Sunlu Filament Dryer Modification

The Thing…“with warranty”

Followed by the thing “void of warranty”

I’ll be posting the full Mod having found an easier way to remove the LCD screen and the lid.

Having had a closer look in side, it appears this might be another way of mounting the circulation fan to the bulkhead.

Mock up, Just needs a 24V Fan

Like this

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Reviewing the Sunlu Filament Drying Box.

Having powered the Sunlu Drying box, it’s become more apparent that as is, it’s not fit for purpose “my personal opinion”.

The box did get hot quite quickly and reached it’s set temperature because the thermistor is at the bottom and only “mm” away from the heating element.

To get to the thermistor, the heating plate needs to be removed, it’s held down by 4 screws, 2 on each end. The heater will not simply lift off as it’s wires pass through the bulkhead and into the controller board

To make life easy pop these hinges suing a small screw driver, pop them off at the ends as shown making sure that they will pop straight up, otherwise there’s a possibility something will break.

To remove the facia first pop this clip, you’ll need a thin screw driver, “warning” it requires some force to bend it far enough to release, use just the right amount of force. When it pops the screw driver may follow through and damage the display pins…

I filed a little off this to make it easier to remove should I need to later…

This was a bitch to pop off but maybe it’s me as I’ve lost some strength since the stroke. I’ll be notching a slot for the screw driver should I need to dismantle it later.

Unscrew the PCB and remove these connectors, be careful with the 2 small ones, they are very fragile.

Now you can draw the heater connector back into the box and lift the heater out.

The thermistor is now accessible

Get all your bits together

Some minor adjustments to the dimensions and adapter test print is ready. This red PETG filament as can be seen seems to be more hydroscopic than the black.

I’ll be printing one adaptor with ABS later, the next job will be to solder the fan wires to this jack.

I made up a lead with a servo connector to facilitate a quick and easy replacement of the fan.

A servo connector to the fan and it’s now plug and play.

I cut and extended the thermistor wires to be long enough to reach the top of the box.

I slotted the screw holes in order to push the heater a few mm back so that the top of fan has clearance from the heater element. I also cut and bent the plate up for greater air flow.

Same to the other end.

Short power up to make sure all is well.

Thermistor ricer wire

Thermistor in place, just taped for now.

All assembled and ready for the next job.

I was thinking of mounting this inside, more for the humidity gauge, I want to experiment with humidity to find the best printing range.

Changed my mind and bought a round one as I have got some hole saws, easier and less messy.

Unexpected bonus this box fits perfectly in the printer, almost made for it.

I’ll be box converting the box to a cosy, using behind the radiator insulation, also notice I cut the top of the box and glued it to the bottom so I have a handle to lift it with.

A 24H test showed that the humidity only increased by 2% therefore I’ll insulate the ends too.

Max Temp is 50C

Since the box is a fit in the printer, I decided to mod the printer, first a 4 mm hole.

Passing the tube through.

Into the box which will be powered up during printing too.

Conclusion, this dryer needs this mod to work at it’s best, but I will be starting the filament off in the fan assisted oven as it draws a lot more moisture quicker than this dryer.

A nice little project that has kept me busy….:grin:

You’ve modified a modification? :slight_smile:

How long has this project taken so far mate?

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The box was delivered Oct 29, so 8 days from delivery, so not counting all the other things I need to do daily and once a firm decision was made as to how I’ll do mine, I’d say approx. 4 Days.

I really want to have a go at rotating the filament while it’s drying and maybe I might build a custom box with a motor… :thinking:

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This mod has driven a complete reset of my printing profiles.

I’ve had reasonably good prints in the past, now that I have printed with an average humidity of 25% and a filament at an average temperature of 37C the surface finish is brilliant.

Armed with my setup spreadsheets I’ve begun to go through all the settings.

Filament and dryer inside the printer where now it’s also benefiting from the printing heat.

In order to have consistency in my prints, I’ve had to reset most settings, here a speed block.
In this picture there’s stringing and ringing and the bed is now too close to the nozzle. I had to raise the bed by 0.02mm otherwise the plastic bed will not fully release the print.

To follow, a mod is brewing….:thinking:
“How to consistently set the nozzle gap” at all points exactly the same.