Thread: Slitting Saw Runout

Originally Posted by jack620

Thanks Dave,
I think in future I will only buy quality brand name blades. I will keep an eye out on eBay for NOS.

Yep, dont think India is the home of quality cutting tools.
Video is a pisser, looks more like a cam spinning around.
Pity these cheap imiatations have wrecked the market for manufacturers such as Suttons to make these style of cutters.
No money in it when you make quality and compete against rubbish.

Agreed. I bought a special edition boxed set of 25 Sutton drill bits at Bunnings a few weeks ago. The metal case was slightly twisted so I made them an offer of $80 and they accepted. Fixed the case when i got it home. I figured Sutton might not be around much longer.

I have one NOS Osbourne 6" that is fine. I also have a few CTC's that are just like yours......

Here are a few. HSS Milling Slitting Slotting Cutter Saw 6" x 1/16" x 1". Sutton. NEW | eBay HSS Milling Slitting Slotting Cutter Saw 4" x 3/32" x 1". CARDINAL, P&N, TEC | eBay HSS Milling Slitting Slotting Cutter Saw 4" x 5/64" x 1". YTO BUS. NEW | eBay

Just out of interest... this is the link to the SOBA-Tools website in India:
Shobha Industries :: Homepage

I am surprised how many familiar tools sold by H&F etc are actually made by SOBA. I did not know they even make a full range of woodworking planes.... Obviously they are following in the footsteps of China, which will soon become too expensive to manufacture hobby grade tools. Chris

Thanks for the links Ewan. All those saws have fairly course teeth. I don't know how a 3/4HP lathe would go driving one of those. I'm not sure if my keyless arbor would be able to hold on to the saw tight enough either. To date I've been looking for 1mm wide blades with fine teeth.

Originally Posted by jack620

Thanks for the links Ewan. All those saws have fairly course teeth. I don't know how a 3/4HP lathe would go driving one of those. I'm not sure if my keyless arbor would be able to hold on to the saw tight enough either. To date I've been looking for 1mm wide blades with fine teeth.

It depends how deep slits you are going to cut, and what meaterial. If you are going the whole available depth and are cutting a fairly wide area, you will find that you need coarse teeth. You get nowhere with fine teeth, because it becomes very difficult for the saw to clear the chips out (remember, there is no tooth rake, and no tooth setting, the saw cuts exactly its own width and not any wider). Also you will find the saw disc wants to bind in the slit, you must lubricate generously and constantly. And for this binding risk reason, especially with such a thin 1mm blade, you should NOT use a key to drive the saw, but only rely on the friction to the arbor and hope it slips soon enough.... even then, the saw can very easily shatter if allowed to seize in the slit.

Also, when doing this in a lathe, please be aware that the cross slide is NOT moving at 90 degrees to the main spindle (it is slightly offset to ensure the lathe faces concave -- the cheaper the lathe, the more of this offset you must expect). This becomes clearly visible when using a sliting saw and doing deep cuts into a large area workpiece with a thin slitting saw.... the slit that you cut is not in the same plane as the saw disc, and that tries to twist your saw blade, making it want to bind even quicker than if you did the job in a mill. Leave the spindle drive belt loose, you need very little power to drive a 1mm slitting saw.

Workpiece material matters too, for Aluminium you want a coarse saw, but if its only a thin cut say into plate or for a screw head, then you want a fine saw. A coarse slitting saw can look frighteningly coarse, with only very few teeth at all, but it will work well. But if at the moment you can afford only one saw to do everything, go for the finer teeth. Hope my experiences in this matter will help you not to break your saw


EDIT: I forgot to mention something that will sound crazy to a seasoned machinist used to large machine tools.... but here you go: I found that it actually is an advantage if a slitting saw has some runout (when used in a not so rigid and low powered hobbymill or hobbylathe). The saw cuts only on a few teeth, and the teeth that do not cut actually help in clearing the chips (or dust) away and carry coolant lubricant into the slit. I know it sounds crazy, but small hobbymachines often behave differently from large industrial machines.

Thanks Chris. In that case I might get a course blade too and compare. I have found the fine blade clogs when cutting Al. I've been using a toothbrush to clear the chips as it cuts. Lots of WD40 helps too.
Chris

Originally Posted by Ueee

I have one NOS Osbourne 6" that is fine. I also have a few CTC's that are just like yours......

Here are a few. HSS Milling Slitting Slotting Cutter Saw 6" x 1/16" x 1". Sutton. NEW | eBay HSS Milling Slitting Slotting Cutter Saw 4" x 3/32" x 1". CARDINAL, P&N, TEC | eBay HSS Milling Slitting Slotting Cutter Saw 4" x 5/64" x 1". YTO BUS. NEW | eBay

Thanks Ewan.
I just purchased the 6" x 1/16" Slitting Saw
Been after one of these for a while now.
regards
Bruce