Trying to build the First Mendel in Greece (Brainstorming...)

Hello fellow Reprapers!!!

My name is John and I am now finishing my studies in Greece.

For many months I was thinking on building a Mendel but always the cost was a massive problem... Now I managed to save up about 450-500€ and I thought that is a nice idea to spend my summer on that project!

First of all I started looking for reprapers in Greece, but no luck, as it seems, if I manage to build it, I'll be the first one to have a mendel in Greece!!!

Then I started looking for the vitamins and I just want to give you a picture of the prices here.
The same part,from the same company (RS Online) has three different prices with the highest price on the Greek version of the shop. For example the BZP cap screw,M3x20 (1 box of 100):
Germany €8,45
UK £11,05~€13,28
Greece €19,64

And the price in Greece doesn't include VAT (which is 23%) so the price goes to the extremelly: 24,15€ just for 100 M3x20 cap screws!!!!!!

Anyway, then I decided to buy everything from Europe and just have to pay the extra shipping costs.
I found a cheap store Mendel-parts which probably from there I'll order Belts, Bearings, Nuts & Bolts, Bars, Motors, Thick & Thin Sheets and I calculated that with the shipping till here will be 300€. That sounds ok, I don't thing I'll be able to get some cheaper prices...

Then the electronics problem occur. Nowhere in Europe I can't find the makerbot electronics, but if I buy everything from the states the custom here will charge me enormous amounts of money.
Being lucky here, some really nice folks from irc informed me that is possible to have for electronics an arduino (mega or even 328) and for stepper motor drivers the Pololu A4983 which is ~12€/each. That probably will be the way I'm gonna follow. I haven't yet found available the optoendstops but I'm still looking. So the cost of electronics will be at most 100€.

Another 120€ for 5kg of ABS (including shipping) will automatically put me out of budget, and I still haven't the printed mendel parts...

The prices on ebay are a bit high, because of the big demand and small supply of parts, but I can't afford it.
I found some "Laser Cut Replacement for RepRap Mendel Printed Parts" at about 210€ (with shipping costs) but I don't know if they will last till I print a whole set of parts to replace them... They look so fragile.
Afterwards I decided to build ta mcwire and print the parts and then build the mendel, eventhough it gonna take days to print the parts, but only the cost of mcwire equals my budget. Here is an example:
That shop, [shop.grrf.de] , has almost everything I need to build a mcwire, but the shipping cost is extremelly big, 1 kg 53.87 €, 3 kg 61.44 €, 5 kg 65.52 €, 10 kg 81.49 €
and the parts are quite heavy. I know that some of you may suggest to go to a local hardware store and buy the parts, but for example the acrylic parts, here in Samos Island, Greece is really hard to find etc. x(x(

I really want to build a mendel and I'm trying to save some more money but I can't really...
The only viable sollution as it seems to me, is to buy the LaserCut parts, save from everywhere some money, like don't buy the thick sheets for the electronics, buy 2kg of ABS etc.

Oh and I just remembered the extruder cost....

Does anyone have any ideas on what can I do? I'm quite sad with how the thing are going and I want some alternative ideas...


Have a great day from sunny Greece!

John

PS1: If I'm posting in the wrong sections please move the topic wherever it should be
PS2: Sorry for the huge message...
PS3: The last couple of days I joined the irc room and I have to say that I felt more than welcome on that community! In only two nights I learned so many things that I haven't learned in months reading the wiki etc... My nickname in irc is stam_greece...

First of all, welcome to the forum!

Just wanted to say that you don't have to use the cap screws if they're expensive to source locally. Personally I use cheap hex bolts like this one. The m4x40 bolts only set me back about 2.5€ for 25 at my local hardware store, and work just fine. (A few places is a bit tight fit).

You can use wood instead of acrylic if you can't find it. The thick sheet is really simple and fast to make if you have a jigsaw and a drill press, and you can also make them by a regular hand saw and a drill. Wait until you have the electronics and only drill the holes you need, then you'll save a lot of drilling.

We also have 25% tax (if the value is above 25€ excluding shipping) when importing to Norway. But there is an 14€ fee to pay the tax as well, so importing something costing 30€, in the end cost 51€.

Good luck with your build, and keep us posted about your progress!

Budget seems to be a daily topic :-)

The probably cheapest RepStrap for people without significant workshop capabilities is the Wolfstrap. € 70,- (Germany) for all mechanical parts sans extruder: [reprap.org] [reprap.org] . On top of that you need motors, electronics and one extruder, all of which can be re-used for the "right" Mendel.

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thank you guys for the replies!!! ><

I wasn't aware of the existence of WolfStrap... It seems a really good and cheap solution compared to the mcwire...

Does anybody know how long it will take to print the mendel parts? It says on the wiki: "Threaded rod 2x approximately 350mm M10; X-Y-axis (I started out with M5s, which I cannot recommend. The machine will move too slow) " but I can't really find any other occurrence of the speed subject...



I'm a bit happy again!

It depends somewhat on the stepper motors you have. Some can run 5000 steps/second, others more. 5000 steps/s / 200 steps = 25 revolutions/s. Applied to a M10 thread, this is 25 s^-1 x 1.5 mm = 37.5 mm/s = 626 mm/min. With a belt-driven drive you can go ten to twenty times faster, as one revolution moves the belt a full perimeter of the gear. Please note this assumes a sufficiently fast extruder and is an educated guess anyways, as I don't have a machine running, yet.

I'm currently building a WolfStrap myself and to be honest, I don't care much about how fast this thing will be. First I have to build the frame, then solder the electronics, then get the motors to run at all, and so on. With all this there's a lot to learn and it wont's matter wether I have to run the RepStrap for another 20 or 200 hours until I can upgrade to a better mechanism.

That said, it should be easy to equip a WolfStrap with belt-driven drives in case you can get hold of the gears and belts. Or have manufactured them as first pieces ...

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thanks for all the replies Traumflug!

I have a problem with my broadband connection but now I'm back again!

I'll follow your idea by making a Wolfstrap and print the parts for the mendel!

You provided some really nice math info up there!

I just have a question. You mentioned before that the extruder has to be really fast, but the whole structure doesn't move really fast, so why is this necessary? Or you mean when you have a belt driven system?

So basically the only printed parts we gonna need is the extruder parts! Are you going to select the
Geared Nema17 Extruder Driver from Adrian or Geared Nema17 Extruder from Wade ?

Have a great day!
John

Quote

I just have a question. You mentioned before that the extruder has to be really fast, but the whole structure doesn't move really fast, so why is this necessary? Or you mean when you have a belt driven system?

The faster the machine can move, the faster the extruder has to be. Reading this forum, most people have belt driven machines and are limited by extruder performance. With a threaded rod design, printing speed will be limited by the stepper motor max. RPM.

BTW., yesterday I've found a picture of a belt driven WolfStrap: [forums.reprap.org]

Quote

Are you going to select the Geared Nema17 Extruder Driver from Adrian or Geared Nema17 Extruder from Wade ?

I'll use my Dremel as my first toolhead ;-) Adrian's and Wade's are often mentioned to perform equally well. Looking at the build page of each of them I'm wondering what's the difference between both. Can't be much :-)

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thanks for that link Markus!
I wasn't aware of that topic! Some seriously effort is being done there on the wolfstrap to run on belts!

I read the topic (with the help of google translate of course!) and fellow repraper Stoffel15 mentions that it took him 26 hours to print just one frame-vertex!! (he used a M5 threaded rod)

In fact I did a bit of reading and one of the main differences between wade's and andrian's extruders is that andrian's is "# Designed to work at higher extrude speeds than the standard Mendel extruder, giving shorter build times."

How far on your Wolfstrap have you reached?

Quote
stam
... one of the main differences between wade's and andrian's extruders is that andrian's is "# Designed to work at higher extrude speeds than the standard Mendel extruder, giving shorter build times."

I think you are a bit confused here. The two geared NEMA 17 stepper driven extruder designs by Wade and Adrian are both intended to allow high extrude speeds. Both are significantly faster than the older DC motor driven extruder design (which was also originally Adrian's design).

See the Choosing a Geared NEMA17 Extruder topic for discussion of the (relatively small) differences between Adrian and Wade's current (Geared NEMA 17 stepper based) extruder designs.

---

---

Jonathan

Thanks Jonathan for that!

I couldn't really understand the differences between those two extruders! Now I'm gonna read that topic and I'll try to find out!

The forum and the wiki are huge that I'm lost, everyday I discover new and important topics/pages!

Cheers from Greece,
John

John,

We have one user,
[reprap.org]
who translated the main page into greek:
[reprap.org]

If you add a note here, AlexCY should get it.
[reprap.org]

Let me know if you'd like me to create a Greece RepRap User Group and announce it using the blog. (I have a backlog of 5-6 new RUGs to create.)

---

-Sebastien, RepRap.org library gnome.

---

Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

Hello Sebastien!

I didn't know that the main page was translated in Greek! Tomorrow I'll drop a message to AlexCY to see if he has a fully worked printer etc!

It would be great if you could create a new rug for the Greek reprapers!

I don't know how many we are, probably not many , but I believe it might/will help the future reprapers to have a reference point!

Have a great day,
John

Quote

How far on your Wolfstrap have you reached?

Just finished building the bottom frame with the moving table on top of it. The frame went a bit bigger than designed by Wolfgang, the wood pieces are 650 mm and 500 mm long. This way, the table will never need more space than the bottom frame and you can put the machine right to the wall.

Instead of the angle pieces, I used long wood screws 5.0x50 mm to connect the slats directly. Pre-drilling the holes is a very good idea. If that turns out to be not stiff enough, I'll reinforce later.

When mounting the drawer linear bearings, precision alignment turned out to be difficult. I had to rely on careful measurement, the flexibility of the frame has to account for the remaining inaccuracies. These cheap bearings can't be disassembled ... anyways, the table now moves by touch of a single finger easily.

Markus

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Traumflug Wrote:
-------------------------------------------------------
> anyways, the table now moves
> by touch of a single finger easily.

Those are good news!!

Do you have uploaded any pictures on flickr or somewhere else so we can ourselves??

I am just finishing all the searching about everything and probably till Friday I'll order everything!!

Did all the sizes of the wooden parts on the wolfstrap page on the wiki were correct or you discovered any mistakes etc?

Cheers from Greece,
John

Quote

Do you have uploaded any pictures on flickr or somewhere else so we can ourselves?

Sorry, I can't, because I don't even own a camera. :-/

Quote

Did all the sizes of the wooden parts on the wolfstrap page on the wiki were correct or you discovered any mistakes etc?

Roughly, all the sizes fit. For the exact sizes, I measure them as needed. The bottom frame is finished, now I started with the Z axis. That done, I'll fit the X axis in between. Yesterday stepper motors arrived, so I can build that right with the driving rod.

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

That's really good news Markus!
It's ok with the pictures, as long as you don't have any problems, probably your wolfstrap looks like the one on the wiki!!

I'm a bit jealous! When I order all the parts, I'll have them delivered in my parents house, because where I live some of the parcel might be lost I'll be there at 15/7 and start the whole project!

You will have threaded rod for Y and belts for X,Z or threaded rod for all the axis?

You don't want or need belts for the Z-axis!

The X and Y axis on the other hand will only be fast enough with some kind of belt/chain drive. Using threaded bar for these axis is just simply too slow!

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

You are right Bob!
I was confused with the axis!
John

John

There is an easy way not confused with the axis!



Edited 1 time(s). Last edit at 06/24/2010 01:34PM by Stoffel15.

---

Mfg
Wolfgang

Aller Anfang war schwer - Wolfstrap

Reprap-fab.org

Erfahrungen kann man leider schlecht weiter geben, die muss man selber machen.

Thanks for the photo Wolfgang!

Now I am sure I will remember the axis correctly!!

Cheers from Greece!
John

Edited 1 time(s). Last edit at 06/24/2010 05:48PM by stam.

Hello there!

It's been a while since my last post.

I was trying to save up some money and I finally have ordered everything!!!

The next week I hope all the shipments to be delivered to my place...

The plan is to build a wolfstrap and then slowly slowly print the parts for a mendel!

My only problem is that I run out of money and I don't have any pulleys. So I might try first to do the bar/stud version of wolfstrap so I can print the pulleys and then turn it to belts version.

Hm, know that I'm really thinking it I don't have a ready extruder but I hope to be able to use something like that till I print a proper one...

When everything arrive I'll go and buy all the woods that the wolfstrap needs...

I'm a bit worried to be honest, I've spend 450€ and I if I fry/broke anything then it might be difficult to replace it

Anyway, next week I'll post pictures of everything that have been delivered!

Cheers from Greece,
John

glad to see you doing well, John.

The carthesian robot part of the Wolfstrap here is about finished. The last two weeks I worked a lot on getting steppers running, including refinements of the firmware. Next step will be to hook up these steppers to the robot, so I hope I can see some real 3D movements this week.

Cheers,
Markus

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

Hello fellow reprapers!!! ><

Finally I have almost everything here except the mendel parts

Now some of my problems if anyone knows a possible solution to help me...

First of all my setup will be one Arduino Duemilanove (328P), 4 Pololu Stepper Driver Boards, 3 OptoEndStop Boards and one Temperature Board (just a resistor and a capacitor basically).

I've succesfully tried the optoendstop boards and the temperature board with that demo code.

Then I have uploaded to my arduino some demo codes founded on the wiki and all the 4 pololu drivers seems to work fine!!! I did some minor adjustments of the potensiometers on the pololu driver to adjust the current that goes to the motors and everything seems nice!! Also I have attached some heatsinks to avoid frying them!

Now the first problem is that I can't get running the FiveD Arduino firmware. I downloaded the firmware and via the Arduino v18 software I uploaded it to my board. Then I connect everything correctly, fire up the power, and run the reprap host software. Then when I choose for example to move X axis the program freezes.
It seems like there is no communication between the board and the reprap soft... Any ideas???

Then I tried that firmware which probable is not 5D but still I wanted to test everything (GCode_Interpreter.pde). I uploaded it successfully and I have movement on every single axis and the optoendstop work. Then I decided to connect the extruder with the nicrome wire and the ntc thermistor attached.

I fired up everything and I pushed some abs through the extruder and seemed that everything was ok. But afterwards I discovered that the temperature sensor board didn't work at all, and the temperature was stacked to some weird values, either 0 or 255. So that resulted the firmware to have the extruder (nicrome wire) ON for a long time and the whole extruder barrel etc thing melted


Anyone has anything to propose?? To sum up the main probs are the fived firmware on arduino 328p and the value of the thermistor which with the demo code provided on the wiki works fine.

Also here I uploaded a couple of photos of my setup!

Thank you all!

Cheers from Greece
John

I don't know in what stage you are on your project. But if you are still looking for plastic parts consider doing what i have done. Use expanded polysterene and mdf for your parts. The first material is very easy to cut but not very solid. Think which parts take much load and make them from mdf. I' ve done this and it works quiet fine. Now I' m printing my own parts. reprapgreece.blogspot.com