Tag Archives: anet a8

Anet A8 and TPU : First Steps in Getting More Flexible

Think it is difficult printing with the Anet A8 and TPU? Read this article to the end to find out my hints and tips

Ok so you have bought an Anet A8 3d printer.

You have downloaded some models from Thingiverse or other sites.

These have been hit or miss, but more hit than miss.

Only using PLA.

But you know your printer is capable of much more than this.

It can cope with PETG, ABS, nylon and flexible.

You have done your research.

ABS – too toxic without an extractor to remove the fumes ( or from my point of view – memories of trying to repair motorcycle plastics)

PETG – need an enclosure to prevent draughts and get stable (ish) temperatures over the bed to prevent warping.

Nylon – soaks up the water and needs special drying.

This leaves flexible (TPU or TPE).

So what is it exactly

Flexible polymers are lumped under the heading TPE (ThermoPlastic Elastomers), with TPU (Thermoplastic PolyUrethane) being the most commonly available.

ninjaflex tpu filament
Check Out Ninjaflex Filament Here

Most are known by their brands name – like Ninjaflex or Flexismart.

They are comprised of a rubber compound along with a hard plastic, the mix of the two giving the degree of flexibility.

You see the images of people bending this, but until you have tried it you won’t believe how flexible it can be, or how useful that can be – for phone cases and the like.

What do you need to know about printing TPU

You know how to set your printer for PLA…

So now you need to know how to set your Anet A8 3d printer up for TPU.

There are two main things to remember when printing with flexible filaments.

You can’t push too hard, as it is flexible and will bend.

And take your time, slow your printer down.

With PLA you managed to get close to 100mm/s printing speed, well if you try that with TPU you are likely to fail.

You can’t melt it fast enough or push hard enough to get the filament out of the hotend.

Typical printing speeds are in the order of 30mm/s max, ideally 20-25mm/s, so things are going to take a bit longer to print.

You ideally need to switch off retraction as well.

Pushing and pulling back on the molten filament may cause a jam, the last thing you want.

Careful setting of the temperature will reduce to a minimum the amount of stringing you get.

So set the nozzle temp to about 225C and if you suffer too much stringing then reduce your nozzle temp by 5C and try again.

You will know when the temperature is too low by the poor adhesion between layers or the part not sticking to the bed.

The bed needs to be about 50C, I also used blue painters tape.

You are not supposed to heat the bed with blue painters tape, but I found it worked better with heat and tape.

You can print onto glass and get a very smooth finish to the bottom of your prints.

I will be trying onto polyamide tape in the future and will keep you updated on the progress.

That all important first layer

With PLA – you know that unless your nozzle is just right you will be starting again…and again…and again.

With TPU as it is rubbery there is a little more flexibility in the gap between the nozzle and the bed.

This doesn’t mean that you can be sloppy when leveling you bed, but it does mean that there is more leeway.

If the gap is too small and the pressure builds up in the nozzle and backs up the molten filament, you may get a blockage, so err the gap on the larger side.

As long as you get a bit of pressure onto the bed it will stick.

Especially if you are using heat and blue painters tape.

Make sure there are no overlaps on the tape, butt the edges together.

I tend to lay the edge down and wipe away to lay this down.

Replace any strips that get damaged when removing parts.

If it is not sticking then increase your nozzle temperature by 5C and see if that helps.

But check the nozzle clearance.

Replace the tape after 5 or 6 prints in the same area.

First prints

So what did I print as a first TPU print?faceted ring thingiverse

A faceted ring, why – this was the only model which said it finished in under 5 mins.

Did it go well?

The first time the filament had not fed into the hotend quickly enough, so I had half a layer that didn’t print. so I stopped the print.

The second attempt showed up the flexibility of the filament as it decided not to go down the throat and wrap around the extruder gear.

But with this filament, unlike PLA, you can just reuse that bit.

So I printed off a flexible filament guide to reduce the gap between tpu faceted ringthe extruder gear and the throat.

That appeared to cure that and the ring printed perfectly.

So another challenge I have had is printing a windsor chair – I failed a few times with PLA as the bed wasn’t set correctly so…

With it sliced again for TPU, the four leg patches stuck perfectly, so hopeful…

Then printing higher I could see what they said about stringing.

Between the legs was this fine webbing, ok so I will get rid of that when it finishes.

Watching it do the bridges between the legs, I wasn’t so sure about the bridging ability of the material.

The seat turned out ok and the back with it’s open frame was covered in stringing.

Overall it printed ok.

Not the prettiest print but it stayed on the bed and finished.

Cleaning up TPU

New scalpel blade.

and….tpu chair cleaned up with scalpel

Damn this stuff is flexible.

Rubbery and hard to cut.

So yes with complex models I will need to play around with the temperature to reduce the stringing, I think mine is too hot at the moment.

Am I impressed that you can print a flexible filament – hell yes.

I still smile picking up the chair and flexing the back of it.

The ring looks more like an o-ring, so is less impressive, but the chair…

Am I going to continue with this stuff, hell yes.

I designed some covers for a motorbike, they cover up the swingingbike bolt cover arm bolt.

Previously I had printed them in PLA, they fitted quite tightly, but at the speeds this bike goes are on the roadside somewhere.

With this flexible filament then they will have a lot more grip, so are on the printer as I am typing this up.

I can here it singing…Oh hang on…. it’s stopped so may have finished.

I have now found I have a lot to learn about flexible filament design.

The flanges are too thin and too flexible to hold them in.

Using the outer face onto the bed of the tape causes them to be too bike covers matt finishmatt.

I will try to post process them, but probably will struggle to find a material flexible enough bend with the filament.

Will I give up …no way.

What other ideas do I have?

Well what about replacement heels for shoes?

It does bring up a few questions…

  • Is it strong enough
  • Will it withstand walking on
  • How long will it last
  • Is it grippy enough to be safe?

All of these questions will be answered soon as I have a pair of my other half’s to reheel.

Am I impressed.. Oh yes.

So thanks to 3d warhorse on Amazon.

I bought the 0.5kg reel to try.

Apparently it can be used in a 3d pen as well.

I wonder how well it will stick to PLA to create hinges.

All I have to do is to keep it dry.

So back into the bag with some more silica gel.

Would I Try It Again?

If you have only tried PLA till now, then I reckon your next step is to buy some of this and give it a go.

Just remember to slow your printer down, raise the temp of the nozzle, switch off retraction (or at least keep it a very low value) and use blue painters tape on the bed…and you should have some good initial results.

From there you can tweak your settings to make it even better.crushing chair

If you have any more tips on printing TPU then please leave them in the comments below

If your printer has a bowden extruder, can you print with flex filament.

The theory is yes as it is the bit between the extruder and the throat that is important.

But you have to bear in mind that along the full length of the bowden tube the filament will be compressed so there will be a lag when the extruder starts to push and the filament comes out of the hotend.

So add a couple of skirts around the outside.

I do have a printer with a bowden extruder so can try this out.

And you won’t be able to use retraction with any accuracy on this machine – but may be able to take the pressure off to reduce stringing.

But I don’t see it as a restriction.

kitchen blow torch
just be careful how long you keep it on the model

I have heard that if you use a kitchen blow torch (you know…the ones to caramelize the top of things) and wave it over your model, not stopping in one place, that you can melt the stringing and make it disappear.

Oh another tip – from what I hear TPU can jam easily.

So I have got into the habit of leaving my Anet A8 printer nozzle to cool down to ambient before switching it off. This will prevent heat creep into the throat making it more difficult to push the filament through next time.

And don’t forget to take your model off the bed while the bed is still hot – taking it off cold may prove tricky!

Please leave a comment below if you have used a bowden extruder with flexible filament- either successfully or unsuccessfully. or you have used your anet a8 3d printer with TPU.

Thanks for reading

Phil

 

Anet A8 hotend problems : leaking filament

This article is how to find out whether your Anet A8 hotend has been assembled correctly.

 Common Problems with the Anet A8 hotend

There are three main problems associated with the hotend which anet a8 hotend :leaky nozzlewill be dealt with in this article.

  • Filament leaking from the top of the heat block
  • Filament leaking from the bottom of the heat block
  • Hotend loose when heated.

When you receive your Anet A8 the hotend will probably be assembled, mine was. What you don’t realise is that it is probably assembled wrong – as mine was!

You assemble the unit onto the printer and start printing.

After a short while there appears at the top of the heatblock some molten filament.

If you are unlucky this can increase and drop down onto your printed model and either catch with the nozzle or cause detaching problems when the nozzle knocks your print off.

In the best case where it doesn’t drip you are left with a lot of filament stuck to the top of the heat block, requiring cleaning up.

Or the filament starts oozing from the top of the nozzle and drips onto your model causing problems.

Or after heating up the printer you start printing and notice that the heatblock is spinning around and causing printing problems with your model.

Whichever it is this needs to be rectified.

 What is the hotend made up of?

The Hotend is contructed of a few parts. these include:hotend components

  • The throat
  • The liner
  • The heat block
  • The cartridge heater
  • The thermistor
  • The nozzle

The liner is usually made out of PTFE material, slippery and heat proof. This is the insulation while the filament goes through the extruder.

The PTFE tube is fitted inside the throat, made of stainless steel. It goes right down to the bottom to be butted up against the nozzle. The throat forms the connection between the extruder and the hotend. It also forms the heatbreak to prevent heat from the hotend from backing up the throat causing blockages.

The metal heater block holds all of the parts of the hot end block together.

The Cartridge heater, a 12v 40w heater raises the temperature of the heat block above the melting point of the filament.

The thermistor gives the controller some feedback on the temperature of the heat block. Once close to temperature the heating is cut back so that it doesn’t overshoot. It closes the loop of the cartridge heater into the heatblock to the thermistor, back to the controller.

The nozzle is the melt zone. Once liquid the filament is forced through the opening in the tip of the nozzle. The semi melted filament forms a plug which pushes the molten filament out of the nozzle.

How to disassemble your hotend properly

Once you have used your hotend it will be fill of filament.extruder assembly removed from printer

If you try to disassemble this when it is cold then you stand a good chance of breaking it.

If the nozzle has stuck this can shear off when trying to unscrew it.

Or the throat may snap, again with the filament stuck to it.

So what do you do?

I tend to cut off the filament at the top of the extruder rather than trying to remove it by pulling out.

Switch your printer on and warm it up, it doesn’t have to be at the melting temperature, just above the transition temperature from rigid to flexible – which on PLA occurs at about 50C.

So set the printer to preheat PLA – if PLA is what you are using, and go back to the main screen. Watch the temperature until it rises above 60C and you can then switch the printer off.

To remove the nozzle at this time, use a pair of molegrips ( visegrips) to hold the heatblock- carefully avoiding the heater cartridge and themistor.

With the correct size spanner unscrew the nozzle. This should turn relatively easily now the plastic is warmed.

Place it down on something that can withstand the heat without melting or being damaged. – I put it on the printers bed.

On the Anet A8 the hotend is held in place with the lower bracket of the extruder motor.

If you undo the nut and the allen bolt holding this bracket to thehotend removed frame and the two screw holding the extruder motor you can remove the throat/heatblock/retainer completely.

Now while it is still warm the nut can be tightened up to the mounting block and the heatblock gripped in the molegrips again.

The throat can be removed from the heatblock at this time.

If it proves difficult then remove the mounting block and add throat removedanother nut to the throat.

Tighten the two nuts together, and using a spanner on the nut closest to the heatblock, use the molegrips to remove the heatblock from the throat.

You may need to clean out the threads of the heatblock or replace it if there is damage to the threads.

Check the throat for damage to the threads or to the PTFE liner. If it is blackened it may have been overheated or bits of filament may have overheated – these can break off and cause partial blockages in the nozzle while printing.

As they are only a couple of dollars then replacement would be the

removed nozzle
all the black is overheated filament ready to block the nozzle

best move – keep these in stock as consumables.

Remove any remaining filament and make sure that all of it is cleaned before reassembling.

 Assembling Your 3D Printers Hotend Correctly

To assemble your hotend correctly make sure you have all the pieces available.

Nozzle, throat, heatblock and that’s it. If the heatblock has the hotend partscartridge heater and the thermistor installed make sure you are careful with the wires. You don’t want to reassemble the hotend onto your printer just to have the wires break.

Personally I reassemble the hotend cold and have had no problems, others are not so lucky and perform the last stage hot. This is something you will need to try and see which way works best for you.

Taking the nozzle, screw this into the heatblock by hand until it goes

tight.

Then unscrew it by 1/2 a turn.

Now take the throat and screw that in until it is stoped by the nozzle.

Using the molegrips, hold the heatblock to stop it rotating while using a spanner to tighten the nozzle onto the throat.

Don’t over tighten the nozzle, it need about 1/16th of a turn to take up any slack in the threads and to prevent it leaking from the joint between the nozzle and throat.

After you have tightened this examine the nozzle to see that there is still a small gap between the body of the nozzle and the heat block.

Now the nut to hold the hotend to the extruder can be screwed down the throat, if it was removed.

And the mounting block screwed onto the throat.

The throat end should come to the top of the mounting block or slightly protrude. The wires for the heater and thermistor will orientate themselves to the correct position as they were when you took the assembly off.

Offer the assembly up to the extruder and screw in the allen bolt – do not tighten. Align the mounting block and tighten the nut up to the extruder mount. Tighten the allen bolt.

Place the spring for the extruder in the correct position and holding hotend installeddown te extruder motor screw this back in with the two allen bolts. It is easier to locate the one furthest away from te spring first and using that as a pivot locate the one closest to the spring – then tighten both up.

You now have a reassembled hotend which should not leak.

Note: if your hotend becomes loose when you have heated it then hold the heatblock in molegrips and tighten the nozzle  – make sure it is not tight against the heatblock when fully tightened.

Testing your hotend

Switch on your printer and make sure that it starts up ok.

Locate the hotend temperature menu and start the process.

Go back to the main screen and watch the temperature rise on the hotend.

Make sure it stabilises where you set it.

Straighten the end of your filament and feed it into the extruder. Pressing down on the tension spring will allow you to feed the filament in without turning the motor.

Manually push it through until you see filament coming out of the nozzle.

Stop pushing. and release the tension spring.

Look for signs of leaking, both at the top and bottom of the heatblock.

If there are then hold the heatblock with the molegrips and tighten the nozzle.

You now have a working hotend on your 3d printer which will not leak.

After clearing and reassembling your hotend you will need to go through leveling your bed as the height of the nozzle will not be the same as before.

Other solutions for the Anet A8 hotend

I have heard that people are putting teflon tape around the threads to prevent leakage- if you get the joint tight between the nozzle and the throat then you really don’t need anything else.

And don’t use thread lock on the threads of the throat as you may not be able to disassemble it in the future. If there is still a problem then the joint between the nozzle and the throat is not correct and needs attention.

If you really cannot get it to stop leaking then try to flatten the faces nozzle flattenedof the nozzle and the throat on some wet n dry paper – if you don’t get it really flat it may cause more problems than solving.

The complete new assembly is available relatively cheaply to purchase from Amazon. Don’t forget to check it before fitting as most manufacturers don’t assembly these properly from the factory. Go through the assembly process of loosening the nozzle and tightening the throat down onto the nozzle.

If you find that the teflon tube is blackened at the end where it meets the nozzle, it will be worth checking your temperature settings for the material you are using. too hot and it will start to overheat and stick internally leading to more blockages.

I tend to polish the inside of my nozzle before the first fitting – does this do anything? well I have very few problems with partial blockages so every little helps, and it only takes a few minutes.

Thanks for reading and please fill in the survey whether you tightened your anet a8 hotend hot or cold.

Do you assemble you hotend hot or cold?

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Phil

Anet A8 Bed Leveling : How do You do Yours?

Having had my anet a8 for over a year now I am getting quite used to it.anet a8 bed leveling : smashing printer

I am just going through a mod for adding an e3d v6 all metal hotend clone, with interesting results, but that’s another story.

One of the main things I with my anet a8 at the start was bed leveling.

I would go through the Anet A8 bed leveling process and the prints would not stick (nozzle too high) or the filament would not come out (nozzle too low).

What was I doing wrong? Why wouldn’t it work properly?

But I understood that bed leveling was nothing to do with using a spirit gauge to get the bed perfectly level. It was to do with getting the nozzle the same distance above the whole of the bed. So you are adjusting your bed to the height of the nozzle with the Z axis set to 0.

Make sure your Z axis height is the same on both sides first.

Before You Start the Anet A8 Bed Leveling Process

Well there were a few things I had to do first to stabilise my machine before the leveling worked.

One of the main ones was to add a base and screw it down.anet a8 screwed down

If you move the front up by 0.4mm then the bed leveling will be out- and this may happen with the weight of the bed moving back and forth if you don’t bolt it down.

Create a Solid Base for the Anet A8

So screw it down to a flat piece of wood or a cabinet top.

I created a box for mine so I had storage underneath it.

The top was is made of laminate floorboards.

The sides of the box are made out of tongue and groove floorboard with the groove modified to accept the top ( the inner part of the groove is gone and the top rests on the ledge left).

A brace has been put across the top at the front to stiffen up the structure. As can be seen in the picture above.

Sort out the Z Axis Stop

z stop mod
Anet A8 Z endspot holder for 2017 version by daveposh

The other one which makes all the difference to stock parts is to change the z stop. Mine would always start to work loose, so the z zero height would be adjusting, messing up the bed leveling.

So I used this anet a8 z stop.

Make sure the screw goes into the plunger straight – mine is crooked, as this can give you unexpected results when adjusting the z height.

With this mod one turn of the screw will adjust the Z axis about 2mm. So you need to be light with the adjustment.

If this is the adjustment before your first print then tighten up the z stop as much as possible and use the bed adjustment to bring the nozzle close. Once printing, make it a priority to print off the z stop adjuster.

Check your Bed Flatness

Another thing to do is to check your bed for flatness with a steel ruler – you may find that at the very edges it does bow up or down as well as a little bit close to the hole where the thermister is.

You can either accept this as I have or flatten it on a piece of float glass with a sheet of wet n dry taped to it – don’t forget to add water with a little dishsoap as a lubricant.

I have not tried this but it should give you a flat surface to work with if the bow it too much.

Clean Your Nozzle

Before leveling the bed check that the nozzle is clean of any filament clean the filament offsticking out. This will cause an error to the height adjustment and will cause failed adhesion prints- from experience!!

If there is filament sticking out then switch on the printer and go to control → temperature and set the nozzle to 190. Press back until you get to the home screen and wait for the temperature to stabilise.

Wipe the nozzle with a clean paper towel or cloth, making sure you don’t burn your fingers.

Set the temperature to 0 and allow to cool, make sure there is no ooze as it was cooling down!

Tip for the Threaded Bottom Plates

If you have one of the older Anet A8’s then you may have the screws going through the bed and threaded into the lower plate. If this is the case and they are stiff to turn then carefully remove them and add a bit of grease ( I use lithium grease) to the threads and put them back in. This will prevent the threads from binding and stripping. Makes it a lot easier to adjust as well. I used a spray can as my screws were starting to bind and this could spray between the spring. It worked and they are loose.

If you have one of the newer ones with a clearance hole and wing nuts underneath the lower plate then it might be worth considering printing off the easy to use round adjusters. The only thing I would add is some kapton tape over the lower part of the bed where the washers go to add another layer of insulation, I have heard of the bed shorting out with the washers.

Anet A8 Bed Leveling Process

Switch on the printer, leave it cold.

Make sure there is no filament sticking out of the nozzle.

Send the printer to its home position.

Manually raise the z by 2-3 mm.

Move the X axis by 25mm.

Move the Y axis by 25mm.

Move the Z axis slowly down to the bed and place a piece of paper between the bed and the nozzle. Or a feeler gauge of 0.2mm.

There should be drag on the paper or feeler gauge.

Looking down from the top

Turning the screw adjuster anticlockwise will raise the bed and turning clockwise will lower the bed.

With the nut adjuster turning anticlockwise will raise the bed and clockwise will lower the bed.

If there is a large gap then you will have to go around two or three times before it settles.

Don’t press down too hard as this will possibly put pressure on the lower plate and throw out the adjustment.

Once you have adjusted this corner then raise the Z axis by 1mm and move the x axis to 175mm ( you don’t need to be exact).

Lower the Z axis to 0mm.

Now adjust the front right adjuster to feel the drag on the paper.

Raise the Z axis by 1mm.

Move the Y axis to 175mm.

Lower the Z axis to 0mm

Adjust the rear right adjuster for drag on the paper.

Raise the z axis by 1mm

Move the X axis to 25mm.

Lower the z axis to 0mm.

Adjust the rear left adjuster for drag on the paper.

Raise the Z axis by 1mm.

Now adjust the Y axis to 25mm.

Go to the home position then raise the Z axis by 1mm and go back to X 25mm, Y 25mm.

Lower the Z axis to 0mm.

Check and readjust if necessary for drag on the paper.

If the drag is still the same as it was then good. If not, it is a pain, but go around again and readjust all four corners until you are confident that the gap is consistant.

After the Manual Process

Test print

I use a single layer circle test print 100mm diameter 0.2mm thick.

Download the test circle.

If you now load up the test print, wait for it to start printing.

You will see what is happening with the nozzle as it comes down to make the first part of the print.

If it doesn’t stick then adjust the corner to either raise the bed if the nozzle too closenozzle is too high or lower the bed if the nozzle appears to be too low.

If the print hasn’t stuck after the first half circle then abort the print.

Remembering that a turn of the screw is 2mm tweak the adjusters in the direction you need to and start the print again – after wiping the printers nose.

Once this test print sticks and prints completely then use a marker pen and mark the forward direction so you can orientate the print. Peel it off carefully and measure the thickness of it. Measure in the two axis – both diresctions – is it consistant at 0.2mm (ish).

Use this test print to more accurately setup your printer – don’t be too obsessive.

Print it again and check for consistancy.

Once you are at this stage then you know that any print you do now should stick with a first layer squished down.

Remember to go slightly more squished rather than less as once your model goes upwards it has less chance of detaching if it is adhered to the bed more.

Every few prints ( preferably before every print) clean your print bed.

Did you manage to get Your Anet a8 bed leveled?

Good luck with this, and leave some comments if you feel that you have a better method for anet a8 bed leveling.

Thanks for reading

Phil

3d print journal 01-12-17 : bed screws binding

3d print journal 01-12-17 : bed screws binding

A tale of woe about the dilema to drill out the base bed screw threads or not, and what a lucky chap I am, how I overcame the problem and what you should do if you haven’t got to this stage yet.

And how I initially level my bed to prevent the nozzle crashing into the surface of the print bed.

Read on to find out what happened. Continue reading 3d print journal 01-12-17 : bed screws binding

5 Mods for the Anet A8 3d Printer

The Anet A8 is a cost effective introductory printer into the 3d 5 mods for the anet a8 : Anet A8 3d printerprinting world.

As a build it yourself model, it is up to you how you modify it.

The standard build is good and will teach you a lot about 3d printing.

But it can be improved on easily and cheaply. Continue reading 5 Mods for the Anet A8 3d Printer