Aluminum will stick to the end mill and gum up without lubrication. coolant, WD40 or kero works good.
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Aluminum will stick to the end mill and gum up without lubrication. coolant, WD40 or kero works good.
Thanks. Sounds like its a common issue.
Simon
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Hi Guys,
I've seen an article very recently about machining gummy materials, particularly aluminium, brass, copper and nickel. The article suggests that coating the surface to be machined with permanent marker or pritt adhesive, makes it machine as though it was a much harder metal. It doesn't mention whether any lubrication or coolant was used in the tests. I've not tried it yet but I have some brass that I need to machine.
Meths works really well on Al and leaves zero residue.
If it's a long/wide cut and you don't want to intoxicate yourself you will need ventilation. :drunk22:
Thanks Bob. Today I received in the post a slitting saw arbor. Been wanting one for a while now and it reminded me that this particular cut would have best been done using a slitting saw.
Cheers,
Simon
Hey Simon,
If the slitting saw arbor is similar to this it's probably a good idea to replace the countersunk socket screw. If the setup allows it, a cap screw would offer even more insurance.
BT
Attachment 374355 Attachment 374356 Attachment 374357
Bloody hell Bob, yes I have the same type. Yes, I'll be spending all of 50c and replacing that socket screw.
In all honesty Bob, I would have thought you would have sniffed out some exotic swiss made version of that. :rolleyes: So we do share some similar tools!
Thanks mate!
Simon
Hi Simon, Guys,
Do yourself a favour and grind a pair of spanner flats on the cup ! I did that to mine because after the first use the screw was so bl..dy tight I had to use an impact driver to loosen it. One other point replacing the CSK screw with a cap screw will reduce the clearance under the saw arbour. I've since made an MT3, 1" X 1" arbour with collars and a large, M8, 32 mm diameter headed screw, 3 mm thick head, with pin spanner holes in it.
In regards to the slitting saw arbor do you get any slippage on the spindle if you take a full depth cut?
Thanks Baron, I'll do that too.
These slitting saws are a whole new animal to me. I think i'm going to be extra cautious the first time I use it. I can see things going bad real quick if your setup is not spot on.
Hi PC, I'll leave that question for someone else to answer. I've never used one yet.
Simon
Hi Guys,
The stepped cone in those arbours and the thin edge on the clamp is not very good ! There is only a very narrow clamping edge to grip the blade. The saw blade does slip quite badly and causes the clamp to rotate tightening the screw to the point that it is almost impossible to remove without damage.
Putting spanner flats on the clamp helps because you can get a lot more force on a spanner than the hex key, to loosen the clamp.
NOTE: Some of these arbours had a slotted CSK screw... !
The MT3 arbour that I made doesn't slip anywhere near as much as the cone one did, but it does tighten up. I think this is because I don't have a keyway in the spigot and the collars are only about 3 mm thick. A thicker collar should help with this. I did try a paper gasket one time, it helped, but not much, which suggests that the screw that I made should have been dished slightly. I did look for the screw last night in order to take a photograph, but as usual I can't find it. I'm sure that I put it in the plastic box that the arbour came in.
One other thing, I've seen many comments about slitting saws running off centre. Even on the arbour that I have made they still run side to side, only a few thou, but they do !
Hi Kryn, Guys,
These are pictures of the slitting saw arbour that I made ! The MT3 X 40mm blank end arbour came from Arc Eurotrade, here in the UK. It has an M12 drawbar thread. It was designed to support 1" bore cutters up to 1" thick.
Attachment 374406 Attachment 374407 Attachment 374408 Attachment 374409
It helps when you look in the box for the screw ! :):):) I was sure that was where I put it. Anyway I lied about the diameter :- The screw is 40 mm diameter and 5 mm thick with an M8 X 1.5 thread and 3 mm diameter pin spanner holes on a 1 inch circle. Now where did I put those spacing collars ?
Hi all,
When I wrote about this it was a little tongue in cheek, well I have tried it ! Much to my surprise it works. I machined a small brass part with a brand new slot drill and didn't get any build up on the cutting edge at all and the chips came off in little curls. I'm going to give it a try on an aluminium part later and see if it works the same.
I've not posted any pictures yet but will later in another thread.
Thanks:
Hi Baron,
Thanks. I will have to remember that for next time. I too am curious how it goes. I also just realised I didn't reply to your last post regarding the slitting saw. That's nice work. I'm yet to use mine yet. I still don't have any cutters for it. There are so many, I got no idea which to buy, in terms of having a couple in stock for future use.
Simon
Hi Simon, Guys,
FWIW, I bought a six inch diameter by 40 thou thick slitting saw, among others, because the clamping cone on the original arbour would not clear the vise if I used my original 3 inch one. Since making the new one I can use smaller diameter saws because I can get within a 1/4" of the top of the vise.
A point that I will mention is that the saw blade will heat up and bow as it expands, particularly a larger diameter one. It was the saw blade bowing and cracking that caused the jam on my mill, stripping teeth on the plastic gears. Since replaced by steel ones.