Sunday, 24 October 2010

Heater works very Well.

After getting my machine going, I installed my design of heater.
I built a new connections board for it. - 2 LED's, Resistor and a 4 pin Molex header.
Why 2 LED'S ? - I install em both ways around so 1 is on nomatter which way the heater is connected.

I also had to make a new Z flag as the new heater is longer.

It gets Nozzle temp much quicker than the Block Heaters.
The nozzle is only 2 degrees lower than the heater (According to my IR beam thingy doofah).
The Block heater was 5 degrees C cooler.

It prints well, even after turning up the Extrusion speed.
It stays put, no noticable movement in it.
The M4 screws that keep the PEEK in plase stay Cool.

I really can't see any operational disadvantages here and now, howerver it is not easy to make.

You need a good lathe with a 4 jaw Chuck.
You need to be able to hold and spin a lump of  brass 10mm x 20 mm x 35 mm. 50% Off Center.
You also need to hold the whole thing steady enough and fast enough to get the 0.5 mm hole in the end.

I'll get some pictures up either later tonight or tomorrow.

Heater: Update 2

Spent the morning completing my new Heater.
I glued, with Fire cement, the thermister into a 1 mm hole, about 3mm deep between the heater and Nozzle. That seems to me to be the most logical place for it.

The whole thing is also encased in kapton Tape so it can't ping out.

The PEEK block needed some thought or I'd never do up the nuts on the bottom, or worst still, transfer all the heat up the M4 rods.
The Heater side nut is recessed into the PEEK with enough space to get a socket on to it.
The resistor wires have been crimped and Insulated and I'm prety much ready to go.

Once i get the machine printig later today (I hope) I can swap over to the new design.

If this works I'll get on and do some propper drawings and maybe even make some more and try out the removable nozzle.

Saturday, 23 October 2010

Update: New Heater / Extruder Design

Today i have spent most of the afternoon in Terrys Workshop.

I made a new Style heater first. there is a fair old bit of Turning involved in that.
All went to plan and only broke 1 0.5 mm drill.....

I then started work on my own design.
Once the 4 jaw chuck was in place, I hacked off a lump of Brass about 35 mm long.
It Took a while to set it up in the chuck but once it was centered away we went.

Starting  with the 13 mm M10 Thread first, then just moving 2 jaws turnd the job around and turned the nozzle. I decided not to do the Removable nozzle. If I need to I can do that by machining this one.

Once the Nozzle was machined, I drilled it to suite my 1.8 mm filament and put the 0.5 mm hole in the end.
Turned it around a second time. Put in the M7 thread for the PTFE in, then the M10 Thread for the peek.

The job was moved sideways 12 mm and the hole for the resistor drilled.

The results i think are really good.

The PEEK I drilled at 8.5 mm and Tapped it to M10.
the Teflon is standard design.

Sunday, 17 October 2010

Extruder / Heater design

I have been thinking all weekend about how I can improve on my Heater and Nozzle design.

Looking at the current designs HERE I keep thinking that the heat block is the wrong way around. 
The resististor needs to run in line with the filament....

It would also be good to have easily interchangable Nozzles.

This is what I have come up with. (I only have MS paint so the drawing is not great).

The PTFE insulator is the same.
Drill and Tap the PEEK insulator to M10 then screw it on to the Heater.

You will need a bit of Brass 10 mm x 20 mm x 30 mm.
Cut the insulator end out with a hacksaw and turn it a lathe with a 4 jaw chuck.
Screw the Heater on to the teflon.
Add the whole thing to your extruder plate.
Make you Nozzle shorter than usual.
Screw in your nozzle to suite. You may need a Brass m6 nut to retain the Nozzle.

You could always turn the nozzle on the other end of the heater if you wished.

I plan to try and make this in the next week or so.

Your comments and ideas are as always welcome.

PTFE End                                                                                                     Nozzle end

Friday, 15 October 2010

Will this work ?

I bought 20 mm doa PTFE so there is plenty of space.
after pushing 2 nozles out of their threads i came up with this idea....

You reccon this will work ?
There is a nut on the Nozzle resessed into the PTFE.

Monday, 11 October 2010

After the Success of yesterday......

I'm now 2 nozles down :(

The first I broke yesterday - it pushed itself out of the PTFE heat shield, but I had just turned up the extruder speed so blamed my stoopid for that.
I also badly gouged the bed so that went in the bin as well. thankfully MDF is cheap :)

Drilled out the Old PFE last night and re glued a new heat shield.

I wound the heater today, new Thermister new everything.

I then started a Print which delaminated again. Similar to yesterday and upped the Temperature before starting again.

 The Tape on the heater was flush with the PTFE Heat shield. It's moved several mm.

Thankfully this Print bed will survive.....

Back to the drawing board........

Sunday, 10 October 2010

First attempts at printing

I Got my electronics on Friday. I went for the Gen 6 Offering from Mendel-Parts.
These boards are Professionally produced to a VERY High Standard.

Install was Plug and Prey, (As I turned the power on for the first time) Nothing did anything nasty and the Magic Smoke stayed contained as it should.

Saturday AM I connected it up to my Lappy and worked out how to set the USB Port in the RepRap Host software, however it flatly refused to play.
RepSnapper was downloaded and the default settings used, but that also refused to do anything usfull either.

I also broke the Extruder, repaird that and then the Heater failed.

Attempted a Print late Saturday evening and the Repsnapper software refused to do anything like waht i was expecting.

Sunday AM I got the copy of RepSnapper from the downloads page at  Fired it all up and loaded the "Test Object" file from the RepRap Host software.

This is what I got after about an hour.
It looks good from the top, Unfortunately the result is in reality far from good enough.

The base lauer Peeled up from the Tape on one end. The next layer then failed to stick to the base.

As you can see there is a lot of air in there as well.

The base also Curled on one side.

On a positive note, the angles are all correct and the sides are Vertical in both directions.

All in all - not to bad for a 1st attempt.

Monday, 4 October 2010

more tweaking....

Spent the past few days going through every Nut, bolt  and screw. It's taken me ages but i know everything is done up tight.
Broke a Y axis belt clamp in the process :(. Now reinforced with a bit of steel.

My Bed is square - I think I went a bit ott on this bit.

The machine is square and the Z axis is Vertical to the bed.

 Also added a Big Red button !

Anyone got A "Panick" sticker to go on it  ?
The 2 LED's are Power To the Button and Power to the Electronics. They will also act as a double check on polarity.

My Electronics are in the post. I may well video and broadcast on the installation and Power On.
Lets hope the magic smoke stays where it should.....

Sunday, 26 September 2010

More Pictures.....

My Extruder Cogs. I just hope they survive. The quality is VERY poor.
 Spot the Crack in the end plate. There is a steel plate holding it together.
 More repairs - they don't show up well.....

Images of the Final build.

My Machine in all it's Glory :)
The filament is1.7 mm Dia.
The Extruder has been modified to cope with the smaller filament.
 The back of the machine.
You can see the "Dust covers"  over the Motor Spindles.


Hot End / extruder.
Notice I recessed all the Bolt heads.

2 LED's to indicate the heater is on.
I made a small cable clip to prevent srtess on the motor wires.
Y Axis drive.
Spot the missing Lock Nut !

Tuesday, 21 September 2010

Heater Update

I have been working on a circuit board design for a RepRap heated bed. Far tidier than mk1.
The maths really did my head in I tell you !

I have made circuits in the past with Toner transferr, but only small ones.
Trying to do 200 x 200 mm just don't happen.
The Thermal expansion pulls the tracks off the paper :(

This is the best image I managed after 4 attempts.

Thursday, 16 September 2010

Heated bed: Update

Hi All

I got a bit of 5 mm aluminium sheet today. It's a little rough but it did come out of a skip !
I coated the heater Side in Kapton Tape to provide the electrical insulation.

The heater mat remains unchanged with a resistance of 1 ohm.

My Type K thermiter registered 5 mv after 10 or so mins and water boils away furiously.

My Type K thermiter registered 5 mv after 10 or so mins and water boils away furiously.
I call this viable :)
Next question is how do I mount this on my reprap.

I'm also working on a PCB based heater.

Saturday, 11 September 2010

2 great sites that have helped me with the Heater

Maths is not exactly my strongest point.
I did the maths to work out the resistances i needed but then found an Ohms Law calculator
Type in what you know or want and you get the answer.

Another site I used has a Paralell Resistor calculator.

Thnaks to both the authors for taking the time to put these sites up.

Heated bed:

I dropped the cheap n nasty Thermostat out of the circuit and wired the heater Direct.

I got the bed to 120 C in Still air - that may just be enough to hold 110 C

Then there was a Ping and the Glass cracked.

I'll put this idea on the shelf and revisit another time for now.

Heated bed: Result.

This Method is NOT Suitable for ABS.

However for PLA running at 50 - 60 C this method will work reasonably well.

The big issus is that 12 Volts is simply not enough to generate the heat output required at any reasonable current to power the bed above about 90 C.

The Voltages, Currents and Heat Outputs we are talking about here are more than enough to Burn your House / Shed down as well as burn your fingers.
If you do try this be VERY CAREFULL !

Heated Bed Update.

Well this is not going to get any where near hot enough for ABS if people are saying 110 C
After 30 mins it got to 76 C 

I also checked the Voltage on the 12 Volt rail - 10 Volts with the heater connected. That about 75 watts. 

My PC Power Supply is simply not up to the job :(

Friday, 10 September 2010

Heated Bed: ParCan Style

With all this talk of Heated Beds, I decided i'd jump on the Band waggon cos i like a nice warm bed !

The design brief is simple: easy and low cost.

1 reel resistance wire from Maplin: £6.49
1 Plumbers heat risistant Matt from plubing Shop: £2.00
1 Bit of 4 mm Plate galss 200mm X 200mm  from the glass shop: £1.00

This is not yet tested in real life but is working (The Glass gets hot)

Maplin resistance wire runs at about 1 ohm every 200 mm.

Draw around your glass amd measure 4 mm in from 1 side.
Then mark 8mm Intervals and put lines 8 mm apart. use a light coloured Pencil.
You should end up with 24 or so lines and about 4 mm at the other end.
Now draw another line 6 mm from the other side.
Cut 8 X 800 mm lengths of resistance wire.

With a needle sew the wires onto the surface of the Heat Matt.
Each wire makes 3 passes over the mat along the lines you marked.

To connect this up:
Solder all the ends along 1 side to a bit of a bit of 22 swg copper wire so that the glass plate buts up aginst it.
(You can solder Constantine wire but NOT Nichrome)

Along the other edge you need about 2 mm space for the glass to expand. I used my Ruler.
Solder the other ends in 2 sets of 4.
That will give you about 1.5 Ohm resistance or about 100 w at 12 V

I then covered one side of the glass in kapton tape so that if it cracked it won't shatter everywhere.

 The completed bed .
It's drawing 7.7 amps at 12 volts.
That's 92 watts.

Thursday, 2 September 2010

Reprap build Notes: Part 5. Belts, Wiring and the Extruder.

The Belt Runners on the X and Z axis seemed somewhat ineffective. I was not happy that the M5 large washers I had were only slightly bigger then the bearing.
The M8 Washers I have are 0.75 x the thickness of the M4 washers.
So from the end I have:

M4 Screw | M5 LG Washer |  2x M4 washer. | 1 X M8 Washer | Bearing M4 Washer

The M8 Washers spin on the M4 washers and are approx 2 mm larger than the Bearing.

Extruder Manufacture and Assembly: (Adrians)

Brass Nozzle.

The Rod came from the arm off an old Ball Valve which was 7mm dia. (many people have said that M6 is to small and fragile) 
I ran an M7 x1 die down the rod to put a thread on it.

To make the Nozzle on a lathe:
I faced the end off, centered it, and drilled it 28 mm deep at 3 mm then ran a 3.5 mm drill down to 30 mm deep. 
Use the scale on the tail Stock to get the correct depth.
The drills were all flatted off for drilling brass.
I then parted it off and turned it round.
Center drilled it and put in the 0.5 mm hole before putting the 45 deg angle on the end.
I left the hole recessed by about 0.25 mm.

PTFE Insulator.

I turned that on a Lathe from 20 mm dia rod.
Faced it off and drilled it through with the small hole.
Turned the end down to 16 mm and used the parting tool to put 2 X 2 mm deep groves in. That should give the glue plenty to get hold of.
I parted it off then drilled the large hole 1.5 mm under size then tapped it with a sharp tap to 7 mm to suite my Nozzles.

2 further nozzles and PTFE insulators were made to suite the 1.7 mm filament I have. They were drilled to 2 mm with 0.5 mm in the end of the Nozzle.

Extruder Assembly:

I didn’t have the correct length screws to assemble the extruder so bought some M4 studding and Thread Locked nuts on 1 end.
The large cog is assembled as per the instructions but with NyLoc nuts.

I held the Brass Nozzle in a drill chuck and screwed on the PTFE with some Plumbers tape to provide a good seal.

The Ni Chrome Wire I have is Insulated. 
I wound that on the threads of the M7 Nozzle. The 28 cm required to get 6 ohms is the perfic length for the M7 nozzle.
1 Winding then back to the top.
The Nozzle was covered in Kapton tape and the Thermister installed.

I used Brass Tube to make the crimps and insulated them with silicon sleeving.

The wiring: ( Still work in progress )

Power Supply.

That was made from an old PC Power Supply. See the instructions on the wiki.
I added several big red LED’s so you can see if it’s on.

Need to add a BIG “Time to Panic” button !

Electrical headers and Wiring:

Most of the connectors were provided by the Power supply.

The 4 Pin PCB headers got salvaged from old floppy drives.

Ribbon Cables are old IDE and SCSI Drive cables split down.
10 way IDC Headers are from the Serial Connections on old PC’s.
10 way IDC Header sockets were salvaged from old Motherboards.

Other connectors are from various bits of old PC parts.

Reprap build Notes: Part 4. Getting the whole thing together.

Now you can complete the assembly.

Remember the Back Left corner is your Datum / Home point.

The Rods for the Z Axis must be perfectly vertical.
Make sure your frame is flat both ways with a spirit level.
Start with a Plumb Line, get the rods in place then use a spirit level to make sure the rods are vertical then remove the rods.

Now you can add in the X Axis assembly. Take care not to twist it on the lead screws
Make sure cogs and bearing are centred on the lead screws, Do them up tight and add some Thread Lock. You really don’t want these coming lose.

Now put the Z Axis Rods back in place and re-check them with a level.

Tighten up the bed and check that the bed runs free and square.
Do Not tip your frame with the bed running free. I locked mine in place with a rubber band

Check and adjust all the bearings. 
The bearings should all touch the rods and you should be able to turn the bearing with your fingers against the friction on the rod.
Check the X carrage and Y bed run free and true.
Add in the Belts, and motors and adjust. The belts should not rub on the washer or reprap parts either side of the bearings in a perfect world. Reality however makes this somewhat impossible to achieve.

Once the motors are fitted the bearings looked a bit exposed. I fitted an M5 washers and a small grommet over the shafts to stop dust getting in.

I made the flags from the case of a dead CD Player.
Thick enough to work, Easy to cut with Snips.

The Motor wires looked a bit exposed. I stripped the insulation off a bit of coax cable and ratted the wires through with a paper clip tied to some cotton thread.

With a bit of luck it shold look something like this:

Reprap build Notes: Part 3. A few hints and Tips on the Build process.

Gather the parts you require and check them.
Remove any Burrs, sharp edges and rough bits.
Check every hole size and drill as required.

CLEAN UP Dust and swarf before you start each section of the build.

Use parts Bins for all your fixings. Lay them out the way you like – you will soon memorise what is in each parts bin.
Have a “Dump” parts bin to put extras in and the stuff you drop on the floor etc.
Use NyLoc Nuts wherever reasonable.
Many of my fasteners were done up with Std Nuts then a Nyloc was added as a lock nut.

Once a section is complete Check it. Then check it again. 
It's far easier to make adjustment when the parts are small and managable.

I started with the X Axis, as per the Build Instructions.
No real issues other than the parts I bought needed a lot of finishing work.
The Bearings on the end plates I used m8 washers with m4 washers inside for the belt guides. This allows the Belt Guides to rotate with the bearings.
Store your X axis assembly somewhere clean.

The Z Axis was straight forwards.
Make sure the 4 large Blocks are drilled so that the studding holes overlap slightly.
Check the teeth on the Lead screw cogs are good. 
I used large support washers and shakeproof washers either side of the cogs.
Make sure nothing protrudes to far down or you will scratch your work bench.

The Y Axis and Bed was more challenging to get nice.
This was mainly due to the poor quality parts I bought.
Get the bearing Blocks built and done up tight.
Assemble the base Lose, then tighten up with the 8mm rods in place.
I made the belt clamp nuts Captive. Far easier to tighten later.

The Frame:

The M8 nuts on the end of the rods are all NyLoc.
I tried twice to get my fame square using the method described in the build Instructions.
On the 3rd Attempt:
To get the Triangles square I used 8mm rod offcuts in the horizontal holes. I then measured the frames with a vernier to get them within 0.1 mm and built the 2nd exactly the same.
Once the triangles were built I used the uprights to get the widths correct.

If you have them, put a ½ nut and washers between the Z axis blocks.

Once your frame is assembled check it for squareness before you add any extra parts. It should sit flat on all 3 sides.
Double check all the measuremants.
Lock any plain nuts in place with a dab of Locktite or nail varnish.

Add in the Z axis support rods and check the blocks are square and level.
Loosely put the bed in place and check that the bed does not catch on any of the rods underneath.

Reprap build Notes: Part 2. What you need to get started.

You will also need the following Consumables:

Selection of Heat shrink tubing.
Selection of Cable Ties.
Selection of Glue ( Cyanocrylate, Epoxy, UHU)
Electrical tape, kapton Tape, PTFE Plumbers tape.
Some Coax cable ( great for sleeving, De Solder brade and copper wire )
Selection of Grometts.

You need a bench at comfortable working height with Power, Lighting and ventilation. Minimum 2 M wide and 600 mm deep.
Try and organise a clean area and a dirty area in your Build space.

General hints and Tips.

Gather the parts you require and check them.
Remove any Burrs, sharp edges and rough bits.
Check every hole size and drill as required.

CLEAN UP Dust and swarf before you start each section of the build.

Use parts Bins for all your fixings. Lay them out the way you like – you will soon memorise what is in each parts bin.
Have a parts bin to put extras in, stuff you drop on the floor etc.

Use NyLoc Nuts wherever reasonable.
Many of my fasteners were done up with Std Nuts then a Nyloc was added as a lock nut.

Reprap build Notes: Part 1. What you need to get started.

This is probably going to turn out a rather long and Listy blog. bear with me - it will be worth it....

To build a Reprap you will need the following tools.

A Drill and Drill set covering at the minimum 2 mm to 8 mm in 0.5 mm sizes.
Small drills: 1.5 mm, 1 mm, 0.5 mm for PCB work and the nozzle.

Selection of Allen keys, Spanners, Screwdrivers, Nut Spinners to suite your fixings.
A selection of Pliers and Cutters.
Crimp Tools to suite your electrical connections.

Exacto Knife, Stanley Knife and SHARP Blades + A Cutting mat.
Tweezers: Needle Nose, Screw catcher and curved.
Files and a selection of Needle Files.
Small Bench Vice.
Junior hacksaw and good blades.
Good quality Soldering irons and soldering Kit.
Test Meter and selection of leads.
Vernier calliper (digital makes life easy)
Engineers Ruler

Tools that will make your life much easier.

A Pillar Drill + Accessories to go with the drill.
Dremell + good selection of tools.
Access to a Lathe.
Parts Bin stack.
“Helping Hands”
Small Vacuum Cleaner