[alexccmeister]

Hi all,

Ever since I got my X2 mill and C3 lathe, I have been playing around with aluminium. Just today I thought why not do some machining with brass and guess what I found out. Brass is easier to tap than aluminium. I thought brass is harder than aluminium, but why is it easier to tap. Also, when I drill hole in brass, the brass bits coming off the drilling is powdery unlike aluminium which is sharp.

I am new to metal machining so apology if the above sound silly. Anyway, after finding out what happen to brass I am now thinking about getting some steel to machine and tap. I wonder if it is easier to tap than aluminium.

Also why aren't people using more brass to work with? Is it because its more expensive? Is brass stronger than aluminium? Thanks in advance.

[rustamd]

steel is cheapest out of 3 you named, probably strongest for most part, aluminum is slightly more expensive but easier to work with, but will cost you that strength, brass is soft and expensive, not much of structural material. Everything is relative to each other. Of coarse everything is just my opinion

[rustamd]

also your speed might be wrong for brass, thats why it was like powder. Try to have correct speed for different materials, tools will last longer, and maybe get job done faster.

[alexccmeister]

Hi Rustamd,

Thanks for the reply. When you say brass is not much of structural material, what do you mean by that? Does it have less strength than aluminium? Or it is more expensive hence not worth to use for structural purposes.

As for the speed, I am drilling at roughly 2000rpm with my X2. I don't mind the powdery stuff, I just find that its odd that brass does that when drilled. I have not milled brass yet so I am not sure how hard it is to mill. I am converting my mill to cnc and thats why I am thinking of using brass to do the job. Since the quantity is small, I am not paying an arm and a leg for the materials. Thanks.

[Crashmaster]

Aluminum and Brass are much easier to tap than Steel.

[rustamd]

Hi Rustamd,

Thanks for the reply. When you say brass is not much of structural material, what do you mean by that? Does it have less strength than aluminium? Or it is more expensive hence not worth to use for structural purposes.

As for the speed, I am drilling at roughly 2000rpm with my X2. I don't mind the powdery stuff, I just find that its odd that brass does that when drilled. I have not milled brass yet so I am not sure how hard it is to mill. I am converting my mill to cnc and thats why I am thinking of using brass to do the job. Since the quantity is small, I am not paying an arm and a leg for the materials. Thanks.

Yes, brass has quite a bit less strenght than aluminum.

[alexccmeister]

K. I am using brass rods (3/8") for supporting a nema 23 motor to the X2. I hope the four rods are sufficient strength to support the motor. Any take on using brass as oppose to aluminium rods? Thanks.

[rustamd]

I personally would not use brass on anything that requires some support, at least decent amount of support. For me brass is mostly used on decorative stuff or soft hammers/jaws.

[alexccmeister]

Hmm... Now I will have to rethink my strategy. I was hoping to use aluminium rod, but so difficult to get from where I am. I might try steel rod then. Will see how the brass rods perform. Thanks for the comments guys.

[rustamd]

aluminum should be good for that i would think. My whole machine is made out of aluminum.

[The Blight]

Brass is good when it comes to bearings, valves and moving parts. It's also stiffer then aluminum, but it can't bend too much without breaking (except some special types of brass), but when it comes to structural support, I would go with alu, or steel. You might have a hard time working with steel on these small machines, so have a bit of patience when doing so.

[alexccmeister]

Thanks guys. I have completed the X axis cnc conversion. Using both brass and aluminium. I am using brass for the coupling and rod support for the stepper and aluminium for the plate screwed onto the X axis X2 table end plate.

Tested with mach3 and its working fine. Now onto Y axis. I will put up photos when I am able to. At the moment in my machine shop trying to configure mach3 to run properly with the stock lead screw.

[alexccmeister]

Here are a few pics of the X axis cnc conversion.

[S_J_H]

I think brass will be fine. It's plenty strong in this case. It's just an expensive material to be used for that sort of thing.
Steve

[alexccmeister]

Hi Steve,

Thanks for the info.

Anyway, what luck I had yesterday. Managed to damage a stepper motor by accidentally dropping it on the floor. Broke a bolt hole where I mount the support rod to the stepper so now one of the stepper has only 3 legs support instead of 4. I hope it doesn't any worse than this. Now I have to order a new stepper motor. I wonder if I can switch the head of the damaged motor to the motor that has the broken bolt hole.

[alexccmeister]

Another thing I found, my stock acme leadscrew just has too many threads on it. Although accurate, the movement of the table is real slow.

I think its probably time to change to ballscrew or leadscrew with 5 or 8 tpi.

Anyone know where to get this? Thanks.

[ataxy]

i dont know how slow is slow for you but remember the 10 thread will give you more precision then 8 or 5 also keep in mind that those machine can not be pushed like industrial machine so you may end wishing it would go slower

[rustamd]

Hi Steve,

Thanks for the info.

Anyway, what luck I had yesterday. Managed to damage a stepper motor by accidentally dropping it on the floor. Broke a bolt hole where I mount the support rod to the stepper so now one of the stepper has only 3 legs support instead of 4. I hope it doesn't any worse than this. Now I have to order a new stepper motor. I wonder if I can switch the head of the damaged motor to the motor that has the broken bolt hole.

It is not recomended to take stepper motor apart. Almost everytime someone takes it apart it will loose alot of its torque(just what i read)

[alexccmeister]

rustamd, I did the unthinkable. I went ahead and changed the cover, the motor still runs fine after the swap. As for the damaged motor, it now doesn't run. I think the shaft is bent. When I turn it with a plier, it will turn fine and then gets harder at one point. I suspect the shaft hit the ground and was bent to one side causing the motor to stall. So thats $60 down the toilet.

Ataxy, The motor is fine running at 300mm/min. I set to 200mm/min and it stalled as the table gets closer to the end of its run. I would prefer it to go all the way to the end but it stalled at around 50mm from the edge. Still alot alot travel to lose. I think it may be the alignment of the leadscrew and the motor shaft. Will adjust it and see what happens. I think I am comfortable with 200/250mm/min velocity so I may stick with that when churning out parts.

[The Blight]

It stalls because of the ways. They are uneven on these types of machines, and I would reccomend lapping the ways. I spent a couple hours doing this, and I can tighten the gibscrews up to the point where I can't move the table from side to side (twist it) without it binding at any point, and it has just as little slop all the way. I would not use screws with a pitch greater then 4mm as you loose some precision. 2mm would be perfect. I don't like microsteps so with a 2mm pitch, you would get 0.01mm per step (10micro).

One of my motors also has a hard point when I turn it, but it works just perfectly. Does yours not run at all?