[ishi]

Upgrading to the larger HS610 double-sided spindle head has introduced an interesting challenge: the head is much wider, and it will be virtually impossible for it to reach a tool without interfering with adjacent tool holders. We've tried different solutions to work around this problem, but it looks like we will have to move from a basic conveyor to a full-blown automatic tool changer with double arm. Therefore, we've decided to upgrade to the MUL 105:

http://www.cdsindexers.com/cnc-machi...mul-series.php

You can watch a video of the system in action there:

https://www.youtube.com/watch?v=GRw__hiXioE

Obviously, it will be quite a bit more complex and expensive, but I do not see any way around this. Fortunately, this upgrade will bring three side benefits:

1. Chip-to-chip tool change will be much, much faster.
2. The conveyor won't have to be offset from the center's column.
3. We could eventually design a system for many more tools.

We hope to get CAD models for the MUL 105 sometime this week. Stay tuned...

[ishi]

Take a look at this presentation:

https://docs.google.com/presentation...405ca24a66_0_8

There, you might notice that we have red lines on the vertical side panels. These colored lines will actually be produced by LED stripes mounted behind translucid plastic t-slot covers. As a result, we will be able to control their color and blinking. In fact, we'll be able to display multiple colors at the same time on different sections of the lines. This will replace the traditional light tower that is typically mounted on the roof of CNC machines.

Originally, we got the idea from the DATRON M8 CUBE, which does something similar with their gantry.

"Il faut rendre à César ce qui appartient à César."

[RCaffin]

I think we've found a proper way to drive our rising front panels: telescoping air cylinders.
We will use two cylinders, one on each side of the panel assembly.

TWO telescoping air cylinders? They will get out of sync and jam. Murphy's Law.

Cheers
Roger

[ishi]

TWO telescoping air cylinders? They will get out of sync and jam. Murphy's Law.

Cheers
Roger

Roger,

I am concerned about that as well, but I wonder if there is a way to sync them up. What would be the alternative?

[ishi]

Here is the HSD HS610 Double-Sided spindle head in all its splendor:

https://drive.google.com/file/d/11G-...ew?usp=sharing

More than a meter long... 290kg of Italian high-precision engineering.

It will cost us $87k, adding about $50k to our bill of material. That is quite steep, but the benefits totally justify the price increase in my opinion. In fact, I was expecting it to be quite a bit more expensive, because it's four times the weight of the HST310, but only just a bit more than twice the price.

The connector panel on the back side is certainly intimidating...

***

High-res pictures on public drive:

https://drive.google.com/drive/u/3/f...3dQrx?ogsrc=32

[ishi]

Here is the HSD HS610 Double-Sided spindle head in all its splendor:

https://drive.google.com/file/d/11G-...ew?usp=sharing

More than a meter long... 290kg of Italian high-precision engineering. It will cost us $87k, adding about $50k to our bill of material. That is quite steep, but the benefits totally justify the price increase in my opinion. In fact, I was expecting it to be quite a bit more expensive, because it's four times the weight of the HST310, but only just a bit more than twice the price.

The connector panel on the back side is certainly intimidating...

***

High-res pictures on public drive: https://drive.google.com/drive/u/3/f...3dQrx?ogsrc=32

[ishi]

Here is the HSD HS610 Double-Sided spindle head in all its splendor:

https://drive.google.com/file/d/11G-...ew?usp=sharing

More than a meter long... 290kg of Italian high-precision engineering. It will cost us $87k, adding about $50k to our bill of material. That is quite steep, but the benefits totally justify the price increase in my opinion. In fact, I was expecting it to be quite a bit more expensive, because it's four times the weight of the HST310, but only just a bit more than twice the price.

The connector panel on the back side is certainly intimidating...

***

High-res pictures on public drive: https://drive.google.com/drive/u/3/f...3dQrx?ogsrc=32

[ishi]

It took us two weeks to get the CAD model for the HS610 spindle head, but it was worth the wait...

Here are the updated drawings with that new spindle head:

https://docs.google.com/presentation...05ca24a66_0_50

High-res pictures on the public drive:

https://drive.google.com/drive/u/3/f...3dQrx?ogsrc=32

[trb100]

Ishi, maybe you could use a scissor mechanism like a car's side window has.
Something like this, but with pneumatic actuator instead of electric motor:

https://www.google.hu/search?hl=hu&a....0.-I3O_ct9anc


Anyway, I follow this thread since the beginning, your enthusiasm and vocation is inspiring. Keep up the good work.

[RCaffin]

Yes, you can get rough synchronisation using combined hydraulics and pneumatics, but it is messy, and can still drift. I have used it before to get speed control.

A solution which is probably over 100 years old is to lay the pneumatic cylinder down horizontally and use it to drive two flexible cables, one at each side of the pane. You can get absolutely beautiful flexible SS braided cables these days ... and pulleys on little bearings. Really smooth.

Cheers
Roger

[ishi]

Here is the HSD HS610 Double-Sided spindle head in all its splendor:

https://drive.google.com/file/d/11G-...ew?usp=sharing

More than a meter long... 290kg of Italian high-precision engineering. It will cost us $87k, adding about $50k to our bill of material. That is quite steep, but the benefits totally justify the price increase in my opinion. In fact, I was expecting it to be quite a bit more expensive, because it's four times the weight of the HST310, but only just a bit more than twice the price.

The connector panel on the back side is certainly intimidating...

***

High-res pictures on public drive: https://drive.google.com/drive/u/3/f...3dQrx?ogsrc=32

[ishi]

Here are the latest drawings for the machine's enclosure, to which we've added the HS610 double-sided spindle:

https://docs.google.com/presentation...05ca24a66_0_50

[ishi]

Yesterday, we received the CAD model for the HS610 double-sided spindle. It won't be cheap: $87K. And it's big, really big: 1m long, 290kg heavy. But if we want to match the 3 micron accuracy that we have on our linear axes with a 500mm diameter turntable, we really need the 5 arcsec accuracy on the rotary axes.

[ishi]

Our current roof design made of two panels won't work: the rear panel will interfere with the ATC.

The only solution I can think of at this point is to mount the rear panel vertically and have it rotate around the X axis, but this is way too funky...

This one promises to be a real challenge...

UPDATE: I think I found a solution. The panel can indeed be mounted vertically, but pointing downward instead of upward (as I was originally envisioning it). This panel would be closed only when loading heavy parts with a crane, which means that we won't have to actuate it whenever the front panel is lowered or raised.

[ishi]

Sorry for all the repeat posts regarding the spindle: yesterday, CNCzone.com was still flaky, and I could not get access to page 43. Somehow, the thread got stuck at page 42, which is kinda cool if you're into geek numerology... Anyway, seems to be back to normal, and regular posting will resume.

[ishi]

Ishi, maybe you could use a scissor mechanism like a car's side window has.
Something like this, but with pneumatic actuator instead of electric motor:

https://www.google.hu/search?hl=hu&a....0.-I3O_ct9anc


Anyway, I follow this thread since the beginning, your enthusiasm and vocation is inspiring. Keep up the good work.

Thanks a lot for the kind words trb100. I will definitely take this as far as I can, solving problems one by one.

Regarding scissor mechanisms, this could work, but we would have to engineer some complex mechanical components ourselves. Instead, I'd rather buy something off the shelf if at all possible.

[ishi]

Yes, you can get rough synchronisation using combined hydraulics and pneumatics, but it is messy, and can still drift. I have used it before to get speed control.

A solution which is probably over 100 years old is to lay the pneumatic cylinder down horizontally and use it to drive two flexible cables, one at each side of the pane. You can get absolutely beautiful flexible SS braided cables these days ... and pulleys on little bearings. Really smooth.

Cheers
Roger

Roger,

That could work, but it's mechanically quite complex, and I am concerned about possible maintenance and adjustment issues.

That being said, I really like the idea of having multiple solutions to solve the problem, because it will ensure that we do not get ourselves stuck in a corner...

I'm also considering some telescopic linear actuators with servo motors, because these would be much easier to synchronize. But they would likely be much more bulky and expensive...

[ishi]

What I love about this project is the variety of technical domains that I have to learn about. In no particular order:

- Kinematics
- Physics
- Mathematics
- Mechanics
- Mechatronics
- Robotics
- Electrics
- Electronics
- Hydraulics
- Pneumatics
- Thermodynamics
- Metallurgy
- Informatics
- Ergonomics
- Economics

From there, the main lesson that I learned is that when working on a complex project, any change in one area can have ripple effects on many other areas, in indirect an non-linear ways. There is no free lunch, and every decision will be a matter of compromise. I believe this to be true for any kind of engineering project, but I come from a software engineering background, and software engineers are notoriously bad at this, because software (wrongly) appears to be "softer" than other domains, and software changes always look simple at first. But in reality, the same logic applies.

Therefore, one has to be very clear about the set of parameters that are important for the project, and very open minded about everything else. Otherwise, you quickly end up with an over-constrained problem that cannot be solved. And one should always consider the fact that any changes to the design will be a lot more expensive than they might have seemed at first...

To make a long story short: I am learning a ton, and this is a ton of fun...

[ishi]

We've extended the top part of our machine enclosure 50 mm forward in order to fully protect our spindle head. This will ensure that if our loaded part clears the enclosure's frame, it will clear the spindle head as well, as long as the spindle is moved 90 degrees around its A axis.

As a side benefit, it will also ensure that our rear roof panel does not collide with our spindle head when the roof panel is lowered.

[RCaffin]

but it's mechanically quite complex, and I am concerned about possible maintenance and adjustment issues.
A bit of string going over a couple of pulleys - complex?
Adjustment would be set-and-forget.
I have done this recently on my hydraulic press to lift the cross-arm, with two lengths of 'string' over pulleys at the top and down on each side. Works dead easy.

Cheers
Roger