Designing an Aluminum Y-carriage

Hi guys, I'm currently in the process of designing my own Y-carriage.

Before I've made the same kind of thing by hand, but the machines I use (plate cutter etc) tend to deform the aluminum slightly so now I'm going to make a design in Illustrator and have it cut out by a laser cutter somewhere later this week.

I am very open to any comments, and advice on the design.

The carriage is made with two plates of aluminum, the bottom one has holes in it to lower the total weight, in respect to it's flexibility/strength. The small holes are 3mm holes, in which spring-loaded M3 bolts are placed (maybe I'll make it 4mm and M4 bolts, still not decided on that one yet).

The top plate is the exact same outer shape, and only has the four holes in the corners and the heated plate will be pushed against the top plate by the springs. So the springs have a double function.

The springs give:
- Easy leveling (only need to do this once and every time I replace the Kapton!)
- Nozzle-crash-protection (however I am also using the Prusa i3's vertical X-construction, so it's already pretty safe)
- The springs push the heatbed onto the bottom of the top aluminum plate, the plate that functions as the print-surface

Included in this post is a screenshot of the bed with measurements.

The thickness of the aluminum will be 6mm for the bottom plate and 4mm for the top plate (or maybe even 4mm for the bottom one and 3mm for the top one).

The heated bed that will be used in this setup is:
[gadgets3d.com]

Now note that this carriage is specifically designed for a MendelMax 1.5 where the smooth rods for the Y-carriage are 100mm apart from eachother heart-to-heart.

With love,
Marinus



Edited 1 time(s). Last edit at 07/24/2013 08:47AM by Ohmarinus.

Hi Marinus,

On my first Prusa printer I was forced to redesign the X and Y carriages due to breaking the plastic bits - and my wish to use LM8UU bearings instead of the printed PLA parts. As a consequence I ended up with very heavy aluminium X and Y carriages - and have been trying to keep to this rigidity while reducing the mass as far as possible.

One idea that i have come up with for my latest X carriage may be useful. In the pictures below I have mounted LM8UU bearings in a milled recess in a 2mm hard aluminium plate. Almost all forces are taken out in the plane on this part: Forces in the Y plane are almost non existant and the inertia of the more massive parts is carried cleanly to the bearings. The result is a carriage which weighs a little over 300 grams with extruder and hot end.


The recess is chamfered so that the bearing is located against a surface and ont on a corner. It was also useful to chamfer the holes for the cable ties so that they would not jam while being pulled tight.

My Y carriage is still little more than a trinkle in my eye, but will probably have three sprung adjusters between the carriage and the heat spreader plate - and these adjusters will be as close as possible to the three (only) bearings on the Y shafts, thus dispensing with all of the mass outside of the bearing mounts. I use 2mm aluminium for the top plate and rely on it and the glass build stage to be as flat as needed.

Hi LL, thanks for your reply. I like the chamfered recesses, however, planned to used a lasercutter instead of a mill because I have a lot of experience with that and it has no hidden problems for me that I need to be aware of.

Second to that, I have to design custom bushing holders, because I have bought Hard-Chromed rods and really nice linear bushings that are much smaller than LM8UU bearings (this is easy for me to design as I already have the required files ready with exact tolerances when they come out of my current printer).

And third, I cannot have the bushings sit on the surface directly below the aluminum plate, it is like this because the Chromed Rods for the Y-axis are embedded a bit into the machine, therefor I have to raise the platform a cm or two above the top of the rod so the platform doesn't hit the aluminum extrusions of the machine when moving to 0,0 and 200,200 etcetera.

See the picture for an explanation

However, I am doubting, if there maybe is a better way to connect the smooth rods, because it would be better to have the carriage as close to the bushings as possible.

In the process of designing my own printbed/Y-carriage, I have found out that using two aluminum plates makes the carriage virtually warp-resistant.

When looking at others' designs, I have found out that a lot of people are using 6mm thick aluminum plates, however, my findings are that 4mm for the bottom plate (with holes in it to make is lighter) and 3mm for the printing surface, is more than enough to maintain a flat printing surface that doesn't warp or go out of calibration.

The design I have come up with, loses a bit of Z-height in the process, but the bowden extruder system will completely solve that problem and give back a bit of that precious height.

I am still strugging with the design of my X-ends and carriage.

ps, it's so not funny to see almost NO companies do lasercutting for non-companies, or they ask a substantial amount of gold/money for a small order And the companies that are available are all closed until half of August! I don't have time to wait more than half- a month for this part... What kind of world are we living in? Or maybe it's my shitty country (The Netherlands) that always tries to ruin my fun. Hell, the hardware stores in my country don't even sell normal 4mm inner-diameter tubing. Eventually I found it in an animal store where they use the tubing for fish-tanks to hook up the water-pump.

Edited 2 time(s). Last edit at 07/25/2013 10:03AM by Ohmarinus.

sometimes simple is best. i would think that aluminum is light enough to not need to cut out the pattern.

Maybe a stupid idea, but what about Dibond? If I remember correctly some people make Mendel90 builds with it. It's two sheets of aluminum 0.30mm thick with a solid polyethylene core. Being laminated a panel is very rigid and light. No need to make cutouts.

But availability in Europe may be an issue.

Okay, i'm pissed and swearing out loud.

Just for two lasercuts panels in 219x219 in 3mm and 4mm, I get quotes of 80 euros ex taxes (so that will be around 100 euros and probably like 110 with delivery cost).

All in all this would mean it cost me $146.06 to have two small panels lasercut.



Impossible, I know, I'm 29 years old but I feel like a six-year old swearing at the world saying everything is unfair.

The deal is, they must have a minimum order charge. You are asking for a very small custom order.

I work for a manufacturer, we purchase a lot of lasercut sheet metal from a supplier, and their minimum charge is $125 CAD.

Just think of the time needed to process your order. Then a technician will take your DXF files and use software to generate gcode for the laser cutter. The same guy or someone else will operate the laser cutter. Then it will be packaged and shipped. These people have to get paid you know!

Now ask for a quote on 10 or 50 pieces of each. The price per unit will be a LOT cheaper. Sorry but that's how things work in manufacturing!

If you fined a nearby hobbiest of the model engineer type who has a fretsaw (U.S. scrollsaw) then I daresay they would cut it out for a pint of beer. A good fretsaw will cut without distorting the metal and can easily handle aluminium up to ca 10mm.

Mike

Hi Mike Thats great. BUT....

My country (The Netherlands) is a weird place.
The Hardware shops here only have small selections of materials and tools for example. When you're looking for a specific item it soon is a quest that moves to Germany/UK/US because a lot of manufacturing companies simply don't want to deal with non-companies, and hardware stores usually only sell a few popular brands.
My favorite hardware store in my town even doesn't have tubing of any diameter! How is that possible? They just don't sell tubing. And I pay around 4 euros for a bolt that I can order from another shop somewhere in germany for around 50 cents per bolt. The hole 'way things work' in my country when you're a hobbyist makes me seriously doubt if I even want to live here.

Not ready to move out yet, but since I know my languages well it is tempting, the problems I'm encountering in finding things I need shine a new light on how things work around here (also in my study: Architectural Design, we need a lot of materials that are easy to get in other countries, but in my country are treated like they are made of gold and are very special items etc etc etc blablabla).

I have everything ready, the DXF file has a green light, all it needs is to be put in the software and machined.
The companies I've contacted all say on their websites that their laser-cutting machines are specifically great for smaller orders because there is less preparation time. But then, when I get a quote it's not like they advertise and when I point that out to them they don't answer anymore.

It's unfair.

Meanwhile I've moved my focus to just getting a few aluminum plates cut in 219x219 (2 plates of 2mm and 2 plates of 3mm) and I will manually drill the holes needed in the plates on the right spots because four plates will cost me around 10 euros and the rest I'll have to do manually. It may not look as good, but it doesn't make much difference and I get the feeling I can never ever go that extra length to make something really nice because I would have to sell a kidney to be able to afford it all

So it was nice to fantasize about developing this laser-cut aluminum design and working on it for hours and hours, measuring, drawing, re-measuring, checking, drawing, sketching etc for nothing. I learned something from it. But now I'm just going the easy way.



leadinglights Wrote:
-------------------------------------------------------
> If you fined a nearby hobbiest of the model
> engineer type who has a fretsaw (U.S. scrollsaw)
> then I daresay they would cut it out for a pint of
> beer. A good fretsaw will cut without distorting
> the metal and can easily handle aluminium up to ca
> 10mm.
>
> Mike

so be smarter.

go to shop, ask for samples, tell them if they are good you will order large quantity, and they will be for free....simple

I hear what you are saying about companies that are unwilling to do business with individuals. While much of the U.K. is becoming O.K. with this*, some companies which are pushing their commitment to the new 3D community will still not do business with the same individuals who are driving it. I am particularly thinking of Igus which won't do business with individuals, and also the upcoming TCT/Personalize show which requires a company name if you try to register.

Mike

* As long as minimum order quantities are large enough.........

'so be smarter' ...?

- Dumb comment
- Use capitals at the beginning of a sentence, and a dot on the end (and no, lists don't need to be ended with a dot)
- 'simple '?

I am not the kind of person to fake as if I'm interested in a companies product as a big buyer and then get freebie samples and stuff, come one, thats not very honorable.

Look, I don't mind you giving me advice, but if it's like a somewhat childish reply I feel insulted for I am seriously agitated by the way everything is going when I am trying to fuel my hobby so I don't need these kind of replies (and maybe I'm a bit too much of a serious person, but thats my problem ).

Anyway, it's not that easy, there is no shop within 200km radius or something where I can just walk in and ask for samples. Most of the companies are only reachable through the web of have a machine-park somewhere far south or east and I don't have a car and public transport will cost me more than the thing I'm trying to have them make for me so it's useless




woo Wrote:
-------------------------------------------------------
> so be smarter.
>
> go to shop, ask for samples, tell them if they are
> good you will order large quantity, and they will
> be for free....simple

Have you tried eMachineShop? Here is a link to their site:

[www.emachineshop.com]

They can do laser cutting, CNC milling, water jet cutting, etc. And they specialize in low volume, low cost (kind of like Shapeways). I've never used them, so I don't have first-hand experience with them.

Hey thanks

Their software is only Windows though (I'm on a mac).

And I've decided to go ahead and make my heatbed the old-fashioned way.. By hand!
Just making two square 219x219mm pieces in aluminum and putting springs in-between.

it's cheap, easy and still proven to work flawlessly (my Reprap Air 2 is also sporting a similar design and ever since I have it like this, I have never had to calibrate the Z-height anymore).

From the 35 companies I've emailed, only eight have replied of which only one gave me a price estimate...




JohnSL Wrote:
-------------------------------------------------------
> Have you tried eMachineShop? Here is a link to
> their site:
>
> [www.emachineshop.com]
>
> They can do laser cutting, CNC milling, water jet
> cutting, etc. And they specialize in low volume,
> low cost (kind of like Shapeways). I've never used
> them, so I don't have first-hand experience with
> them.

Quote
Ohmarinus
From the 35 companies I've emailed, only eight have replied of which only one gave me a price estimate...

And that estimate was fair considering, as I told you but you ignored my response and chose to stay in your little reality distorsion field.

Ah, that would be an issue unless you have something like Parallels on your Mac. Here is another option, which is probably a little more expensive, but still perhaps cheaper than the quotes you got:

[www.quickparts.com]

They have both CNC machining and also sheet metal operations. And you just upload a file to get a quote, so no special software required. I used them many years ago for some 3D printed parts, before ShapeWays and personal printers existed.

Unless Quickparts have an European workshop from which they can produce and ship, Marinus will get hammered by customs fees and international shipping. But this looks to be located in the USA.

Still it may be worth to check it out, if cheaper all his hard work won't go to waste.

Edited 1 time(s). Last edit at 07/26/2013 03:11PM by NormandC.

I didn't tell you the whole story.

I've had much better offers, but when they found out I wasn't a company they showed me the door.
~30 euros was the best offer, they told me 30 euros because the DXF file was correct and they would only charge me for aluminum and cutting time, their minimum price was 25 euros, but mine took longer than their minimum.

Anyway, I've been trying to get a part lasercut before (different thing) and there were companies offering me between 115 (which was a reasonable price) and 365 euros (which was crazy).





NormandC Wrote:
-------------------------------------------------------
>

Quote
Ohmarinus
> From the 35 companies I've emailed, only eight
> have replied of which only one gave me a price
> estimate...
>

>
> And that estimate was fair considering, as I told
> you but you ignored my response and chose to stay
> in your little reality distorsion field.

Quote
ohmarinus
it's so not funny to see almost NO companies do lasercutting for non-companies, or they ask a substantial amount of gold/money for a small order.

There's nobody to do your project for cheap because it's not cheap to run a laser. Find a shop that has a plasma cutter.
( Edit; Gold!!! Classic)

Quote
NormandC
Maybe a stupid idea, but what about Dibond?

I'm surprised there's not more people using it too.

Quote
CHIMPANZEE
Not ready to move out yet, but since I know my languages well it is tempting,

I don't know if I'm doing the math right, but paying shipping from China or wherever, is more expensive than moving to Berlin?

Quote
NormandC
And that estimate was fair considering, as I told you but you ignored my response and chose to stay in your little reality distorsion field. eye rolling smiley

Reality distortion fields are a tricky lot. Aren't they ?

Ohmarinus,
Dude, the global economy is tricky, but I'm pretty sure you don't have to move to get what you need. Get a drill press, get a mill, get some aluminum and have at it.
If not find a plasma cutter. I don't know much about Europe, but there's bound to be tons of shops that'll make it for not that much money.
Cheers,
ohioplastics
Edit; Look at water jet cutting too.

Edited 2 time(s). Last edit at 07/26/2013 11:18PM by ohioplastics.

At my previous job for a medium-size manufacturer the shop had pretty decent machinery. We had an Amada laser-cutter/turret punch hybrid (something like that), very versatile but the laser was too weak to cut through aluminum (it could cut through 12GA/2.77mm #304 stainless steel or 5/16"/7.92mm steel plate). Problem with aluminum is refraction I believe. I have no idea how much the machine cost at the time but it must have been between $500k and $1M with tooling. I think it was costing $150/hr to operate.

So a laser that can cut through 4mm aluminum will have to be more powerful. Such a machine couldn't cost less than that hybrid we had. Imagine how many 80€ jobs it takes to pay the mortgage on that machine.

As for businesses not wanting to deal with individuals... I am on the other side of the fence, even if now I don't need to bother with stuff like quotes and customer service anymore, dealing with individuals is totally different from dealing with companies that will hopefully be returning customers. Much less of a hassle, bigger orders, less risky payments...

Yes, for an individual such as you it sucks, but that's the way it is, and not only in the Netherlands.

If we were in the same country (or heck, same continent) I would offer you to purchase the plates through my current employer's supplier. As an employee I can do that. But I'm pretty sure the price would be in the same bracket.

Edited 1 time(s). Last edit at 07/27/2013 02:36AM by NormandC.

I had a similar problem when designing my machine.
I overcame it by laser cutting a lower plate from 3mm aluminium with an upper plate of 3mm aluminium.
The two plates are connected together with silicon rubber donuts rather than springs. The donuts allow the small amount of movement needed, allow the bed to be adjusted very easy and is very rigid when printing.
The LM08 bearings are mounted to the lower plate with some printed standoffs. The upper plate has a silicon rubber heat pad attached.
The print surface is a sheet of 3mm glass.
All works very well and is simple to do. Check out the photos below for some ideas of what I have done.

photo1
photo2
photo3
photo4
photo5

Hope it gives you a few ideas.

Cheers,
Reg

Awesome, I managed to get the job done for 20 euros!

Don't know how I did it, but I am very happy.

Tomorrow I'll hear when it will be delivered so I'll post pictures when I receive the package

Hi Marinus,

How did your aluminium Y-carriage work out?

I ask because I have moved on from my aluminium X carriage and am starting to put together an ultra light Y carriage for my Prusa. The X carriage with extruder and hot end weighs slightly less than the ABS version that it replaces and is about 3 times as rigid - measured with a spring balance to load in the working direction and a DTI to measure displacement. I am hoping for results as good with the Y carriage.

On the Y carriage, I have dispensed with the glass plate, replacing it with a 2mm aluminium plate which is clipped to the FR4 heater. The heater is mounted to the main Y carriage by a triangle of 3 sprung adjusters and 3 pins, the pins fitting snugly into nylon bushes to provide X and Y stability. I have kept the adjusters very close to the bearings on the bearing mounting plate - which is just another piece of 2mm aluminium.

I have attached a photo of my new heater, along with a drawing of the tracks. This is laid out as a Hilbert Curve in order (hopefully) to prevent diferential heating in the X and Y directions from bendint the plate while it is heating.

Mike