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Aluminum Sheet Between Heater and Glass

Posted by Shachar85 
Aluminum Sheet Between Heater and Glass
November 16, 2015 05:43AM
Hi

I'm in final stage of developing a printer - Buying stuff.
I want to buy an aluminum sheet - 3mm thick.
Silicone heater will be attached underneath it and 3mm glass above.
Printing area = 200*400

I've heard that the aluminum plate must be milled.
Now, the plate 400*230 is expensive and hard to find to begin with. Milled....much worse.

My question - if I put a glass on top - Is it still important to get a milled sheet? What happens if I don't?

thanks
Re: Aluminum Sheet Between Heater and Glass
November 16, 2015 05:59AM
The problem is getting an aluminium sheet that is flat enough. For a small bed, you may get away with ordinary aluminium sheet. For a large bed such as yours, it's better to buy an aluminium tooling plate to make sure. It needn't be expensive, for example I found I can get a 400 x 200 x 6mm Ecocast tooling plate for £15.90 + VAT.


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Full disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: Aluminum Sheet Between Heater and Glass
November 17, 2015 02:11AM
Thanks for the answer.
The thing is I can't get such a price over here.

If I have no other choice - I'll buy a tooling plate, but I wonder what happens if I use regular plate?
I'm not going to print on it - It's just a buffer. I print on a glass, which will flat for sure.
Re: Aluminum Sheet Between Heater and Glass
November 17, 2015 04:56AM
If you go for a thinner plate and thicker glass e.g. 2mm alu and 4mm glass then it should work. If the alu is slightly bowed, put the convex side against the glass, and the bed clips will hold the edges against the glass.


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Full disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: Aluminum Sheet Between Heater and Glass
November 17, 2015 05:40AM
That's great

Could you tell me a bit of the theory behind the answer?
Re: Aluminum Sheet Between Heater and Glass
November 17, 2015 05:49AM
The idea is for the glass to provide the stiffness and the aluminium to bend to match it.


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Full disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: Aluminum Sheet Between Heater and Glass
November 17, 2015 05:51AM
Thanks again for all the answers.

I hope to post some photos as soon as the printer is assembled and printing
Re: Aluminum Sheet Between Heater and Glass
November 22, 2015 05:59PM
Many printers have large beds and don't use special bed

I would use:
base plate --- silicone insulator --- heater --- thin aluminum -- glass.


ie: Aluminatus TrinityOne

[www.3ders.org]

Print Bed:

The Aluminatus TrinityOne ships by default with a true Borosilicate print surface as well as a kapton heating element that allows for printing of PLA, ABS , resins and other types of plastic.

The print surface has a 290mm x 290mm 24V, 200W kapton heater installed under a 300mm x 300mm aluminum heat spreader. The entire assembly is supported by a G10 and Aluminum Y platform machined for a light-weight and rigid/aligned print platform that hardly needs to be leveled.



confused smiley
Re: Aluminum Sheet Between Heater and Glass
November 22, 2015 06:52PM
I don't get it. Everyone knows you need a flat surface to print reliably, yet so many keep buying thin, flexible aluminum and then put glass on top of it. Why do people keep buying the thin, flexible aluminum? It makes no sense. Why not just get a flat aluminum plate such as cast tooling plate in the first place and be done with it? Unlike galss, aluminum is thermally conductive so the temperature will be even across the surface and you won't have print adhesion problems. Surely the cost of a thin flexible aluminum plate, plus glass to fit, and the goop you're going to have to slather on to get prints to stick can't be much less than the cost of a piece of cast tooling plate. We're talking about a few dollars/euros here, not hundreds. Are the few dollars/euros you save worth all the screwing around to find a magic formula to try to get your prints to stick?

Since you're developing the printer yourself, I advise you to try out a 3 point leveling system. When you level the print bed you're adjusting it so that it lies in the XY plane defined by the printer's guide rails. It takes only three points to define a plane. The typical 4 corner "leveling" system bends the bed plate and the undercarriage. You can't level a bent plate, neither can autoleveling. With enough screwing around you may get the center of the bed flat/level enough to print on but you aren't likely to be able to use the entire bed. The further you get from the center the worse it will get. Auto leveling assumes that the bed is a plane so its not necessarily going to help.

Here's a 250 mm diameter ABS print on my 317 x 305 x 6.35 mm cast tooling plate bed supported by a three point leveling system:


I have never seen anything of similar size done on a thin piece of aluminum with a glass plate and a 4 point leveling system.

What's the point of building a machine with a 200 x 400 mm bed if you can't print on the entire surface? The thin aluminum/glass/4 corner leveling is done in cheapo (and some not so cheap) printers because it is a couple dollars/euros cheaper than doing it the right way, or the "designers" don't know any better. The whole point of developing your own printer is to do something better than you can get elsewhere. If you're just going to copy their mistakes, just get one of those cheapo kits and save yourself a lot of trouble sourcing the parts.

Edited 2 time(s). Last edit at 11/22/2015 07:30PM by the_digital_dentist.

Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
November 23, 2015 03:20PM
Can you provide link / price for 16 x 9 inch aluminum flat tool plate?

What are the flatness spec on your printer bed?

Tnx

confused smiley
Re: Aluminum Sheet Between Heater and Glass
November 23, 2015 03:54PM
Places like Speedy Metals and any of a dozen other on-line metals dealers will cut any size you want. My 12.5 x 12 x 1/4" plate ran about $40. Try:
[www.onlinemetals.com]
[alcobrametals.com]
[www.speedymetals.com]

Speedy Metals has a 12" x 18" x 1/4" plate for $57. If you don't want to cut it, they'll cut it to the exact size you need for a few $ more.

Search google for "cast aluminum tooling plate", "cast jig plate", etc.

Alcoa's MIC-6 spec says flatness is within 0.015" on 1/4" plate, but that's over a 36.5" x 96.5" sheet. Smaller pieces are much flatter.

Here are videos that demonstrate the level/flatness of my printer's bed along with sag/misalignment in linear guides and supporting structures, etc.:

unheated flatness test

heated bed flatness test

note: the gauge is reading in 1/100th of a mm (10 um in the rightmost digit). The heated (105C) bed flatness test may be off a bit- the longer the probe stays in contact with the heated bed plate, the more negative the readings become. I don't entirely trust the readings toward the end and think the bed is flatter than it reads. I should rerun the test going in the opposite direction to check it. Regardless of what the gauge reads, the bed is flat enough to print almost edge to edge.

I would love to see similar measurements done on the typical thin aluminum/glass/4 point leveling scheme bed.
'

Edited 3 time(s). Last edit at 11/23/2015 08:04PM by the_digital_dentist.

Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
November 23, 2015 05:48PM
Very nice!

The Modified MegaMax is marching along in modifications and upgrades

Perhaps Shachar85 should consider PIR (polyisocyanurate) foam print bed?

See:
Alternative Print Bed at [mark.rehorst.com]

Have Phun

confused smiley
Re: Aluminum Sheet Between Heater and Glass
November 23, 2015 10:02PM
Anyone knows a decent place to obtain a 14.5 x 14.5 inches tooling plate in Canada?.. Those mentioned above stores quote me from $180 to $350 for that! That's... not even close to $40 mentioned by digital_dentist.
And does precise thickness really matter in case I wish to use 0.8 mm nozzle? Will a plain 1/4" piece of sheet aluminum do?.. I can get it in my town for ~$30.
Re: Aluminum Sheet Between Heater and Glass
November 24, 2015 05:27AM
1/4" extruded aluminum sheet that is 18" wide will be bowed. The metal grains tend to orient themselves along the direction of extrusion, so when it heats it will expand unevenly.

At 18" x 18" the expansion (tooling plate or not) may be a problem depending on how you mount it. You can expect about 1 mm expansion at 3D printing temperatures. If you're putting it into a machine in which the bed moves in the Z axis or not at all, it will be easy to deal with expansion- just put flat magnets on the bottom of the plate to hold it down. In a machine in which the bed moves in the Y axis it will be a little more of a problem to design a mount that controls its movement, levels it, yet allows it to expand.

Here is a picture of a piece of 12" wide x 1/4" thick extruded 6061 aluminum plate that I originally purchased for my printer about 3 years ago, before I knew that tooling plate exists. After I saw the curve in this plate I did what many people do and got myself a piece of glass to print on- hey it was cheap and I didn't know any better! That was a disaster for all the normal reasons- not very flat, uneven heating, etc. Once I learned about tooling plate, I ordered a piece and never looked back. Since then I have been extoling the virtues or cast tooling plate to a mostly deaf audience. It's sad how the small difference in price between a cast plate and everything else can close people's ears.

What you're seeing in this picture is a steel ruler stood on edge across the width of the plate. The gap under the ruler at the center of the plate is about 2 mm. Good luck printing on that!



Ebay is chock full of cast tooling plate cut-offs for very reasonable prices. Here's a shopping tip: if it isn't called "cast tooling plate" or "jig plate", or "MIC-6" or similar descriptive term, you can't count on it being flat.
Here's a 12 x 12" plate for $40 shipped: [www.ebay.com]
Here's a 24 x 24 x 3/8" plate for $160 shipped. [www.ebay.com]
If you're going to build a quality, custom sized printer, you're going to have to put in a little effort (and spend a little money). It took me all of 30 seconds to find those listings.

I've seen people justify their cheapness by saying "the surface of the aluminum is too delicate so it has to be 'protected' with a piece of glass". I think someone in a $300 printer company marketing dept came up with that idea. What happens to glass when you stress it in the way that scratching a piece of aluminum would? It breaks in tiny shards that get into your bearings and if you're lucky, don't cut you during the clean up process. What is the consequence of scratching aluminum? Zero. You're going to put kapton tape, or PEI, or PET tape, or painter's tape on it. The tape covers scratches and they never appear in the print. My bed has several scratches from head crashes, etc. when I was first setting up the machine and controller board. They are of absolutely no consequence.

Then there's the "factory production" argument. "With a glass plate I can take it off the printer and put on a fresh piece of glass and start printing again right away." I print almost daily and have never felt the need to produce prints so fast that I need to swap plates out to print the next part. If you're depending on your printer to earn your living, you'd better invest in multiple printers or step up your marketing program and select your paid print jobs more carefully. You can print $10 doodads all day long and make about $10 by the end of the day or you can print skulls or other body parts that sell for $500 each (or more) for surgical planning. Of course, if you want to do that sort of work, you'll need a very high quality, very reliable printer even to start. The few $ you may save by making your printer look like its capable of large, high quality prints vs the few $ extra you'll spend making it actually capable of large high quality prints can mean the difference between eating instant Ramen and a steak dinner.


Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
November 24, 2015 02:29PM
I hear you, dentist. I am still struggling finding it though, and that's not because I am dumb or am ignoring your advice. Apparently, situation is a bit different over the border: the listings that you've provided do not ship to Canada, my "local" "dealer" is located 4 hours of driving away and wants me to pay 250 for a scrap he has and 350 if he cuts it for me, Canadian ebay starts the prices with 250$ tag without shipping included. Shipping from most of the companies located in US requires some sad stuff like brokerage, GST, VAT, WTF and whatnot. Price is getting prohibitive pretty quickly.
Funniest thing ever: I wanted to print over PIR foam as someone advised to avoid that situation with tooling plate alltogether, but guess what? There are no suppliers of PIR foam around me in 250 km radius. Man, that's just depressing. I know, I know, I shouldn't have build a printer this big in the first place.
Re: Aluminum Sheet Between Heater and Glass
November 24, 2015 05:16PM
If I bought a plate or some PIR for you
Would the Canadian Mounties track me down?
or
track you down for accepting contraband 3D printing material?

confused smiley
Re: Aluminum Sheet Between Heater and Glass
November 28, 2015 05:12PM
Quote
toxuin
I hear you, dentist. I am still struggling finding it though, and that's not because I am dumb or am ignoring your advice. Apparently, situation is a bit different over the border: the listings that you've provided do not ship to Canada, my "local" "dealer" is located 4 hours of driving away and wants me to pay 250 for a scrap he has and 350 if he cuts it for me, Canadian ebay starts the prices with 250$ tag without shipping included. Shipping from most of the companies located in US requires some sad stuff like brokerage, GST, VAT, WTF and whatnot. Price is getting prohibitive pretty quickly.
Funniest thing ever: I wanted to print over PIR foam as someone advised to avoid that situation with tooling plate alltogether, but guess what? There are no suppliers of PIR foam around me in 250 km radius. Man, that's just depressing. I know, I know, I shouldn't have build a printer this big in the first place.

I feel your pain, I've been running into the same problems. I used to ship most of my metal over the border from onlinemetals, but it was always horribly expensive and with the exchange rate it's just got down right painful. I've been trying to make do with what I can get from Lowes and Princess Auto, but that really only covers the basics. Metal Supermarkets is the advice I'm normally given for a Canadian supplier, but between their awful website and limited hours I've yet to buy anything from them. Amazon.com has quite a lot of metal, but trying to find what you need on their website is a royal pain. It's enough to drive you nuts!

PIR seems difficult to find here as well. I think Home hardware has it, but I haven't actually seen it in a store yet.

Edited 1 time(s). Last edit at 11/28/2015 05:13PM by JamesK.
Re: Aluminum Sheet Between Heater and Glass
December 25, 2015 12:57PM
Quote
the_digital_dentist
I don't get it. Everyone knows you need a flat surface to print reliably, yet so many keep buying thin, flexible aluminum and then put glass on top of it. Why do people keep buying the thin, flexible aluminum? It makes no sense. Why not just get a flat aluminum plate such as cast tooling plate in the first place and be done with it? Unlike galss, aluminum is thermally conductive so the temperature will be even across the surface and you won't have print adhesion problems. Surely the cost of a thin flexible aluminum plate, plus glass to fit, and the goop you're going to have to slather on to get prints to stick can't be much less than the cost of a piece of cast tooling plate. We're talking about a few dollars/euros here, not hundreds. Are the few dollars/euros you save worth all the screwing around to find a magic formula to try to get your prints to stick?

Since you're developing the printer yourself, I advise you to try out a 3 point leveling system. When you level the print bed you're adjusting it so that it lies in the XY plane defined by the printer's guide rails. It takes only three points to define a plane. The typical 4 corner "leveling" system bends the bed plate and the undercarriage. You can't level a bent plate, neither can autoleveling. With enough screwing around you may get the center of the bed flat/level enough to print on but you aren't likely to be able to use the entire bed. The further you get from the center the worse it will get. Auto leveling assumes that the bed is a plane so its not necessarily going to help.

Here's a 250 mm diameter ABS print on my 317 x 305 x 6.35 mm cast tooling plate bed supported by a three point leveling system:

I have never seen anything of similar size done on a thin piece of aluminum with a glass plate and a 4 point leveling system.

What's the point of building a machine with a 200 x 400 mm bed if you can't print on the entire surface? The thin aluminum/glass/4 corner leveling is done in cheapo (and some not so cheap) printers because it is a couple dollars/euros cheaper than doing it the right way, or the "designers" don't know any better. The whole point of developing your own printer is to do something better than you can get elsewhere. If you're just going to copy their mistakes, just get one of those cheapo kits and save yourself a lot of trouble sourcing the parts.
You answer why yourself a fem posts farther down. Not many people knows about that type of plate, and neither did you.

Also: I can't find any such things in Europe. That and I like to have several plates, so borosilicate glass is much better suited. Many people like having the option to replace plates.


My Instructables - both total newbie instructables and some for intermediate users.
My Designs on Thingiverse
YouTube channel containing a few 3D printing videos - they are videos for my Instructables, and mostly not standalone.
Ultius / Tantillus Thingiverse Group
Re: Aluminum Sheet Between Heater and Glass
December 25, 2015 01:51PM
Quote
dintid
Also: I can't find any such things in Europe.

See EcoCast here [www.aluminiumwarehouse.co.uk].

Quote
dintid
That and I like to have several plates, so borosilicate glass is much better suited. Many people like having the option to replace plates.

So do I. But I use an aluminium heat spreader between the heater and the glass, so that I can use ordinary float glass instead of borosilicate.


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Full disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: Aluminum Sheet Between Heater and Glass
December 25, 2015 07:32PM
Quote
dintid
Also: I can't find any such things in Europe.

Cast tooling plate is a raw material for any and every machine shop on the planet. I'm certain there are at least a few thousand machine shops scattered around Europe. If you can't find cast tooling plate it may be because it's called something else, but it's there and it's available.


Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
December 26, 2015 03:39AM
Quote
the_digital_dentist
Quote
dintid
Also: I can't find any such things in Europe.

Cast tooling plate is a raw material for any and every machine shop on the planet. I'm certain there are at least a few thousand machine shops scattered around Europe. If you can't find cast tooling plate it may be because it's called something else, but it's there and it's available.
It might be the case, but I have tried searching by the 3 different terms you list here without any hits at all.
I try to use Trading sites like ebay, amazon etc due to buyers protection, so I do not just Google.
"cast aluminum tooling plate", "cast jig plate", etc....MIC-6"

Instead of being derogotary, try giving direct links or explain in plain terms what it is you mean. You could be helping a lot of people out by spreading the Word instead of defaming everyone for not doing it the same as you,

Quote
dc42
See EcoCast here [www.aluminiumwarehouse.co.uk].
Thanks. smiling smiley

Quote
dc42
So do I. But I use an aluminium heat spreader between the heater and the glass, so that I can use ordinary float glass instead of borosilicate.
I have some plain glass as well.. I do like to being able to dump the glass into the freezer though, which isn't a good idea with plain glass from 100c

Edited 1 time(s). Last edit at 12/26/2015 03:41AM by dintid.

My Instructables - both total newbie instructables and some for intermediate users.
My Designs on Thingiverse
YouTube channel containing a few 3D printing videos - they are videos for my Instructables, and mostly not standalone.
Ultius / Tantillus Thingiverse Group
Re: Aluminum Sheet Between Heater and Glass
December 26, 2015 05:14AM
I wasn't trying to be derogatory, just pointing out that the stuff has to be available. I don't know any plainer terms than to call it what it is, at least in English. The plate is cast (not rolled or extruded), then milled flat. That's as simple as anyone can make it.

If you can't find tooling plate, try finding a machinist and asking about it. Go to any town with a manufacturing plant of some sort, and go to one of the bars that are located right across the street from the factory just after a shift has ended. Machinists are frequently big guys who like to drink beer, and have very dirty hands. Once you have found a machinist, ask them about where they get their jig plate, tooling plate, or whatever they call it locally. If you find the right guy, they may even take an interest in what you're doing and you might be able to get them to help you do it (though it may cost you a few glasses of beer).

Edited 2 time(s). Last edit at 12/26/2015 05:22AM by the_digital_dentist.

Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
December 26, 2015 07:15AM
Quote
the_digital_dentist
I wasn't trying to be derogatory, just pointing out that the stuff has to be available. I don't know any plainer terms than to call it what it is, at least in English. The plate is cast (not rolled or extruded), then milled flat. That's as simple as anyone can make it.

If you can't find tooling plate, try finding a machinist and asking about it. Go to any town with a manufacturing plant of some sort, and go to one of the bars that are located right across the street from the factory just after a shift has ended. Machinists are frequently big guys who like to drink beer, and have very dirty hands. Once you have found a machinist, ask them about where they get their jig plate, tooling plate, or whatever they call it locally. If you find the right guy, they may even take an interest in what you're doing and you might be able to get them to help you do it (though it may cost you a few glasses of beer).
It's ok. I might have misinterpreted your meaning/intentions. Can easily happen on forums, and English is not my primary language - I just sort of read it like: anyone not using tooling plate is dumb.

I take it you print directly onto the tooling plate?

Most people I know would not want to do that as they wish to be able to start a new print immediately after the first, so a change of plates is necessary. Unless you have multiple tooling plates laying around, the best, or at least most common, soloution is to use glass plates as surface.

If using glass plates, even if it is just standard (ie. not borosilicate) glass it really doesn't matter if you use a tooling plate or not beneath the glass.

A thin alu-heater can be forced to fit/align to the glass, but the glass can't be forced into the being flat by mounting it on top of a tooling plate.

This leads to the simple fact, that for most people it really does not matter what sort of Aluminium plate you use - if you use glass on top of it.

Edit: regarding Cold spots: while I havn't measured for cold-spots I do not believe it amounts to anything remotely influential to printing performance: at least I have not noticed any parts of my plates suffering from non-stickiness.

Edited 1 time(s). Last edit at 12/26/2015 07:18AM by dintid.

My Instructables - both total newbie instructables and some for intermediate users.
My Designs on Thingiverse
YouTube channel containing a few 3D printing videos - they are videos for my Instructables, and mostly not standalone.
Ultius / Tantillus Thingiverse Group
Re: Aluminum Sheet Between Heater and Glass
December 26, 2015 09:28AM
I print on clean kapton tape applied directly to the aluminum tooling plate. Prints stick very well, sometimes almost too well. I've never been in a situation where I can't wait the 20 minutes or so for the bed to cool so I can start the next print. Unless you're in a production type situation I can't imagine when it would be necessary to get the next print going so quickly, but that's just me. I am likewise not in a big hurry to get my prints really fast.

I have never printed something where I felt like I could give up some of the quality to get more speed. When is print quality unimportant? I usually print at about 50mm/sec or less and if it takes two days for a print to finish, it takes two days. I do something else while its printing.

We have a Taz 3 at the makerspace which has a silicone heater directly attached to a glass bed plate. We looked at it with a FLIR camera a couple months ago and found 20C variation in temperature across the plate's surface, including a cool spot about 75mm dia right at the center of the bed. It would be better if there were an aluminum heat spreader under the glass, but I'm not a fan of using glass at all- I think it would be best with a flat piece of aluminum tooling plate.


Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
December 26, 2015 10:03AM
I do a lot of prototyping where quality is secondary.. or tertiary. Where speed is often the primary. That said: my quality is most often flawless... by printing perimeters very slow (60mm/s) I get top quality.

Regardless of wheter I do print prototyping, contruction parts or tiny parts for my children, I just can not stand waiting for more than a few minutes after each print... it just kills me waiting. Especially if it is failed for some reason - might be I notice the part is flawed or similar and I need to print a new one, or an extra one... I do not ever want to wait longer than it takes for bed and hotend to heat up.

Regarding Cold spots:
Taz 3 is OLD and... not that good really. That said, the question is not wheter it has Cold spots, but wheter it has any impact on what you print? Most people seems satisfied with what they do.

My point really is that your preferred solution really isnn't optiomal for me (and a lot of other people). We all have different requirments and printing slowly and having to wait ages is just not ok with me.

I realized my new build can't print faster than 96mm/sec as it can't melt plastic faster than that - for larger surfaces... result = I had to change the entire print-carriage to accomodate an E3D instead, which I know can print much faster.

Edits: typos

Edited 3 time(s). Last edit at 12/26/2015 10:05AM by dintid.

My Instructables - both total newbie instructables and some for intermediate users.
My Designs on Thingiverse
YouTube channel containing a few 3D printing videos - they are videos for my Instructables, and mostly not standalone.
Ultius / Tantillus Thingiverse Group
Re: Aluminum Sheet Between Heater and Glass
January 07, 2016 03:57AM
I'm sold on the cast alu plate, but it is tricky here in the UK, ebay are skewing results for sure, maybe they dont want us to have the manufacturing good stuff here in the UK, for fear of what we'll make with it. I'm waiting to hear from a US supplier about shipping, if I get the 6mm plate (220mmx220ish) I'm wondering will I have to redesign the bed from belt to leadscrew due to the weight or will the belt handle it, wondering about judders, though plan on keeping the speed down.

thinking of using this for the leveling


Edited 1 time(s). Last edit at 01/07/2016 03:59AM by MechaBits.

[mechabits.co.uk]
[mechabits.wordpress.com]
Re: Aluminum Sheet Between Heater and Glass
January 07, 2016 04:02AM
Quote
MechaBits
I'm sold on the cast alu plate, but it is tricky here in the UK, ebay are skewing results for sure, maybe they dont want us to have the manufacturing good stuff here in the UK, for fear of what we'll make with it.

See EcoCast here: [www.aluminiumwarehouse.co.uk].


Delta printer calibration calculator, mini IR Z probe, and colour touch screen control panel: [escher3d.com]

Large delta printer, and other 3D printer blog postings: [miscsolutions.wordpress.com]

Full disclosure: I have a financial interest in sales of the Panel Due, Mini IR height sensor, and Duet WiFi/Duet Ethernet.
Re: Aluminum Sheet Between Heater and Glass
January 07, 2016 04:49AM
I tried that site yesterday(spotted your earlier link), but didnt use the tool to find item and nothing came up in the search, just did it again and used the quote tool, nice price only about 10-13 quid for 6 or 8mm, it'll probably get here before I get a reply from the US supplier smiling smiley
Yes I think I'm going to use http://www.aluminiumwarehouse.co.uk/cutting_calc.php
now to decide 6mm 8 or 10, I'm thinking 6 is fine for this smaller setup.
Cheers!

Edited 1 time(s). Last edit at 01/07/2016 04:57AM by MechaBits.
Re: Aluminum Sheet Between Heater and Glass
January 07, 2016 05:28AM
Quote
MechaBits
thinking of using this for the leveling

Depending on how that device is made, it might be very good. Assuming it is well made (no play in the top plate regardless of screw settings) I can see three potential problems. If your bed moves in the Y axis, the small base will allow it to flop a little back and forth every time it starts/stops unless you set acceleration/jerk very low, especially if you have it riding on sloppy bearings on end-supported guide rails. The second problem is reaching those adjustment screws under the bed. Neither is a problem if the bed only moves in the Z axis. The third problem is how to attach that device to the bed if you are using a heater on the underside of the bed.

If the bed moves in the Y axis and you use a fully supported linear guide, that device might work quite well. I am using two small linear guides in my printer's Y axis and have been considering the possibility of rebuilding it with a single, larger guide and either one or two bearing blocks. Supporting a heated bed from its center eliminates bowing of the bed when heated because of the expansion of the bed plate against widely spaced support/leveling screws.

The closer the level adjustment screws are to the center of the bed, the more the adjustments get magnified at the edges of the bed. It will take only tiny adjustments of the screws to tilt the bed and you may find it tricky to get the level set just right.

If you're building a new printer and plan to print on a heated bed you can leave out any sort of mechanical bed leveling system and use autotramming. If you print on a sacrificial foam bed, you can leave out mechanical leveling, autotramming, and a bed heater, and use a smaller power supply.


Son of MegaMax 3D printer: [www.instructables.com]
Re: Aluminum Sheet Between Heater and Glass
January 07, 2016 06:35AM
Thanks DD for reminding me of a few of the issues,

"Assuming it is well made - looks ok and is designed to keep camera steady but yes it might have a few quirks of its own, (no play in the top plate regardless of screw settings) "

screw pitch might cause some issues, vibrations could make them loosen.

3 potential problems.

"If your bed moves in the Y axis, the small base will allow it to flop a little back and forth every time it starts/stops unless you set acceleration/jerk very low, "

yes I have thought about this one, it does concern me, currently testing a few configurations but waiting for more parts too, as my Y axis bed will be supported by a single flat bar (25mm) but with plate or leveler, or 15mm tube with leveler, joining the 2 bearings the tilt of the those short bearing is one area that i can hopefully solve with the longer 12mm bearings but maybe it wont be enough? At the moment I'm hoping to have the joining bar in line with the rails, but I have 2 other positions, underslung & above the rails, each with its own pro's n cons.

"The second problem is reaching those adjustment screws under the bed. "
Currently the whole bed assembly can be moved and access to the underneath is quite easy, but I am worried about single screws for fixing anything especially without some anti rotation pins, though the base of the leveler looks like I could add a few more holes in the pockets.

"The third problem is how to attach that device to the bed if you are using a heater on the underside of the bed.
The closer the level adjustment screws are to the center of the bed, the more the adjustments get magnified at the edges of the bed. It will take only tiny adjustments of the screws to tilt the bed and you may find it tricky to get the level set just right."

Yeah one pivotal screw again, which I think the heatbed has a hole in center, but I always wondered why!
as some of these heatbed plates say you can print on top of it, but yet there is a hole in center, maybe squirting a little molten filament in there helps with traction? But I plan to add a silicon sheet, heatplate, then tool plate,
but will have to drill n tap the underside, but if Im going to do that for one hole, I might as well do a few more at the extremities, and get a more precise leveling mechanism. I've also been thinking about replacing springs, with repelling magnets, but that might be too bouncy or cause other issues, but i still want to play with the idea in a form similar to the leveler above, should be fun.
"If the bed moves in the Y axis and you use a fully supported linear guide, that device might work quite well. Supporting a heated bed from its center eliminates bowing of the bed when heated because of the expansion of the bed plate against widely spaced support/leveling screws."

The fact that it has a fairly large diameter should provide enough support for the plate, pity the pads weren't silicone as they will melt the rubber pads, I'm not using fully supported in this build but other options are being considered, and as you know, even if the part does get used in one iteration, there is always another use for most of the items that make up my printer.

The next comparable leveler with almost identical design is £50-120, maybe there are some cheaper ones on theodoliites or something, but it's not a complicated device to replicate. I've just ordered a few parts to make my own leveling feet some 6mm grubscrews & nuts, dome nuts for feet, I considered spikes, but at the moment its freestanding on some rubber, maybe it'll get bolted down when finished but I'm trying to keep free at the moment.


The pic shows the bed support at the highest above the rails but hope to take it down 30mm or so, but this is not final config', it's evolved a little since this pic.

"If you're building a new printer and plan to print on a heated bed you can leave out any sort of mechanical bed leveling system and use autotramming. If you print on a sacrificial foam bed, you can leave out mechanical leveling, autotramming, and a bed heater, and use a smaller power supply."

I've not got that far yet, but it sounds like a good place to start, I bless this printer with a sacrifice!

If I get 500mm rails I can probably incorporate the leveling screws directly into the crab clamps which may also be the best way for me to go, cuts out the need for quite a few of my current components, but a 1m belt might not be advisable?

Edited 9 time(s). Last edit at 01/08/2016 11:02AM by MechaBits.
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