HicTop Metal Alum Build Mods and Upgrades

I have been "PLAYING" with my HicTop metal Alum printer for about 6 weeks now. I have noted a major problem in the Z axis rod capture on the Z axis motor plates. They wobble badly, I reported the problem to HicTop and designed a solution. I added a thin plate to the outside of the Z axis motor plates, this stabilizes the lower Z rods. I kept the plate thin as to still used the original screws. My attached design is attached.

Happy Printing.

Bob

Another mod from Bob

I went to a local glass shop and bought a glass pane to set on top of the aluminum hot bed using small bulldog clips. This provides a flat surface to print on, and a hard surface to prevent scratching the soft aluminum plate. Does not need to be a special type of glass for PLA, have not tried with ABS. Working Great So Far!

Bob

Hi Bob, can you show me a picture of your mod? I noticed something wrong when assembling that part, so I used the dremel to enlarge these holes to avoid the rods to come out.

I am still trying to get mine printing with abs, the bed takes ages to heat! and the movement is not so smooth due the linear bearings (support send me 3 more, because there was some missing balls in some of these)

Here is my Z-rod mod installed. I have install one on each side on the metal plate that holds the Z stepper motors.
Hope this helps.

Bob

I see. Mine does not have that problem after dremelling the piece. However the screw axis wobble. Did you used something special to keep them centered in the spring coupler?

The screw axis is also wobbling in mine, predominantly on the right side, I figure that if the z rods do not wobble, the affect is minimized. Since the z axis screw coupling has two screws, pushing the screw to one side, I do not see a solution for that wobble.

I have also designed a cover for the electronic board and caps for the end of some of the aluminum frames. Still do not have a good solution for a guide on the wiring going to the y axis. Currently using a rubber band to keep slack out of y axis wiring.

What is your design software of choice, I have tried sketchup and 123d. My choice between the two is 123d. Both are free.


Bob

Quote
bob414
The screw axis is also wobbling in mine, predominantly on the right side, I figure that if the z rods do not wobble, the affect is minimized. Since the z axis screw coupling has two screws, pushing the screw to one side, I do not see a solution for that wobble.

I have also designed a cover for the electronic board and caps for the end of some of the aluminum frames. Still do not have a good solution for a guide on the wiring going to the y axis. Currently using a rubber band to keep slack out of y axis wiring.

What is your design software of choice, I have tried sketchup and 123d. My choice between the two is 123d. Both are free.


Bob

I have designed some caps for the frames because I was unable to find good ones, they fit nicely: [www.thingiverse.com]
My design software of choice is Inventor. Sketchup was good when learning but there is no contest against Inventor. For customizable stuff (like this: [www.thingiverse.com] ), I use OpenSCAD.

I am going to try to fill the rods with something so the screws don't wobble them when turning. This certainly affects the quality of the prints (the nozzle oscillates)

Edited 3 time(s). Last edit at 10/03/2015 02:16AM by eried.

Guys,

I did the same thing for the smooth rod, dremeled a lil so that the chamfer on the rod sits in the z-stepper plate. But still the rods come out every time the z axis moves up. So, I used a nut as a spacer on the top support to keep it in place. (see image)
My zaxes threaded rods are just grinding through acrylic every time it goes up n down. I have an idea in mind, trying to use a ball bearing to keep it in place. Will post the design soon.

Do you guys have the CAD files of the acrylic parts and plastic parts by any chance ? I am not sure if I can accurately measure the holes and the distance bw them.

I am also trying to put an emergency stop or power off switch somewhere. any ideas ? The carriage wires sometimes get caught and rattle the whole printer.

Any designs to upgrade to dual extruder ?

Guys,

I had similar issues with my HIC Aluminum printer but approached it somewhat differently. I had the same z-axis wobble, but didn't have any problems with the rods slipping. I ended up replacing the stock threaded rods & z-axis motors with NEMA17 Threaded Rods from robotdigg (http://www.robotdigg.com/product/31). Now my prints have zero z-axis wobble. The only downside was that I had to modify the firmware to adjust the step size, plus the pin configuration for the new motors didn't match the stock motors -- ultimately these issues were easy to address, but somewhat difficult to track down initially.

Another issue I had but haven't seen mentioned as much was the nozzle heating element slipping out of the hot end and pulling the thermo-sensor with it -- resulting in eventual over-heating of the hot-end making a big mess. My solution was to wrap the hot end with ceramic & kapton tape -- as I've seen on many other printers. Have any of you guys had this issue?

John

I used a little dot of heat resistant silicone for the thermistor in the nozzle and bed. I hope it works well because in the makerbot they use a thing that goes screwed into the aluminium block (I have an old one) not a cristal thermistor that goes loose inside the block

There small grub screw used to keep the heating element in place is doing the job for me. The wires for both the heating rod and the thermistor seem to be tightly wrapped and hence the thermistor is not slipping out. But the silicone glue might be a good idea to consider

Also, I had designed a small guide for the z-axis wobble. Its on thingiverse (http://www.thingiverse.com/thing:1097692) . check it out.. No more grinding of acrylic.

Neat, I straighten the rods but I am still playing around: [www.youtube.com]

Does the filament guide you made really works? How did you thighten the spring couplers for the z rods? did you stretched out the coupler first to keep it with tension?

The filament guide does the job, its not a perfect or neat design. The guide although clamped, has a play along the horizontal axis, which actually gives way when the filament is rushed along the x-axis. But by far it has kept the filament from kinking or snapping when i move the z- axis and x axis all the way through.

I wrapped the lead screw with a thread seal tape, just a couple of turns and then used the grub screws to tighten, not sure if this actually helps. I didn't keep the coupling in tension or anything, am not sure how that is going to help as the load directed downwards, the coupling may not remain in tension. Can you explain how it could help >?

great apparatus btw.

Do any of you happen to know the exact size of the Z-Axis screws for the HICTOP Prusa i3 Aluminium frame printer?

I have already installed Bob's shaft retainers and they are working wonders with the quality of prints, but I have to run the machine super slow to avoid binding/backlash on the Z axis. I am thinking of replacing both the Z-Axis Screws and couplers. I aslo want to try Warankarp's top guides, but I need to know the screw size so i can order the correct ball bearings.

As a side note, I am having to re-solder every end stop that came with the kit. Only one of them worked straight out of the box.

In the future I want to try and installing an auto level system for the bed, but I still need to figure out exactly how I want to go about doing that.

Thanks Bob! Your mod saved my printer! I still have Z banding but I think I can get it fixed now that I can print decent replacement parts/mods.

Thanks for all of your parts.
It is extremely appreciated! Ive done my best to straighten the Zscrews... not perfect, but your guides may help
I think I will be shimming the couplers with some tin foil also, I read that works well to bring the couplers into center.

Got my fingers crossed, and again, thank you so much!

Quote
bob414
I have been "PLAYING" with my HicTop metal Alum printer for about 6 weeks now. I have noted a major problem in the Z axis rod capture on the Z axis motor plates. They wobble badly, I reported the problem to HicTop and designed a solution. I added a thin plate to the outside of the Z axis motor plates, this stabilizes the lower Z rods. I kept the plate thin as to still used the original screws. My attached design is attached.

Happy Printing.

Bob

Your pieces do not fit perfectly, the screws are a bit off (like 1 mm), but thanks anyway! great idea. Problem solved with a dremel

I made a replacement for the whole Z axis to use leadscrews, here are the parts: [www.thingiverse.com]


Also I made a turbine replacement: [www.thingiverse.com]


Edited 1 time(s). Last edit at 01/19/2016 01:48PM by eried.