Gina

This printer is based on the RepRap principle with all parts readily available and all designs open source. Furthermore, this principle often makes use of one 3D printer to make parts for another and this printer embraces this principle wholeheartedly. The construction is based on a box to provide the main framework and this also provides a fume cabinet for using ABS filament which gives off noxious fumes when printing. To provide views of the printing process three sides and the top of the box are clear acrylic sheets. An opening front door provides access. Base and back are currently 6mm plywood with appropriate bracing but I'm considering replacing it with thicker material. In line with the RepRap principle the corners of the box are made from many 3D printed plastic sections including door hinges and catch. For the main movements in X, Y and Z directions, V-slot aluminium extrusion is used in combination with matching ball bearing wheels. This provides smoother, more accurate and more reliable movement than stainless steel round rods and linear bearings. It is also a lot lighter than stainless steel rods. This printer (as can be seen) moves the nozzle in the XY plane and the print bed to provide Z motion. This arrangement was chosen because the X and Y axes have the main movement and reduces the effective moving mass. The drives use ultra-low stretch and very strong fishing line cord rated at 100lbs breaking strain. This is driven by drums and runs over ball bearing pulleys for the X and Y drives. This arrangement uses fixed motors and avoids having their rather high mass on moving parts. The Z drive uses 3D printed spur gears to provide a reduction drive from stepper motor to drive drum. The drum is on a horizontal axle and simply lifts or lowers the bed with cord. As with the X and Y stepper motors, the Z motor is also mounted on the back panel.

Titan printer front view with door off.

As requested, a photo of the finished clock. I'll be adding details of the construction shortly, copying relevant excerpts from my rather long thread in the DIY Astronomer forum. It's not really a blue moon, it's lit with a white LED but the digital photo has coloured it blue

A couple more photos. X carriage and rail just on the table and top view of both X and Y carriages.

The X carriage partly equipped. Needs hotend heater and various cables.

This top view diagram shows the principle - this actually refers to my biggest 3D printer project but the same principles apply. This Mini printer is simply a smaller version of the bigger one. The orange square with the red border is the print bed, the rail sticking out from under each side guides the bed and holds it in the right horizontal position. The ends of that rail are attached to two carriages that run on the side uprights which form the Z rails. The print bed moves up and down to form the Z axis. The X axis is comprised of the horizontal rail shown above the bed, which the X carriage runs on. At the ends of the X rail are the two Y carriages which run on the two front to back rails. XY motion is controlled by cords running over pulleys and attached to drums on a pair of stepper motors. This drive arrangement for the X and Y axes is called Core-XY.

Decided to use a different corner fastening instead of the plates. Once built the sides will be boxed in with clear acrylic sheets. This will stiffen everything up (if it isn't stiff enough anyway) and provide a fume cabinet for printing ABS. The frame will be constructed from V-Slot rails some of which will take the wheels of the carriages. The Y carriages run on the lower top horizontal rails and the Z carriages on the inner vertical rails. V-Slot extrusion is actually cheaper than other sorts.

I can't seem to be able to edit the description of this entry I haven't been using blogs until just recently but found this and thought I could edit it to a proper entry.

I am new to blogs but I think I have sussed this out. The forums are more suitable for posting things where the main purpose is to ask questions or have a discussion. Blogs seem to be more suitable for build projects where the main content is going to be contributions by the originator and there may be fewer questions or comments. Also, unlike the forums, blogs have a two level structure where each blog can have a number of sub-sections with each of those similar to a thread in the forums. If I have this wrong maybe @Ant can correct me

This is a larger 3D printer with a print bed size of 300mm square and a build height of 350mm.

This clock runs off a stepper motor controlled by Arduino and Real time Clock module. It is about 300mm square with analogue display of hours and minutes with a sweep seconds hand. Atop the main clock face is a globe displaying the phase of the moon. The clock face is of clear acrylic to show all the gears etc. This clock is finished and has been running for several months.

The main frame.

This is a 3D printer with a 200mm square print bed and probably around 250mm build height depending on how things work out. It will use many of the parts from my "GinaRep Pilot" printer which has now served its purpose and needs upgrading/rebuilding. The Pilot printer had a moving print bed for the Y axis whereas the Mini will use Core-XY and the print bed will move up/down to provide the Z axis. This arrangements minimises the mass of moving parts in the XY plane where motion is fastest.

I think I need to look at some other blogs. Have to see how I do that...

Do I add the next post here?

Do I continue here like on the forums? Curious!!

I'm new to blogs - never used them before so I don't know what I'm doing I'll just experiment and see what happens...

I use the ubiquitous 28BYJ-48 geared stepper motors for focussing, with timing belt or geared drive and A4988 stepper driver modules running directly from the RPi 3. I posted a thread about it - I'll see if I can find it...

Yes, I see your problem with the geometry, Dave. One advantage of using your own design is that you can increase the frame size to accommodate things like that. OTOH I can see the benefit of using a tried and tested design. In my case I'm using experience from building previous printers in my latest build.

Just one disadvantage I see with your Titan extruder bracket Dave. The gear on the hobbed shaft is inaccessible, I use this on my printers to feed filament down into the nozzle once hot, when changing filament. I find it very convenient in addition to the lever to take the pressure off the pinch wheel. Inadvertently I obstructed access to mine on my larger printer (also called Titan) and ended up moving the obstruction away from the gear. Otherwise, good job - coming on nicely. BTW I'm just about to start building my third 3D printer

Thanks for the offer Dave but I think the rod I have will be fine

I've found an M6 250mm long threaded rod which is long enough (needs about 230mm), Not stainless steel but zinc plated (galvanised) which is probably adequate - I can coat it with grease and I think M6 should be strong enough.

Looked on ebay and Amazon for M8 studding and no joy. Anything between 200mm (too short) and 500mm (same length as I already have) seem unavailable. Guess I'll just use what I've got and let the excess hang down below the base part, beside the pillar mount. May do more to this tomorrow (I have too many projects on the books I just multitask between several at the same time!)

Here are a couple of photos of the mount sitting on the pillar. I'm using a scrap part as spacer to raise the bearing plate to about the right angle.

Found the M8 threaded rod and it's more than twice as long as I would need so I consider it unsuitable. I know I could cut it shorter but I think I would rather not cut it up as it could be more useful for something else. Probably better to buy a shorter length.