Kitty Bandsaw 513, 613 and 612 shedding blade

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

Garden Shed Projects

Established Member
Joined
21 Apr 2021
Messages
334
Reaction score
340
Location
Northamptonshire
I am currently in the middle of a project which will take a couple of weeks to complete. Will drag the band saw out after that and check wheels for coplaner alignment using the method above.

I think I need to start at the beginning, take the table off and zero everything in. Tyres appear to be in good condition with little wear visible, my machine looks to have had little use at all. Can I assume that the tyre would look worn out if they were or is there something else I should be checking?
Can someone advise on blade tension. Am I better over tension than under. As I said before I am using tuffsaw blades so the risk of snapping is reduced, what other issues can over tightening cause?
 

Chippymint

Established Member
Joined
1 Jun 2016
Messages
154
Reaction score
51
Location
Devon
In a recent post problems with the kitty bandsaw came up, see links below.

I have a kitty 513 which seems to be identical to the 613. Cannot get on with it. Nothing seems damaged or worn but the blade will not stay on the wheels. I have taken the table off, used a rigid straight edge with wooden blocks to get the wheels in line, checked with the blade tensioned. Have adjusted the bottom wheel as well. Nothing seems to work.

I am using the blade which came with the machine, plan was to get it working then buy some tuffsaw blades. I am wondering if there is a problem with the blade. My other thought is that these saws have flat wheels so the blade is positioned with the teeth overhanging the edge of the wheel. Perhaps the more normal crowned wheels have a self centring effect.

It would appear that other members have had problems with these machines and I am asking if anyone else has any experience of these machines, good or bad and if there is something needed in the setup to get them working.

Garden Shed Projects


Linwoodjoinery
Well Jonm, you have had lots of advice and I'm not sure how far you have got.
I've been helping people with Kity (and other makes) bandsaw problems for a very long time. I have a 613 which I have owned for over 25yrs - they are great machines. I use it for smaller work now as I have a large Startrite for the main tasks.
I can only give you advice based on my experience, and it is not intended to be detrimental to other feedback you have had.
Kity bandsaws have been in use since the late 80's. They have a substantial frame for a 10inch alloy wheel assy and lower powered motor. The manufacturer says a you can use 1/4 to 1inch wide blades.
The main problem with these machines is the tyre compound used (vulcanarised rubber). Over-time the tyre can lose it's firmness leading to it eventually breaking down. Not every machine suffers from this but the vast majority do. The tell-tale sign of matters going wrong is that the blade slips off in use (especially narrow blades) or regularly goes out of adjustment. Matters worsen when one applies more tension than is normally required.
My guess is; this was your origonal problem or this and other issues.

You can fix this by fitting new tyres. A word of caution, make sure you buy the correct tyre thickness otherwise you will have blade tensioning issues. Bedford Saws offer these but be careful what you buy.

You infer that you have made adjustments to the lower wheel easy. Normally this is a last resort adjustment. My thoughts are that when you have installed new tyres, go back to basics and give the machine a thorough check and set up.

I'm not sure of your experience with setting up bandsaws. If you know what to check and do then great. If you don't it would be a good idea to read up on bandsaws and their set up. A great read is: Band Saws by Mark Duginske. This book is not expensive but a superb reference manual for any bandsaw. There are some useful guides on 'how to'.

If your bandsaw is second hand, then it would be a good idea to go through everything and set it up properly. This book gives you everything you need to do.

My only gripe with the book is the insistance on Coplanar wheel alignment. I understand why this is said to be important but not all machines makes work better with 100% Coplanar. What is important is that adjustments are made to ensure your blade tracks correctly.

I'm a fan of Alex Snodgrass. His videos on YouTube are very good. He too states that Coplanar is not a worry, in fact he advocates leaving manufacturer settings as they set them.

All my machines and the ones I have set up are as per Alex's suggestions and I've never had a issue. My Kity is set up with the blade running centrally on the wheels. Yes there are slight blade teeth indentations on the wheel tyre but as the teeth run in the same position for every blade width, I've found that the tyres are fine. However, in order to do this I had to reengineer the blade guide assy to enable the guides to move further back.

My last thought is that, you do not over stress your machine by fitting wide blades. Yes manufacturers say up to x but this is often just a selling ploy. You are far better to fit a blade that is 75% of what the manufacturer says. It will do a great job. A 5/8 blade for a 613 will do a splendid job so long as it's sharp and of good quality - I use a 3/8 6tpi blade most of the time and I'm amazed at my machines performance with European Oak.

Hope this has been helpful. Good luck.
 

imageel

Established Member
Joined
27 May 2011
Messages
134
Reaction score
91
Location
Essex
Further to what others have advised -
I have a Kity 613 bought new at least 27y ago and I have used it regularly for lightish work and sometimes heavier work such as ripping 140mm sawn hardwoods and I have never had issues with the blade popping off.
I know the designs did change in some details over the years however I always follow this procedure to remove a blade -
1. Back off all the guides and the thrust bearing - so 2 upper + thrust and 2 lower ones
2. Release the blade tension and unscrew the cap nut sealing the slit on the edge of the table and slide the blade out.
I know my model has a crowned top wheel and against others advice the instructions that came with the machine and the labels printed on it clearly show that when the blade has been correctly tensioned it should be riding with the teeth hanging off the outer edge of the upper wheel. Achieving this and the correct tension is a bit of trial and error but takes no time to achieve a satisfactory result
Only then - when the blade is sitting at the correct tension and the correct position on the top wheel/tyre adjust all 4 guides so they are lightly touching the blade and then set the thrust bearing similarly or maybe 1-2mm off.
I did once see a video on YouTube where a guy demonstrated cutting veneers from a largish block after having set up and tensioned a new blade correctly but with all the guides retracted to demonstrate I guess that the blade should ordinarily run true and the guides are there when and if either the wood grain force the teeth to try to wander or if the workpiece is not fed consistently inline with the desired cutting line.
Backplate label -
20220428_114859.jpg

Blade setting label -
20220428_114914.jpg

The diagram indicates that the blade should be set such than 1/3rd of the blade kerf should be on the rubber and 2/3rds hanging off...

Unless as others have commented your wheels need new rubbers then following this procedure has always worked for me.
As to correct blade tension - this is a bit subjective however the blade should give a dull twang when deflected off a square edge, but the correct tension will depend upon what type of blade you have fitted - the wider and thicker the blade the higher the tension needs to be.
I suspect I tend to err on the lowest tension possible - if I'm struggling to say rip through a thick block then it's more than likely I'm either using an incorrect blade type or else it is blunt!
I too use a range of blades from TuffSaws and find them pretty robust and only rarely have I broken any and usually when I do it's as a result of abuse on my part as opposed to blade failures itself.
I did recently try sawing off the bases of reclaimed woodblock flooring using a jig to hold the blocks which itself was running in a hardwood T-slot and I found even using some of the cobalt tipped M42 blades that after cutting around 3-4sq m of blocks the blade was truly quite blunt and struggled to cut true to the jig - and this was starting out with a new blade.
Am sure the above and the advice from others should get you up and running!
/Ed
 
Top