Kennedy Hexacut machine hacksaw

[Graham MeekParticipant @grahammeek88282]

A few days ago I promised that I would post a few photographs of the conversion.

The next photograph shows the new ribbed pulley. Which is all that is required to be made to convert this machine.

Lastly the saw in action, if you notice from the the blurr on the hacksaw frame this is taken with the saw in motion.

The material is 40 mm Aluminium and the saw cut through this in several minutes.

You might also notice the Brass swarf from the previous cuts this morning.

Regards

Gray,

[Leo F Byrne 1Participant @leofbyrne1]

I think I’ll do this. What length belt and where did you get it? I can turn up a new pulley in aluminium.
You should be ashamed of the brass swarf – but don’t worry too much. I’ll post pics of the area under MY saw!

[Graham MeekParticipant @grahammeek88282]

Hi Leo,

My apologies for not getting back to you sooner. I seem to have had computer problems this end.

The belt Ref No. is 559P/220J _10 RIBS. I purchased my belt form Simply Bearings, (Usual disclaimer), it was here with in two days.

I am going to send you an PM with my email address so that you can have the PDF drawing of the pulley.

Regards

Gray,

[ianjParticipant @ians]

I have a Kennedy model "90" hacksaw, which is much larger than the "60" (Hex bars are 21mm AF)

I've never managed to get the flat belt to run on the centre of the large pulley.

So seeing Graham's Poly belt conversion I decided to do the same to mine.

Been a larger machine the dimensions are different to Graham's.

Large pulley diam. 9.875" (251mm)

Small pulley diam. .96" (24.38mm)

Centre distance of pulleys 6.8125" ( 173mm)

Graham very kindly calculated the Poly belt length as 34" ( 864mm)

This was purchased from "Simply Bearings" Part No. 864PJ/340J-14Rib

As can be seen in the photo the belt now runs nicely on the centre of the large pulley and is far easier to put on than the old flat belt.

[BazParticipant @baz89810]

Graham you have a PM.

[Graham MeekParticipant @grahammeek88282]

A while ago I noticed on Ian’s 90 Saw above that there is a blade tensioning facility. While I have not as yet checked to see if this was standard on the 90. I thought the blade on the 60 would probably give a better finish if it was under some form of Tension. Plus it may even lead to extending the life of the blade.

Using a similar arrangement as the 90 was not really possible as the blades for the 60 are cut into two. The standard hole in the hacksaw blade would only work for one end of the hacksaw, (NB, tooth direction on the blade). Duplicating any such adjustment was deemed too much of an overkill.

I tried compressing the frame of the 60 using a Record 12″ “G”-clamp. The amount of effort required was negligible and the resultant cut surface did not show the previous striations of the previous set-up and was generally much better. The saw blade would ring slightly as it was cutting, so it was under tension.

While I could of continued to use the “G”-clamp the set-up. The size of the clamp pad faces made extracting the old blade and inserting the new one time consuming. Something simpler was needed.

The above shot shows the finished design in-situ. It will be noticed that the blade can easily be removed as the clamp does not go high enough to cause a problem.

(Please ignore the Brass thumbscrew, the Camera, or the Operator were having difficulty getting the focus right)

In use the 4mm Allen key in the M8 grubscrew is very easy to turn, due to the ball bearing at the bottom of the hole in the clamp pad. There is an added bonus in that when the adjuster is put onto the machine and slightly “nipped-up”. Before releasing the clamp screws on the blade to remove the old blade. This setting will not interfere with the original blade setting. Thus once the optimum setting is found, (This I found was about a 1/4 to 1/3 of a turn from the free state), this initial setting will remain for ever and a day.

Regards

Gray,

[Clive FosterParticipant @clivefoster55965]

Nicely done Graham.

Which reminds me that over 40 years ago when I first encountered a Hexacut saw I was told to push moderately hard on the end of the bow to put an “unspecified” amount of tension on the blade before tightening the second clamp as it would last much longer than if simply installed loose. Which was true.

But your little device is vastly better than shove’n hope.

Hafta say I was most impressed by the way the little, clearly made down to a price, beast coped under the conditions of casual carelessness with which it was used.

Clive

[Graham MeekParticipant @grahammeek88282]

Thanks Clive, It is nice to know I am on the right track.

I thought other Kennedy owners might want to make this little item, so I have loaded the drawing below. Having this here will save the un-needed exchange of PM’s and emails. The manufacture of this device took hours rather than days, so will no doubt repay its construction equally as quick.

 

Regards

Gray,

 

 

 

[Dave WoottonParticipant @davewootton]

Thank you for posting that Gray, I bought a very used one of these a while ago from the Facebook marketplace and am looking forward to giving it a good overhaul. The previous owner had attempted some fairly desultory repairs and fitted a new flat belt, and posted his efforts on Youtube, however none of the bodges are undoable, and the machine is fairly sound, so hopefully given a little time to get round to it it should be returned to full vigour. I had been thinking of some form of blade tensioning device, this is simple and doubtless effective, far better than my overcomplicated musings, I had not thought of a seperate tool for tensioning using the existing blade clamps, very clever.

Thanks again for sharing

Dave

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