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Hi Blight,


Thank you for your suggestion of using brushless outrunner motor! Your suggestion is a much better solution than the rc car motor I had in mind! The belt gearing problem is solved!...

Thanks LongRat. I thought the efficiency of brushless motors are in the 90% and higher. If so a 1000 watt going into the motor should only generate 100 watt in waste heat. That's similar to a 100...

Not sure if folk have done this setup before; at least I didn't see any mentioned after a quick google search. My solution has worked amazingly well for me. I thought I share.


My solution...

Just found this: A simple high quality 12Volt 100Amp Power Supply- Part1 - RC Groups

Apparently HP server power supplies can put out 100 amp at 12 volt! Muhahah, more power!

Let's tackle the...

Thanks jfong! Good to know that dell server ps put out 60amp at 12v! I don't have to mess with their internals!

One more idea to get some feedback.

Most of the time, machining on my mill will not require 1.3hp. It is really the occasional high load (maybe lasting 10+ minutes) that needs to be dealt with. ...

Thank you, very good point.

I didn't realize each 12 volt line in a 1000 watt ps only provide around 32amp.
1000W ATX Power Supply Quiet Gaming 14cm Fan Dual SLI Ready for VGA ATI NVIDIA |...

Hi all,

I want to upgrade the dc motor on my old x2 mini mill. I want a brushless dc motor with direct belt drive. However, the brushless dc motor with at least 1 hp rating are quite expensive;...

Concrete Filled Column Twist Result

The amount of clockwise and counter clockwise twist of the z column is approximately the same. I've also verified the bending of the mill in...

Hi all,


I am back. Sorry for the long absence. I had to tend to other priorities.

In my previous post, I discovered another source of flex is from the Z column twisting. To increase the z...

Eldon_Jon,


Thank you for the feedback. Actually, I have high hopes for concrete filled steel tubes (CFT). However, first let me admit that I have not study the physical behavior of concrete...

Source of Flex Episode III: Twist Again!


In my previous post, I demonstrated the mill base is susceptible to twisting. I really had hoped that the z column would not have this issue since the z...

rs4race,

You mentioned in your post that either the wood bench or the mill base is not level and that your bet is the table. However, my previous reply is that I think it is the mill base. After...

rs4race, I think you are right. I didn't check but most likely my mill's back left corner is slightly lower ( a few thousands of an inch) than the back right corner. Because the back left corner is...

Another Source of Flex

In my previous post, I've shown that just by rotating the mill on my wood bench by 45 deg, the right column flex was reduced by 60%.

This was the smoking gun that...

From my previous post, I was puzzled by the remaining large right column flex. I've now figured out why! However, to engage my reader in a fun puzzle, I will hold off disclosing my finding until my...

Today, I was able to improve the rigidity further by enhancing yesterday's implementation. However, I am also a bit stuck and can use some suggestions. I will describe the issue further below.

...

Hi,

Thank you all for the kind words and encouragement.

My day job has been keeping me really busy for the past few weeks. I finally have some updates for implementing plan A. Please see...

Giterdun, you sounded like a miserable old thing and you are desperately clanking the last few coins in your pocket to the whole world as loudly as you can!

Go on miserable old thing! Spend...

Thank you for the feed back. What do you mean by "open y axis casting"? Do you mean the underside of the mill's base is hollow and therefore not rigid?

Anyway, I think the mill's existing base...

Any idiot can spend money. Many good and decent folks across the world spend untold hours to build little silly things for its own pleasure. My thread is for these people.

Really don't worry...

Plan of Attack A

Now we are get into the exciting stuff!

Please note that not only will I share my successes, I will also share my failure. This way, readers of this thread can read about my...

Thanks Eldon!

Like most problems of this nature, I am positive that the mini mill column flex problem also follows the 80/20 rule as well. By that I mean the bulk of the rigidity gain can be...

Please see my first post on this thread where I stated my goal and detailed the baseline measurement of flex at the spindle. To say the least, when the spindle can move around +-0.004" (or 0.008"),...

Retest of Joint Area Flex (blue box)

This is a follow up to the my post on identifying the source of flex.

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Test setup:

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A Much Safer Way To Apply Test Load


I came up with a much safer way to apply test load.

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Now if the clamp should slip, the dumbbell weight will drop 1" onto my bench! No more...

You probably have not read my first post.

I already read the link in your post and many others before the start of my effort. In fact, from reading what others have done, some improvement are...

Thanks! This is an excellent approach. I'll put up my findings.

Source Of Flex


The following is my analysis of the sources of flex in the mini mill Z column and the magnitude of their contribution to the total flex.


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The sources of flex are:

For the baseline, I always put the weigh at the end of the clamp and the spindle at the same height.

I put the weigh further out from the spindle to reproduce a reasonable amount of torque on...