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Mendel 90 - Anyone want dibond parts?

Posted by isolt 
Mendel 90 - Anyone want dibond parts?
April 02, 2013 10:56PM
Thinking of building a Nopheads Mendel 90 Dibond.
I've got a quote for getting the dibond cut and drilled, but as with all things it's cheaper in quantity.
About $70+gst each for 2 off, cheaper if more people are interested.
Any takers?

Re: Mendel 90 - Anyone want dibond parts?
April 17, 2013 10:06PM
Hi isolt,

I'd be interested (hopefully I'm not too late). I've been looking at the upright frame printers with great envy for a while now, time to take action! Hopefully the conversion from a traditional Prusa frame won't be too much of a pain...

I'm also looking forward to becoming a more active member of the NZ reprap community.
Re: Mendel 90 - Anyone want dibond parts?
April 17, 2013 11:30PM
Hi Sandvich!
Haven't ordered yet, I was holding off in the hope someone would be interested.
Where are you in NZ? I'm in Auckland.
How's your part sourcing going? Getting some of those small hex screws was a pain.
Re: Mendel 90 - Anyone want dibond parts?
April 18, 2013 12:09AM
Great! I was a bit worried you might have ordered already.

I'm near Hamilton. Haven't sourced much yet, I'm mostly going to use the parts from my MakerGear Prusa Mendel to build this one, I was just starting to look around when I found your post and thought I'd better say something before it was too late.

As for hex screws, I've still got a few spare from the original build and some philips head ones from Jaycar.

So far the parts I do need to find (from a quick look at the dibond BOM) are star washers, wing-nuts, the polypropylene sheet, and I'm thinking about upgrading the power supply. I'm sure there will be more things needed come build time, but for now my biggest job is to start printing the plastic parts.

EDIT: Oh and I need to find the M4 grub screws

Edited 1 time(s). Last edit at 04/18/2013 12:17AM by King Sandvich.
Re: Mendel 90 - Anyone want dibond parts?
April 18, 2013 04:53PM
OK you could pick up the dibond if you're out this way, or I could courier it or something. Haven't ordered yet.

I got most of my fasteners from EDL except for the hex heads and M2.5 washers, I had to go to Atom fasteners for those.
You want to use hex heads where they're specified, otherwise there is no way to tighten them later in the build.

The polypropylene strip is just cut out of plastic folders I believe, the ones that have living hinges in them.

I don't have any plastic parts yet. I'm still trying to modify the scad files to match the GT2 belt I have, but I'm realising I know nothing about python...

Looking forward to building this Mendel90

Edited 2 time(s). Last edit at 04/18/2013 04:58PM by isolt.
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 12:52AM
Yea I make it up to Auckland on occasion, I would certainly prefer to pick it up rather than pay the huge amount couriers charge for rural delivery.

EDL and Atom, good to know, thanks! I'm still scratching my head as to why some of the bits and bobs on the BOM are needed, but I'm sure it will become clearer with time.

Folders, ha! Didn't think of that, thanks!

I've only just managed to get the scad file not to crash! Let alone editing it much. I'm planning on upgrading to GT2 belts too, what modifications to the design are you making for them? I cannot think of any reason for change (apart from perhaps a larger or second bearing for use as an idler).

I think this will be somewhat of 'figure it out when we get there' build in some regards for me as I will be mixing and matching a lot with stuff from my existing printer. If only a student budget could stretch to having two machines.

I take it you already have a printer or someone who can print the parts for you. Otherwise I'd be happy to help.
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 02:38AM
If you get the SCAD up and rendered it really helps, so does the build PDF.
I'm trying to edit the "belt.scad" under vitamins to add in a GT2 option.
Where the belts mate to the carriages there are matching teeth at 2.5mm pitch, If we stick our 2mm pitch belt in it wont match up very well and I'm worried it'll just catch on a couple of teeth.
I can edit the files OK, but can't manage to compile it. Maybe you could look into it as well?

How do you feel about red dibond? I'm getting a good price but the guy doesn't have many colours in stock.

This is my first printer, I know a guy who knows a guy who has one though, so he should be able to print me some bits. I'll keep you in mind though, thanks for the offer!

Ha I know all about student budgets, I'm impressed you have a first one!
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 05:29AM
Oh ok, I see what you mean. If you send the files over I can have a go at compiling it. For some reason python and openscad seem to be working much better on my old pc.

If that doesn't work I can import the standard parts into solidworks and modify them manually. Not the ideal solution, but it should work.

Red sounds good to me, I don't really mind what colour it is.

My first printer was a... challenge... but I'm feeling a bit more more relaxed this time around. I'm thinking I'll just start putting the frame and plastic parts together and gathering all the fasteners as I need them. Then, when I feel ready, I'll decommission the old printer and start installing the parts in the new one. For the moment my current printer is working semi-fine so I'm not in too big a rush.
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 06:29AM
Here's a zip with all the openscad as well as existing stl's
Looks like there is also a Prussa retrofit option, might be perfect for you.

You'll want to add a line to the belt like this I think
GT2 =[2.0, 6, 1.33];
then make a new "dibondGT2_config.scad" referencing the new GT2 belt. There's a bit of info in the read me.
Or just edit the existing T2.5 belt if you're lazy, might be easier.

I tried opening the parts in solidworks as I'm much more comfortable with it, but the STL's had too many facets and couldn't be imported as solids. Tried running them through meshlab and exporting as DXF's too, but the files seemed to crash on opening in solidworks.

Learning Soldiworks a? What are you studying? I did Product design a few years ago.
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 09:08PM
Yep, got the files already thanks. Prusa retrofit isn't really of interest to me, I'm keen on the whole mendel90 design, not just it's x-axis.

Ok I'll have a go at adding the GT2 belts today. I'll let you know how I go but I wouldn't get your hopes up too much, I'm still new to openscad.

I've managed to import the standard dibond x_belt_grip.stl into solidworks through freeCAD (only function of it I use), I'd rather get the scad working myself but if that doesn't work at least there is a backup option. I've attached it so if you want you can check it works for you too. Just let me know if there are any other files you want as solids and I'll post them.

I'm currently in my first year studying electronic engineering. One of my reasons for picking this was the fun I've had working on my current printer.
open | download - test.zip (144.4 KB)
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 10:15PM
Oh I thought the retrofit might be a model more suited to use Prusa parts, didn't really look into it sorry.

That file you sent works really well! FreeCAD you cay? You just open the part and export it as an .igs. I'll have to give that a go, couldn't find any solutions on the solidworks forums.

The parts we'll need to change are

Nophead's just said "Changing the belt and pulleys will also also affect the Y bar clamps slightly as they align the bars with the belt centre."
So fixing the SCAD sounds like the best solution if possible.
Re: Mendel 90 - Anyone want dibond parts?
April 19, 2013 11:25PM
I think I got the scad working with the GT2 measurements. I measured the resulting belt grip in solidworks and it says it has a spacing of 2mm. See attached dibondGT2 stls (including printed), sheets, and BOM files. Unless you consider it useful I won't bother with the 'render' folder, and it didn't gererate any 'manual' folder but we can just use the one from the 'dibond' files as they should be accurate for our purpose.

Here's how I convert a mesh to solid in FreeCAD:

1. In FreeCAD, click File>new on the top menu bar
2. Click File>Import and select your mesh
3. Select from the workbench selector drop down list on the main toolbar "Part" (default is "Start")
4. Select the mesh from the object tree under the projects tab of the left side pane
5. On the top menu bar click Part>Create shape from mesh...
6. Click "Ok" on the popup box (I use the default 0.10 but you can change this if you wish)
7. Select the newly created shape from the object tree on the left
8. On the top menu bar click File>Export...
9. Save the solid in the format and location of your choosing

Edited 1 time(s). Last edit at 04/19/2013 11:25PM by King Sandvich.
open | download - bom + sheets.zip (275.6 KB)
open | download - printed (part 1).zip (510.2 KB)
open | download - printed (part 2).zip (472.6 KB)
open | download - stls (part 1).zip (406.1 KB)
open | download - stls (part 2).zip (392 KB)
Re: Mendel 90 - Anyone want dibond parts?
April 21, 2013 01:33AM
If you haven't ordered yet, I'd be keen on a set of the dibond parts too. Red sounds dead sexy :-). I'm also near Hamilton, and have been gradually accumulating the parts for a Mendel 90 to replace my venerable Sells Mendel.Mostly there, just remains to sort out the fasteners and GT2 belts/pulleys (working on that with a friend who's doing a Rostock at the moment).

Re: Mendel 90 - Anyone want dibond parts?
April 21, 2013 02:29AM
Hey Lenbok. Ha small forum, just replied to your other post.
Haven't ordered yet as no one seemed in a rush, the more the merrier!
If you get stuck for belts and pulleys I ordered extra and could give you a good price on them.
As above ELD seemed to have most fasteners, and the others I got from a specialist here in Auckland.
I've still got a few things to get like smooth rod. I'm thinking building a hot end, so we'll see how that goes.
Re: Mendel 90 - Anyone want dibond parts?
April 21, 2013 04:07AM
Hi Lenbok, great to have another along for the ride! (and to know I'm not the only Hamiltonian(ish) RepRapper!)

Isolt, do you know if there are any other things in the scad that need changing? I added and used the GT2 belt measurements you posted but didn't change the pulley config. Off the top of my head I can't think why it would need to be changed but I'm still not fully familiar with how it all works together.

Also good luck with your hot end build! I've heard it can be quite frustrating at times, but I'm sure you'll get it done.

I take it that the files I posted earlier work ok for both of you? First time uploading multiple of files on this forum.

For those who may need them, GT2 belts/pulleys and some smooth rod (as well as a few more things) are available at: http://www.makershop.co.nz/
(just in case you didn't know already or for others who may read this later)
Re: Mendel 90 - Anyone want dibond parts?
April 21, 2013 05:17AM
Thanks for the files. I've since managed to get openscad working finally!.
Apparently the Dia of the pulleys effects their height in relation to the extruder carriage. If you use larger or smaller pulleys your belt loop may not be parallel. I'm not sure it that'll matter though.
I added in some GT2 pulleys and compiled some parts, I'll see if I can import them into solidworks and measure them against the originals.
Maker shop has a good range of parts, but $15 a pulley seems a bit steep?
I may just bite the bullet buy a Jhead. they're only about $80NZD. We'll see how busy I get
Re: Mendel 90 - Anyone want dibond parts?
April 21, 2013 05:27PM
Great to hear you got the scad to work! Could you could perhaps post the GT2 pulley measurements? I haven't yet been able to find all the measurements for it, and it would be better to have things parallel as you say.

Yea $15 might be more than what is available overseas, but its the only local place I know of that has them, and I do like the idea of supporting the local RepRap community.

If your looking for a cheaper hot end, this may be worth a look: http://diamondage.co.nz/?wpsc-product=hot-end-kit
(might need to add some insulation though, perhaps polyamide tape (aka Kapton tape)? (need that tape anyway, good stuff))

I would also recommend trying to track down some Acme threaded rod for your z-axis. My kit came with a pair under the heading "experimental" and after switching to them after using a pair of M8 rods, I must say they are nice. The main benefit is in that they are designed for powering (pushing and pulling things) unlike the M8 threaded rod which is to my knowledge designed for fastening (hence why they are used to make the frames of most RepRaps). Of course this is of a different diameter so will probably require another change to the scad, the location of which I have yet to find. Found it, it's simply a diameter value in the machine config.
They are rather hard to find machined couplers for however, but there should be some machined ones on http://www.aliexpress.com/

Edited 2 time(s). Last edit at 04/21/2013 05:32PM by King Sandvich.
Re: Mendel 90 - Anyone want dibond parts?
April 21, 2013 06:28PM
I measured this off the ones I have, they may be slightly different than yours. As long as they're 20 tooth geometrically they must be the same, and the length could always be compensated for.

GT2_metal_pulley= ["GT2", 20, 12.35, 12.35 / 2 - 0.6, 8, 12.65, 6.3, 5, 16.0, 1.5, 4, 3.75, [0, 0,1.3], 0, M4_grub_screw];
Edit: having second thoughts about this variable.
I fudged the last few variables as I don't know what they are. They seem to mostly relate to the tapped hole, so shouldn't effect the model for our purposes. I left offset the same as a T2.5, I think it's just how far off the motor body the pulley is.

Hmm I have been considering some rods more suited to driving things. I'll have to think about it more.
What do the "nuts" look like on yours? The Mendel90 seems to be set up to take a hexagonal brass nut and the acme shafts I've seem have a large carriage.

Edited 1 time(s). Last edit at 04/21/2013 06:55PM by isolt.
Re: Mendel 90 - Anyone want dibond parts?
April 22, 2013 04:34PM
OK there's enough dibond for 3 sets in red.
Can you guys confirm you definitely want a set so I can order?
I was going to take the holes out for Melzi as we're probably using different electronics. I could put in some holes for a mega, or just leave it blank for people to drill themselves.
Re: Mendel 90 - Anyone want dibond parts?
April 23, 2013 12:30AM
Thanks for the pulley measurements. I found the tooth depth online as 0.75mm so I used that and the diameter/length dimensions of the Makershop pulley to end up with:
GT2_metal_pulley= ["GT2", 20, 12.35, 12.35 / 2 - 0.75, 8, 18, 8.5, 5, 18.0, 1.5, 4, 3.75, [0, 0,1.3], 0, M4_grub_screw];

I also added the Acme nut (near identical to M8 but differing ID):
ACME_nut = [6.35, 15, 6.5, 8, M8_washer, M8_nut_depth];

And changed the z-axis rod part of the dibondGT2 machine config to:
Z_screw_dia = 6.35;
Z_nut_radius = M8_nut_radius;
Z_nut_depth = M8_nut_depth;
Z_nut = ACME_nut;
I don't think it will change the sheets so there shouldn't be any problem with us using different rods.

As we will all probably be getting our filament from Diamond Age, seeing as they are the only ones in New Zealand that make the stuff, I would suggest we use the measurements of their 1kg spool for the spool holder (unless you intend to buy the 500m spools but at $160 each I would think that unlikely for a hobby machine). I measured the ones I have and added it to the spool scad:
spool_205x60 = [205, 60, 48, 2, 5, 34, 100, 100];
and changed the corresponding line in the dibondGT2 machine config to:
spool = spool_205x60;
Do you two agree or disagree to the change? Thoughts? (assuming we all have to order the same sheets)

Yep, I'll confirm I'm ordering a set. How would you prefer I pay?

I'll be using my mega so that hole config would be preferred, but I'm happy to drill my own if needed.

Edited 1 time(s). Last edit at 04/23/2013 06:33AM by King Sandvich.
Re: Mendel 90 - Anyone want dibond parts?
April 23, 2013 04:45PM
Good work with the SCAD'n. I'll stick with the threaded rod to start with, upgrade later if I want to. I think I just need to actually start with something rather than trying to achieve the best and never start.

Ah great I was wondering what size spools Diamondage had. Does that spool change effect the dibond parts, or just the spool holder parts?

It'd be easier if the dibond parts were all the same, otherwise there might be more set-up fees and such.
Re: Mendel 90 - Anyone want dibond parts?
April 23, 2013 05:38PM
Fair enough, the normal threaded rod should do the job nicely. Might pay to put a drop of 3-in-1 oil on them occasionally though.

Changing the spool size seems to change both the printed parts and move the location of the bottom spool bracket hole in the dibond down. I'm not sure exactly how well the 1kg Diamond Age spools would work with their thick card stuff rims instead of the plastic rims the holder seems to be designed for, but it's worth a shot. Otherwise it's just going to be in a size that's near useless to us anyway.
Re: Mendel 90 - Anyone want dibond parts?
April 23, 2013 08:52PM
Yep, confirming I'm in. I got the payment info in your PM, will do it soon.

I'll be using RUMBA electronics, so would prefer if we drill our own electronics mounting holes.

I currrently use an external spooling system, which I will probably stick with for now anyway. Presumably it only affects holes for spool bracket mount and the printed parts for the spool holder itself. The rest of the printed parts shouldn't change?

Re: Mendel 90 - Anyone want dibond parts?
April 23, 2013 09:04PM
Yep, I'm fairly certain it only affects the spool related parts.

RUMBA eh? Nice. I'm envious of your triple extruder support!
Re: Mendel 90 - Anyone want dibond parts?
April 25, 2013 04:17PM
Hey just been emailing Vik, he's got some all plastic spools that are "100mm centre hole which are about 280x100mm"
He'll give them to us at $3 a piece.Interested?
I'll try making some new DXF's this weekend to suit, want to have a go as well? Then we can compare and make sure I'm not messing up.
Re: Mendel 90 - Anyone want dibond parts?
April 26, 2013 03:19AM
The plastic spools are a good idea and would work better, but I think we could get away with not using them. The rims of the 1kg spool might not be plastic but they should be strong enough to work. That would avoid the extra cost and having to rewind all 125 meters off one spool and on to the other. It's a shame the rolls of plastic sold without spools wouldn't easily fit as they are rolled with a diameter of around 200mm.

Up to you. I'd prefer to use the 1kg spools but I'm flexible.
Re: Mendel 90 - Anyone want dibond parts?
April 26, 2013 06:13PM
I'm looking at building a Mendel90 at some stage (would be my first printer) but not ready yet. Can you tell me a bit about who is able to supply and machine the Dibond material here in NZ? I did a quick search online but didn't turn much up on Dibond locally.
Re: Mendel 90 - Anyone want dibond parts?
April 28, 2013 12:49AM
Hi danz. Looks like mende90's are popular.
In NZ people tend to call it ACM or aluminium composite material.
I'm getting mine cut at Creative Cam
But any sign making place should stock it and be able to machine it.
If you need help sourcing any other parts here's probably a good place to ask as we're doing the same thing.
Re: Mendel 90 - Anyone want dibond parts?
April 29, 2013 06:53PM
Thanks for that info. I see it is available in 2,3 and 4mm thickness and the aluminium surface also varies in thickness. What specification did you go for? I assume the thicker the aluminium surface the better. Were you able to get the colour you wanted on both sides?

The Mendel90 didn't grab my attention initially but I found I kept coming back to it due to the inherent structural rigidity of the design. If you want a reprap with parts that are relatively easy to obtain, accessible design with rigidity in the right places I reckon it's hard to go past it.
Re: Mendel 90 - Anyone want dibond parts?
April 29, 2013 07:30PM
The kits use 3mm, if you wanted to use anything else you'd have to edit the scad. I imagine it'd only be screw lengths that change though.
Yeah a thicker Ali surface couldn't hurt, to be honest I didn't really know it varied. I was able to get red on both sides, but most of the other options were just coloured on one side. If you're willing to pay they could probably get in anything you want, I just went for something in stock to keep costs down.
I chose the Mendel90 after looking at nopheads blog and being impressed with the amount of work he'd put into it and his systematic approach to design.
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