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Which one ? Mendel Max 1.5 , Prism X, or OB1

Posted by mrfunk 
Which one ? Mendel Max 1.5 , Prism X, or OB1
October 06, 2013 08:39AM
Hi wish to upgrade my prusa i3

I'm really happy with the results, detail & speed.. but feel the bowden might let it down

I'm looking at DIY Mendel Max 1.5 , Mendel 90, Prism X, OB1

Which would you recommend as an upgrade, and with what extruder.
I really want super fast print speed, and top quality..(don't we all)

Whats your experience - ?

I really like the PrismX, but no plans at the mo.

I would want at least 200x200x180 build volume..

Thanks for any advice
Re: Which one ? Mendel Max 1.5 , Prism X, or OB1
October 16, 2013 04:21PM
Speaking from personal experience I've always had good results with the MM 1.5, the only drawback in my opinion is that it's a little complicated to build, other than that though it is a fantastic printer in terms of speed, quality, and rigidity.

Through self sustaining actions comes freedom

DIY Tech Shop
Re: Which one ? Mendel Max 1.5 , Prism X, or OB1
October 16, 2013 05:11PM
I have a MM 1.5, (built from a kit), and have been getting really good prints almost straight away.

However I think that MM 1.5 build height may only be 150 not 180mm depending on X Carriage design.

MM 2.0 is now available and I think all the designs are available on the web, so this may be a better option than MM 1.5 as MM 2.0 has 50mm more build height.

BTW.. Not all MM 1.5's are created equal. My kit uses the older round rod design for the Y axis, which has been superseded by a metal rail (which I guess is better).

Also, from personal experience with stepper motor drivers overheating :-( Make sure that the stepper drivers have heat sinks, and also that the FET that drives the heated bed has a heat sink. I'd also recommend fan cooling the whole of the controller board (RAMPS 1.4 in my case).
My original kit didn't have heat sinks, and also didnt have a fan, and i had to replace the the whole RAMPS board and stepper drivers after a major failure.
Re: Which one ? Mendel Max 1.5 , Prism X, or OB1
December 22, 2013 10:52PM
Wish I'd seen this when it was posted but we rarely have enough time for RepRap forums or IRC yet. For those that don't know I created the PrismX so you can accuse me of bias at your leisure.

Of the list MendelMax 1.5, MendelMax 1.6 (MMax 2.x for that matter), PrismX or OB1...the Prism variants are better. Why?
* PrismX and OB1 assembly from a kit is faster and easier than a MMax 1.x. I don't know about the MMax 2.0.
* The PrismX frame is easier to assemble for excellent alignment than a MMax 1.x. The MMax 1.x relies on printed parts to dictate key parts of the frame alignment. In fact, the standard MMax 1.x has printed parts to "jig" the placement of drilled holes and the y-axis; nevermind that calibration errors expose themselves even more on large printed parts. There are some interesting videos and writeups on aligning the z-axis on the MMax 1.x frame. Ever heard of the "bob plunger method" for z-axis alignment? That one is attributed to MMax. The Prism Mendel and Prismx don't have that because frankly it's difficult to build any other way. R3DWOOD OB1 is probably just as easy to align.
* Frame alignment is directly proportional to: print quality, faster print speeds, overall machine reliability, a happy user.
* Not many printers can move like the PrismX while printing, not to mention just sounding off.
* We adapted the 00str00der from the PrismX to work with the MendelMax. The MMax+00str00der prints with higher quality and reliability like the PrismX - just slower.

PrismX vs. OB1:
They're kin, they shouldn't fight. Again I'm biased and have not used or commissioned an OB1.
* PrismX has a smooth and well-constrained belt-driven z-axis. It's very fast and efficient. This means PrismX has 4 motors, OB1 has 5 like MMax.
* PrismX has a lightweight and compact Y-axis that also slides around very quickly and accurately.
* PrismX has press-fit LM8UU mounts and holders that align nicely and are extremely durable.
* OB1 mixes more design ideas from MMax - specifically the notion of plastic parts that dictate frame alignment.
* PrismX intentionally avoids design concepts from MMax. Machined parts dictate alignment where possible, printed-flat plastic parts elsewhere. There are no captive nut slots in plastic parts to make printing and assembly riskier.
* OB1 has a more compact footprint and profile on the workbench.
* R3DWOOD OB1 Prism is a much cooler name. The name PrismX is not as cool, for a variety of reasons. My bad.

For me it would be a choice between Prism variants. The MMax 1.x series maintains its popularity even though much better designs exist - for beginners and experts. TW has received remarkable criticism for making claims about speed and accuracy on the PrismX - but at the end of the day I'll tell anybody a PrismX is worth 2 or 3 MendelMax 1.5's to me.

Edited 1 time(s). Last edit at 12/22/2013 10:53PM by tenacious.
Re: Which one ? Mendel Max 1.5 , Prism X, or OB1
December 27, 2013 09:52AM
I created the original Prism, and it's great to see that it's still active.

I just created a new vertical X axis for the Prism based on the Vertical X Axis standard, so it should work with mendel as well.


I just had to work on the printer to add the new X axis and it was so easy to work on compared to the Sells mendel I had years ago. That's one of the main things I focused on when designing it; ease of assembly and maintenance. I'm still very happy with the design choices I made and the print quality is better than ever.
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