Help please. Feeds,speeds, and run time

I am carving 30/40/50mm circles into oak plywood. I am trying both 1/8 and 1/4 end mills. Upcut unfortunately as I did not know down would be better. I don’t think I am
Getting the feeds and speeds correct as with the 1/4 it sounds like the bit is grinding and vibrates a lite. When they both do the plunge cut, started with .9 mm went to 2mm with the 1/8 withite problem. But the 1/4 sounds like it is having trouble when it does the first pass. Spindle speed for the 1/4 is currently at 10,000 and the 1/8 is 14,000.
Mm/min is around 600 for both. I don’t know if I’m doing something wrong or not. But could this be better? Should I go up or down somewhere. I am just asking because I know there are lots of people out there with more experience.

Lastly the job run time… It took 8 hours with the 1/8 bit to make one of my pieces. It was 12.5 by 19" will this go down if the feeds and speeds get corrected? The depth per pass at 1mm or so makes a lot of passes. But if I go deeper won’t it mess up the board?

Sorry, lots of questions. Didn’t know where to start.

What spindle are you using?

The stock one that came with the 1000mm kit. Acme screw. Nema 23 stepper motors.

I figured. I couldn’t get the stock spindle to work for me. Mine was not capable of using 1/4" bits at all. If you have a dial gauge you could try to measure how far out of round the shaft is and physically try to bend it straight. But, the bearings simply are not designed for that kind of load anyway. I have a feeling you’ll be upgrading to a router or a heavier duty spindle.

Here is an interesting thread for you: Convince me, Dewalt 611 or 400w Quiet cut?

Out of round? Not sure what you mean by that. I only get “chatter”? I think that’s what it is. Sometimes. After the initial plunge it seems to do good. I was hoping my spindle was just too slow. Or my current feed rate was too high. Or something.

“Out of round” or “Run Out” is how much the bit “wobbles” in the collet.

There is another thread where @AllenMassey posted a spread sheet to help with feed and speed calculations for the Dewalt. You may be able to use it for the stock spindle.

You might want to try reducing your cut depth instead of slowing your feed speed. It seemed that faster speed with shallower cuts is better?

If you are still having problems and are in a experimental mood you can try replacing the stock spindle with a Dremel (assuming you have one handy) and see if that makes any difference.

I recommend eventually replacing the stock spindle. But unless it is actual going bad you should be able to get pretty good results with wood :smile:

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My problem with shallower cuts comes into it taking way too long to complete a job. 6-10 hours is terrible. Esp when I don’t have a dust collection attachment for it.

I’m just trying to figure out how to make this spindle work for me. If at all possible. Since I spent $60 on the spindle. And more on bits and extra collets for it. I would be highly irritated if I ended up spending that just to have to spend more on a trim router and the holder for it.

I felt the same way. But unless your stock spindle is made of better stuff than most of the stock spindles, it is just a matter of time before you start hearing the bearings go out. The good news is you can use all your bits in whatever spindle/router you wind up with, The bad news is that you will need to purchase new collets for them unless you get another ER11 type spindle.

Ok. So for now. If I drop my dpp I should be able to speed up my feed rate? Correct? So I could finish some projects now before I end up upgrading. Also. Do I have to reinforce the axis to hold the weight of a trim router? Or will I be able to get away with how it is. At least in the interim.

I had to reinforce my machine AND loose the stock spindle to be satisfied with the results. It only took an hour to put that 3/16" steel in there (once you have the steel - available at Lowe’s just get the 36" length and you won’t have to cut along with the furniture bolts). And then add brackets to the other axis as detailed in the stiffening mods threads.

But the stiffening mods made a big difference with the stock spindle (mine literally self-destructed).

Self destructed after you stiffened it? When I am only cutting 2mm deep it goes decent fast. But when I am going 12 total mm deep it take a lot of passes. I am just trying to get by until I absolutely have to upgrade.

Yes. It is a toy really. I had a CNC machine before the x-carve so those shallow passes and near zero torque of the stock spindle was particularly maddening. I just can’t afford that kind of time. You should really just pop a Dremel into your STOCK spindle holder, BEFORE the stiffening mods and try that. You will be AMAZED.

Then you will want to do the stiffening mods… probably. Maybe a buddy has a dremel you could borrow for a test? Just pry open the spindle holder and slide it in. You will be limited to 1/8" bits and smaller but it is a very capable little beast.

I have the 500x500 X-Carve and did not need to stiffen the X-Axis. I think it is only a problem if you have the 1000 mm size.

You can try the 1/4 bit with a .1 inch DOC and a 30 ipm feedrate. But it will cause more strain on your spindle.

A toy. Very expensive toy. This was supposed to make my production easier and smoother of stuff. As for the Dremel. I will try that tomorrow or Thursday. Today I most rage quit on it. Since so far does next to nothing that I was hoping.

Other than it did make one nice board so far. Mostly. Some of the slots were not the same diameter and needed sanding while others were perfect.

I am hoping it is just a few minor tweaks to get it to work, wether I use dewalt or the stock spindle. Otherwise I am so far disappointed in my toy decision.

If you want to use this for production you will need to upgrade the spindle and do a stiffening mod of some kind.
You will not regret it. It is like a whole new machine, as it addresses the 2 biggest issues with the XC.

The stock spindle just doesn’t have the strength or quality to hold up to serious production use.

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I think the Dremel will demonstrate such an improvement in capability, it will restore your enthusiasm. I remember this exact same feeling.

I kind of went nuts on the upgrades though. But it is FAST, reliable, accurate and I am only limited by my very limited creativity. That’s where this forum pays off. So many talented, creative people… lots and lots of ideas.

Lots of ideas. Lol never would have thought of Dremel. The stifening mods are a good idea too. I just hope I don’t regret this in the long run. Thanks guys. I’ll let you all know how it fares after more upgrades.

Also, is there a link to stiffening mod forum? Other than the t steel one?

Ok, doing at least the gantry axis stiffening mod. And probably the Dremel test. Not sure if I will have time but hopefully at least the stiffening helps

Here is a good overview of the mod. I just used a 36" x 1 1/2" (or maybe 2") piece and it required no cutting. It is very simple. The furniture bolts are used because they have low profile heads and nuts. I happened to have these laying around AND they happened to be black. Happy coincidence. Just get it square, slip it in, test movement, clamp the bejeesus out of it, and drill away. I am certain you can use a hand drill, just be patient. If you did, you might not even have to remove the gantry.

There are threads where this very simple mod is vastly overcomplicated… ignore them. Unless you are an engineer, in which case, enjoy them.

I am an engineer… A combat engineer in the national guard. Lol so our idea of fixing is c-4.

Yea I ended up grabbing a few parts, the steel, bolts, not as many as I would have liked but they didn’t have nuts for all of them. And will be stiffening it up shortly.
Thanks for all the help and I apologize for my stress, was just hoping for something and worrying it was my fault it wasn’t working.

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