 was not impressed with the 2 mm deep Vee grooves in one hit. In the end I worked out a routine which used four cuts, two of which were off-set and formed the width of the groove at the top of the Vee.

There was a bit of a setback with the Phos Bronze bearings. I think they were inserted when the main body was cast. They did not want to budge when using a puller, and the only way these are likely to come out now is by boring them out.

However the saw works fine with the new belt and I have so far tested it on 25 mm Mild Steel. I did also try using an 18 TPI blade which the saw easily took in its stride. Even though the manufacturer states 24 TPI blades on the machine plate. Tomorrow I have some 40 mm square aluminium to cut up so we will see how it performs on this and maybe get some photographs.

Regards

Gray,

Edited By Graham Meek on 17/08/2023 19:33:28

I remember that item in Parks Pumps in Norwich from the 60s and 70s and if I remember correctly it was made for FERODO.

If it works for Hotpoint it will work for me.

The polyvee belts used on tumble dryers are not the same construction as "standard" belts – they use a slightly elastic tension member to make the belts "stretchy"

The reason I know this is that a company I worked for modified the "belt building" machines used to make the belts (by a company in Wigan) to have a closed loop tensioning arrangement to wind on the tensioning cord, which had to be applied at a specific tension to get the correct stretch required. Normal belts used a non-stretch cord.

The stretchability may have been to enable the removal of a separate tensioning mechanism ( engineering by accountants ! ) & the installed tension was high. Tumble dryer installations used grooves cut directly into the motor shaft (around 12mm or so diameter IIRC) & a large diameter plain face "pulley" on the rear of the drum, giving a very large gear reduction.

Polyvee belts in general require a lot of tension to work correctly & wear fast if under tensioned – the amount of wear required on the flanks of the vees isn't much before the belt just ends up driving (more likely slipping) on the points when they hit the bottom of the grooves.

Can't say I am a fan of polyvees though, to be fair, the installations I designed them into were normally "challenging" and where a traditional vee belt solution would not fit the space available.

Nigel B.

I could never get the two pulleys parallel on my saw so the belt just kept coming off.   Its been dumped under a bench for years now.   

Edited By Buffer on 18/08/2023 15:29:47