[CarveOne]

If you get concerned about how hot the motors are running, Harbor Freight sells a small non-contact digital temperature probe that has a laser pointer to help locate the point you are measuring. The pointer is off to one side of where the sensor is "looking".

After an hour of running, my 495 oz motors on the X axis were showing between 145F and 150F at 1" away during a fajita tray cut job yesterday. That's a bit hotter than I would like. Putting a small fan on them would help with air flow. The shop's ambient temperature was around 85 degrees yesterday.

[RomanLini]

I've got dual shaft size23 motors, with home made plastic pulley/dampers on the end of the shafts.

I was thinking of making some aluminium pulleys instead, with "fan" blades for spokes? It should still function as a flywheel pulley for damping and manually turning but when the stepper is moving provide a little bit of airflow. It has not been a priority but I think it's a cool idea (literally).

[CarveOne]

I've got dual shaft size23 motors, with home made plastic pulley/dampers on the end of the shafts.

I was thinking of making some aluminium pulleys instead, with "fan" blades for spokes? It should still function as a flywheel pulley for damping and manually turning but when the stepper is moving provide a little bit of airflow. It has not been a priority but I think it's a cool idea (literally).

I like it! Small AC motors in certain appliances have lightweight aluminum or plastic fans on them and typically have 1/4" or 5/16" shaft holes. I have seen a lot of them with 3" - 4" blade diameters. Only problem I see is keeping stuff from getting hung up in the blades. Making a round shroud that covers the blades and motor would give protection and forced air cooling. Shouldn't be a difficult to make affair. (Unless you want to machine the blade on your 3 axis CNC machine......)

[BanduraMaker]

If you get concerned about how hot the motors are running,

Here's a really cool solution I picked up here as well:

McMaster-Carr

I picked up a pack and put one on my spindle. Very handy and with 10 per pack, you can stick them all over the place.

[JerryBurks]

A medieval map of my hometown (A.D. 1576):


Converted to V-Carve and cut from a maple board with Amana In-Groove bit (20 MByte G-code with 672,795 lines). Machine time was 3 hours 25 minutes:


Stained and lacquered. Some of the real fine detail got lost doe to the tip radius of the V-bit. But still quite nice.

[Drools]

Nice work Jerry!

[harryn]

That is some really nice carving work there.

It is interesting to see what you are doing with changing power supplies and motors. I had not really paid much attention to PS needs for routers until I got my new nema 34 motor from gecko on Friday.

Now I am on the hunt for a PS, and of course they recommend a linear supply. I am still trying to figure it out, but clearly it is not cheap.

Edit, I listened and watched your video from post 260 a few times. The Y axis has a distinctly different sound than the X, but I have no idea why or if it is good / bad / does not matter. Do you notice anything different about how these two behave ?

[RomanLini]

I like it! Small AC motors in certain appliances have lightweight aluminum or plastic fans on them...
Shouldn't be a difficult to make affair. (Unless you want to machine the blade on your 3 axis CNC machine......)

Yeah why not? It shouldn't be that hard as they are low RPM and don't need any great amount of efficiency. They just need a basic slope on each blade and could be machined flat (3 axis) then turned over and machine the reverse of the blades with the same pattern.

(Apologies to Jerry for getting a bit off topic).

[JerryBurks]

Yeah why not? It shouldn't be that hard as they are low RPM and don't need any great amount of efficiency. They just need a basic slope on each blade and could be machined flat (3 axis) then turned over and machine the reverse of the blades with the same pattern.

(Apologies to Jerry for getting a bit off topic).

Ah, no problem. It's related
Actually I am not sure if fan blades on the steppers would be very helpful, since they need a minimum speed to move sufficient air. If the machine is running slowly, the motors still get hot all the same but the fan is not working well.

[JerryBurks]

That is some really nice carving work there.

It is interesting to see what you are doing with changing power supplies and motors. I had not really paid much attention to PS needs for routers until I got my new nema 34 motor from gecko on Friday.

Now I am on the hunt for a PS, and of course they recommend a linear supply. I am still trying to figure it out, but clearly it is not cheap.

Edit, I listened and watched your video from post 260 a few times. The Y axis has a distinctly different sound than the X, but I have no idea why or if it is good / bad / does not matter. Do you notice anything different about how these two behave ?

Increasing the voltage from 48V to 72V improved the reliable speed by at least 50% if not more. I wish I had even ordered the 80V version. But I still have the option of swapping the motors and will make an experiment with the y-axis sometimes.

Yes, the Y and X axis sound distinctly different. X is much louder to the degree that I asked for some advice here a while ago. The howling at mid range speeds carries farther than the noise of the router bit. But in a way I got used to it and just ignore it nowadays.

The 2 axis behave exactly the same mechanically. They accelerate similarly and stall about the same speeds. But the X-axis has 2 steppers that are mounted with an aluminum bracket to a large hollow box table that has openings on the underside while the y-axis has only one stepper and is on a closed torsion box gantry. I believe the loud x-noise is just the sounding board effect of that table.

[JohnZ]

That is some really nice carving work there.

It is interesting to see what you are doing with changing power supplies and motors. I had not really paid much attention to PS needs for routers until I got my new nema 34 motor from gecko on Friday.

Now I am on the hunt for a PS, and of course they recommend a linear supply. I am still trying to figure it out, but clearly it is not cheap.

Edit, I listened and watched your video from post 260 a few times. The Y axis has a distinctly different sound than the X, but I have no idea why or if it is good / bad / does not matter. Do you notice anything different about how these two behave ?

A linear power supply is actually extremely simple consisting of just a transformer, rectifier, and a capacitor. Antek Inc sells very inexpensive kits to build a torroidal (linear) power supply. I think you can build a 72 or 80v linear ps for about $100, with the higher wattage versions costing more. I have no affiliation with them other being a happy customer.

Sent from my DROID4 using Tapatalk 2

[RomanLini]

Ah, no problem. It's related
Actually I am not sure if fan blades on the steppers would be very helpful, since they need a minimum speed to move sufficient air. If the machine is running slowly, the motors still get hot all the same but the fan is not working well.

That's a valid point for sure, and I know on a lot of my cutting jobs there are straight lines too, where the X or Y stepper is stopped for the whole line anyway.

But from a design point of view I was going to machine some aluminium handwheels to replace my original plastic ones, and it's not much work to add some 45 degree fan blades on the design (as spokes).

What I remember from heatsinking class was that even a tiny bit of airflow has a huge effect on the device heat, even something like making the heatsink fins vertical (to get some convection air movement) makes quite a few degrees difference to having the fins horizontal. I'm sure having some fan effect on the flywheel will have at least some beneficial cooling effect, and the part I like is that the cooling increases with motor speed, which is when the motors make more heat.

[Kazik_Wichura]

It is a pity that I can not buy this bamboo plywood here in Poland. It looks great.
I like your solution with two screws and one motor with belt. I will use it in one of my future machine.

BR,

Kazik

[JerryBurks]

It is a pity that I can not buy this bamboo plywood here in Poland. It looks great.
I like your solution with two screws and one motor with belt. I will use it in one of my future machine.

BR,

Kazik

Bamboo is great but Baltic plywood is almost as good (and cheaper) and you should have it right in your back yard

You may want to have another look at my motor configuration...I made quite a point using 2 screws AND 2 stepper motors. The belt does not have a function in normal operation. It is purely an insurance that both screws/motors do not get out of sync.

If you can live with the elasticity and backlash of a long belt, a single motor would be good enough, if it can handle the acceleration of the gantry. But I would never go for a single x-screw other than a small desktop machine.

[JerryBurks]

After several electronics modifications, adding a linear power supply and 4th axis control/drive with jury rigged wiring the machine looks pretty much like cr@p now:


Therefore I decided to start from scratch and build a new box to house all the components, including power supply, five 203V stepper drives, USB controller, spindle VFD, solid state relays for dust extractor and several control instruments. To allow for proper cooling, the back plate of this 12" x 36" box is 1/4" thick aluminum sheet, acting as one mighty heat sink for the stepper drives and SSR. There will also be a fan with dust filter to remove the heat generated by the power supply and VFD.


Side walls are 3/8" Garolite so I guess the box will be ample strong....


So far so good, now all to be assembled with aluminum angles and then the dreaded re-wiring

[Drools]

Great Work Jerry.
Hey did you ever find time to do the final finishing pass on the chess piece?

[JerryBurks]

Great Work Jerry.
Hey did you ever find time to do the final finishing pass on the chess piece?

Nah, I got stuck with rotation axis acceleration problems and questionable surface speed (bit tip feed rate) calculation as function of the distance from the axis. Otherwise I would have shown it off already ;-) Doing rotation axis control properly is apparently not trivial.

I think I have the system set up correctly now but my priority was fixing the hardware to be reliable. I will give it another try when the control box is complete.

JB

[Drools]

Yep I agree, making the machine more reliable is a priority.
I didn't realize you were having issues...

[JerryBurks]

...I didn't realize you were having issues...

Well, yes and no. The machine itself is very reliable now (maybe I should not have said that). But I have a hard time dialing in the parameters for the controller to work reliably with a 4th axis, especially when using compound movements of all axes. If I just spiral slice the part around the a-axis with small x-movement no problem. But, when I use the waterline strategy of DeskProto CAM, the controller gets confused with the acceleration of the complex movements.

Well, all a matter of trying different settings.

[JerryBurks]

Not much progress lately due to vacation and other distractions.
But at least I got the new electronic box together and the components installed. Now the wiring fun starts
I am an electrical engineer but I hate it......





The box with the heavy back plate and power supply got a bit massive, I must say. But I can still move it around without help (barely)