I’m having issues with the cut not being straight on one side and being in steps(see picture). I’ve tried drawing with a pen and it works well but with an end mill it doesn’t cut accurately? The piece I cut was just a square so no complex shapes.
Is it like that in all directions? Which side is that? I am guessing that this is the edge parallel to the wheels, and they are moving laterally. I saw something like this and I cut some strips of 3/4" ply 3/4" wide and nailed them in next to the wheels to keep it going straight. I’ve seen others use a router to cut a round channel to keep the wheels in place.
Otherwise, Are you skipping steps? I’m guessing not, since you are clearly chewing through a lot of material at the end.
Yep it’s parallel to the wheels (y axis) Only both sides. I think you are right the wheels aren’t moving perfectly straight along the table. Is there any more solutions to this? I have used the wide skateboard wheels (see picture)
This is what I did: Jeffeb3's Low Rider Build
It doesn’t happen on Ryan’s machine. I suspected at the time that my pipes were in a trapezoid shape. But we don’t really know what causes it.
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That’s a good idea! Will my wheels get stuck if they do not travel along the edge of the table I.e collide with the edge of the barrier? Also can I tighten the belts or do anything else to ensure the y axis runs perfectly straight?
Mine don’t bind up. Just be careful about placement. You want them as close to perfect in these aspects:
- parallel to each other
- exact distance between the wheels
- perpendicular to where you start the gantry.
Mine are parallel to the edges of the table and I used the gantry to determine their width. I always start my gantry at the front edge of the table, so it stays as perpendicular as my table (very).
They aren’t tight to the wheels, just enough to keep the wheels moving straight. Just a nudge.
I will check all of these and run a test to see if anything has changed! Thanks for your help
I have noticed I can get a bit of stepping when using a 1/8" bit to do deep cuts, or when the speeds are a little too fast for a harder wood. I especially notice it with 18mm plywood and solid wood of similar thickness. If I need detail and am not going too deep I prefer to use a 1/8" bit with a 1/4" shank.
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Ah okay what speeds should I be using for 12mm birch plywood (also spindle speed)? I noticed both sides are leaning back under the weight on both sides. I have tried adjusting the position of it on the metal poles but it still leans out. Any advice?
I am using a Dewalt 611 router as Ryan recommends, at full speed usually. This is something like 24000 rpm. Many Spindles do about 15000 rpm I think. I only get wood burning with old bits.
I set the speed for no faster than 30mm/sec for the rapids and usually something like 15 to 20 mm/sec for a 1/8" bit to cut. The router can cut faster with a 1/4" bit of course but the edge might get a little ragged with fuzzy bits. These are easily removed with a bit of sandpaper. I could use a faster ‘rapids’ speed but I am not that impatient and have found I just get into trouble faster… Solid carbide bits usually and carbide edged bits for V Carving.
I will usually do the project Cutout at the end with a 1/4" bit (like a sign) and don’t get a stepped edge as a result. If the material is 3 or 6mm plywood I just stick with the 1/8" bits. If it is a small project then 1/8" works well usually.
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If i use a a 6mm bit instead with a 6mm shaft what speeds would and depth of cut would you reccommend?
6.3mm = 1/4". I suggest starting with 3 to 4mm depth at 25 to 30mm/sec on cut on a scrap piece and see how it turns out. If it’s too ragged or your spindle doesn’t like the load then start changing things. If the project is not too big it doesn’t hurt to go a little slower or shallower. I prefer upcut bits unless you need a really smooth top surface, then use a downcut bit. The problem with downcut is they tend to pack the sawdust into grooves and increase the workload as the depth increases as a result. The bottom surface will be ragged with a downcut just as the top can be that way with an upcut. I haven’t tried compression bits which are supposed to be a compromise.
For carving with a round nose you could start with 2 to 3 mm depth and check your finish.
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That is pretty fast. and a good bit of depth at 6mm. I would start much slower than that. Like 10mm/s. Deeper is easier than faster.
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