@Heyward43 Excellent info, H. Tks much. Iāve read on a few sites that, when we are doing intricate 3D or 2.5D pieces like these, the machine never really gets up to the speed we set. The ramp up time gets in the way. In pieces like yours, where there are a lot of small moves in all axes, Iām betting that this is the case.
I tend to be very conservative in plunges in particular, but I do end up using the feed speed bump up feature in UGS quite a bit.
Thanks again.
Another tidbit of info on the poplar material. Being soft like pine it cuts very easy. One advantage Iāve noticed is it doesnāt leave āfeathersā or āfuzzā all over the place like pine. It cuts very cleanly and makes sanding or hand finishing much easier. And Grant I used CNCjs for this one. You can bump up or down by either 1% or 10% at a time. I bumped mine up from 100% (100"/min) to 150% (150"+/min) a little bit at a time listening to how the bit sounded. Wasnāt much difference in the sound each time so I let it fly. I think 150"/min is about the maximum you can run the longmill. It was actually a noticeable difference in movement.
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@Heyward43 H: I make picture frames for 2 local artists and I use a lot of poplar. Here in the Great White North, Iāve learned that is a different species than in the southern US. I understand that, up here, it is a bit harder. I love working with it. It mills very well, takes stain very well and as you have said, it routes well, too. On top of that, itās not too pricey.
Thanks much for the feeds and speeds info. Iām still playing with that, and any experience that I can grab onto is very welcome.
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Heyward, good info on the poplar speeds & feeds. Itās a wood I havenāt tried, but Iāll certainly add it to my next order list.
Another positive for cncjs. Iāve been using it almost exclusively. If they ever get the autoleveling working Iāll be locked in.
@BillKorn Thanks Bill. I really like the poplar. The grain is so much finer and it really carves well. Plus you can find pieces with some color such as browns, purples, blonds and greens running with the grain. CNCjs has really been doing the work for me. I will probably stick with it for a while at least. Is the autoleveling something you use on your CNC mill or is it for 3d printing? I havenāt come across that before in cnc work.
Autoleveling was originally developed to help circuit board makers. Since they cut traces that are very shallow anything that makes an area of the board higher or lower, like boards that are not flat, causes incomplete traces or traces that are so wide they run into the adjacent trace. I thought it would be an easy way to use boards with cups without surfacing them, or large intentionally non-flat stock like previously milled topos. I tried bcnc, but it is really flakey, and has about the most cluttered and confusing UI Iāve seen. Another sender, OpenCNCPilot, has a decent autoleveler, but the manual controls are hard to get to, and I broke a couple bits and pegged the X axis when I thought I had zero set correctly but didnāt.
Iāve been impressed with your long jobs. The longest Iāve been able to sit and watch the action has been about two hours, even if Iām doing something else at the same time. Are you keeping an eye on things directly, or are you using a camera? Or have you done enough of them that youāre comfortable leaving them unattended? BTW, thereās a phone app called DroidCam that uses your phone as a web cam. I loaded it and it works, but Iām still antsy about walking away.
Two last question about poplar. How does it finish - Is it stainable, paintable, etc.? If it machines as well as it looks in your pics Iām thinking itās going to replace pine and plywood. And, is it available in 8 or 10" wide boards?
Thanks.
Bill
@BillKorn. Glad you like the jobs, Bill. I havenāt tried to stain any of the poplar yet. I may give that a try today on the Tree of Life that crashed. I have several different stains and finishes I can try. Dark mahogany, Danish oil, light walnut shellac, clear shellac and clear acrylic. Iāll cut the crashed piece up into smaller pieces and try them all. Iām fairly sure it will paint ok.
As for the long jobs. I usually sit and watch the carve from start to finish. Yep, itās boring but it has been so cool (40, 50, 60 degrees) I donāt think itās warm enough to try finishing in my shop/garage while itās carving. I may run into the house to get a drink, food or potty break but itās usually for only a few minutes. Like you I donāt want to leave it unattended for long. Iāll check out DroidCam. Sounds interesting. Iām not comfortable enough to be 30-40 feet away if something goes wrong.
I buy my poplar at Loweās. They have a section of precut pieces of pine, red oak, poplar, plywood and MDF. From 1x2, 1x3, 1x4 up to 1x12 and up to 48" long. I need to check out Home Depot to see what they have too. It can be a little expensive but the pieces are usually cut and finished very well. The 12"x24" piece of poplar I used was just under $12. I bought a 12"x24" piece of red oak and it was right at $16 but it was as close to perfect as one could expect. Of course you need to check measurements to be exact when using.
Thanks for the explanation on autoleveling. At this point I donāt really see a need for me.
Iāll post some pictures of my finishing experiment on the poplar soon if the weather will cooperate. Right now itās about 55 degrees with the wind blowing 20-40 mph. Not good for finishing in the shop and my wife wonāt let me stink up the house.
Poplar is great for painting. Staining, howeverā¦
It can be pretty blotchy if you use a penetrating stain (or any dye). If you want to go the stain route, your best bet would be a wiping stain or a gel.
@Iguana, @BillKorn, Thanks for the tip Mark. I sure you have the experience but I still want to try penetrating stain just to see what happens. I think I have seen some videos showing what you are talking about. Iāll have to pick up some wiping or gel stain.
@Heyward43 @BillKorn @Iguana I use a lot of poplar for picture frames. I think maybe the base of the penetrating stain may make a difference. I use both a wipe on and a spray on lacquer based stain, and I get no blotches at all. One key for flat work is to sand to 120, no finer. The fumes are likely taking years off my life, but other than that, itās a great product. I get it from a local supplier, so I canāt point to it at any box box store.
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You can also use a stain conditioner to reduce blotching with a penetrating stain. The drawback is that conditioners reduce the ability of the wood to absorb stain, and therefore you donāt get as dark or saturated color as you might want.
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Hey guys, thanks for the info. Itās apparent Iām way behind in my wood finishing skills. Maybe we should have a section for what you do with your prize milling job after it comes of the table.
Iām with you Bill. Iām not very experienced with the finishing skills. Just what I see on youtube. Iām sure there are a lot of people on the forum with lots more experience. Mark, Grant - hint hint. Sounds like we need another category for the forum.
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@Heyward43 @BillKorn @Iguana Guys: Iām happy to help any way I can. Iām far from expert, though. I have an excellent local source of lacquer based stains and use them almost exclusively. The only other stain that I use is a gel that is also very good. Wipe on, wipe off. For clear coat, I spray pre-cat lacquer mostly.
I laughed when Bill mentioned another section for our prize milling jobs. In my case, almost all of them go into the recycle bin. The exception being the few inlays that Iāve done.
Iād really enjoy seeing what the others here are doing, though.
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@andy @chrismakesstuff @gwilki @BillKorn @Iguana - Chris or Andy what think you about a Finishing Techniques category? Might help us less experienced finishers. There are so many different kinds of wood, shellac, paint, lacquer, dyes, etc. out there itās hard to figure out which to use. Itās too expensive in some cases to experiment even with scrap pieces.
Iāll open one up because you asked Heyward 
I donāt mind opening up a new category if it seems that it will help to better organize and share information 
EDIT: here it is: https://forum.sienci.com/c/finishing letās give it a try
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Thanks Chris. Hope it starts to fill up soon.
Thereās a whole science about feeds and speeds to maximize the life of the bits and produce the best cuts. A couple of years ago I purchased a license to a feeds and speeds calculator called GWizard. It does an incredible job of giving the correct feeds and speeds for just about any size bit, including the 1/8" shank bits with small cutting tips. With my previous CNC machine, it gave me very close to ideal results and I had to hand-tune only slightly on occasion, due to the fact the spindle I was using was a fairly low-power spindle (< 100 Watts, if I recall).
The relationship among the size and composition of the bit, the depth of cut, the power available from the spindle/router, the speed of the spindle/router, the feed speed, and the type of bit can get very complex; the program allows you to input all those variables and produces the resulting unknowns, including a warning about exceeding the amount of deflection that increases the possibility fo broken bits. Believe me, from experience, you donāt want a bit spinning at 20,000RPM breaking and flying off into a random direction. Fortunately, the one time it did that for me, it went in the opposite direction, but took a chunk out of the enclosure in the back. The only other times Iāve had a broken bit was when I had my zero point in the wrong place and the bit ended up digging far too deep into the material I was cutting. In those cases, the broken end was buried in the material.
For anyone who is interested (no, I donāt get any kickback), it is based on what I call a pseudo-subscription. For each year you pay, you get an additional 1HP rating on the spindle/router you use. During the time you pay, there is no HP limit, only if you stop paying. So, for example, if you pay two years and then stop, you get 2HP of power for the calculations. I donāt get any kickback from this, so, if youāre interested, just look for Gwizard using a Google search to find it - thereās a free trial period.
Michael
Hi! Is the max feed rate of the Longmill (30x30) 150 in/min? Iāve been trying to find the max listed somewhere, but canāt. Thanks.
@KMed Welcome to the group, Kevin, Iām sure that you will find it a friendly and informative place.
As to your question, the default speed settings on the Long Mill are 4000 mm/min (just over 157 in/min) for X and Y and 3000 mm/min (118 in/min) for Z.
You can find all the settings here:
The specific ones that you are asking about are $110, $111 and $112
Here is a post by Chris explaining why they chose those speeds and the implications of increasing them:
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