Bulldog XL all metal extruder.

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Flateric
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Bulldog XL all metal extruder.

Post by Flateric »

I just got my bulldog all metal direct drive extruder today. Got the XL model with the gearhead on it.

I'll let you know how it goes.

http://www.indiegogo.com/projects/bulld ... t/x/906263

Anyone ever use a Merlin hotend before? Tiniest little nozzles I have ever seen in my life. Like the size of 5 grains of sand.

**Aparently the nozzles are from airbrushes. An interesting idea. I had thought of using a gas nozzle from a Oxy/Ace cutting torch at one point, this would offer up to 6 very closely packed nozzles with a central larger nozzle for cooling or other uses.
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Nylocke
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Re: Bulldog XL all metal extruder.

Post by Nylocke »

Is the merlin all metal, or is that PEEK running up past the heater block?
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Eaglezsoar
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Re: Bulldog XL all metal extruder.

Post by Eaglezsoar »

Quick, Quick, Quick. I want to know before the campaign ends! :P
Did you buy just the XL or did you get the two hotends with it?
Does it come with any instructions?
Inquiring minds want to know and so do I!!!
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Re: Bulldog XL all metal extruder.

Post by Flateric »

Does not come with instructions, bought the whole kit with all the trimmings, have not yet used it because I had to go and help a friend with computer problems.
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Nylocke
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Re: Bulldog XL all metal extruder.

Post by Nylocke »

BUT IS IT ALL METAL? this question is killing me mate!
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Re: Bulldog XL all metal extruder.

Post by Eaglezsoar »

Nylocke wrote:BUT IS IT ALL METAL? this question is killing me mate!
Mike, the picture I saw of the Merlin hotend looks like it is made from tan peek.
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Re: Bulldog XL all metal extruder.

Post by Nylocke »

I saw that, but I wanted to double check that it wasn't some kind of weird coated copper or brass or something else. So its basically a thiner J-head with replaceable super thin nozzles?
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Re: Bulldog XL all metal extruder.

Post by Eaglezsoar »

Nylocke wrote:I saw that, but I wanted to double check that it wasn't some kind of weird coated copper or brass or something else. So its basically a thiner J-head with replaceable super thin nozzles?
They don't give a lot of info but flateric says that the tips are from the air brush line. Can you imagine how long a print job would take with a .1 nozzle?
Must be used for small highly detailed parts. I'm just guessing here, I have no idea what the nozzle size would be but they appear to be ridiculously small.
I'm really anticipating flateric's report on the extruder.
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Re: Bulldog XL all metal extruder.

Post by cope413 »

The thing with smaller nozzles, though, is that you can typically print faster with them.

My .25mm nozzle does take longer to print with, but I can really crank up the speed with it, so it's not THAT much slower than my .4.

But .1mm seems superfluous. If you want that fine of detail, get it printed on an SLS machine
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Re: Bulldog XL all metal extruder.

Post by Flateric »

The extruder is a great piece, really quiet, very fast retracts and very precise. The Merlin hotend is a nice hotend for low temp filaments. The airbrush tips really make very very nice clean deposits but I have found the it does seem to plug up fairly easy. These tips are VERY tiny in overall size and in nozzle sizing. Still playng.
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Re: Bulldog XL all metal extruder.

Post by Eaglezsoar »

Flateric wrote:The extruder is a great piece, really quiet, very fast retracts and very precise. The Merlin hotend is a nice hotend for low temp filaments. The airbrush tips really make very very nice clean deposits but I have found the it does seem to plug up fairly easy. These tips are VERY tiny in overall size and in nozzle sizing. Still playng.
The two holes labled adjustments, I take it that is what you use to tighten the filament against the hobbed wheel but why two?
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Re: Bulldog XL all metal extruder.

Post by Eaglezsoar »

Nylocke wrote:I saw that, but I wanted to double check that it wasn't some kind of weird coated copper or brass or something else. So its basically a thiner J-head with replaceable super thin nozzles?
How would you like to find out for yourself? I have two of the Merlins 1.75 and 3mm filament and I do not have a use for them and since I like you I am going to offer you a great deal.
Shoot me a PM with the shipping info and I will send them to you for free. These are brand new with all the accessories and they are not all metal, I told you the tan color gave away the fact that they are PEEK.
This offer is to Nylocke only so don't everybody hit on me about them.
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Re: Bulldog XL all metal extruder.

Post by Flateric »

Ya, those two holes are the spring tension adjustments.

This is a really great extruder, I have only had to make one modification to it however to prevent the filament jamming up in the roller area.

Basically the extruder is no doubt designed for 3mm filament IMO, you can see this by how the holes align with the roller when using the 1.75mm collet fittings. The alignment seems to force the thinner filament over towards the drive wheel a little more than I am comfortable with. I also feel that the distance from the exit point of the drive wheel to the entrance to the lower hole and then out of the body is a little too long. I solved this problem by using an e3d style bowden connection that allows the bowden tube up and right into the extruder near the drive wheel. This prevents the filament from kinking because there is now space for it to before entering the tube.

Very precise extruder though, very fast, quiet and solid.

Make sure you get you steeper current set right so that you do not overheat the stock nema17 motor.
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Re: Bulldog XL all metal extruder.

Post by Eaglezsoar »

Flateric wrote:Ya, those two holes are the spring tension adjustments.

This is a really great extruder, I have only had to make one modification to it however to prevent the filament jamming up in the roller area.

Basically the extruder is no doubt designed for 3mm filament IMO, you can see this by how the holes align with the roller when using the 1.75mm collet fittings. The alignment seems to force the thinner filament over towards the drive wheel a little more than I am comfortable with. I also feel that the distance from the exit point of the drive wheel to the entrance to the lower hole and then out of the body is a little too long. I solved this problem by using an e3d style bowden connection that allows the bowden tube up and right into the extruder near the drive wheel. This prevents the filament from kinking because there is now space for it to before entering the tube.

Very precise extruder though, very fast, quiet and solid.

Make sure you get you steeper current set right so that you do not overheat the stock nema17 motor.
Did you tap the holes to fit the special threads of the E3D bowden connector?
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