Reinforcing acrylic frame

Hi all,
I purchased a Sunhokey, at least I hope so, because it was REALLY cheap
I was already looking at different cheap 3D printers with acrylic frames and wondering about ways to make the frame more sturdy.
I intend to bolt the printer down on a piece of plywood, so the base cannot warp and it will be easier to move without the need of recalibrating. Perhaps screw handles to the plywood so it can be carried around be 2 people.

Another thing I was thinking of was to glue the acrylic frame together to make it more rigid. In fact you don't glue acrylic parts, it chemically welds together and basically becomes one piece.
Downside being off course it will be impossible to disassemble, but it would be more solid.
No idea if this will help reducing the flex in the frame though..
Anybody ever try to do this ? other thoughts ?

Bolting it down to a wooden plate is a good idea if you tend to move it around. I would not glue/melt the parts together it really wouldn't be more solid. It is a really sturdy printer as it is. Don't over tighten the bolts so you don't get cracks.
However the one you ordered is probably a scam see [www.reddit.com]

Thanks for the heads up, there is also a thread about this too good to be true deal on the forum.
Maybe I'll be testing the Alixperess buyer protection instead of starting a build..

If you do get a Sunhokey there is a good series of videos on building it here [www.youtube.com]

Here are some comments that I have shared with him

The basic Prusa I3 design is very good but it needs a stable base to hold its calibration and stay reliable. I used an off-cut of kitchen worktop (£5 from B&Q) and bolted it down with the z-motor clamps from [www.thingiverse.com] and some screwed in blocks front and rear to make it immovable on the base. I have mounted the base on a wheeled cabinet that I can easily move around that makes working on the back and sides very simple. I would regard this as essential before trying any of my other suggestions.

Basics
The Sunhokey implementation of the design is OK but as you have noticed there are a number of areas that can be improved. The 2015 model does address some of your observations about rod retention etc. but takes a step backwards with the control board as the new one is incapable of driving a second extruder. It is easy and relatively cheap to address this by replacing it with a standards RAMPS 1.4. I used [www.ebay.co.uk] which makes following standard How to's on the net easier than trying to translate them to a custom board.

Bed leveling
The Z-stop is a very bad design and will never hold calibration, a search for Sunhokey on Thingiverse gives a number of alternative designs to address this. I chose to go beyond this with an inductive sensor so that I could do auto bed leveling (basic concept shown here using a mechanical switch [www.thingiverse.com]). I have found that using a sensor rather than the servo/switch design better but glass on the heat bed can be a problem as inductive is very low range. I am waiting on delivery of a capacitive sensor which has a longer range to see if this is better I will also be trying an opto solution and will let you know my results when it arrives from America.

Hot ends
The hot end that comes with the kit is the cheapest of the cheap and not worth installing, I have tried various replacements from eBay and Amazon ranging from £6 to £30 which are a bit better but nowhere near as good as a genuine E3D-V6 [e3d-online.com] not cheap at £47 but less than the cost of all the failed replacements that I have tried.
Having a good hot end makes a huge difference in the reliability and quality of your prints.

X-Carriage
Although I haven't had a problem with X-Carriage stability, I decided to upgrade to this [www.thingiverse.com] so that I could different hot end mounts. This is a definite improvement on the original as you can easily switch mounts without having to disassemble the X-Carriage.

Dual Extruder
Having tried dual J-heads I now run an E3D Chimera [e3d-online.com] mounted with [www.thingiverse.com] this makes using PVA support very easy. My E3D-V6 is now used on my Kossel Delta printer. A second extruder drive is needed for this, I use [www.ebay.co.uk]

Thanks for your elaborate reply!
I have seen the build by Hiboson, excellent instructions, will be very helpful to get all parts mounted the right way.
The fact that sunhokey takes the trouble to make improvements to their design for 2015 was one of the reasons I decided to purchase one. It shows they want to deliver a good product instead of a lot of similar kits that don't evolve after it 'sort of ' works..
The challenge of getting the printer working as good as it possibly can within it's limits, is as important (if not more) to me as having a 3D printer in the home, so I will probably be making a lot of upgrades like you did.

I will definitely be bolting it to a solid base, I'll see how much flex there is in the parts once it's put together, if there are parts that show movement where there shouldn't be any I may still apply some glue to see if that improves rigidity.

BTW; it looks like my order is definitely a scam, well it was too good to be true.. Waiting to get refunded by Aliexpress and buy the real thing..

Edited 1 time(s). Last edit at 10/07/2015 03:35AM by fDutchman.

Hi guys,

Acrylic frame looks good. But it's the only good thing about it.
IMHO, at low cost you'll get a better machine purchasing a Delta printer.
If you want the good and the cheap, don't buy a kit,
follow a bom and source good components by yourself.

Don't even think to buy any good printer under $250.

++JM

Edited 1 time(s). Last edit at 10/09/2015 08:48AM by J-Max.

Thanks, I went for a Prusa i3 because it seems to be the most used for DIY builds and there is lots of information on building and troubleshooting them.
The sunhokey gets good reviews and many people get it running pretty decent (which at this price point is probably as good as it gets..)

I looked into building one from a BOM, but there are so many possible variations it dazzled me. I decided to go for a kit so at least I know I have all the bits that should fit together.
Once I get the sunhokey kit running and learned how every piece and setting interacts, I may build a better quality one from scratch, I definitely like the challenge, but are too much of a noob now the dive in that deep..

I got the acrylic from sunhokey a month ago. IMO it is good to get started with and build up some experience in 3d printing. If you are from the netherlands (which your name suggests), be prepared to pay about 58 euro in taxes a week after it has arrived. The only few things I improved was adding a fan to cool the board, else your extruder driver will get too hot. Using a glass plate to print PLA. Calibrated the steps for xyz and the extruder. This can easily be done in the display menu, so no need to flash new firmware. It prints fairly well, of course there are always be things to improve.

Yes, I'm in the Netherlands, I was expecting around €60 (48VAT+12 for FedEx), so it's good to see that figure confirmed.
Is there a glass plate included in the kit ? I guess that will put off the heat measurement quite a bit with the PTC on the aluminum plate, or don't you need to heat the bed for PLA ?
I read some people are using the cheap 22x22cm IKEA mirrors for the bed (they are very thin), not sure if that will fit on this printer.

Did you print some kind of cover to mount a fan on the control board ?

I printed [www.thingiverse.com] and mounted it above the board to blow down. I also used an extra output on the MKS board to drive the fan only when starting a print. More details [www.thingiverse.com] . The glass plate I cut myself from some picture frame I had lying around it is about 3 mm thick. I scratched the glass with a ceramic knife and then gently tabbed on it to break it along the scratch. Of course you will need to be a bit handy to do that. I also will not be responsible for any lost fingers... The glass works really well. The print will stick much much better to the plate then when using tape. BTW no hairspray or other stuff just keeping the glass degreased. 22x22 will be a bit large, You would need to break the corners of with some pliers else your adjustment screws for the bed will be in the way.

Cool, I'll definitely join the owners group on thingiverse, already seen some other things I want do modify -auto bed leveling looks like a very handy thing to have.

Do you still heat the plate with the glass on top ?

I think I have some larger heatsinks somewhere in the house will have to try if they fit the driver boards..
Can't put anything too big on there I guess, especially since they are separate boards.
Better cooling paste does wonders sometimes.

Can't wait to receive my kit

Edited 2 time(s). Last edit at 10/09/2015 02:14PM by fDutchman.

Having tried a number of auto bed leveling options servo with switch, inductive and capacitive sensors. The best one on my machine is optical from here [www.pibot.com] it is cheap and simply plugs into the Z end stop socket.

Quote

Do you still heat the plate with the glass on top ?

Yes, else the filament won't stick also you have to wait to let it cool down to get the print off. I use 65 for first layer and 60 for the next ones. This is for PLA. I am extruding at 225 -230 which seems a little high for PLA, but I guess the temperature measuring is a bit off on the Sunhokey. I still have to try ABS, I will soon order some to try out.

Wow that reflective optical end stop seems perfect for glass beds. If I ever need to level my bed again (it seems to stay in place for weeks) I'll look into it.

Yes it works well with glass. I forgot to mention that you need to watch out for other light sources (sun through the window etc.) to make sure it is not confused. Not a major problem, I just had to slightly adjust one of my spotlights. Also try and adjust the range as low as possible <8mm to maximize repeatability.

Ok, that's good, I was expecting infrared would not work on glass. That's definitely the sensor I want to use for bed levelling then.
Do you also use a sunhokey ? Which mount did you use for the sensor ?

Yes I have a 2015 Sunhokey but have done a number of modifications, please see my earlier post. For mounting the sensor, I simply used one of the screw holes on the fan of my Chimera dual hot end. Very quick and easy.