AL320G and HXX GCS900-3D - Lathe DRO Setup

[Joco]

This series of posts will show setting up a Hafco AL320G with a 3 axis DRO.  The linear scales are Dalco low profile scales and an HXX GCS900-3D display unit.

The linear glass scales just "do the business" where as the challenge is in the display unit.  The GCS900-3D is not an expensive unit and from what I have seen it seems to be a reasonable option for the hobby user.  My unit cost NZD135 delivered to my door.

Hopefully these videos will give some ideas and save anyone using these units some time.



[youtube1]https://www.youtube.com/watch?v=PIfvKATDJag[/youtube1]
EDIT: I have been in some conversation with HXX and they have told me to use DISP 7 not DISP 8.

[youtube1]https://www.youtube.com/watch?v=ZkgP44dbsQw[/youtube1]
[youtube1]https://www.youtube.com/watch?v=ca8dJNJRWK8[/youtube1]

Next up will be some installation notes and pics.

Cheers,
James.

[Joco]

One of the insights from my investigations so far is that if you want to use the Taper Measurement function you need to consider the following in your setup.

While a little mind bending (for me at least) the lathe's long axis (that which the saddle travels on) is considered Z or more correctly Z1 and the cross slide is X. Cool. 

The Top Slide (Compound) is normally considered Z2.  3 axis lathe DROs usually have a feature to combine the measurements of Z1 and Z2 into a single Z measurement.  Clearly the assumes you have the Top Slide facing in the same direction of travel as the Saddle.

SO, how does that relate to a multi function DRO?  The DRO has X, Y and Z axis.   X is mapped to the Cross Slide.  And on first blush you would map
Z to the Saddle (Lathe Z1) and
Y to the Top Slide (Lathe Z2).

HOWEVER the Taper measurement function takes is measurements off X and Y. This means you will have very limited travel along lathe Z2 for your taper measurement. Not necessarily the end of the world but something to consider when thinking about how you map your DRO axis to the Lathe's logical axis.

Edit on the edit: If you link Y and Z so that they act as combined Z then having the lathe Z on DRO Y should all work out correctly as it will be combined to the Topslides value which is on DRO Z resulting in a combined Z reading, which is what you normally want and you have the easy to move Lathe Z on the DRO Y for the taper function to work ok.

Cheers,
James.

[Joco]

Making progress on the Z1 axis.

Template to mark out the interference area for the lathes back shield.


I needed to make a quick tool to act as a drilling and tapping guide.  However got a little carried away and instead of just doing it for the M5 I needed I ended up making this little guide for M2.5, 3, 4, 5, 6 and 8.


The drilling tapping begins



I needed to make some spacers to hold the scale ~3mm off the lathe casting.  So some 3mm Ali flat bar to rescue


Scale mounted and DTI setup to test for alignment.   I finally managed to get the scale aligned in the vertical and horizontal to within 0.05mm over its length of slightly over 700mm.


Cheers.

[Joco]

Finalising the Z1 axis.

I needed to create a wide bracket with slotted holes to link the saddle to the aliuminium angle that bolted to the scale reader.   I wanted something 5-6mm thick but only had 3mm Ali sheet.  So having an ACDC welder I cut two sheets and plug welded ito all togther.  Then surfaced things a bit.  In hindsight I should have just left things alone. But in a burst of enthusiasim I was trying to make things better, instead I just created work for myself.


The plate in place linking saddle to scale reader.


You can see the linkage and how the nuts stick out.  This created an interference problem with the protetctive guard. A cunning suggestions from a friend (Bruce) had me creating a countersink for the nuts.


Here is said countersink.  This means no need to get a spanner to tighten the nuts.


And the finished install of Z1. Pretty happy with it so far.




Cheers,
James.

[Joco]

Starting the X axis and trying to figure out how best to mount it.

Showing the mounting back plate that came with the scales.  Its temporarily secured here.


A couple of views of the mounting position.




Here is where I think I will place the mounting holes.  They can go into lots of "meat" in the cross slide.


Cheers,
J.

[Kim]

Joco, you're doing a nice job of attaching your DRO. 
It always takes more work than you think, and there's always several fixes you have to get yourself out of, and you're doing an excellent job!

You'll love having the DROs when you get it completed!
Kim

[Joco]

This is the mounting plate that is also part of the cover assembly that came with the scales.   It's mounted so that with the cover in place said cover will be just slightly under the top of the slide casting.

From this photo it should be visible that there is still good access to the gib adjustment screws.

Cheers,
J

[Joco]

Working on the cross slide tonight and got the 3 holes drilled 6mm deep and tapped M4.


Test fits with the mounting bracket and cover before moving on to next stage which is drilling the required holes in the mounting bracket.

[Joco]

Some more progress shots from the last week and this weekend.

Cross slide post drilling with the mounting plate drilled and mounted.


The scale in place.


Testing with the cover on.  Nicely just below the surface of where the topslide will mount.


Been working on a bracket for the scale reader to be mounted to.  Here is the result test mounted on the top-slide scale.




Finally a test mount on the real deal.  since I have all four holes on the reader drilled into the bracker I can use two on the left side and reach up through the casting to tighten them once I have the head aligned with the mounted bracket.  Then carefully take off the slide to allow the last screws to be put in place and remount it all.  Should work and allow for repeatable positioning within acceptable tolerances.


Cheers,
J.

[Joco]

A small update to show the finished X axis scale.

Slide all mounted, on the backing plate, aligned to within 0.01mm on its travel, custom aluiminium block fitted to the reader and mounted to the saddle with M5 bolts. I'm still on the fence about how best to put a stop in place for the tail stock.  Maybe just drill/tap for and install an M8 cap screw into the ali block bolted to the saddle.  That would allow an adjustable slot and will be pretty solid.




Cheers,
James.

[Admiral_dk]

Look like you managed "to get away with it" as a resonable compromise 

I where not happy until my third try  ..... but then again - those old machines where not planed to have DRO's ....

[Joco]

The next real challenge is the topslide (compound).  As I don’t have tapered Gibbs I need to work out how to not interfere with the side screws and the locking bolt. 

[Joco]

Started on the compound scale this weekend with most of the progress being made today.

Initial test fits of the scale to get an idea of where the best placement will be and where the reader will sit in relation to the compound.




Having figured out the placement I measured the backing plate for where I would need to make holes in the both it and into the compound.  Here is the result post drilling etc with an initial fit with no standoffs.


Cover in place and starting to feel reasonably confident this is going to work out.  Now remember I still need to make some standoffs as my lathe does not use tapered gibs.




The stand-offs being created.  One is tapped M4 so the mounting/backing plate can be secured using the existing mounting holes in said plate.  The other hole is a through hole to the tapped hole in compund.


The result with stand-offs mounted onto the back plate.




Trial fit on the compound.  Everthing lined up perfectly.


These last two are the scale mounted on the compound with only the mounting block for the reader to be solved.




Cheers,
James.

[Steamer5]

Hi James,
 Oh bugger! Now I’m going to have add this to my list!

I should’ve got an I Gauge set when I went & saw youngest son in June, it was my birthday at the time, so who better to by me a present! Ah well on next years shopping list.

Cheers Kerrin

[Joco]

Hi James,
 Oh bugger! Now I’m going to have add this to my list!

I should’ve got an I Gauge set when I went & saw youngest son in June, it was my birthday at the time, so who better to by me a present! Ah well on next years shopping list.

Cheers Kerrin

 

For anyone who might be interested the scales I got are:
Z1-Axis: 600mm travel    https://www.aliexpress.com/item/New-linear-scale-5micron-linear-encoder-with-3-5-meter-cable/32830594556.html?spm=a2g0s.9042311.0.0.7BzZOZ

Z2-Axis: 70mm travel     Using the same slim slide as the X axis from the same supplier but cut to a custom length by asking said supplier.

X-Axis: 200mm travel   https://www.aliexpress.com/item/Slim-linear-scale-18-23mm-5micron-KA500-linear-encoder-lathe/32812469530.html?spm=a2g0s.9042311.0.0.7BzZOZ