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.

January 14th, 2014 | Categories: Electronics, Machining, Personal Projects | Tags: ,
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.

November 3rd, 2013 | Categories: Electronics, Machining, Personal Projects | Tags: , , ,

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. 🙂

October 1st, 2013 | Categories: Electronics, Work | Tags: ,

Well, It’s been three years at Rejent (plus a week). Since I haven’t updated in a while I figured I’d go through some of my Solidworks files and post a few of the things I’ve worked on during my time here. After looking through the files I am quite amazed at how freakin’ many parts I’ve worked on over the time I’ve been here. Hundreds of different things!

Anyways, here are some pics of a few things I’ve worked on during my time here, albeit a very limited selection of them.

That was just a few of them that I randomly found, nothing too crazy since some of I couldn’t really show. Well, let’s see what the next few years brings.

June 21st, 2013 | Categories: Electronics, Machining, Work | Tags: , , ,

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.

June 7th, 2013 | Categories: Electronics, Work | Tags: , ,

This device is almost complete. Yes, It’s missing its buttons but the device seems to work well and nice and smooth. The real anvils are almost done and the device will ship to our customer fairly soon and I’m glad to see these guys be done!

DigiGage top Digigage from the right Digigage from the top panelThere are still some tweaks to make especially in the realm of overall rigidity but overall it’ll be a neat device to attempt to bring to market in different ways.

 

April 30th, 2013 | Categories: Electronics, Programming | Tags: , ,
The prototype gage and the gage ring. looking good so far.

The prototype gage and the gage ring. looking good so far.

Well, it’s coming along with some speed. I am now going to build the final version complete with internal battery charging, better logic and a severe reduction in mass. Hopefully this will go down well with the customer.

The display of the gage. the large 18650 batteries are housed in the right hand side. This will be rectified in later versions.

The display of the gage. the large 18650 batteries are housed in the right hand side. This will be rectified in later versions.

Anyways, this post was for posterity. As always I hope it turns out well. 🙂

April 24th, 2013 | Categories: Electronics, Work | Tags: , ,

Something I haven’t worked on in a while but is coming up is my new electrolytic deburring machine. I figured I’d post a couple of pictures for posterity.

In it’s current state, it does work to a degree. I need to work on the chemistry of the fluid. Right now it seems to just pit the material. Perhaps the voltage is too low or too high but I suspect it’s purely a lack of conductivity or the incorrect chemistry for this type application.

Eventually we should be able to deburr cutters and various other items. Just thought I’d share.

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. 🙂

March 16th, 2013 | Categories: Programming | Tags: , ,

I’ve been playing around with Game Maker HTML5. Pretty neat I must say. This game is pretty simple and revolves around multiple balls flying along the screen and you protecting your net. The grey, recently created balls do not count as a score so you can ignore them. Nothing special really.

pongo

Well Check it out!

 

February 24th, 2013 | Categories: Work | Tags: ,

Well things are proceeding apace in the shop these days. Over the last two years we’ve been pushing ahead and growing the shop in terms of equipment and technology.

I have a couple of photo’s, taken from the same spot over a difference of a little over 2 years.

A look at rejent too in November 2010

A look at rejent too in November 2010. a little empty looking.

A look at Rejent in February 2013

A look at Rejent in February 2013. A Bit messy since the machine on the right has just been moved in.

You can see that the shop is much fuller and has much different machines in it. We’ll see what the next couple of years brings, perhaps a new shop?!?

February 9th, 2013 | Categories: Work | Tags: , ,

Just posting some images of a die I made. It came in for servicing and so I decided it’s be prudent to post some images of it for posterity.

A broad view of the simple die, it just simple accepts conduit and punches a couple of slotted holes in it. nothing special.

A broad view of the simple die, it just simple accepts conduit and punches a couple of slotted holes in it. nothing special.

A closer view of the die. As you can see, the punches and dies are both insertable. Since the material it punches is quite thick, the gap is quite large, like .006"

A closer view of the die. As you can see, the punches and dies are both insertable. Since the material it punches is quite thick, the gap is quite large, like .006″

Anyways, nothing too special but I figured I’d keep it here for posterity.