Everyones status

Hey [UK] RepRap builders!
I am looking at the feasibility of building a RepRap in Leeds, West Yorkshire. Putting a RepRap together is a Uni design project, from which I am hoping to then contribute back to the RepRap project.

I have read through all you posts, I see most of them are about the difficulties of ordering components in the UK.

Can you all let me know what the statuses of your builds are, and if not complete what the limiting factors are. Perhaps also list the names of the component suppliers you have already used successfully.

Cheers!

Also advice will be very useful at this early stage.

Joe

Howdey,

I have just started on my RepRap build. Just soldering up my opto endstops as I type. I started back in November but I did not have the space to build a reprap so I have spent the last few months converting the space under my flat into a basement where I can start the build.

I used the list that greenarrow posted to order my components from rapidonline. I found the electronic components a bit of hurdle because I have little experience in this area. I wouldnt have minded taking a risk on a few items when ordering but I found a lot of items were just named differently so I would have had trouble identifying them on any uk site.

I havent really thought about anything past soldering the boards I have, so any other hurdles arent on my horizons.

Cheers

Keigh

I've been working on the RepRap as my final year project for a design degree at Leeds Met.

Sourcing Parts
=================
PCBs are from Zach store.rrrf.org

Electronics are from Mouser in America - shipping +import. I'm think it was cheaper than the UK over all.

(Bronze) Mechanical kit from Ian (bitsfrombytes.com) included,
Steel
Resin molds of unique parts
nuts & bolts
Stepper motors
MDF board
see websites for full list

JBweld from ebay


=================

The stepper motors from Bitsfrombytes do not play well with the PIC generation 1 electronics. I think the recommendation is to use the Arduino electronics, but confirm with Ian.

For my generation 1 electronics I added resisters in series. Not an ideal situation but seems to work.

Status
==================
I haven't been able to work on the Darwin for a month. The state of the build is...
generation 1 electronics working great

z-axis showed signs of working but my timing belt was either too lose and skipped or too tight and struggled when the join went around the pulleys. I am thinking that the pulleys from bitsfrombytes are too small [EDIT: BETTER VERSION NOW AVAILABLE]. I'm looking into alternatives.
X axis looks to be work beautifully
I haven't added the y-axis

Bitsfrombytes supply uncoated nichrome wire so insulating as you build your heating barrel is important. For my second attempt i did it slowly over a few days building up thin layers of jbweld and nichrome wire. The result works excellent.

The drive shaft I received from Bitsfrombytes was aluminum not steel so it couldn't be blow torched [EDIT: THAT IS WRONG IT IS IN FACT MILD STEEL]. I've yet to bring that up with Ian so I don't know if this was a mistake, in the end I used glue. This was a mixed blessing as it held but it also broke.

I did manage to extrude hot CAPA, that was very a happy day! But I've now had to put the engineering aside and focus on my design projects. I'm sure a couple more week and some fresh extruder parts would have proved very fruitful.

My extruder is now pretty much destroyed after a bad idea to use a belt sander on it went wrong :-) I'm looking forward to ordering a new one over the summer. From what limited experience I've had with the extruder design makes me keen to see a new design emerge.

For my degree I am now working towards,
developing a RepStrap kit which can be manufactured in small volumes and distributed through e-commerce and then assembled in a home environment.

Designing a conceptual interface for personal fabrication. This is narrowing towards an embedded x86 + touch screen.

Exploring the role of a supporting web service for personal fabrication. A big database connected to a SOAP server.

I hope to be posting details on what I've been doing shortly. Just a matter of finding the time :-)

I'd never done electronics or mechanics so this project was a steep learning curve. I spent an intensive 6 weeks with the Darwin. It is just the fact that I am on a design not engineering course that I had to prioritize my time away from finishing the Darwin onto more visible innovations.

Anyone wanting is welcome to come down and see an incomplete Darwin. It is at Leeds met city centre site for the next couple of weeks, after which I'll need to find it a new home. PM to arrange.

Joe



Edited 1 time(s). Last edit at 04/23/2008 04:11PM by Joe.

Hi Joe

Extruder drive is definitely mild steel I don't have any aluminum and yes the Z pulleys are easier to set up if bigger so we now do 40 tooth up from the 20 tooth version you have we have also added a belt tension to break the link between the studding ties and the belt tension this works very well eD & I ran the Z axis up to 30mm/s with no missed steps and at slow speed get a resolution (measured) of 0.01mm

Hope this helps

---

Ian
[www.bitsfrombytes.com]

Ian,

Thanks for clearing those things up! I edited the post.

Joe

Joe,
I got my last drive screw from Ian and it soldered very easily with a 50W electronics soldering iron.

Ian,
30mm/s from threaded rod! What drive electronics? That is fast enough for XY so you could ditch the belt drive.

---

[www.hydraraptor.blogspot.com]

Nophead

That's using a SLA7062M unipolar stepper driver chip the motor does need ramping to get there I drove the driver with a function generator.

You could ditch the belt but i have to say opposite to my expectations the belt works very well when the tension is correct. Threaded rod would probably be cheaper and probably a lot more noise!

---

Ian
[www.bitsfrombytes.com]

Hi,

Just started building a Mendel myself as a hobby project. I'm an engineering graduate working as a design engineer but don't have that much "hands on" knowledge. My current status is as follows:

Thick sheet: Done - 6mm MDF from B&Q hand cut
Thin Sheet: Done - Aluminium drinks can
Electronics: Tech Zone Remix ordered off ebay, not delivered yet.
Bearings: Ordered off ebay, not delivered
Nuts Bolts Rod: Not ordered yet but think I can source locally
RP: No idea yet but might see if I can get one through this RUG scheme. Will make sure I can get the electronics working first.

James

I have a completely built Mendel which mechanically works very nicely.

However, I've not yet managed to get the extruder (Adrians Geared Extruder) to work reliably.

The issue is with the hot end - it works for a bit then stops because the filament has melted back along enough of it's length to bulge outwards, then solidify enough that when the motor continues to drive, it just strips the threads on the heater barrel which pops out and melts a nice hole in the bed!

I've tried half a dozen different heater designs and temperatures (verified with a probe) from 150 deg to 195 - and it still doesn't work.

Unfortunately, this is my busiest period at work - so I've given upon it for the time being. I'm kind of wishing I'd just bought one of the ready built and tested MakerBot printers to be honest! They are about £2k, so about double what I've spent, but it would have saved about a month of my time!

The mechanical build of the mendel only took a day (parts printed by Adrian) and couldn't have been easier. Electronics from Makerbot using Adrians Software - again once I had the right version work nicely.

Any tips would be much appreciated - before I throw it out the window!

Si

What plastic are you extruding? 180-200 is about right for PLA, 220-240 for ABS.

It is crucial that there isn't a gap between the end of the brass thread and the PTFE.

I must admit I don't use PTFE for this reason. Somehow Adrian gets it to work but everybody else gets this problem sooner or later.

Did you get the PTFE from Adrian as we wondered if he had better stuff than me?

---

[www.hydraraptor.blogspot.com]

I've tried PLA and ABS. The hot end came from Adrian - but I simply couldn't get it to work for more than about 30 sec extruding - then have to more or less re-build it!

Adrian's PTFE appears to be glass-filled.

What would you suggest is the best combination of materials and design of hot end? I run a small CNC machine shop - so just about anything is possible!

Cheers,

Si

Stainless steel is totally reliable but needs a heatsink: [hydraraptor.blogspot.com]

Encasing PTFE in a copper pipe is also reliable but again needs a fan. [hydraraptor.blogspot.com]

For a no fan solution the hybrid PEEK / PTFE design sold by Brian Reifsnyder works well.

However, if you can extrude for a while and then it jams it almost certainly a gap between the end of the brass barrel and the PTFE. Plastic that is past is glass transition, but not molten swells into it and jams solid. [www.youtube.com]

If you fix that then the PTFE should work. It is just that it is fragile, so as soon as you have a jam it lets go of the barrel.

---

[www.hydraraptor.blogspot.com]

Has anyone tried using machinable ceramic?

Although most of them are designed to be good thermal conductors - there are some which are very good insulators and have reasonable mechanical properties?

Si