Originally shared by Yuusuf Sallahuddin (Y.S. Creations)
Here is my 3D printed air assist, with the lens holder mounted in it. As you can see, the lens holder is a perfect fit (very tight also), so the 4 bolt mounts that I added were unnecessary. Also, if you look at the photos, on the base you can see that 1 of the 18 outlet nozzles snapped off. And on the side, the inlet nozzle snapped off. This happened with almost 0 pressure applied to it (i.e. I just bumped it). Poor design on my part, as I wasn’t aware of the weakness of the join on such small join areas.
Revising the design now to cater for these weaknesses. Also, have decided that rather than having the inlet nozzle just attached to the main ring, I will have it as an insert than can be removed or swapped with a different one (for different diameter air hose).
Your design has a few advantages from stock air assist nozzels ,1 air dos not come in contact with lens ,so mositure or oil on focal lens and 2 you do not have to have worry aout the laser beam hitting side of air assist-so no aliging laser http://head.it may have 1 disadvantage of maybe moving work peace [stock air assist has the air going straight down
@Phillip_Conroy Thanks Phillip. I think it is possible that it may move the work piece, however as all 18 beams of air that exit are at the same angle & hit the same position, shouldn’t the air pressure in each direction be equal (theoretically at least) and cancel each other out?
You may be right ,proberly overthinking things ,pressure may be diffrent on oppeset side from air inlet,
@Phillip_Conroy Will never really know until I test it. Unfortunately cannot test this one since I snapped it’s inlet. However, I am considering having 2 inlets, directly opposite each other. To even the pressure from both sides. Or, splitting the single inlet down the centre (so it funnels half the air right & half left, equalising the pressure on both sides).
when you get this working and if it does not move the work peace i would be interseted in buying one ,ps nice fingerprint on focal lens,are you using stock 12mm focal lens?
@Phillip_Conroy Ah yeah the fingerprint is just because I was seeing if the lens mount fits in the internal hole. Wasn’t being careful as my machine is not in use for a bit (until I get this sorted). I’ve made a new model for it & tagged you. I am still using the stock 12mm lens 50.8mm focal length. The air beams align to hit that 50.8mm position. I will have to let you know after I get the print done again. The guy I used prints in Resin & the cost for the previous one was $20 setup + $10.51 materials. For extra prints of the same object, it is $10 + $10.51 materials. So will be $20.51 (for the previous one). May be slightly different for the next one as the design and dimensions have changed.
Still cheaper than what i have spent to prevent water and compressor oils hitting focal lens- you should sell them for at least $40 AU
@Phillip_Conroy Can’t hurt to try sell them for $40 if they work as desired. We’ll have to wait & see.
I wonder if those fragile nozzles are really necessary? An open hole may work just as well. I also wonder if there is a way to make a head like this just cutting and drilling acrylic with the laser (that would help those with no 3D printer).
I imagine a multi-layer structure with a ring of holes in the bottom plate, a spacer plate that creates an air space and a top plate. The air would not exit at an angle but a straight curtain of air may work just as well. the air exiting the holes will diverge anyway. MM just pontificationg…
You want to add fillets to the base of each air port. This will add a lot of strength to those at the base.
You could just fuse the nozzles into an annular ring?
Also print undersized holes and ream to size for smoother exit?
You can probably save the 1st one by pressing a piece of tubing in place or using a 1/16" pipe tap (but most people don’t have one)
That should work great for engraving ply wood etc, maybe eliminate the need to tape (and remove ugh - the tape)?
(Gotta build one of them newfangled gadgets - very nice piece, it would take me 2 days (at least) to make one on mill and lathe)
@donkjr Interesting thought to make with the laser. Unfortunately, the air not focusing on the sweet spot defeats the purpose for what I was going for, but it could be a makeshift option for those without 3D printer as you said (although I don’t own a 3D printer).
@David_Cook I’m not certain what fillets are, but I’ve modified the design totally to have more conical nozzles for all the outlets, to give extra strength. I have never done a 3D print before this one, so I was unaware of limitations/strength issues. If you check my profile there will be a recent post with the modified design.
@Scott_Marshall I did consider fusing all the nozzles into a ring whilst doing my newest version of the design (I started numbering them so I can keep track of it… v1.02 now). I think the first one is savable, I will do something to bodge it up to be functional, but will get the new version printed once I nut out the design. I’m working with basic ideas as I have zero engineering/etc knowledge. Input from all of you who have this knowledge is much appreciated.
Also, what newfangled gadgets are you referring to?
@Yuusuf_Sallahuddin_Y I am not convinced that by the time this air gets to the surface it will matter … yet
@donkjr No-one really knows as yet, until I can do some tests of it. But I can tell you for a fact that the air does focus exactly into 1 point (designed for 50.8mm away from lens, however no way to really check if it is hitting this spot). But I do notice that it focuses in a V shape, then after that point where it combines together, it seems to defocus into an upside down V shape.
Not sure if it will make much difference to cutting/engraving, but I dislike the heads that are currently purchasable. My main aim was to create something low-profile, with a cone of air to protect the lens from smoke. Secondary to that is the heat reduction at the point of laser impact & dispersal of smoke in all directions instead of just 1 (the back of the machine) as it leaves stains on leather when I cut it. We’ll have to see if this actually performs what I was aiming to do (when I get a new one printed with the revised design I have done).
Don’t get me wrong I like your idea… I am likely to make a flat acrylic one like I suggested and then just drill the holes at an angle … I am also wondering about integrating a laser pointer with leds positioned the same way …
another embodiment is to integrate a micro blower … eliminate the whole pump thing…
@donkjr On one of my other posts about this (on my main profile page) @funinthefalls mentions an STL file he has for a conical air-assist head that has integrated laser pointer mounts also. You could check with him for the file/thingiverse link for it as it might give you some ideas for your acrylic cut one. Drilling the holes at angles is workable if you are capable of doing so. My concern with me doing that is that I for certain cannot get close to the same angle for all 18 holes.
If you have access to a drill press, just shim one side of a plate up (fire up your High School Trig for how much), or tilt the table accordingly (if it’s capable)and turn, drill, turn, drill, etc 18 times.
There’s a gadget machinists use that’s an expensive version of this called a Sine Plate, actually, this is a cheap version of the Sine Plate…
It was just a thought in any case, I’d bet it works fine as printed, but I’m a machinist at heart, and you know the saying, “When your tool is a hammer, all the world looks like a nail…”
Wish it didn’t cost so much to send me one, I’d buy one from you if you were a few thousand miles closer…
I may make an aluminum one some rainy night when I feel like making chips. Especially if you’re kind enough to send me dimensions…
Just got an idea. Could you integrate a cone type single nozzle and a 2nd inlet to supply it?. Then you would have a software (or manual valves) select air assist system. Outer ring, Center, both. (Engrave, cut, super) The cone would also give protection to the bare lens. Seems to me a marketable device.
Again, just thinking out loud…
Sure wish I had time to try all these great ideas. I can get into trouble myself, now I have ideas pouring in from here.
@Scott_Marshall I do have a drill press & I get what you are saying about shimming up 1 side of the plate. My drill press is an extremely old one that belonged to my grandfather & the main platform is actually rotatable I think. Or maybe I stuffed something up when I did that haha.
The angle is very precise, I already know it because I had to get it in order to angle the nozzles in the first place. 17.25 degrees for this one. It has changed in the new revision (because the nozzles are slightly further away from the centre axis) to 18.4998 degrees (may as well be 18.5, but I thought that 0.0002 may make a difference lol).
You could actually get it 3D printed from a more local printer using 3D Hubs website. That’s where I got it printed (as I don’t have a 3D printer… yet). That would work out cheaper for you.
That’s an interesting idea to integrate a conical nozzle as an extra. Could be done I suppose, can’t see why not. Might have to have a bit more discussion about that idea with you & we can draw up some designs.
I’ve just done a test of the one that I had printed (even though I had snapped bits off). I managed to dodgy up a solution to use it, but I found that my airpump (aquarium one) is too weak to push much air pressure through all 18 nozzles. This is an issue I didn’t consider to begin with. So I snapped off 10 of the nozzles & covered the holes with electrical tape. Using 8 nozzles with my low air pressure seemed to work okay. I’ve posted a youtube video that I recorded (with my LaserCam mod) of the air assist in action whilst testing some vector engrave stuff at the same time on 3 different materials (MDF, leather, ply). So 3 tests in 1 lol.
I’ll share the vid to K40 group once I add some photos of the end results.