After countless hours of adding to and tweaking the design, I am finally excited to say it is 100% done! This post will explain in short which choices and concessions I ended up making, and to what degree I stuck to the guidelines I set out for myself.
But first I’ll address my broken motor. I did a LOT of searching, but I couldn’t find a definitive source of reliable information on this exact model. There were many conflicting opinions on the matter, and the fact that different versions of the K40 have differing motors did’t really help my investigation.
After a while though I got lucky and stumbled upon the website of the original manufacturer of the motor: http://www.baolongmotor.com. In the end, the ‘dragon’ logo was a dead giveaway. I contacted their support team, and they proved surprisingly helpful. Below is the spec sheet they sent to me, accompanied by the sheet of the replacenment motor I bought (not from them ;-)). Seems close enough to me.
And in order to help anyone that is looking for this same info: The Y motor of my K40 with part nr. 17HM4410N is hereby definitively identified as a 0.9deg 1.0A motor. Here’s how the naming scheme works as far as I understand it: (But when in doubt, just mail them)
So, let’s now look at the design I settled on. First of all: I chose a name for my creation: LAYZOR. I kind of like it 😉
disclaimer: this is a K40 conversion, not a from-scratch build.
The LAYZOR houses a 700mm 40W laser tube and has an effective working area of 400 x 600mm, expandable over the X axis with the feed-through hole in the front and back. Overall footprint is 1000 x 650 x 320 mm. Cladding panels are 3mm acrylic (better safe than sorry), bottom side is mainly metal.
There is a hand-cranked adjustable Z with about 130mm of travel. Not that you’ll be cutting this deep, but it allows for thick material to be put in the machine for engraving. 1 full rotation of the Z-wheel equals 1mm of Z travel. Fast Z adjustments are possible with a power drill. The bed has a 400 x 600mm honeycomb.
Fume extraction is handled by an integrated 4″ 270 CFM fan (as opposed to the original crappy 88 CFM one). Water cooling setup is also fully enclosed inside the case.
Other than that, most of its internal parts are still the original K40 ones, as this conversion is only focusing on making the machine a lot better with minimal investments. Future upgrades will tackle the optics, electronics, water cooling, air assist, etc. The idea is that the conversion is modular, so anyone who wants to do the same thing with their machine can choose which upgrades to add and which to ignore.
So let’s have a look at the rules I set out for myself:
- Use as many original parts as possible. Need as few custom parts as possible. Use parts I have lying around when possible. Check!
- Feature a work area of 400 x 600mm. This is 4x the original area and imho a good balance between ease-of-use and size. Check!
- Feed-through design so any length of 600mm wide stock can be loaded and cut via tiling. Check!
- Total footprint must not exceed 1m in width, 750mm in depth and 350mm in height. Smaller is better. Check!
- No external water cooling/venting solutions. Everything must be contained within the case. Check!
- Adjustable Z honeycomb bed. No more rusty nails for me 😉 Check!
- Air assist if possible within the budget. Future upgrade!
- All aluminium profiles must be cut from a max. of 10(!) 1980mm length extrusions. Check!
- All cladding panels must be cut from a single 1 x 2m sheet. Preferably acrylic for safety reasons. Check! Look at the panel layout below to see how little excess there is 😉
- Total conversion cost must not exceed 500€ ! Current tally at 491.18€! Will update when this changes upon building.
So, as you can see, I met every goal, except for the air assist. But, lets be honest. Getting that within the allowed budget was a bit optimistic to begin with 🙂 . I am thrilled this worked out the way it has. The design features some elegant solutions and creative uses of stock parts. The final footprint is as compact as I could physically get it, and given the price at which all of this is possible, the conversion looks to be a no-brainer.
I am sure I’ll encounter some unexpected surprises when building it, but you’ll be able to read all about those (and the solutions) in future posts.
To finish, these are the parts I managed to reuse:
- lens holder
- cables PSU-controller
- controller board
- 4mm and 8mm spacers
- X belt locking plate and pulley
- Y belt locking screws and pulley assemblies
- Y rod bearing + bearing holder
- USB key
- rubber feet
- 1st and 2nd mirror
- laser tube brackets
- Limit switch boards
- X motor
- Y motor
- small metal bracket
- various bolts, washers and nuts
- control panel wiring
- 40W laser tube
- black L profile
- the salvaged metal bottom plate
All the rest I threw away.
Parts are coming in every day now. Expect regular updates next month.