Do you have longer TPU bristles designed yet for LR4 dust shoes? I think you had mentioned it as possibility. I checked the Printables but only saw 22 mm there.
1 Like
Yes thank you! I was just thinking about that this morning!
1 Like
What is your endmill stickout and ultimate depth of cut? I am not interested in Mods until the instructions are done but we will get there. Give me your dims and I will keep a note.
Just to be crystal clear here. With TPU You can not just use a long bristle to solve issue it is tuned to how you cut. Super long and they are just going to suck into the vacuum. On a long bristle there will need to be a rigid part at the top before they get loose again. Do this wrong and you will drag and push on the router and lose accuracy, or get poor suction.
The ones I made are for up to 17mm DOC Standard stick out for all the endmills I sell.
2 Likes
Good points. I think my 1/4" end mill is not as far up in the collet as normal (down by maybe 3-5 mm), plus my dust shoe is mounted a little higher than normal, so those factors combined have me seeing about 1/2" of bit sticking out below the bristles. I can fix some of that by getting the bit a little deeper into the collet. Due to how I have my shoe mounted, I probably ought to think in terms of a set of bristles that are longer by some 5-8 mm. I’m typically cutting 19mm deep (3/4").
Start there. All endmills should be as deep as possible at all times.
3 Likes
Will do.
Just curious since you mentioned it, how important is the location of the end mill in the collet, as in if it is pushed all the way up or if it hangs out a bit?
My understanding is that to do full depth cuts you need all the cutting blade portion showing, but no more. Having more stick than is needed leads to more potential for deflection (“CNC-ese” for bit bending). I guess if you are not needing full depth cuts, you could put the bit even deeper into the collet, kind of like “choking up on the bat.”
1 Like
Always as deep in as you can go.
The more it sticks out the “longer” your Router becomes, the more the load is multiplied, the slower you need to go to maintain the same accuracy.
You can not cut any deeper than the flutes on your end mill so hanging it out does not gain you any depth abilities.
In metals, or super long bits in wood/plastic, tool deflection is also a concern. Shorter is better.
3 Likes
I’m just starting my Lowrider V4 build but one thing I want to resolve is the dust shoe design.
I realize for most people cutting 3/4” or 1/2” sheet goods the standard dust shoe will work fine.
However I’m making inlay cutting boards and when I work on the board itself which can vary in height from 1.5 - 2.5 inch material I am often making depth of cuts that are +/- 20mm for the inlays and when I cut out the profile that is +/- 30 mm depth of cut as you can see in the video linked below.
In general when I cut the plugs they are +/- 25 mm stock with +/- 12 mm d.o.c. The issue for me is that often the inlay plugs have super thin edges like less than a mm thick of wood sticking up. of course it tapers down to a thicker section but the top where the top of the workpiece is can be very fragile. Typically I will set the TPU bristles just above the top of the workpiece like a mm or two so the tip of the TPU bristles never actually touch the top of the material. This way I can insure that the TPU bristles will not damage the fragine thin strips of the plug cutouts.
unfortuanately with the current stock LR4 design the dust shoe will go up and down with the gantry and I don’t want the tips of the TPU to bury themselves below the top of the material. This means at the start of the job the tips of them bristles need to be +/- 12mm above the workpiece if the D.O.C. is going to be 12mm so that at the bottom of the cut the bristles will just touch or be slighty above the workpiece. In essence rendering the dust shoe useless for most of the cut.
it will still help way more than nothing.
Have you touched the tpu bristles? They are one layer thick, tapering up to two layers. They are super light touch. You can actually adjust how light of a touch if you mess with your printing layer height.
1 Like
I’ve not built the LR4 yet still using the Primo.
I’ll print the stock version of the TPU bristles and stock dust shoe (Modified version for a 65 mm spindle) and give it a go.
I agree that for most of my use cases the stock Dust Shoe will work fine.
I guess I’m just stubborn or more politely “Set in my ways” I just don’t like when things other than the endmill start going lower than the top of the worksurface.
If the TPU bristles are so thin that they just end up getting sucked up by the dust extractor again that defeats the purpose of the dust shoe.
Granted something is better than nothing. But optimal (for me) is for the tips of the bristles to remain at all times only slightly above the top of the workpiece. Maximizing the dust extraction.
The TPU bristles I have now on my primo are 12mm tall and .7mm thick.
They are just flexible enough to bend out of the way if they encounter an obstruction but stiff enough that they are not bent by the suction force of the dust extractor.
Yes and no. They do suck in, that make the vac work better until they touch something then they get moved around. The taper really helps with that, stiff up top away from the material, soft at the bottom.
I spent a lot of time on them not to mess with our accuracy. I really dislike seeing giant stiff bristles on some CNC machines. Those can easily mess your Z accuracy up because they are super stiff when over centering them.
Yes, but if the bristles never go below the top of the workpiece and stay fixed at a z-height of +/- 2 mm above the workpiece, then stiffness is a mute point because they are never applying any “force” to the machine.
Anyway, I really do respect your design and the effort that went into making it affordable and attainable for the most amount of DIY’ers possible.
I’m definitely on the edge of the intended users and as such have both the desire, and ability to make modifications and kudos to your design that it’s also easy to modify to each end users own needs.
I lost count of how many modifications I made to my original ANET A-8 3D printer to get it dialed in and printing perfectly for me. Not the least of which was adding MOSFETs to prevent the machine from lighting up like a Christmas tree on fire.
As a research Fellow at the U of M Virtual Reality Design Lab, I had access to high-end 3D Printers from Stratasys.
We designed and printed many variations of our own HMD’s which I found quite rewarding.
In fact, I enjoy modding the machine almost as much as I enjoy creating things with it.
1 Like
Makita mount is already 65mm. But the DeWalt shoe works better for the spindles where you need 2 wrenches. The dust shoes have no bearing on the size of the spindle.
1 Like
Yes I saw those instructions on the printable downloads for the 49/65 mm spindle mount.
Not Shure if I’m going to use those mounts or just make my own versions.
You wont be able to get it any tighter to the core than the ones Ryan made. And thats what you want for sure. Hanging it out farther will hurt the rigidity a good bit.
I ran a 65mm spindle on my LR3 and tried it for a while on my LR4, but the one I had I couldn’t mount the spindle high enough to make the collet the same distance. Having it hang lower than where the routers hang really hurt the rigidity a lot. Switched it out for a Carbide3d router with ER11 collet and it runs REAL good.
1 Like
As someone who does a lot of inlays: doesn’t matter. You could also just use the dust shoe when clearing and take it off for the V-Carve portion. I usually do that so I can see whether the CNC does what it’s supposed to do.
2 Likes
I agree, but then I would not get to experiment and make several prototypes before I get a working version, only to crash it into the side of a board because I forgot to remove it…. Um, or at least that is what has happened to me in the past with other crazy ideas I’ve had.
I could also just go bootless and run the machine all the time without a dust shoe, but the cost in shop air filters and detriment to my lungs might not be worth it.
4 Likes