printers longer than 45cm? Is Rapidbot Mega my only choice?

Hello I’m looking for a printer that prints longer than 45cm. is my only choice the Rapidbot Mega, I’ve heard that Make Mendel don’t have great quality control, are there alternative choices?

Thanks

Print smaller parts and join them. I do not think you could ever print anything near that long without it warping like a banana and wasting tonnes of time and material. Plus they started advertising that machine as working before they had ever built one so I would not trust it to print anything.

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Plenty of blue painters tape and hair spray and you wont see warping of PLA even on an 8' bed.

Edited 1 time(s). Last edit at 03/21/2013 02:57PM by hendo420.

@ hendo

I have had 6" long PLA prints pull the tape off the glass from the warp forces. The bond between the tape and plastic was stronger than the adhesive on the tape.

If thats the case, dont get the rapidbot mega, if it has the same "heated" bed that the rapidbot 3.0 has, its crap. Wont get over 45c.

hendo420 Wrote:
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> Plenty of blue painters tape and hair spray and
> you wont see warping even on an 8' bed.

Umm... no. Print a large enough piece and eventually the warping forces at the ends will exceed the inter-layer bonding strength even if your first layer is bonded to the bed with infinite strength. Snap, crackle, pop...

Also if the rapidbot mega is like the rapidbot 3.0, the only way to level the X axis is by turning a Z axis stepper motor. Good luck leveling the Y axis, support says there is no way to level it on the rapidbot 3.0

Thanks for your replies

Unfortunately joining pieces is not an option

While I respect your experience in this field, can someone explain why a depth (back and forth) print rather than a lengthways (left and right) print would warp?
I understand this is likely to take longer but wouldn't to stop the change the orientation of the forces to a depth commonly printer?

We will be mainly printing long rectangles where the depth would be no issue on many printers, 3 to 7cm

Please see my extremely crude drawing



I'm interested to hear your thoughts, thanks

HI Ben,

For your large format printing needs you should check out Gigabot on kickstarter. We have routinely print 45-60cm long PLA objects without curling. The trick to getting really good results is multi-fold: 1) Flat and level build surface 2) really good adhesion of the first layer 3) optimizing extrusion temp and cooling fans 4) the object's shape.

Here is a video of a larger printer, even if you can keep the base from warping, you will very likely have many other issues.

Note the HUGE delamination gaps in the sides of the print.

Or if you want to really go big, it's a matter of how deep your pockets are and your engineering skills.

HUGE nozzle, recycled refrigerator liners, no heated bed or fans.



Edited 1 time(s). Last edit at 03/30/2013 01:40PM by Dirty Steve.

Unfortunately, a lengthwise print will also warp. It is the overall shape and dimension that is causing this issue. The only way you might get acceptable results is to use a heated build chamber.

By the way: Why is joining parts not an option? I have tried to glue ABS parts to each other with acetone. It works pretty well and - if done right - the joint is nearly invisible. Somewhere I have read that the strength of the glued part is 75% of that of a heat-fused part.
There are also tips for soldering irons and nozzles for hot air guns that are designed for heat-fusing plastic.

If you need longer prints, why not build a mendel with a stretched X axis? The print bed would be the only part that needs any major redesigning.

my printer is sort of aproching the 450mm mark, i think the major thing is having an evenly heated bed, and an enclosed structure to keep the temperature of the piece even. also if i print diagonally, i could print up to 630mm longish. so dont forget about the diagonal. also anything with a moving bed will be likely to warp since the air is rushing past it.

A heated build chamber is something I'm considering
Using a brim is another thing I've looked into

The Gigabot looks interesting, do you know the final, built/flat packed cost?

Ben, I think you will be very happy with the size and strength of Gigabot. The all metal frame makes a rigid machine with very little vibrations and more accuracy with your print. I have been traveling with Gigabot for the last couple weeks with stops in Santiago Chile and the Atacama desert in the north of Chile. We have been doing a lot of printing and Gigabot has been performing really well.

Be sure to check out our YouTube channel for more videos of Gigabot in action. [www.youtube.com]
Lots more content will be coming and we are getting ready to launch our new website soon as well at www.re3d.org

Pricing on kickstarter for the entire kit is $3250. The flat-packed version is pre-build and tested before packing and shipping it to you for $4950. The advantage of flat-pack is the earlier ship date and you will be up and running quicker with the critical sub-assemblies already prepared.

Both pledge levels include free shipping within the USA. We are working with several different international freight carriers to obtain the lowest quotes possible for international orders.

Pricing after Kickstarter will likely be about 20% more.

Let me know if that helps.

Best,
Matthew

Founder:Catalyst
info@re3d.org

Your best bet is to just assume you need a build chamber.