I’m about to do a surfacing run on a new MDF spoilboard. I’ve got a 1 1/8” surfacing bit and it’s using a Makita router as a spindle. What kind of feedrate and stepover % should I use? I haven’t really put much through my MPCNC so I’m a bit risk-averse to having it go too fast, and previous surfacing attempts with this bit had some odd high spots between passes.
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With that size bit you need to make sure your router is trammed in REAL well or you will have big ribs. Its usually suggested to use something like a 1/2" dovetail bit for this because it is much more forgiving and you can go a lot faster with it.
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Dang, I don’t think any places near me sell dovetail bits. I have a 1/4” 2 flute straight bit, could I use that assuming I set the stopover to around 15-20%? I didn’t have much luck with it on my previous spoilboard, but that was crappy particle board.
Tramming seems like it’ll be a bit of circular logic - to tram the router I need a known level surface, to get a known level surface I have to surface the spoilboard.
I would go up to around 40% personally. Probably could go even more. Just take light passes. mm or less per pass. I usually take a pencil and draw lines all over the board so I can see where it got and where it didn’t. Make more passes until it hits it all.
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Just to be sure, this is the 2-flute bit in question that I have on hand - am I OK to proceed with this and 40% stopover? And what kind of feed rate should I use?
I think you’ll be fine at 40%. Feed rate depends a lot on your machine. Without knowing anything about it my first guess is 20mm/s and speed up/slow down from there depending on how it acts. Keep your router speed down lower so you don’t burn up the 2 flute bit.
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One thing I realized I didn’t mention - my spoilboard is around 40”x24”. The 6mm 2-flute will take 90 minutes to run. Is that normal for surfacing? (And how screwed would I be if I use the 1 1/8” bit without any tramming other than squaring my MPCNC and running the regular touch probe at the start of the job)
Its not a fast process. And depending on how bad it is, you might have to run it more than once.
You can for sure try it. You might be good to go with it. But chances are your going to have ribs. But then you could do one final pass with the 2 flute and smooth that out.
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You could also wait a little and order one like this 1/2" Dove Tail Bit
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I ran my surfacing endmill (16mm) with 0.5 to 1mm DOC with 5000 to 8000mm/min with the LR4. There is basically no load and otherwise it gets really hot, because there are not nearly enough chips to dissipate the heat.
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I think I should probably bite the bullet and tram the router. I’ll probably be swapping it in and out for pen and drag knife mounts but at least if I tram it, I can mark where each shim went and keep it close to the right tramming.
I’ve got a tram part printing and have a big mirror that I dug out - do I just measure the tram distance at a few 12/3/6/9 o’clock points, calculate the amount of shim I need on average, then cut enough soda can chunks and shove them between the router and the mounts?
A lot of us just use tape as the shim. Then it will stay on the router when you take it out.
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I’ve spent some time tramming and shimming, but I got to the point where I couldn’t cram any more shims between the mount and the router.
At this point I’m thinking this wiggle is probably related to my tramming issues: https://imgur.com/a/pxNzr0v
Should I be tightening some bolts on the core or core clamps to get the wiggle eliminated and if so which ones?