Folks,
Should I be concerned that my 1”surfacing bit will tip into the 3/4” wide T track channels created on my waste board? I would be running the bit parallel with the T track. Would running it perpendicular to the T track be safer? How would I set this up in V-Carve Pro?
Thanks, Mark
Hey Mark,
usually the wasteboard slats are much thicker than the T-slots height.
Although the idea to have T-Slots flush with the MDF would be nice, in order to use Veritas Bench Blades for T-Track.
Milling the MDF slats flush with the T-Tracks when they are mounted is nothing I would do. I would mill the slats before you assemble them into the tabletop / QCW Frame.
However I would not object if you trust the accuracy of your machine and your g-code program, and your bit length / Z probing, when doing such a milling job. And that the bit diameter really corresponds to the specs.
Be sure that your machine base is properly rectangular (“squared”) (bar gauge) and coplanar (“not twisted”) (fishing line method) and that your Z mount / milling motor / spindle with the bit is absolutely perpendicular to the (squared and untwisted) machine base / table top / QCW frame.
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Thanks for the reply, Aiph5u. I’m going to do what seems the simplest thing, take the T tracks out, push the waste boards together, screw them down and surface from there. I’ll square and coplane according to your advice first. Thanks again, Mark
Are you concerned with the bit touching the T-track? Or are you concerned with the bit overhanging the gap between wasteboard slats? If it’s the latter, this is totally fine.
I’m going to do what seems the simplest thing, take the T tracks out, push the waste boards together, screw them down and surface from there.
This is probably not a good choice. Moving the slats back to their desired position after surfacing is going to reintroduce errors from the table underneath, unless you also plan to surface the table first. But even differences in how tightly you screw down the slats can make a difference when they are moved. It’s best to surface the slats in their final mounted position.
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If the T-tracks are at the same or higher height than the wasteboard, there’s no real point in surfacing the wasteboard, as the top surfaces of the T-tracks will set the plane of the machine. As others have said, usually the top surface of the wasteboard is much higher than the top surfaces of the T-tracks, so the wasteboard can be surfaced multiple times before replacement; e.g. my wasteboard height is 1" and my T-tracks are only 3/8" high.
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Thank you all for the good advice. Matticustard put my suspicions into words-reassembling the whole thing would cause other problems. I am going to put the slats back together with the T tracks and surface. I have ordered a 1 1/2" surfacing bit so that should work better. I was concerned that the 1" bit would not be able to run over the gaps created by the T track channels without accidently dipping into them. Of course, the T tracks are lower than the slat tops. I’ll give it a shot with the 1 1/2" bit. They don’t call it wasteboard for nothing.
Happy Thanksgiving all.
Mark
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You could surface with a 1/8" bit and it would not drop into the T track gap, you could use any diameter bit
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I think there may be some confusion as to what you mean by this. The router has no concept of its surroundings. It will happily cut air — there is no requirement for the bit to be in contact with the material. It will only “dip” if instructed to do so, if by “dip” you mean to move down along the Z-axis.
If you are using a Makita router, make sure you don’t burn it up attempting to use a bit this large.
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Matticustard,
Thanks for the advice. I will try it with the 1” bit. I thought there might be the possibility of the 1” bit “dipping” into the 3/4” channels in which the T tracks were set. From what you say the machine will hold the bit up sufficient to keep that from happening. Thanks for coming back to me on this.
Mark
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Hey Mark,
a 1/4" T-track is 3/4" (19.05 mm) wide and 3/8" (9.5 mm) high.
Image: Jig and Fixture Tracks – Lee Valley Tools Ltd. Ottawa ON
If you take MDF slats of 3/4″ (19.05 mm) (or as Onefinity shows here, of 22/32″ (17.5 mm), then you see that you have plenty of MDF that you can resurface many times before you reach the T-Tracks one day. When you surface the wasteboard, you only take a thin layer away.
Just be careful with the hand trim router burning. Makita sells only bits with 1/2″ (12.7 mm) maximum for it, and they surely know why. As was reported here in the forum multiple times, it was often when using large surfacing bits of 1″ (25.4 mm) or even more that the hand trim router started to overheat and to smoke. This is because of the type of motor (see also differences between hand router and spindle)
Image: QCW Frame, view from the front
An example of what you can use in the slots is:
Leevalley.com Accessoires
Onefinity says
Onefinity Accessories
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That’s correct. The Z-axis has more than enough power to hold itself up, and conversely to plunge into material. Now, obviously, your bit needs to be secure in the collar or it could slip. But that’s a different problem and is far more likely to happen when in contact with the material, due to the forces being applied, than when cutting the air between slats. For example, an up-cut bit will try to pull the material and router toward each other when engaged. This can cause lifting of material if not properly secured, but the machine is specifically designed to withstand these forces (assuming proper toolpath setup).
The machine’s only job is to execute a set of instructions in 3D space — a choreographed mechanical ballet created by the CAM software on your computer. If you tell the machine to pocket a single flat plane, that’s exactly what it will do. The machine itself, despite being capable of amazing things, is not very smart. It doesn’t know your table has slats, tracks, or clamps; nor will it follow any contours of your table. Not unless you add them into your program somehow.
Hopefully, this clears up any remaining doubts. I’m sure you’ll be up to speed in no time.
On a side note: Make sure to add a ramp to your toolpath when using a large surfacing bit. You will be entering the wasteboard from above and most have no cutting surfaces near the center of the bit.
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Dear Matticustard and all,
OK, I understand that ny bit will not fall into the T track channel. But I keep hearing that my Makita does not have enough power to run a 1 1/2” diameter bit for surfacing. The available solutions seem to be: use a spindle motor with VFD (sorry, no, not another $500) or use a 1/2” surfacing bit, which seem next to impossible to find. Would a 1/2” mortising bit work? The last seems like the only viable solution. Do I have this roght? You have all given me a lot to consider. I just want to make sure I understand the options.
Thanks for your help.
Mark
Hey Mark,
many people use large surfacing bits but I would not leave the machine then, and be ready to stop it and the router, and it is not ideal for the (already limited) life expectancy of a hand trim router made for short, hand-held usage.
To be on the safe side, yes you can use a 1/2" mortising bit of course. That’s what I would recommend, and you could plunge into the material with it.
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You just want a bit that can produce a flat surface. The bigger it is, the faster it will likely do it, but the harder the router will have to work (you need to slow down the RPM the bigger the bit and on a universal motor tool like a router, that also lowers the power it has). The less you cut, by stepping over less than full width of the tool and/or by cutting less deep, the easier it is on the router. I used a 1.25" surfacing bit on MDF (perpendicular over T Track slots) and it worked. You could use a 1/4" spiral bit if you wanted. I would watch the temperature of the router though if it is going to take hours to surface a large area with a small bit.
You seem to be new to this, I was too, it may seem scary at first but basically if you don’t get hurt, any mistakes you make are just learning experiences. You might break some bits, you might burn some up, you might destroy your router, but you’ll gain experience. Don’t worry too much about damaging tools or wasting material. I know, they cost money, but really some experience will help you a lot, whether it is good or bad. Stuff that seemed nearly overwhelming in the early days really are pretty minor once you’ve got some experience.
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Here’s a link to the cutter I used to flatten my waste board. I have a Makita router on a Journeyman. Worked like a champ and the inserts can be turned (4) times to a fresh edge when they dull. https://www.amazon.com/gp/product/B08SKYYN7P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
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Atroz, Big Hick,
Thanks for the advice and encouragement. Yes, I am new to CNC (how could you tell?) and was just getting to the point of diving in and start learning the hard way. Your support is valuable. Thanks again.
Mark
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Hey John,
what depth of cut do you choose then?
Me personally would follow Makita’s advice in the manual and not use bits wider than 1/2" diameter. The hand trim router is in danger to be slowed down when using larger diameter bits, which because of the typical motor characteristics of a router will let it become hotter then and finally malfunction (see also warning in the manual), and it was always when using such a large diameter bit that a Makita reportedly began to burn and destroyed itself. See the links at the end of my above post.
But I know that many people use it anyway. In this case I would only remove a shallow depth per pass, and not leave the machine alone (and know where you master power interruptor and your fire extinguisher is).
The advantage of this bit is that with it, you can very well check and adjust the perpendicularity (tramming) of your Z slider / router, as per the Mitz Pellicciotta method, which is a method that works the better the larger the bit diameter is, because it looks at the direction of the patterns such a bit makes when it is not perpendicular to wasteboard surface. Works only as third step after you ensured your machine is rectangular (“squared”) (bar gauge) and coplanar (“not twisted”) (fishing line method).
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I did square, check for coplanar, and trammed head first. Tramming should be done again after the cutting waste board.
I used #2 (12000 RMP) on the Makita and took a .020 deep cut. Ran it twice for cleanup. No extra heat or bogging down that I could detect.
It really helps to run dust collection for this operation otherwise dust will collect all over the machine and the entire shop.
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Hey John,
thanks for sharing your cutting information!
So 0.5 mm, that is a shallow depth and should be more than sufficient per pass. I have not used a Makita hand trim router in another way than for short, hand-held trim router use, and never with such a bit. How much is the router slowed down with these parameters when starting to surface and getting the load (compared to running free)?