Author Topic: Building a 3D Printer, RepRap Mendel Prusa2 by craynerd (Read 53369 times)

raynerd · « **Reply #25 on:** May 29, 2012, 05:15:32 AM »

Hi, thanks for the posts guys.

The prusa has been a little ignored over the last few days but I have had a good few hours with it last night.

Despite my best efforts at machining a coupling, I found the thread was unscrewing while the motor was moving. I could have tapped the coupling for a grub screw on the threaded end but I decided to give the plastic couplings a try and they seem much better. I think consequently my z wasn`t moving.

I`ve also been using M92 g code to set the e-steps on the fly and observing the differences - this has been better.

Got some pretty good prints of bearing holders last night.

I`ll post more pics and progress soon. Once again, thanks for the interest.

raynerd · « **Reply #26 on:** May 31, 2012, 06:26:16 PM »

Cracked it...finally!

If anyone makes one, learn to tune the E step on the fly with M92 E .... with G-code!!!!!!! Two night work sorted in 5 minutes.

Also, I`d got a wierd copy of Marlin. I`ve moved over to Sprinter now.

Z axis was out by a mile... now it is square my prints look v good!

Here is a case for my new Raspberry Pi!!

andyf · « **Reply #27 on:** May 31, 2012, 06:57:44 PM »

Nice one, Chris; raspberry on the front and sort of raspberry coloured, too

I'm often stuck for a box to house some electronic project; being able to make your own custom ones must be a real boon.

Andy

Swarfing · « **Reply #28 on:** May 31, 2012, 07:13:40 PM »

Grand job Chris, might get you to make one for me if your board

PS

Answer that mail will you?

philf · « **Reply #29 on:** June 01, 2012, 03:15:14 AM »

Quote from: craynerd on May 31, 2012, 06:26:16 PM

Cracked it...finally!

Hi Chris,

Super job!

Is the rest of your post in some sort of Cypher?

Quote

"tune the E step on the fly with M92 E"

"I`d got a wierd copy of Marlin. I`ve moved over to Sprinter now"

Phil.

ChrisC · « **Reply #30 on:** June 01, 2012, 04:32:02 AM »

Looking good Chris. I've found Marlin firmware to be ok, I haven't used Sprinter for a while, perhaps I should check it out again. Chris

raynerd · « **Reply #31 on:** June 02, 2012, 03:23:47 AM »

Cheers guys, it has turned out pretty well.

Phil, as you can imagine, you have to calibrate all your axis, so when you tell it to move 100mm it actually moves such! That is easy with the x,y and z because you physically measure the distance moved but with the E axis (the extruder), it is very tricky to measure the amount of filament being pulled through and other factors such as the size of the extruder can effect it....it isn`t an exact science. Lots of the guides tell you to simply extrude 30mm and measure if 30mm has actually come out and adjust from there. However, I just couldn`t get it right. Then someone told me to print a solid layer and enter the g-code M92 E720, this sets the E step value to whatever you like, on the fly - in this case, 720. When your doing a solid layer, you can then check the layer is solid and adjust the E value until it is solid, 100%. That being said, best way is to get it to 95% and then take it up to 100% so that you know your not above (anything over 100% would also look solid!!)

Chris

John Rudd · « **Reply #32 on:** June 02, 2012, 05:23:42 AM »

Quote from: Swarfing on May 31, 2012, 07:13:40 PM

Grand job Chris, might get you to make one for me if your bored

Chris, looks pretty neat, custom made enclosure for your Pi....Are you taking orders for plastic extruded cases?

( only kiddin' )

Seriously, that's some great kit you've built...( where's the jealousy icon? ) well done...

philf · « **Reply #33 on:** June 02, 2012, 06:54:37 AM »

Quote from: craynerd on June 02, 2012, 03:23:47 AM

Phil, as you can imagine, you have to calibrate all your axis, so when you tell it to move 100mm it actually moves such! That is easy with the x,y and z because you physically measure the distance moved but with the E axis (the extruder), it is very tricky to measure the amount of filament being pulled through and other factors such as the size of the extruder can effect it....it isn`t an exact science. Lots of the guides tell you to simply extrude 30mm and measure if 30mm has actually come out and adjust from there. However, I just couldn`t get it right. Then someone told me to print a solid layer and enter the g-code M92 E720, this sets the E step value to whatever you like, on the fly - in this case, 720. When your doing a solid layer, you can then check the layer is solid and adjust the E value until it is solid, 100%. That being said, best way is to get it to 95% and then take it up to 100% so that you know your not above (anything over 100% would also look solid!!)

Chris

Thanks Chris. Now I understand

I guess that Marlin & Sprinter are firmware versions.

The Raspberry case looks superb.

How much did you spend building it?

If only they could print in metal.............

Phil.

Raggle · « **Reply #34 on:** June 02, 2012, 02:00:20 PM »

"Incredible" is a word that is driving me mad when used by politicians, movie reviewers and far too often.

However, your Raspberry Pi cover is truly incredible. Produced as it was by a machine that didn't even exist a month ago.

Even Yoda a part found to play, misshapen troll he was. Proud of yourself you should be, young Jedi! The force is with you.

Ray

raynerd · « **Reply #35 on:** June 02, 2012, 03:58:10 PM »

cheers Ray

John - yea, think I could go into selling them.

Phil - I`ve been so impressed, that I`m making one for school. In terms of cost:

£80 for a Prusa 2 parts set inc. hobbed bolt for extruder (unless you can find a machine to print at cost, in which case £20)
£13 for M8 threaded rods, 110 M8 nuts, 100 washers ... and a few bags of other assorted fixings.
£22 for 6 lengths of 8mm Silver steel
£40 for a nozzle (but anyone on here could machine one)
£20 worth of linear LM8UU and skate bearings

The rest is in the electronics
£55 5x stepper motors (nema 17)
£50 RAMPs 1.4
£40 Arduino Mega
£40 for 4 Polulu Stepper Drivers

Then there are a few extras/mods:
heated bed - £15/20
Metal T2.5 timing gears and belt - £25

Please.... if you add all that up, just don`t post the answer and certainly don`t tell my wife

philf · « **Reply #36 on:** June 02, 2012, 04:53:15 PM »

Chris,

A bargain!

I have added it up - what's it worth not to tell Mrs. Chris?

I'm sure the kids at school will have fun with it.

I'll have to see what parts I've got which might be useable - but I don't think my wife would be too impressed if I spent the time and money on a RepRap before I've built her a garden arbor, had the hall, stairs and landing plastered, fitted a new bathroom and a new kitchen - then there's the new carpets (oh - and she wants a new car!!) etc. etc.

Phil.

raynerd · « **Reply #37 on:** June 05, 2012, 07:09:22 PM »

Phil... that is some list!!!

Here are some more pics from yesterday... once again I`m a bit behind.

The plastic PLA filament that I ordered didn`t come on a reel. I didn`t think this would be such an issue but actually it is really important that the extruder can just nice and gently pull filament off the real when it needs it. Consequently, you need some sort of dispencer. If you get a real with your filament, there are quite a few designs with bearings that just allow the reel to unwind but I needed a reel as well.

Here is the prusa buildings itself a filament dispencer and reel!!

Confidence has grown and so I`m now printing fuller plates. This does mean more that can go wrong if it does fail but of course less time and messing around changing prints.

All parts printed and assembly started. Used just over a meter of M8 rod as well:

I also wanted a way to mount the reel. My workshop has joists exposed above head and so I made these two little clamps. Sadly I`ve no pictures of them in use but the part with all the holes gets screwed to the joist. M8 rod going downwards (clearance from the ceiling), nut is included in the design. The only little brackets then allow you to mount an 8mm bar horizontal which the reel then sits on. It works well..

The reel assembled and on the floor. You can see it freely rotates on skate bearings.

raynerd · « **Reply #38 on:** June 06, 2012, 04:26:31 AM »

Here is a better Yoda:

Chris

edit: Fixed YouTube link. Don

ParCan · « **Reply #39 on:** June 09, 2012, 03:32:17 PM »

Your reel looks nice Chris..

Yoda has come on a long way as well......

My machine is back together but i have not resolved the issues.
What I do now know is it's not mechanical.

I can only guess that i'm simply over extruding.....

Alex.

raynerd · « **Reply #40 on:** June 09, 2012, 05:55:10 PM »

Seems strange that Alex... what happens when you play with the e-step value as it prints?
Chris

raynerd · « **Reply #41 on:** June 09, 2012, 05:56:48 PM »

Just to re-coup a little money on the cost of building the machine, I`m currently mid way through my Prusa Parts print...I`ll be hopefully selling it soon. If anyone wants a parts set to build a RepRap let me know - I honestly believe my prints are very good now.

Chris

ParCan · « **Reply #42 on:** June 14, 2012, 02:20:42 PM »

Hi chris
Problem found.
I was over extruding and the nozzle was off square to the bed.

I set Sprinter up to print the cogs for the 1st parts set I made you.
Forgot to set it back.
doh !

The issue with the sides was the filament oozing over the edge because it had nowhere to go. Add in the angle the nozzle was at and it made a real mess of the finnish.
Prints are now as good as they should be, even with 3 shells.

Alex.

raynerd · « **Reply #43 on:** June 15, 2012, 07:18:08 AM »

Nice one Alex. I must admit, I had a little issue with under extruding over the last few nights. The chaps on the IRC channel were insistant that it was filament slipping but I knew it wasn`t. I installed a fresh copy of Marlin, the pre-config one for Prusa running 1/16th step Ramps 1.4 and it now runs fine again...so not sure what happened there. I have recalibrated the axis and I`m back up and running again now.

I really like the Prusa and the prints come off it just perfectly. However, I wonder for rigidity and stability if the mendelmax is perhaps a better machine. I don`t believe the prints are any better but I do think perhaps it is a little more solid looking and reliable.

Anyway, glad you are back up and running. I`ll send you a link to where you can see us using the parts shortly as we are doing a school blog of the entire project.

Chris

matnewsholme · « **Reply #44 on:** June 15, 2012, 01:00:24 PM »

ok I've bit. been reading this thread with interest.nearly finished my worden grinder and needed a new project. After seeing quality of parts chris and others are getting out of these I've gotta give it a go. Got the basic hardware components and a printset ordered to make a start.

Matt

raynerd · « **Reply #45 on:** June 15, 2012, 06:10:09 PM »

Nice one Matt - what reprap have you gone for?

Also, give me a message if you need any plastic parts printing....

Swarfing · « **Reply #46 on:** June 15, 2012, 06:44:14 PM »

Chris i have to say i am very impressed with the quality of the parts so far. will you be reprinting your own at all which look less superior to yours?

raynerd · « **Reply #47 on:** June 16, 2012, 01:45:48 AM »

Hi Swarfing, I`m currently trying to sell a couple of parts sets for the prusa to get back the costs I`ve laid out in building it. The quality of the set I`ve printed is pretty good and in silver (which looks grey), has come out well. The issue with printing a parts set is the time as there is about 16 hours or more print time!!

matnewsholme · « **Reply #48 on:** June 16, 2012, 12:48:33 PM »

Quote from: craynerd on June 15, 2012, 06:10:09 PM

Nice one Matt - what reprap have you gone for?

Also, give me a message if you need any plastic parts printing....

doing a prusa 2. think im going to go with ramps 1.4 for the electronics.

raynerd · « **Reply #49 on:** June 16, 2012, 02:53:20 PM »

Yes, Ramps 1.4 sounds a safe bet and what I went for. Others are cheaper but the support and seemingly reliability of the ramps out weights.

Chris

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Author Topic: Building a 3D Printer, RepRap Mendel Prusa2 by craynerd (Read 53369 times)