New PC for my bedroom

[Fueler]

In my last post I said that "I'm pretty sure I hurt the gearbox in my mini mill".....I guess I was in a state of denial.....I knew I had killed it. After waiting a little while for the sting to wear off I took it apart to see how bad I hurt it.

 

 

Not too bad just the gear for the "intermediate shaft" That would be the shaft in the foreground that's missing a gear in the pic below. This shaft is driven by the motor and in turn drives the output shaft. By moving the gear up or down on the shaft it engauges different gears on the output shaft for high and low speeds. The motor is a 4/5ths HP 110volt DC motor that has a controller card that converts AC to DC and allows for variable speed. It can run from 0 to 1100 RPM in low gear and in high gear from 0 to 2500 RPM.

 

 

As you can see the gears are plastic. There is two reasons for this:

1) They are way quieter than metal gears (but still loud)

2) They are much more forgiving than metal gears when the mill is pushed too hard (in other words they break before something more expensive to replace breaks)

 

This is the second gearbox that I have lunched in less than six months....I'm getting tired of this. It isn't that the gears are expensive (they're not...$30 for a complete set of replacement gears) it's the down time and just the hassle of having to pull it all apart. I need to upgrade.

 

A set of metal gears is available for $70 but I nixed that idea for the two reasons I talked about before. So I bit the bullet and ordered a $140 (after freight) beltdrive kit.

 

A beltdrive is the best of both worlds:

1) It's nearly silent

2) If the mill is pushed too hard the belt just slips but nothing breaks

3) The gear ratio's were changed so that you get a more useful 0 to 1760 RPM in low gear and 0 to 4300 RPM in high gear.

 

 

The problem with upgrading is that once you start it's hard to stop.

 

So I also ordered a shock kit to replace the spring assembly that supports the milling head. This kit allows for about 5 to 6 more inches of travel on the Z-axis (you can see the difference between the old Z-axis rack and the new one in the pic below) and gives the milling head better support making it easier to move up and down.

 

 

Here's everything installed

 

 

But I wasn't finished yet (remember that upgrade thing)

 

I have always had to guess at what the RPM is (which is highly inaccurate and mostly wrong). The reason you would want to know the RPM is that different metals cut best at certain speeds measured in feet per minute. If you know the fpm that you need and the diameter of the cutting bit then you can determine the rpm you need for the best cut.

I have also up to this point always used cutting oil to lubricate the cutting bit.

 

I fixed both of these problems by ordering a tachometer and a spray mist cooling system. Both of these are universal kits so you have to figure out how and where to install them and then fabricate the brackets. Turned out pretty good.

 

 

 

 

It still no Bridgeport but it's better than it was.

 

 

Now I can go back to work on my HTPC. B:)

[jammin]

Nice upgrades! B:)

 

Interested in that spray mist cooling system.

I would imagine it's considerably less messy than similar things I have seen in CNC machines?

[Fueler]

Nice upgrades! B:)

 

Interested in that spray mist cooling system.

I would imagine it's considerably less messy than similar things I have seen in CNC machines?

 

Not necessarily....it's adjustable from a fine mist (and I'm using the term "fine mist" loosely) to full flood. You will also need an air compressor that can provide at least 8 cfm at 90 psi to make it work properly. That said, at it's finest setting you will get a small puddle of coolant after an extended milling run.

 

Edit: You can find the spray mist system and other variants here Little Machine Shop.com

[kendellrt]

You still don't cease to amaze me. I would love to be able to learn those skilz.

[Fueler]

I needed to figure out a way to attach the aluminum front panel to the oak side panels (giant wood screws was not an option) so I picked up a pack of "Cross Dowel Nuts". These are basically metal dowel pins with 1/4-20 threads cut through the middle. Combined with some case hardened allen bolts they should do the trick.

 

 

Here they are installed in the oak side panels.

 

 

Next I threw the front plate up on the mill, drilled four holes and then counter sunk the holes so that the allen heads didn't stick out too far.

 

Here it is mounted.

 

 

With the front plate mounted I could finally measure and mark where I needed to cut to fit the DVD drive and power/reset switches.

 

Then back to the mill.

 

 

And now mounted again for more fitting and measuring.

 

 

I originally called this a junkyard mod because my intention was to use mostly parts I dug up out of the boneyard but unfortunately I have a problem with doing things halfway right. So what you see below is all that remains of the original parts. A motherboard tray and a side panel that just got another big chunk whacked off of it.

 

 

I drilled the holes to mount the motherboard and used the mill to cut an air vent in the section that will be the front lower part of the case. I was going to just put a vent all the way across the top of the case but the DVD drive will sit in the middle at the top and block part of the vent. The lower vent will allow air to be pulled in from under the case to cool the hard drives that will be mounted under the DVD drive.

 

 

I'm going to use feet for the bottom of the case that will be about a 1/2 inch tall (to allow air to get to the lower vent) but I don't want the case that high so instead of installing the lower panel flush with the bottom of the side panels, it's recessed a 1/4 inch from the bottom. I'll still have a 1/2 inch clearance for the vent but it will look like it's only sitting up a 1/4 inch.

 

 

More to come. B:)

[jammin]

Those cross dowel nuts are the kind of thing used a lot in (decent) flat pack furniture.

Much nicer than just screwing things together, and easier if you need to take things apart and put them back together again.

 

Anyway it's shaping up nicely. :thumbs-up:

[Fueler]

Those cross dowel nuts are the kind of thing used a lot in (decent) flat pack furniture.

Much nicer than just screwing things together, and easier if you need to take things apart and put them back together again.

 

Anyway it's shaping up nicely. :thumbs-up:

 

You are sooo right about making it easier to take things apart and put back together. The lower panel is installed with small wood screws...one is already starting to strip out. I've looked everywhere but can't find any small cross dowel nuts so I bought a 3/8ths inch aluminum rod and I'm going to make my own to replace the wood screws. B:)

[cchalogamer]

I'm not even going to ask how you managed to strip out screws already, though i would imagine it's related to constant over tightening

 

Seriously, you used solid wood rather than glued sawdust (aka nearly all of what you'll find at places like Walmart, Rooms to go, etc) it's not THAT easy to strip the screw holes

 

I guess ill have to get pics of my new err..."case" for the main rig up in a day or two, ive been taking a few minutes from each day this week to make my own little box of sorts to hold it, though it's not meant to be nice looking or anything other than functional.

 

I actually just got to thinking, I should take a quick trip down to the metal portion of the the shop and take a few pics, everything down there's a mess atm (actaully so is the woodworking part), but you'll probably end up hating me for not using what ive got access to

[Fueler]

I'm not even going to ask how you managed to strip out screws already, though i would imagine it's related to constant over tightening

 

Like I said they are really little screws so they weren't holding much wood to begin with

[cchalogamer]

So use big screws

 

I'm off to work on my stuff now actually so ill take dad's camera with me (it's a POS but mine's not doing so well atm :-\ me thinks I may have killed it...)

[hardnrg]

am I the only one that thinks it's funny that Fueler modded his mill?

 

keep it comin Greg

[cchalogamer]

am I the only one that thinks it's funny that Fueler modded his mill?

I woudnt really call it modding, more like upgrading, you know, replacing his celeron with a Core 2 and adding in an 8800GT over his onboard video...and im leak testing my WC atm in the shop yet i screwed up and left the camera down there...crap guess ill have to go back now...

 

EDIT:

I have returned...again

 

It still no Bridgeport but it's better than it was.

A Bridgewha...?

 

Edited March 5, 2008 by cchalogamer