Hot Ends and PCB Heatbed?

Hello all!

The 3d printing phenomenon has come to my attention, and I'm eager to get started.

It's very likely that I'll acquire a Prusa Mendel, but I'm unsure whether I'll purchase a kit or try to obtain all the parts separately. Obviously, if I attempt the latter I'll want to do it considerably cheaper than the pre-assembled kits, or I could be giving myself lots of grief for little reason. The Makergears Prusa Hybrid stands out to me right now. Unfortunately, the only Mendel kits I've seen in the UK (where I live) seem very expensive, and not of the Prusa variety.

Personally, I'm not too knowledgeable about DIY and the practical side of electronics (soldering etc), so the Wade extruder and Gen6 board seem like simple and attractive solutions to me. I understand that the Gen6 board doesn't support a heated PCB, but I was wondering whether it would be possible to safely connect the PCB Heatbed (http://reprap.org/wiki/PCB_Heatbed) to an independent variable power supply? Otherwise I guess I would need to get practical and create my own heated bed.

Also, I can't find many Nozzles/Hot Ends for the Wade extruder. I'm aware that Makergears do an excellent Kit for the Wade's, but unfortunately transatlantic postage is high and the total cost would come to about $130 for the kit (before customs duty). In Europe, Mendel-Parts do a V5/V6 Nozzle/Hot End kit for €25 and upwards (plus VAT and p&p), but I'm not sure whether the parts would fit a Wade extruder? If anyone has had any experience combining a V5 or V6 with a Wades I would appreciate your input!

If there are any other reputable suppliers of Wade compatible Hot Ends or mains powered heated beds please let me know.

Thanks!

Hi Rook, and welcome!

I'm UK based too, though took the home-built route. If you are keen to get going quickly, I recommend getting printed parts (including extruder) from the founding father of reprap, Adrian Bowyer at [www.reprapltd.com] or nophead, who usually sells on ebay. Both are UK based and produce excellent quality parts for reasonable prices. For precut metal bars, try ebay or [thingfarm.org] who also sell nut, bolt and bearing sets, and hot ends based on Adrian Bowyer design, though out of stock at the moment I think.
I got my motors from Zapp automation [www.slidesandballscrews.com], gen6 electronics from mendel-parts.com (took a while) and a bunch of connectors, microswitches and other odds and ends from [uk.rs-online.com] (their range is rather bewildering), B&Q and various other local hardware shops. There's always 101 other things that you don't realise you need until you do - today I've been extending motor wires as they are too short supplied, had a soldering iron already, but had to find heat shrink insulation, wire, magnifying glass, extra solder, and a number of other things I've already forgotten!
The hot end is always tricky, but bought ones usually fit to the Wade extruder. The mendel-parts one will. There's plenty of advice on the forum about which ones people like, for example there's this one too [shop.arcol.hu]. I've been building my own, and again, getting the parts is just the start. For example, just to mount the power resistor in the hot end heater, you need bootlace ferrules to crimp wire to the power resistor, PTFE heatshrink to electrically insulate it, Fire cement (B&Q) to stick it in the heater block, Kapton tape to insulate the block, molex connectors and block to attach it to the electronics. And then there's the thermistor! Very small and fiddly, buy a spare or two - I managed to destroy my first one!
I don't think I've spent any less in the long run than I would if I'd just bought the parts in the beginning. It's just the outlay has been spread over time, and I've ended up with a somewhat limited repstrap. I hope it'll be enough to print a prusa... I'll find out tomorrow when I'll be firing up the hot end and extruder for the first time, and maybe trying to print a tiny celebratory shot glass (it's the 'hello world!' of reprap) *crosses fingers*.

Finally, and more reading for you, there's an excellent blog entry here (scroll down the page to Sunday, April 10, 2011 "Sourcing a 3d Printer") [blog.reprap.org]

Good luck and have fun!

Hello,

Thingfarm.org should have the "Geared Extruder Nozzles" in in about 2 weeks or so.

Regards,

Brian

I run my heated bed on a separate power supply. There is no problem with this except you cant see the temperature on the computer and have to measure it separately.

I just set up the supply so it reaches the temperature I want but if you wanted to be fancy then you could probably add some monitoring and control electronics.

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Make your Mendel twice as accurate.
[www.thingiverse.com]

Thanks for the responses everyone!

@Madkite

Is your heated bed the same one as in the wiki (http://reprap.org/wiki/PCB_Heatbed)? I hope so, because that one looks very easy to assemble.

I'm guessing you could probably obtain an idea of the best power settings for PLA and ABS based on practical experience, even if you are unable to accurately measure the temperature.


@droftarts

Your first paragraph virtually read my mind . Adrian Bowyer, Nophead and Thingfarm are all amongst my top candidates to obtain the plastics and non-mechanical parts (if I take the home-built route). Slidesandballscrews, uk.rs-online and shop.arcol are all new to me though, so thanks! Also I appreciate the link to the blog, it's full of useful information.

The account of your building experience makes a lot of sense. So far I have calculated that it would be somewhat cheaper to create my own Reprap, but each time I revise the total it seems to get a little more expensive, and it's likely that I still haven't considered everything. Anyway, I'm sure the process would have its rewards. Owning a self-built and functional Reprap must raise confidence for future projects. For example, I expect printing/assembling the latest extruder design would be comparatively straight forward. Hope that your first prints go well!

Mine is the heated bed that came with the Kit from Mendel-parts.com. It is an aluminium plate with aluminium heater blocks bolted to it.

It take a while to heat up and I measure the temperature with a infrared thermometer so I know exactly what it gets too. I modified the wiring so I could make it get hotter with a more powerful 24v power supply.

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Make your Mendel twice as accurate.
[www.thingiverse.com]

Probably a bigger factor when 'rolling your own' is the time it takes. I have certainly learnt a lot, but my frame has come apart 5 or 6 times, and undergone 2 revisions! I think I started in mid-April - yes it was, when the weather was nice I was cutting the wood and bars outside. Seens like a long time ago. Fortunately, I'm self-employed and not too busy. I have built a MrKim robotics 1X2 Compact of sorts. See [www.mrkimrobotics.com]

@Madkite

Thanks for sharing that info! I don't suppose you know whether the Mendel-Parts solution would fit the Prusa design? I'm assuming you are using a Sells Mendel, since Mendel-Parts don't seem to sell Prusa kits.

@droftarts

Looks impressive! I'm guessing that you managed to avoid the plastic route by using wooden connectors. Have you managed to print your celebratory shot glass yet ? Btw, do you have a heated bed in your design?

Does anyone have any experience printing with PLA on an unheated bed? I understand that this is possible, but I wondered whether this would really impact the quality of results? I'm toying with the idea of skipping the heated bed for now and printing exclusively with PLA, provisionally at least.

Edited 1 time(s). Last edit at 05/30/2011 11:22AM by Rook.

You can print PLA on un-heated blue masking tape. Its OK for single objects, but I found to do a bed full reliably I had to heat it. The main impact on quality is the bottom of the object has a matt finish rather than being shiny. Also you need to do the first layer a bit low to get it to stick, so you tend to get a ridge around the base that can be scraped off with a knife.

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[www.hydraraptor.blogspot.com]

nophead Wrote:
-------------------------------------------------------
> You can print PLA on un-heated blue masking tape.
> Its OK for single objects, but I found to do a bed
> full reliably I had to heat it. The main impact on
> quality is the bottom of the object has a matt
> finish rather than being shiny. Also you need to
> do the first layer a bit low to get it to stick,
> so you tend to get a ridge around the base that
> can be scraped off with a knife.

Thanks for the detailed summary! It probably makes sense for me to worry about the heated bed after the Prusa has been built, since one can always be added later.

Rook Wrote:
-------------------------------------------------------
> @droftarts
> Looks impressive! I'm guessing that you managed to avoid the plastic route by using wooden
> connectors. Have you managed to print your celebratory shot glass yet ? Btw, do you have a
> heated bed in your design?
> Does anyone have any experience printing with PLA on an unheated bed? I understand that this is
> possible, but I wondered whether this would really impact the quality of results? I'm toying with the
> idea of skipping the heated bed for now and printing exclusively with PLA, provisionally at
> least.

Hi Rook, I've been working hard over the weekend, wrangling with Repsnapper to get something out of my repstrap. I ended up rebuilding my hot end and tightening belts, but something is still slipping on the X axis and causing the mini-mug to look like shoes for small elephants. I know there are several problems, like the motor is mounted too low so the pull isn't straight and the belts are actually nylon packing straps, but I can't see any slipping and they are very difficult to stretch. Pulley are PVC tubing. It probably all adds up to inaccuracy! Can anyone suggest what is happening?

As you can see, I'm printing PLA on to painter's blue masking tape, actually from B&Q, and starting the first layer at 0.2mm, with a 0.4mm layer height. Sticks very well, and i haven't bothered cleaning it with acetone!

The X stepper could be missing steps (stepping to fast or curent not high enough)

Check that your pulleys are not slipping on the stepper shaft use a pemanant marker to check.

Check the belt is not slipping using the marker again when belt is at its origin point x=0 make sure it always ends up at 0.

The problem is not always obvious.

When I had this effect it was self inflicted by enabling and disabling steppers to try an keep them cool.

It was in fact the X axis I was having the problem with not the Y axis..

[repstrapbertha.blogspot.com]

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Bodge It [reprap.org]
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BIQ Sanguinololu SD LCD board	BIQ Stepcon	BIQ Opto Endstop
BIQ Heater Block PCB	BIQ Extruder Peek clamp replacement	BIQ Huxley Seedling
BIQ Sanguinololu mounting	BIQ standalone Sanguinololu or Ramps mounting	Print It Stick It Cut it

My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]

You straps are slipping. It's either that, or the pulley on the motor shaft, but without teeth, the strapping is free to do whatever, no matter how much tension you put on it. If you could put some holes into the strapping, maybe with a paper hole punch, and modify your pulleys, you could get away with this type of belt, but the hole spacing has to be precise.

If skipping is caused by the driver being too hot, you will feel slight clicking in the belt, even when the axis is not moving.

Unless the belt is jumping which I doubt as you can normally hear that quite easily. Then the pulley might be slipping on the motor.

Otherwise its that the motor is missing steps and stalling instead of moving. It could be that it does not have enough current or that the particular axis is too stiff. Its not always easy to hear it miss one step. I had this happen at first, making wonky prints and that is what it was. When I paid careful attention to it as it printed I could hear when it missed a step and stalled.

Yes I do go round feeling and listening to my printer when it goes wrong like some strange doctor. You can find a surprising number of faults that way.

Edited 1 time(s). Last edit at 05/31/2011 04:17PM by Madkite.

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Make your Mendel twice as accurate.
[www.thingiverse.com]

@droftarts

At least you have reached the end of the beginning and got a Repstrap printing. I'd love to offer some constructive criticism, but I'm way behind you right now.

I've just taken the plunge and ordered most of the parts for a Prusa, including the plastics, rods, springs, belts, fasteners, bearings, sheets, steppers, electronics, hot end, power, thermistor and 5ibs of PLA. So no way back for me now!

One thing I haven't purchased yet is a hobbed bolt. I know they are easy enough to make with a power drill, but surprisingly few people seem to want to capitalise on this. In fact, I can't seem to find anyone stocking hobbed bolts in the whole UK!

Hi Rook

I'm sorry for hijacking your thread, but I think it shows how there is community support when things aren't going quite right, which is perhaps more important than the parts or kit you choose. Even buying a complete Mendel still leaves you with a massive amount to learn; there really isn't a turn-key solution yet, because you still need to craft the software settings to acheive good quality prints. So don't be afraid of asking questions. But... do search the forums first, someone else has almost certainly asked the question before.

PS mini-mug, success! Though I just set Repsnapper to home X and Y every layer, which is kind of cheating!



Edited 1 time(s). Last edit at 05/31/2011 08:03PM by droftarts.

Rook, I'll make you one. Assuming you're getting a Wade's or Adrian's extruder and 3mm PLA. I have some spare shanked 8mm bolts. PM me.

@droftarts

Don't worry about hijacking the thread, I've been wandering OT anyway with my hobbed bolts. Your last effort looks much better btw, even if you did cheat a little! Also, I really appreciate your kind offer. PM sent...

Plastic parts arrived today, less than 24 hours after purchase, so many thanks to nophead too!