Saturday, January 10, 2015

Saturday printer and mill progress updates.

Spent the entire day, 3D printing parts, and soldering electronic assemblies.  The stepper motor wiring is a work of art.  Super streamlined setup.  Using shielded Belkin multi stranded wire. 

I'm prob the only person doing entry level printers with these features.  

The control box is coming along nicely.  I think to myself, how would I like to get a machine that is straightforward to assemble, just like how my Torchmate CNC plasma arrived.  Then I took it up a notch with better connectors.  

The design style is a mix of open source electronics, the old military radio layout with the oversized plugs and heavy duty steel parts.  To safe costs on some parts I am printing them, but they are really high quality prints.  Comparing the same parts to the same machined items I had made there is no functional difference.  Although the tolerances were a little tight on the printed parts.  Had to use a hand file for a few minutes to clean things up to spec.

The gantry has to be within a few thousandths of an inch or it binds.  So far everything aligns perfect,y, the linear bearings mounted parallel are all moving smoothly.  

This is the hardest part getting 6 points to align.  The smooth guide rods and the moving part all have to match up or it doesn't work.

Friday, January 9, 2015

Mini Mill and 3D Printer Progress Update

After the haul of parts from the other day, I spent yesterday doing assembly and 3D printing.

I have decided to sell the mill/printer as a knockdown kit.  It will ship from the Philippines where at have my production facilities.  

Anyways first the pictures..

Assembling kits is a pain in the ass.  I suspect that the great majority of kits sold to the noobs never get assembled cause they either are poorly documented or just crappy designs to begin with.

I gotta do a kit cause shipping the thing assembled is gonna cost a boatload.

So to make things much simpler I am putting the electronics into 2 boxes.  

One box is this one here.  It uses a standard computer power supply.  You can trigger the power supply by connecting 2 wires on the main big molex plug, or just connect a molex plug to a regular power supply.

Stepper motors are 4 wires, but I got a really really good deal on 5 pin plugs so one pin will go unused.  

I'm using shielded multi strand cable to connect everything outside the box.  Mostly cause its less messy.  

So,to do the electronics it is plug and play, AND it is easy to break down and move the machine.

I like to call this the desktop factory starter kit.  

Now here is the cool thing.

The same frame and mechanicals for the mill will be carried over for the printer.

So instead of the screw drive with the mill, you get belt drive for the printer.  The frame is setup for both.  Basically you just move the motor and add in the drive mechanisms.

I got a couple orders but I really want to run it thru it's paces so I'm not getting angry calls from someone with a non working machine.  That will prob be a few weeks from now.

So what are the parts?  Someone messaged me after I said it was made of steel, he accused me of selling a printer made from printed parts and a few token pieces of steel.

To that guy I say bullshit.

Yes there are a few printed parts in the machine. It makes good stuff like this bearing holder above.

The gantry will have a couple printed parts and the extruder or Dremel holder will have printed parts.

This is done to keep the cost to you down.  If I machine the print head entirely and the gantry I'm looking at a couple hundred dollars per unit and a couple months more of development. 

I will go with the industrial temp controller for the heat controls.  It's more reliable and less of a pain in the ass than the thermisisters.  Thermisisters require a lot of messing around with cause they are not accurate until you adjust the firmware for each one as they are all different.  I got some that are nearly 30c off.

I would like to cast some gantry parts, but budget wise unless I get 20-30 orders it is not economical.

So projected price will be between 1000-1250 dollars. Plus shipping.

The mills I only have 220v Dremel clones available.  The electronics will work with 110v-240v AC or 12c car battery and one of the tiny $20 10 watt plug in car inverters from a truck stop.

I'll have more pictures coming.  Everything right now is in bare steel.  It is looking pretty though.

This is the inside of the control box.  No real secret magic there.  Standard arduino/RAMPS setup.

What does make it special is the plug and play use. Note shrink wrap wiring.  Fan not installed yet as this one is a work in progress and I don't have newer pics on this computer.

Power supply here is a 30 amp dual voltage industrial model.  I'll prob go down to 20 amps and stick it inside the case with the next one. It really only needs 10 amps anyways.

The bed is heated by AC so if you are running in a limited power area you will be restricted to PLA plastic. You will need 500 watts to run this machine.

Drone recipe updates

Here is the electronic controls for your drone.

FYI if you are looking for endurance, you can go with gas engine powered models.

A friend recounted reciently how he flew 8 hours on 4- 32oz tanks of fuel.

Gas engine drones have to be flown rather high to avoid being seen and more importantly heard.

Thursday, January 8, 2015

Explaining heater controls for injection molding with a Gingery design

The WSRA post on Gingery books has inspired me to do a quick article on the heater controls to use with a Gingery style injection mold machine.

If you have read the book on a DIY injection mold machine, this will be relevant.

Here is a picture of a soldering iron element.

This is basically how the molder works.  It heats up plastic in what essentially is a syringe and then the lever is pulled which forces the plunger to push the melted plastic into the mold.

You need at least 100 watts.  If you can not get one with a large barrel then you can unwind the element or buy the wire to make your own.

I would strongly suggest you buy at least one of these elements, disassemble it and see how they are put together, even a cheap 30 watt element will work for instructional purposes.

Once you have figured that part out and how to do the injection cylinder. You need to either use the soldering iron element or wind it on your tube.  Ohms law is your friend. If you don't know that, you prob should not be building one.

To insulate the wire and keep it from shorting out you use something called flexible mica sheet.  A square yard is less than 10 bucks.

It looks like this

A square meter or yard will last you a very long time.

You can also use something called Kapton tape to tape it together with the mica. 

Once the mica gets hot it will get hard and no longer be flexible. So do not do this with a used soldering iron element.

Once you have wound the barrel with the NiChrome wire and mica, securing it with Kapton tape, you will need to insulate it.  Fiberglass wool will work although not for a long time.  Better to use ceramic wool. Then you can put the whole assembly inside a steel tube and tidy it up.

But before you do all that you need the thermocouple.

Thermocouples are your temp sensor. They work by generating electricity from heat. It's a tiny amount so don't think u can use these with camp fires to charge your cell phone.  This voltage changes with the temperature and this is converted into real world units.

Thermocouples have a positive and negative wire.  If you connect them backwards when you apply heat the temp sensor will read the temp backwards. It is not obvious at room temps but when you turn on the heat, the display will show that it is cooling down.

You have to put this sensor inside the area you want to heat. Don't short out the heating element or let it touch the element. Do not put it on the wires either with mica between. You will read the hot wire temperature and not the plastic you want to melt.

Next thing is the temp controller.

eBay has a combo of this and the solid state relay (SSR) for $30 bucks. You need the SSR to make it work as I will explain in a few paragraphs.

This is a typical temp controller.  

I just bought 2 of these today to use in my 3D printers.

These control the temp, the thermostat. They are much much more accurate than a old fashioned thermostat.  Thermostats don't really work at plastic melt temps anyways.

You will have to read the instructions and wire it up appropriately.

I will only touch on the main parts to program.  I will refrain from going into hysterisis and the details of PID here as that is a book in itself.

First is the upper and lower temp limits.  You will set this up in the instructions. You can set it up s that it is not accidentally set too high of a temp which will burn the plastic or start a fire.

Second is the PID auto tune.  This will tune the controller to maintain the temperature in a stable manner.  PID is a long subject that should be covered in another article.

Sufficient to say you probably should at least read the wikipedia entry on it.

You will also need to connect the SSR.  The controller itself will not handle the current. So it turns a relay on and off to control the heat.  When operating properly, using a scope or multi meter you can actually see the unit pulsing as it controls the heat.  It does this by cycling the heater on and off sometimes once a second, or more or less. Depending on other settings.

Suffice to say you need a SSR.

They look like this:

Fotek makes a nice one. I got some Sommy ones today, I also have Fotek in the shop.

Make sure you get the AC ones for the AC heater.

So with these basics you can now install a proper heater control in your DIY injection molder.

Wednesday, January 7, 2015

It's another Everybody Draw MoHamMad day!

In response to the Paris attacks yesterday:

The most accurate pictorial representation of MoHamMad possible.

Tuesday, January 6, 2015

Foam drones

I have spent the last few hours picking the brain of a guy who makes styrofoam airplanes.

Those little planes made from foam with a 2100mah battery pack will give you 12 min of airtime.

You can extend it by using the lithium 123a batteries for the sure fire flashlights.  Obviously If it is a one time use plane you should use the throw always.

Construction of these is very simple.  You need to get some blue or pink styrofoam for the materials.

Cheapest but ugliest way is to print a pattern on paper, stick it to the foam with some glue stick, and cut it out with a jigsaw.  You will need a lot of post finishing work.

Best way it to get it lasered at a sign shop.

Now here is the interesting thing.  You do not need to shape the airfoil  with this method.  However your performance will not be as good as shaped wings.

These planes only have 2 controls.  They use a servo that when it turns one way, one goes down and the other goes up on the wings.  The tail handles angle so to turn it you bank to the side and use the elevator.

If you want to go bigger, bigger range, bigger payload, you will need bigger wings, which of course means you need reinforcement.  

You can embed carbon fiber tubing into the wing and you are ready to go.


Here is a alternate method.

You get the airfoil section and draw it in CAD. You only need a 2D representation.

Then you get some thick foam insulation, 1-2 inches thick.

You laser out the shape of the airfoil and you include holes to use either very thin aluminum tubing or carbon fiber tubing to fit in the holes. This is your cross support.

You then laminate the pieces together to form a very strong wing yet light weight. Gorilla glue is very good for this.

For the flaps you can use strapping tape or hinges.  The tape method gives you plenty of surface area coverage.  You can glue the tape on to make sure it does not come off.

Then the servos attach to the center with some stainless TIG weld rod for the levers.  

You use the arduino pilot board, motors, motor controller and batteries to assemble the plane.

DiY Drones has the specific info to set it up.

Now it is possible to make a manned plane using this method in the form of a hang glider type plane, although this is beyond the scope of this article.

So here is the scenario.  You are in your forward position.  You do not have the manpower to send out patrols all the time.  Or you are sitting outside somewhere and need to do a sneak and peek.

This is the tool to use.  The US military uses the Raven which is a extremely over priced model airplane.  You got the same tool for a couple days wages.

If you 3d print the motor mounts, camera mounts servo mounts, and landing gear you just saved from having to buy those parts too.

Injection molder for the home shop

Found this a couple years ago.

Gingery books details how to make one yourself.

Basically it is a lever operating a plunger that pushes melted plastic like a syringe.

The heater controls are ordinary digital temp controllers and solid state relays. Costs about $35 on eBay.

You will have to get some NiChrome wire to make the heater or buy a ready made one

A couple of $5 40 watt 12v heater cartridges will work or you can use the heater out of a soldering iron.  

Locally they sell replacement heating elements for soldering irons for $5 for a pack of 5 heaters.  

This is on the list of things to make.

A friend is looking at making fuzes for practice grenades using this for a military contract.  Basically it is just a striker, cap, fuze and a firecracker.

You can make the injection molds for these using 3D printing.  You print the part and cast it using that high temp steel epoxy inside a little aluminum block.

They don't last a super long time but a run of a 1-200 fishing lures is doable with a single mold.

Don't expect to do big parts with these. 1-1 1/2 ounces of plastic is about the max.  Anything bigger and you need to mess with pre heating molds and a  shop press.

Bigger mold machines use around 30-100 tons.  

eBay is full of the bigger machines

I ran into a guy years ago out in Long Island who had a bigger mold to make ice scrapers.  Totally off the radar business, working from his little garage in suburbia selling to those 99 cent stores run by Indians

For home use, you could make a plastic grinder, raid recycle bums for plastic bottles and get your feedstock for free.  

Link exchange.

Shoot me a private message via the contact form if you want me to put your blog on the link list.

Monday, January 5, 2015

Drone recipe

(Update) Just to clarify, the jet recipe is to make something that you might want to send on a long fast trip and cheap enough not to worry about wanting it back.

For something shorter range, cheaper and slower see the plane on the bottom of the page.  They are regularly used with those little keychain cameras for filming. You could put in arduino-pilot and program them as there is a 3-4 ounce payload capacity.  

If you want really cheap see this one:

To build a drone is not going to be easy.  I wish I could cover this in a quick blog post; however to show everything would take considerably longer than the space and time allotted.

So I will give you a recipe.

You will need to study all sorts of diverse disciplines to get to this goal.

But if you do get there... You will be 'that guy' our side needs, and 'that guy' the other side will hunt to the ends of the earth to take out. 

I know what side I would rather be on.   If I have to spell it out for you, then you probably should not be here.

That said.  Here is the recipe and further studying.

I am using screen shots and keeping the direct links to a minimum.  It is better for you to re-type manually than send a referring site info to the next places.

This is the goal above.

You can get a lot of info from here:

Now the site above does not talk much about this little gem below

So you gotta go here

Now what the pulse jet engine site won't tell you is how to make the engine.

I mean, they will tell you but they won't tell you how to make the parts effectively.

So these are the required skills for the engine fabrication:

You need a guy who can do CAD files for duct work.  You take the blueprints from the engine site cause they are not complete.  The duct work guy will have to use a sheet metal program like sheetcam or Solidworks to draw the parts, then 'unfold' the designs in the cad file to get a flat .dxf file. 

 What is that you ask?  

A 2D dxf file is a representation of the tubular parts of the engine.  Since metal comes in flat sheets, you need to cut it from flat stainless steel, roll it into shape and TIG weld all the parts together. You can use a CNC plasma table, laser or water jet for this one.  You could also print on paper, glue it to the steel and cut it put carefully with a hand plasma torch.

You could even use MIG welding for this part, use cheap steel sheet metal painted with the high temp BBQ grill paint if this thing is intended for a one way mission. You could also use phenolic resin for the coating. You are just preventing rapid oxidation of the steel to keep it together and running for 10-30 min.

Ok next part.  

You need a plane.

The easiest way to do it is to 3d print it, of course you need drafting skills and understanding of the limitations of the materials.

Some parts of the planes airframe can not be 3D printed.  They will not withstand the heat.  However you CAN print the parts and cast them with fiberglass resin.  

Forget using the exotic carbon fiber stuff. PAPER and those hollow glass beads filler material will work good enough.  

You are balancing 'good enough' vs High performance here..  Paper and fiberglass resin is also known as  micarta.  It is also known as Bakelite.  That crappy brown plastic they use on AK parts is bakelite.  It is fire proof, strong and light weight it is also low cost.

You will have to do your own judgments and design there as to where to use it.  That is beyond the scope of this article.

Now pulse jets are noisy as hell. They vibrate a lot. The upside is that they are CHEAP.  Cheap as in 10's of dollars cheap.  Pulse jets are also very fast.  They gain power the faster they go. They suck fuel. 

Modern valveless engines do not have the same liabilities as their ww2 predecessors with durability issues however.

This is why you should look at this recipe.

You didn't want to send a $5000 toy on a one way 60 mile trip did you?

Download and SAVE the info above.  Especially the software and drivers at DIY drones.  

Get a website copier and save their entire website even.


Someone sent me this.

3-4 ounce payload

3D printing could revolutionise war and foreign policy

3D printing will revolutionise war and foreign policy, say experts, not only by making possible incredible new designs but by turning the defence industry -- and possibly the entire global economy -- on its head.

For many, 3D printing still looks like a gimmick, used for printing useless plastic figurines and not much else.

But with key patents running out this year, new printers that use metal, wood and fabric are set to become much more widely available -- putting the engineering world on the cusp of major historical change.

3D Printer, mini mill or router kit?

Just a quick poll.

Would anyone here be interested in a low cost 3D printer or router kit?

Specs would be powder coated lasered steel frame.  Cost for a mechanical parts kit would be in the sub $500 range.  I could go even lower cost by using threaded rod instead of ball screws and bring it down to the $350 range.  

Something in this price range would not have the chromed smooth rod and linear ball bearings from China, rather stainless rod and HDPE or delrin bushings.  

It is a real pain in the ass to import from China and then re-export it, so I am limited as to some items I can make and still compete with Cheap China.

For a laser kit we are looking at a sub $1000 laser with 4 watt solid state laser. Working area of 12x12 inches.  

Good for sign making and engraving stuff like tombstones.

I already have the laser mechanicals done and well tested with the 3D printer. It runs extremely fast at almost 500mm/second. Or for the English measurements  19.6 inches per second and 1176 inches per min.
Time wise if someone wanted a bunch of these to sell on eBay. I could do a batch of 100 kits in about a month.

If you wanted a 3D printer mechanical kit, I can do those for $400. I could go cheaper if someone wanted quantity order and got a few parts direct from China.  It won't be as robust as my industrial machine, but it would be better than the china reprap copies.

I am nearly done with the mini mill prototype.  

I would be have finished today except I made a bonehead move with the 3D printer. The temp controller was just zip tied to the frame and I wasn't happy how it looked so I made a nice holder for it to make the whole thing look professional.  Hooked everything back up and the display started reading errors. 

I might have shorted something out.  The terminal screws in the back are a little worn so a relay wire came loose and either connected with the AC 220v power terminal or a bit of stray wire strands got inside the controller unit.  

According to the manual it needs to go in for servicing if it displays the same error after re-set.

Anyways let me know if you want a kit, (or 10)  

I will take Bitcoin.

Leave a comment.

The Gods of the Copybook Headings

Pass this along to those you think it will convince.

Those refuse to change their wicked ways deserve every bit of what's coming.

The Gods of the Copybook Headings

By  Kipling

The "copybook headings" to which the title refers were proverbs or maxims, extolling virtues such as honesty or fair dealing that were printed at the top of the pages of 19th-century British students' special notebook pages, called copybooks. The school-children had to write them by hand repeatedly down the page.

The Gods of the Copybook Headings

AS I PASS through my incarnations in every age and race,

I make my proper prostrations to the Gods of the Market Place.

Peering through reverent fingers I watch them flourish and fall,

And the Gods of the Copybook Headings, I notice, outlast them all.

We were living in trees when they met us. They showed us each in turn

That Water would certainly wet us, as Fire would certainly burn:

But we found them lacking in Uplift, Vision and Breadth of Mind,

So we left them to teach the Gorillas while we followed the March of Mankind.

We moved as the Spirit listed. They never altered their pace,

Being neither cloud nor wind-borne like the Gods of the Market Place,

But they always caught up with our progress, and presently word would come

That a tribe had been wiped off its icefield, or the lights had gone out in Rome.

With the Hopes that our World is built on they were utterly out of touch,

They denied that the Moon was Stilton; they denied she was even Dutch;

They denied that Wishes were Horses; they denied that a Pig had Wings;

So we worshipped the Gods of the Market Who promised these beautiful things.

When the Cambrian measures were forming, They promised perpetual peace.

They swore, if we gave them our weapons, that the wars of the tribes would cease.

But when we disarmed They sold us and delivered us bound to our foe,

And the Gods of the Copybook Headings said: "Stick to the Devil you know."

On the first Feminian Sandstones we were promised the Fuller Life

(Which started by loving our neighbour and ended by loving his wife)

Till our women had no more children and the men lost reason and faith,

And the Gods of the Copybook Headings said: "The Wages of Sin is Death."

In the Carboniferous Epoch we were promised abundance for all,

By robbing selected Peter to pay for collective Paul;

But, though we had plenty of money, there was nothing our money could buy,

And the Gods of the Copybook Headings said: "If you don't work you die."

Then the Gods of the Market tumbled, and their smooth-tongued wizards withdrew

And the hearts of the meanest were humbled and began to believe it was true

That All is not Gold that Glitters, and Two and Two make Four

And the Gods of the Copybook Headings limped up to explain it once more.

As it will be in the future, it was at the birth of Man

There are only four things certain since Social Progress began.

That the Dog returns to his Vomit and the Sow returns to her Mire,

And the burnt Fool's bandaged finger goes wabbling back to the Fire;

And that after this is accomplished, and the brave new world begins

When all men are paid for existing and no man must pay for his sins,

As surely as Water will wet us, as surely as Fire will burn,

The Gods of the Copybook Headings with terror and slaughter return!

Sunday, January 4, 2015

3D Printed iPad case

Could not find a new case for my iPad1 to replace the Otterbox brand  case.

So I spend an hour designing this. Has crush zones in the corners.

Should be 3D printed at 3 outer perimeter and 12% infill with 3 or 4 layers top and bottom.

Held together with four m6 bolts or 3M double stick tape the type used for auto decals with the red label.

drone airpoils

Trying my hand at making wing airfoils for drones based on blueprints from the 1930 EAA flying and Gliding Manual

I have already 3D printed 2 of these to scale today
4 inch wingspan model is 15 grams plastic in ABS.
Printed at:

8% infill
2 layers top and bottom
2 layers perimeter 

Sorry for the crappy cell phone pic.   The good camera isn't here right now.