Bulldog XL with Hexagon hot end. 350g of solid extrusion!
I haven’t used any hardware/software end stops on my ORD Bot Hadron so far. If I make a mistake now and run it too far when going manual I guess I’ll have to look for the X-carriage out in the yard
This has got a very solid feel to it. If I have to complain about something I think it’s alittle much to require 5 different hex keys to take apart the Bulldog XL. Luckily it doesn’t have to be done very often since the drive gear can be removed by unscrewing a grub screw, easily reached without any disassembly.
Took the whole thing apart right away to see how it’s designed and also to clean out any debris from the manufacturing. It was actually pretty clean but it’s always good to be sure no little metal shaving ends up blocking the nozzle.
The heat break has a pretty small diameter, and the hot end will be actively cooled by the radial fan built into the universal mount that’s included with the Bulldog. Other people with the setup have not reported any problems, but I can report back whenever I’ve printed with it for awhile.
@Jarred_Baines Hexagon barstock is easily available and naturally self-centers in a 3-jaw chuck. So…use it as a marketing feature, the reality is, it makes it easier to machine.
Hex bar will be as easy to work with as round, might even be easier because you can hold it across the flats in a vice for further machining processes.
I was just thinking it may dissapate the heat differently, might have to have a sit’n’think on that one later…
@korpx - Where is that hot end from? Did it come with the bulldog extruder?
I’ve run a CNC lathe every second day for about 11 years now (every other day it’s a CNC mill :-P)
Feel free to hit me up if you have any Q’s happy to help.
It’s not as heavy as it looks, actually it doesn’t really weigh that much more than a wade.
The only negative thing i have to say about the bulldog is that it can be a pain to feed it new filament. I modified the pushfit on the feeding side so the ptfe tube goes right up to the transport. For my bowden setup i did the same on the other side and can now print elastic material with it rather easily.
The Hexagon is a thing of beauty, so far i did not have any problems with it at all, even though i tried with quite a few materials using the same hotend.
@Jarred_Baines You can see it in action on my Youtube channel
The setup itself isn’t that difficult. I drilled the pushfits up to 4mm from the thread side, not through but just a couple of mm. Then i inserted a short length of PTFE tube and cut it so it fits nicely between the transport and the idler. If you do this from both sides the filament isn’t going unsupported for more then a few 1/10 of a mm. For elastic material you have to cool the bulldog a bit, a simple fan is sufficent. You don’t see that in the video, since that is from an early try, but you need it for longer prints.
I initially meant to order a E3D but they were out of stock and at around the same time I saw some people in my circles like @Bjorn_Marl and @Adrian_Carter using this setup.
From what I understand the Hexagon also originates from Reprapdiscount. Due to Chinese new year I looked around in Europe and got both items from http://fabber-parts.de
Initial observations;
The whole setup with extruder, hotend, fan etc is 350g.
The gearbox seem to be metal planetary gears.
Axle for drive gear is 8mm with flat side for locking grub screw.
It is all nicely machined with very little debri from fabrication to clean out. Still do take it apart and check.
The heat block is smaller than for example the Stepstruder so the ceramic heater (which is included) is a bit smaller (15mm) than I am used to.
@Bjorn_Marl I agree the Hexagon looks nice. I like how you just remove that brass insert (and add one of the included pneumatic quick connectors) to convert it from direct driven to bowden.
For improvements they could have drilled the thermistor hole in the heat block a little deeper, threaded it for M2 from the factory and included a M2 screw with a washer to attach a thermocouple. Not a hard hack but a nice design feature.
