New Youtube Channel for a new time

I’ve decided to start a new Youtube channel simply because I feel as though adding my projects and the things that I like to a video channel will drive me in ways I hadn’t had before. Thus far, I have 0 subscribers (aside from myself) and I’m genuinely curious to see how well I can make a Youtube channel work out. I believe I have some interesting things to share and some boring but popular things to share as well and a new Youtube channel that explores all those things.

Here’s a link to the channel

https://www.youtube.com/channel/UCwxvlEKdkh9eV9qLXHBh3fw

Not the most graceful URL but I will get a better one once I get some subscribers and I’ve been around for a while. I will explore things that I do such as electronics, gaming, machining, photography and whatever else I come across.

Here’s a video detailing something mundane, my calculator collection.

So, feel free to look at my channel, subscribe and like a video or two. 🙂

Diminutive, a small EDM prototype

For the last little bit I’ve been working on a small EDM prototype for use on large parts, pipe sections or for use in the field. While they do make and sell these things, the vast majority of them require the use of vibratory assistance, aren’t terribly accurate and are relatively low powered. I intend to make one that is accurate and could potentially be used as a ram EDM in a pinch. Also, I’d like it to be able to use copper and graphite electrodes so polarity reversal is necessary.

This is the linear drive of the small EDM. It has 8 inches of travel and is surprisingly rigid and play-free. I was going to use a gear motor on the top with a rotary encoder but since the loads are quite small a stepper should be OK, even at higher speeds.
This is the linear drive of the small EDM. It has 8 inches of travel and is surprisingly rigid and play-free. I was going to use a gear motor on the top with a rotary encoder but since the loads are quite small a stepper should be OK, even at higher speeds.

I’m currently trying to come up with ways to mount this guy on magnetic bases but also allow for small amounts of fine adjustment so that if there is a need for precision work, the unit can be dialed in. Right now the coupling is made of two pieces of steel. I’m going to replace one of them with nylon to reduce noise. I was going to use a spider coupler with rubber in between but I didn’t have one kicking around on the weekend when I was making it so I just made my own.

It's all made from 7075 aircraft aluminum. Pretty strong stuff. The movement was initially pretty stiff because the screw, which is just hot rolled, was a little bit out so I had to run it back and forth to wear in the brass acme nut. I may put two acme nuts into the travel block simply to take up play, as it stands though right now there is less tan .0003" of play, even with significant force applied.
It’s all made from 7075 aircraft aluminum. Pretty strong stuff. The movement was initially pretty stiff because the screw, which is just hot rolled, was a little bit out so I had to run it back and forth to wear in the brass acme nut. I may put two acme nuts into the travel block simply to take up play, as it stands though right now there is less tan .0003″ of play, even with significant force applied.

So next things next, the prototype electronics. Right now I’m simply going to use what I have laying around, so a TM1638 display, a cheap chinese stepper driver with a toshiba stepper driver and I opted for an Arduino to drive the motor. I will be making a full fledged PCB that will nicely fit in a box but I need to get the pulse generator and sensory circuits working first, then I can integrate them fully on to one PCB.

Just a rough testbed for the motion control and a simple interface. I would like this thing to be nice and easy to use.
Just a rough testbed for the motion control and a simple interface. I would like this thing to be nice and easy to use.

Well, anyways, I have quite a bit more work to do for this project. Even a single axis CNC can be a little more tricky since it’s doing more than simply positioning. A ram EDM is a dynamic machine that reacts to the sensory input to keep the cut running smoothly and with appropriate voltage and gap settings.

More later.

3D printing, some thoughts and a potential design

Some recent developments, whether they are fruitful or not, have got me thinking seriously about the design of 3D printers, their use and some of their current drawbacks.

Additive manufacturing has come a long way even in the last 15 years when it was just a novelty and not useful for much more than rough prototypes. While 3D printing will probably never supplant ‘subtractive’ methods such as turning and milling for most things, I believe it will be a real boon for strange, esoteric and one-off parts with limited mechanical demands.

This got me thinking about my own design and what I perceive to be some of the issues with current machines all the way up to commercial machines. A couple of those issues are of concern when making a upper-tier hobbyist grade machines for making prototype parts.

These two things are, the effects of gravity on the part when heated or produced, and the effects of uneven heating throughout the process of printing a given part. This will not only increase accuracy but reduce the need for support structures while printing.

Here is a rough pic of my idea for a 3D printer:

A rough mockup of the 3D printer
A rough mockup of the 3D printer

Having a heated suspension fluid eliminates the wow caused by uneven heating and the droop generated from gravity when the part is properly heated. By keeping the liquid level slightly lower than the workpiece you can still generate lattices without the fear of them filling in. The inflow and outflow should be computer controlled via electric pumps and valves, this way the fluid can remain hot without having to heat the whole enclosure. Draining from the bottom will partially help ensure that the cooler fluid is drained first. You could even add a filter to remove detritus.

For the fluid height sensor, I would probably try to tie it in with the nozzle height somehow without interfering with the work envelope. The level would need to be maintained very accurately in order to ensure maximum efficiency. For this sensor I would probably use my old design for a viscometer with the two Piezo discs, instead of measuring viscosity, I would just check for fluid contact, for this purpose it proved to be very accurate and resistant to fouling.

For the fluid, it should match the density of ABS fairly closely. Mineral oil or Propylene Glycol might be good candidates. The idea is to have a fluid that is non-toxic, non-flammable, somewhat viscous and chemically inert with plastics.

Some drawbacks

  • Fragile hollow objects with no holes (a ball) may become deformed due to fluid pressure. though this would require quite a bit of depth to achieve. Not to mention that the item would want to float.
  • Structure needs to be very rigid and acceleration and deceleration needs to be toned down as to not allow the fluid to slosh around which could shake the part loose during printing.
  • potentially messy with fluid being added to the mix.
  • mechanically more complicated and motion components need to be at least resistant to fluid being used.
  • Fluid would probably need to be changed with different materials. A fluid denser than the plastic being laid down may cause issues.
  • Stronger binding to the table is required especially with lattice heavy designs, floating will occur.

Anyways, that’s my idea, posted for posterity. Maybe someone will find it interesting or foolish.

VariGage moving along nicely

The ugly prototype of the Varigage Circuitry.
The ugly prototype of the Varigage Circuitry.

Well, things are proceeding, slowly but well. I’ve been busy with Christmas and general work and relaxing but it’s time to carry on with the device.

This prototype currently has the following features:

  • An Arduino Mega (will be replaced with a PIC)
  • HD44780 display module, may replace it with a nice flat transflective LCD
  • an ugly keypad
  • Input for quadrature from linear scale
  • Output to DC motor
  • Switching 12v to 5v supply
  • rs485 transciever for communication to the anvil

All of the parts are made but not entirely finished. Going to finish them soon. I was able to assemble them and the actuation is smooth as silk.

Anyways, gonna try to finish the mechanical soon so I can have the ungly prototype up and running. Hopefully I’ll be able to get a finished version ready for the oil show.

Enough fucking around… The VariGage

Well, After some time thinking about it, it’s time to take things into my own hands and design what I want, the way I want it. Since it’s shortly after my 34th birthday I’ve realized that time is getting short and I have to forge ahead.

Hence, the VariGage. I’ll change the name later but it suits it just fine for now.

The prototype VariGage. Not much to it right now but the implications of a miniaturized version are great.
The prototype VariGage. Not much to it right now but the implications of a miniaturized version are great.

This device will allow for a multitude of gaging options with full communication between the anvils and expansibility. Gagemaker makes something quite similar however, mine differs in a number of ways in both design and use.

  • Affordability, the average machinist should be able to afford a unit to fit in their repetoire. While it’ll be a very expensive tool, it’d be nowhere near the 12,000 bucks or so of the GageMaker device.
  • Anvil communication. The device will communicate with the anvils allowing for future use of anvils that weren’t available upon first creation of the device. also this allows for cheaper calibration of anvils rather than the device itself.
  • The device is motorized. It will position itself to the desired location and hunt when the user is pressing and calibrating a gage on the device. The final version will involve a clutch to allow rapid hand positioning
  • Light weight with modular display design.

These are a few of the differences. The market is completely different from what GageMaker sells. I’m not even completely sure it’s sell able but I simply have to build it. I have a few other ideas and designs I have to get done but this is the first in the line and I think it’ll be very interesting when done. Heck, it’ll be nice to have if I go to another shop even, who knows. 🙂

The project is finished! And other goings on.

I have just finished the project that has taken up the last 3 months. Delivered to the customer and they are very happy with it.

A view from above on the two sizes we made for the customer.
A view from above on the two sizes we made for the customer.

I’m so glad to be done this project. While it wasn’t a terribly long project, I’m glad it all went off without any real problems. It measures better than they’d hoped and it’s a pretty attractive little package, for what it is. Next iterations will be significantly smaller and I will look at new encoders to use.

Also, as an aside I have set up my new office. It’s nice to get out of the basement. I now have a lot of free room now so it’s nice to spread out and be able to sort through all my shit and set it up as efficiently (for me) as possible.

This is my new office for 2013. I have a new computer coming soon.
This is my new office for 2013. I have a new computer coming soon.

The Mitutoyo AT715 and me

It’s been a while since I’ve posted and that’s primarily because I’ve been working on a project. I have to keep some of the details to myself but I will show some pictures of the prototype that has taken me a couple of weeks to design and build.

The precursor to my project, the Ultigage.
The precursor to my project, the Ultigage.

The device uses the AT715 from Mitutoyo and what an interesting device it is. With a resolution of .0005mm and an RS485 interface, it is an ideal device for measurement and for use on machines. The device, which uses magnetic induction, uses 30ma whereas a lot of other glass scales use up to 250ma @ 5v. This is a pretty cool device.

The prototype board for this device
The prototype board for this device

Well, I can’t get into a great deal of detail because the product I have in mind may compete with other gaging companies like Gagemaker with a universal, handheld, high precision, digital gage that has active, rugged and dynamic probes. The images shown are that of a rough prototype, I’m not normally secretive but once one is built in a few weeks I can post some images of the more refined version.

After all, this is simply a post for posterity. 🙂

A look at the waveforms from a CNC EDM

I decided to try out my new Hantek DS1060 and get some waveforms from the head of the EDM (Electrical Discharge Machine). The probe was hooked to the head of the machine and the ground was connected to the frame. I only took a few measurements but it may be interesting to some to see what the pulses look like when it’s cutting. This cut was burning at 75us on and 37us off.

This is the waveform while cutting at 75us on and 37us off. 8A current
This is the waveform while cutting at 75us on and 37us off. 8A current

You can see that the voltage doesn’t drop to zero, and there seems to be a dropoff after the ionization path has started to cut the material. These dropoffs after the spike seems to indicate that the path is ionized and current control has kicked in, providing 8 amps. Once the time is up, the current shuts off and then there is a ringing spike, perhaps due to inductance. From there the voltage doesn’t reach zero but probably sits at a continuity testing voltage for a little under the 37us. From what I can tell, 75us is started from when the ionization path is established, and 37us is the time it cuts off the current, event though there is still voltage (and maybe a bit of capacitiance).

A view of the measurements taken from the oscilloscope
A view of the measurements taken from the oscilloscope

The measurements seem to correlate to the settings a bit. The EDM itself is set for a 240V cutting voltage so the VMax of 181V is pretty close. I think those values are a quite flexible, I know that before it cuts at all, the voltage is at approximately 240VDC.

Anyways, I thought this would be interesting to post since some people are into EDM machines. I may take some waveforms from the wire EDM and two more different EDM’s. Here’s a final image of a zoomed in view of the peak.

A wider view of the burning process, the short ringing spike must be a check for proximity
A wider view of the burning process, the short ringing spike must be a check for proximity or from inductance