'Project Overkill' 4 Axis Heavy Duty 5'x10' Servo

[nlancaster]

I like the overkill rubber conduit!

Can't wait to see this thing rock and roll.

[slimneill]

I like the overkill rubber conduit!

Can't wait to see this thing rock and roll.

It runs now. Just needs a spindle and table top.

[Bl@ckrat]

got some awesome idea's from this machine ! thanks for sharing and the variety of pics

[slimneill]

got some awesome idea's from this machine ! thanks for sharing and the variety of pics

Thanks, that's the idea, we have learned a lot from others here, why not help others come up with bigger and better machines from our new ideas.

[slimneill]

We haven’t ordered the cable track for the Z yet but it’s on the list of things to do. So I’ll move onto the Z for now.

Once the 2 half’s of the Z were put together it became a must that the counter balance system was up and functional to prevent the Z from dropping hard and hitting its hard stops. It's too heavy to lift by hand without putting out your back and if we were just relying on the motor to constantly support that weight it would result in a very hot and worn out motor in no time and potential premature wear on the Z-ball screw.

And as an added safety measure if the power goes out, there is safety switch (spring loaded pneumatic cylinder) that will fail safe (power does out, solenoid opens and releases air pressure, spring forces shaft downwards) to bind with a 4 sided cog on the ballscrew and stop the Z ballscrew from moving. And if for some reason this doesn’t fail safe, the Z will not drop because the air pressure in the reservoir tank will continue to support it until it gradually depletes and then the whole Z slowly move to and rest of it’s hard stops.

The Counter balance for the Z consists of 2 pneumatic cylinders. 2.5”bore x 17” stroke connected to an air regulator adjusted so that the force applied upwards is equal to the mass of the Z cart. When the Z motor drives downward it exhausts the air pressure through the top of the cylinder, when the Z drives upwards, it fills the lower half compartment.

The top of the cylinder is mounted to the stationary section of the Z that travels back and forth in the Y direction. The bottom half of the cylinders are mounted to the part of the Z that moved up and down.

As you can see from the pics the Z is pretty standard, the motor is mounted directly to the ballscrew. The ballscrew has one mounted bearing block at the top, other than that, the screw just hangs down. The nut is mounted to the part of the Z that goes up and down. There are hard stops on both ends of the Z travel located behind the plate. You can see them (rectangle blocks between the Z rails) when the Z travels low. There are two bumper stops bolted on the backside of the moving part of the Z that will hit the stops if it over travels or loses power and air.

[slimneill]

Guess what just showed up on our door step!

[slimneill]

The table top is all made up of 2” x 3” by 3/16” thick steel tube. It’s broken up into 2 table tops each 10’ long by 2.5’ wide. This is done so that we could install the table without using a crane.

Each half of the table is made up of 3- 10’ long stringers which run the length of the X with 12” braces installed every 2.5’. Where the two tables meet in the middle Cap screws were used to bolt the two long stringers together in the middle of the table to act like one 4”x3” bean in the middle of the table.

On the outsides where the tables ends butt up to one another a large piece of bar stock was fabricated and installed inside the tubes then the tubes were bolted to the bar. The end surfaces are perfectly flush, it’s like having a single 5’ length on each end now.

The first layer of material to sit on top of the table top is 1/2” thick aluminum plate. The plate was cut with our table saw with the blade swapped out for a 7” aluminum cutting blade out of our Milwaukee cold cut steel saw. We then placed the aluminum plates on the table frame and had the machine drill out all of the screw holes in the aluminum. Then those holes were used as a template to punch the hole locations into the steel table frame below, aluminum removed and the table frame was drilled and tapped. The aluminum was put back on top of the table frame and fastened down. We now have a sturdy table top we use to walk on to work on the rest of the machine 7 feet up in the air. It’s finally looking like a full machine. Plus we have a 5x10 work bench now!

[matth]

Great to see some progress. Really looking forward to seeing this machine in action.

[slimneill]

Yeah, progress has been slow and steady. I live 4 hours away so when I come back to help out its all business and not much time to post updates here.

The addition of the HSD ATC Spindle has increased the complexity of the set up quite a bit. Now needing additional wiring, and pneumatics. hopefully it will be fired up in the next few days.

[slimneill]

We wanted to incorporate limit switches into the machine so that they would be easy to adjust, but look tidy when in installed and hidden.

We are also using Servo motors for every axis, we had to retrofit the encoders in the servo motors to use current technology, in doing so, we were able to spec out encoders that have an index signal which is a pulse that gets sent once every revolution of the encoder wheel in our case it’s very precise since it’s only seen 1/1800 of a revolution. Because we have this feature in the encoders we are able to get very precise homing every time. To use this feature we added proximity switches to each axis and then wrote a C program to perform the homing sequence. When the home command is sent from Mach Kflop sends the X axis back towards the home position at a slow speed, a proximity switch is located right before the limit switches. When the proximity home switch fires, Kflop then moves at an even slower speed and waits for the encoder index pulse to fire. Once it sees this pulse it stops, waits 5 seconds then moves back off of the encoder pulse a set amount of encoder pulses and zeros the X axis in Mach3 DRO. It then repeats the same operation for the Y and Z axis. This gets the cutter in the exact same home position every time to within a thousand of an inch. Eliminating the variance inherent when using the mechanical limit switches as a homing switch.

X Limits & Home
The X Limit switches were installed under the table and the wiring run inside of the 6x6 table frame. The gantry cart has 2 slotted flags on the bottom of the gantry cart that can be adjusted to get the limits exactly at the end of the machine travel. The X axis also has a set of redundant limits used for E-stops in the case that a limit switch doesn’t work properly, the same flags in the bottom side of the gantry were used to give it another ¼” of travel beyond the limits before it trips Estop.
A proximity switch was mounted facing up on the 6x6 frame. It will light up when the gantry cart travels overtop of it signalling that the cart is very close to the home position. These pics were taken during initial setup. Not the final product.

[slimneill]

Y Limits & Home
The Y limits were installed on top of the Gantry and two flags (painted black) were fabricated and mounted on to the back of the Z plate that travels back and forth in the Y axis direction. A Y-proximity switch was also placed on a slotted piece of angle iron and fixed to the top of the gantry when the Z moves back and forth. When the Proximity is fired a LED in the back of the switch and lights up the plastic tubing to indicate that it is close to home. All of the wiring for the limits and homing are routed into the 5x5 gantry steel tubing using metal conduit and ran inside until they reach the cable track conduit.

[slimneill]

The Z limits had to be placed properly because real-estate up there is limited and we didn’t know what the cable track would look like or where it would go. In the case of the Z limits, two limits were placed side by side on the back of the Z axis. An aluminum bar was machined with slots on both sides, the left side was used to trip the Z+ limit. The right side had to be machined with a longer slot on the bottom to allow for that limit switch to not be contacted but when the Z axis is fully down the end of the slot contacts the limit switch and triggers the Z- limit.

On the other side of the Z is an adjustable bar used to set the proximity switch for the homing function similar to the Y homing.

[slimneill]

I'm looking for advice on cutters, Do's & Don'ts.

What places have good cutters, good prices, which should I stay away from?

The uses will vary, from panel cutting, to v carve type stuff to 3d molds.

Should i buy sets or singles?

Is there any threads here that i should be reading up on?

[slimneill]

700 views since my last post and no one has any cutter suggestions?

[LeeWay]

Ooodles of info here here at the Zone that you can research. I don't think you can ask a much broader question about cutters than you did. Specific questions generally get answered much faster. Places for cutters are numerous as well as suggestions for different type bits might be. Sets are not the way to go. Buy specific high quality bits for each specific task you would like to do. Ebay is always a good source to search. You can often find new old stock US made stuff.
Some of those above the Border might have more specific local sources.

[ger21]

Don't buy sets. You won't use most of what you get in a set.

As Lee said, more specific questions are really needed.

When you say panel cutting, I'm assuming you mean sheet goods, like plywood, MDF and particle board. Typically, you'd use compression spiral bits for those. My preference is either Vortex or Onsrud.
For V carving, you need V bits.
You want to make sure they have a sharp point. for small letting, you need steep angle bits, like 30°-60°. For larger areas and bigger letters, you might want 90°-120° bits. A lot of people like CMT bits in the sharper angles. For large V-bits, the Amana bits with replaceable carbide knives are nice, but pricey.

For 3D stuff, it depends on the application, and amount of detail you need. You can use tapered ballnose, straight ballnose, or even inexpensive core box router bits.

[slimneill]

Now that we had the spindle we had to figure out a way to mount it to the machine and still have it be adjustable but secure at the same time. The way the spindle is designed there are two T slots on the back of the spindle casing along with a key way down the center of the casting. The manual said to install 4 T-nuts into the 2 slots to secure it to the machine.
We decided that we wanted to make it a little more sturdy (overkill perhaps) so we milled two T-shaped bars from steel bar and drilled and tapped three - ¼” threaded holes in the back of each of the T-bar. We also made up a Key that would fit into the keyway slot to help with perfect alignment and to prevent any future twisting under load.

We then made an adapter plate by welding a ¾” steel plate onto a larger ½” steel plate. Then milled all the faced flat again to eliminate any warpage effects during welding. The ½” steel plate side is what gets mounted to the Z axis to allow for fine adjustment of the spindle once installed, slots were milled into the 4 corners of the plate to allow for minor rotation of the spindle in the Y-Z plane.

The ¾” thick side of the plate secures the Spindle rigidly to the adapter plate. To secure it and prevent any future motion, we machined a slot into the plate that would line up with the key way on the spindle. Once the key was installed between the spindle and the adapter plate there was no way for the spindle to rotate relative to the adapter plate, we also knew the spindle was square to the 4 mounting holes because they were all machined on the mill at the same time. Six counter sunk holes were drilled into the back side of the adapter plate which would allow for six capscrews to clamp the spindle body on to the adapter plate while hiding the capscrews below the mounting surface to eliminate interference with the mounting surface between the adapter plate and the Z axis plate.

The back side of the ½” plate was also had a large relief machined into it to create an air gap underneath the spindle. Doing this ensured that the adapter plate would only make contact with the Z plate at the 4 corners where it was bolted on. Doing this made shimming it much easier because there was never a chance that the plate could be high in the middle and cause a rocking of the adapter plate against the Z plate.

We also chamfered the front edges of the plate to give it a cleaner appearance. Then painted it black and installed it on the machine. The sharpie marker was added to give some perspective of the size, that’s not a super small Sharpie, just a normal sized one.

[ger21]

I used to use a Masterwood machine with basically the same spindle. It had two spindles on the Z axis, and they were lowered and raised with pneumatic cylinders. Each spindle was mounted to a 1/2" aluminum plate a little taller than yours, but only the width of the spindle. The plate was attached to two roller bearing linear guides, which rode on a single rail, about 25mm. It was a pretty solid machine. Yours is much more rigid.

[slimneill]

I used to use a Masterwood machine with basically the same spindle. It had two spindles on the Z axis, and they were lowered and raised with pneumatic cylinders. Each spindle was mounted to a 1/2" aluminum plate a little taller than yours, but only the width of the spindle. The plate was attached to two roller bearing linear guides, which rode on a single rail, about 25mm. It was a pretty solid machine. Yours is much more rigid.

We will have 2 linear slides on the Z too, one on either side of the rigidly mounted spindle. One slide will have a drill press mounted on it the other is still empty for now. Maybe a laser cutter or a super sized 3d printer head but for now it's empty.

I thought I had attached pics of the spindle mounted on the machine, I'll add them tomorow.

The spindle was a bit of a risky purchase at first, it was a huge investment and we hadn't seen any hobby machines on here or any build threads to get info from on info for how to install it. I'll update With spindle info soon too.

[louieatienza]

I'm looking for advice on cutters, Do's & Don'ts.

What places have good cutters, good prices, which should I stay away from?

The uses will vary, from panel cutting, to v carve type stuff to 3d molds.

Should i buy sets or singles?

Is there any threads here that i should be reading up on?

Buy them as you need them, and buy spares of each one to minimize downtime. Compression spirals for panels; the faster your machine can cut and the more HP your spindle has, the more flutes you can use. I like Onsrud tools. Insert V tooling from Amana is great, since you get two edges from each insert, and they can be honed in a pinch if needed. You also don't have to remove the tool to change the insert which is a good thing should one break or go dull in the middle of a job.

I'd hold off on 3D cutting tools until you really need them, because some 3D jobs will require a tapered ball endmill, and some can use a larger core box or ball nose bit.