3D Printers, Makers, DIY hacks, solutions and post printing tools

well, just a couple off the top. I would not go with wood at all, try acrylic pieces or Alum. would be even better. also, If you set it up for two Z axis steppers you will need a belt or chain drive between them to keep them synced up, otherwise one will always be slightly higher or lower and you will constantly be adjusting them by hand ( I do this on my core x-y printer) kind of a pain. I'm not familiar with the rail and attachment system you are showing, but I assume these are alum. with a nylon or teflon glide? if so, try to minimize the surface contact area to lower the overall drag on your steppers. With the build volume size, you could easily save some headaches and just get a kit off GearBest.

just some thoughts.

thanks Mark

Acrylic gets brittle and cracks, a common problem on the Anet A8.

Ok, but it is much more stable than any wood product. :)

Mark

Wood is good because is cheap, make it in wood if you have limited budget and options, and use it to print most of your next printer in something sturdy like carbon fiber mix with PTEG and a metal chassis, let's call that; 'going pro'. Wood will give in pretty soon, maybe before one year of intense use.

(unless if you use solid palisander or solid oak or similar)

The bowden tube, KISS made please. (Keep It Simple) too many sharp bents, place the extruder motor a bit higher and upside down, so that the filament enters from above and exits below, if the tube must take shapes than the curves must be as large as possible.

You can always place the spool on top, unless you have space limitations, than place it anywhere and another bowden tube from the spool to the extruder motor.

I have no clue how the sliding of those cylinders will take place on the supports, unless if you drown them in grease or oil (not good for an open mechanism), the other option is to replace them with carrier wheels of some sort, necessarily with bearings to ease the frictions.

The printing head support must allow for some elasticity for at least 20 degrees of a circle in any direction, be it from the flexibility of elements or hinged plus return springs, anytime you scartch the surface of your printed object (happens often) you risk to snap it away from the bed or to lose some steps in the motor, none of them a good option, better some small imperfections due to elasticity of your printing head support.

Your Z axis is short, make it higher, not all objects you need to print are flat.

Put a spacer bar on top between the Z axis columns, sturdiness is paramount, you can use it to also place on it the extruder motor and the filament spool (I did that, four columns, two central and to at the rear end, plus I enclosed the rear and sides in Acrilic, and am still not happy with the sturdiness, now making a more solid one, I placed a platform on top for my filament supports.)

Used plywood suggest that your objective is to keep cost low. I assume your using threaded rod instead of acme screws. The aluminum rails I do not see as the low cost solution.

Plywood is stable for the period generally important for 3D printing. It will expand and contract due to humidity but plywood doesn't cup due to changes of humidity which means that the growth or shrinkage in a plane is uniform, face and thickness. Thus a fixed motor position will set the zero for that axis and let the other end slid.

Use the three surface approach for flatness to get the edges of the plywood really straight. Two skate board wheels on a flat face will define each axis plane and the third with a spring pushing it against even a less the perfect but close to parallel opposing edge will hold the two wheels in contact. should also have the same setup on the face of the plywood Can have just two skate board wheels for example on the Y axis beam on the other end. Just need to hold it to the vertical post at one point. The plate for building the 3D adding material part should follow the same basic approach as the Y axis beam Two sets of fixed Double wheels one one the edge and the other on the bottom face, and for the edge a spring loaded wheel pushing the plate against the two edge wheels. For the bottom two wheels where one is above the fixed two wheels pressing on the bottom. and two wheels near the opposite edge, fixed pressing against the bottom and above it spring loaded.

If your going to need a heated bed. Then I suggest getting a glass mirror of the sized of the bed to define flat. An adhesive like silicone rubber is good for the temperature. The nature of the heater will determine if the rubber can be filled with typically aluminum of ceramic particles to improve heat conduction. A temperature measuring sensor will also be bonded to the glass. near the center.

The advantage of screws is that they weight of what is being held up can not cause motion. Pay for this with more work needed to move the item.

The typical approach is a timing belt. Both screws and timing belts have some clearance between the driving and driven parts so when direction is reversed the clearance switches to the opposite side. Motion happens when a surface presses against a surface.

Zero back lash only occurs when a load always holds the contact. The weight of the Y axis beam holds contact to one surface pair.

A less common approach is to have a cable that is always in tension converting rotational motion from the motor to the axis moving component. The cost of this is the need for bearings to carry the high load, double the tension on the cable for a looped cable. The couple used on the screws that move the Y Axis beam to the motor will be needed for all the motors. One advantage with a cable is that the approach used on drafting tables with a straight edge beam can be applied to the building bed and the Y Axis beam so they never skew, never. This site has pictures. https://www.instructables.com/id/Build-a-Parallel-Straightedge-Drafting-Table/

Slippage can be handled in a few ways. Multiple turns of the cable on the drive pulley will reduce the likelihood of slippage. And the safest way is to have a large enough drum to fix the cable to it. Thus cable is fixed in the middle and as cable is being taken off on one side it is been added on the other. For small angles that the cable leaves the drum the cosine is very very close to one.

Note on the cable approach show in instructables.com. Figure 2 principle. There is another common approach where the cable is attach, fixed at the four corners and the pulleys are on the straightedge. The cables cross as the cable goes from one side to the other of the straightedge.

Hey Ahmed! great discussion about the 3D printer evaluation, such I have no idea of 3D printers. And also have not knowledge of any community. I have Smart Hard Disk Error Code 301 which at times displays uncertain error message.

you get me confused Linda, what is this having to do with... everything above?

Ahmed, that is a real honor and pleasure to hear from you these nice words, I am happy to see your work and wish you all the best in your professional life.

yea, thanks Mark for opinion , i agree with you if used material is an acrylic..that's will be better, ......my brother have a small workshop, that's my first project and my available material is PLY Wood so, I planed my project on that.

Thanks Mark

aluminum rail not supported me on the cost, actually I'm not put the cost factor as a core factor but, when i'm finished that design on that showing, I pleasured to put it as a first project....there are many of modification maybe yield by openning this discussion......Actually i pleasured to see that discussion.....sure, Plywood is stable and powerful too, and the modulus of elasticity: 7GPa...

Thanks Thomas