And one more Mini mill dro upgrade

[tumutbound]

After seeing John Rudd's thread on mini-mill DROs, I thought I'd post the the progress so far on the DRO addition to my Sieg X2 mini-mill.

Brackets for X and Y scales are finished and mounted, I still haven't worked out the best way to mount the Z axis scale.

I was undecided as to the whether to mount the Y scale vertical or horizontal hence the two slots in the mount.
 Horizontal would make for easy reading of the display but then I remembered that once I connect the Shumatech DRO, seeing the displays on the scales wont be necessary.
I'll remove the display and plastic housing from the scale read head  as per these photos http://cnc.turkeys.net.au/workshop/scales

The read head will be connected to the X/Y castings via a .305mm shim - once I work out the best way to mount it.

[raynerd]

Good going mate. I don`t know if my pictures will help of how they are mounted if following the figNoggle plans as I did:

http://www.raynerd.co.uk/?p=411

[tumutbound]

Thanks for the pointer to your website.

I've based my plans on looking at the various methods used by other people, mostly on the Yahoo mini-mill groups.
The Y axis mounts are based on a design from Chris at the Little Machine Shop. The X axis - I'm not sure.
As I will be removing the display from the scales which makes the read head smaller, there's a bit more flexibility as to how I mount them.

I'm not sure if my setup will be practical as I haven't yet tried tested with the axis locking level to see if it gets in the way.
Still, I've lots of spare time and lots of little bits of aluminium.

[tumutbound]

A bit of work today saw the Y scale mounted - 2 more to go.

The Y axis casting is joined to the scale read head via a piece of stainless steel shim - but it's too thick.
I'd ordered 0.254 but received 0.305mm instead, It was marked and invoiced as 0.254mm but it wasn't until I cut it that I noticed.
It's only a couple of thou (for the imperial brigade)  thicker but it makes all the difference. Probably 0.20mm would be better.

Once I get my hands on the correct size and I have the DRO mounted, I'll remake the shim piece.

[raynerd]

Looks good - noticed you have clamped both ends, on the plans I followed the front is clamped and the obviously the display to the table but the back end just floats.

Chris

[tumutbound]

Looks good - noticed you have clamped both ends, on the plans I followed the front is clamped and the obviously the display to the table but the back end just floats.

Chris

As far as I can tell, leaving one end floating is to allow for any inaccuracies in the brackets/mounts etc that would cause the scale head not to run true.
The shim connection wasn't my idea (Chris on the Yahoo 8x18lathe group has a write up on it.) but it seems like a simple way to allow for any necessary flex without causing any stress on the scale.
This is probably true with a thinner shim, the current one does put a surprising amount of pressure on the read head.

The X axis will have a similar setup - still haven't decided how to do the Z.

[No1_sonuk]

The X axis will have a similar setup - still haven't decided how to do the Z.

On my Warco Mini Mill, I'm going for a removable, no-drilling setup (will post a thread when it's done).
For the Z axis I made a bracket for the fixed read head which fits in the rack groove and is secured by the vertical stop screw.
The moving rail is attached by a p-clip to the pin which is pushed up by the torsion arm.  I'll post pics when I get home if you like.

[tumutbound]

On my Warco Mini Mill, I'm going for a removable, no-drilling setup (will post a thread when it's done).
For the Z axis I made a bracket for the fixed read head which fits in the rack groove and is secured by the vertical stop screw.
The moving rail is attached by a p-clip to the pin which is pushed up by the torsion arm.  I'll post pics when I get home if you like.

I'd like to see what you've done for a no drill option.
I no longer have a torsion arm on my mill having removed it to install an air spring which is mounted on the left hand side using the holes vacated by the torsion spring.

I'd prefer not to have to drill the X2 column unless absolutely necessary. I was a bit nervous drilling the 4mm holes I needed to mount the  Y axis scale. The X axis is mounted using the holes from the thin metal ruler that is on the front of the table.

[No1_sonuk]

My X is mounted on the back of the table. I'm using a DRO350 external display, so I don't need the scale readouts to be visible.

My Y axis is the last one to do, and the hardest to do without drilling.

WRT Z:
Depending on how your air spring fits, you might still be able to do it in a similar way to me.
It may even be easier - i.e. clamp the parts to the air spring to measure the difference between the moving and standing parts.

I'll post a new thread this evening with what I have so far, and put a pointer here for you.

Edit: ooh, I just managed to look at those cut-down reader photos.  Hmm. I may try that...

[tumutbound]

I'll post a new thread this evening with what I have so far, and put a pointer here for you.

Edit: ooh, I just managed to look at those cut-down reader photos.  Hmm. I may try that...

Thanks for that, every picture helps.

The scale mod is fairly easy to do. The biggest problem I had was finding some 2mm thick fibreglass PCB. I ended up making my own about 3mm thick.
Soldering an SMT capacitor is fiddly but doable. So far no damage to the electronics but just in case, I bought a few spare read heads.

Once I get the X axis connected, I can mill out the case for the DRO-350 and mod the remaining scales.

[No1_sonuk]

Here. What I have so far:

http://madmodder.net/index.php?topic=3530.0

[tumutbound]

Well got the X axis scale installed and working. I was able to mount the read head using the screw hole that originally held a pointer for the ruler/scale attached to the front of the mill table. The ruler was  removed and the mount holes used to mount the body of the digital scale.
Used the scales for the first time to mill the case for the Shumatech DRO-350. If you look closely, you'll see the bottom slot is a bit bigger than the other 2. I used the measurements provided by Shumatech but forgot to compensate for the end mill diameter  

Soldering up some cables this evening to complete the assembly.
Next step is to remove the battery from the scale and solder in the capacitor and wires.

I would have completed all this tonight but got sidetracked fixing my laser printer. It decided to start printing halfway down the page. Having taken it apart and reassembled it, I'm reminded why I got into software. All those gears and switches! At least it's fixed.