Has anyone tried a mod where the dremel is mounted in its nose thread? The nose thread is 3/4"-12 and is exposed by spinning off the back plastic collar just below the collet chuck. Maybe mark has tried this and found it not to be strong enough?

 

Meistek,

I have done this.

I have been working up a part that will be universal.

Grabbing the spindle buy it's collar really brings up the tolerance.

Should have some pictures by the weekend.

Eric

 

I have thought about it and might do it in a future mod. There are clearance issues, for example if the mount will hit the top of the PP. Also, clearance with the Y-axis top. For some reason it is slight higher than the z-axis surface. The y-axis, bottom on the other hand, is perfectly level with the z. I found some thin steel brackets at home depot, but at the time nothing to enlarge the hole to 3/4". But I just got a set of step drills, the ones that look like a cone that dill multiple sizes all-in-one. Another benefit is the elimination of two heavy u bolts, which I would replace with a cable tie. I agree it would be alot easier to get the bit perpendicular and stay that way, with the mount much closer to the cutting force.

-Kwok

 

I am not sure I am on board with what you are saying about the Y and Z clearance from one another, could you elaborate on the subject?

As far as the issue with the clearance of the dremel, I would have to say that if your dremel is coming up so far that the collar nut/ nose threads are or would be hitting the bottom of the table top then it's time you re-adjust your spindle height.

On the subject of the U bolts, the weight of them will not affect the speed of your Z movement in the slightest and that you are more than likely going to find the zip ties are going to leave a lot of play in the spindle. You may be ok cutting foam along with this but I have a hunch you won’t be sticking with it for too long.

My .02

Eric

 

Hay Eric,

I meant add a nose mount and then also cable tie the dremel body.

Regarding the Y clearance. If you bolt the mount directly to the z-axis top, it will hit Y-axis top. Just check it with a straight edge. It sticks out about 1/16". No doubt it's easily fixed, but need to be addressed. I drew a 3d model of my PP, so at the time I looked at it closely. And finally decided not to do it. But I am limited to what I can do with off the self parts and a few junky tools.

-Kwok

 

Gotcha

Yea your saying if the part was made to mount to the top of the Z Tool holder it would hit or at least limit the Z travel? If so, then you are most certainly correct.

The part I have designed takes this into consideration and this won’t be an issue.

Eric

 

I am working on modeling the entire PhlatPrinter in 3D and will model a gantry to hold the dremel by the threaded nose and the small circular diameter just above the cord strain relief. This way the dremel is held by areas that are the farthest apart and are designed to take pressure.

I have been also considering using a Proxxon 12-Volt Micromot Rotary Tool instead of a dremel since they are a lot quieter. Although most of the noise from the PhlatPrinter seems to emanate from dremel vibrations transferring through the gantry and then to the bushings buzzing on the Y axis rods. I am actually amazed at how quiet the stock set up is, but I would like to improve it.

I live in apartment and the neighbors are going to start wondering what is going on with the dremel running for hours at a time. They are probably thinking why are they vacuuming so much?

It was helpful to hear everyone's ideas on this, thanks.

 

A few people have said they use the low speed setting on the dremel and it cuts fine. That should be alot quieter. Also, I have been wondering if a brushless airplane motor would work? I would think a brushless motor would be quiet and light also.

-Kwok

 

Mark,

I saw a picture of something similar. Will have to try and locate it again. That looks expensive. How much money you figured is invested there? I am more inclined to think cheap and simple, like a small, cheap outrunner. Blue Wonder size maybe. It would in essence be disposable, with possibly the 1/8 bit doing dual service as the motor shaft. I won't care if it only was able to cut foam. Gear reduction? The park 400 outrunner is already low kv. You want to make the rpm lower?

-Kwok

 

I picked up this cheapy rotary tool. Think it was on sale for $6. It's got the 1/8" collet assembly, on top, that could be salvaged. It's pressed onto the shaft of a 12V brushed motor, so not the easiest to deal with.

Attached files

 

16,250 rpm. Yea, got it from Harbor Freight, a while back. It's listed @ $10 on the website. This is it here:
http://www.harborfreight.com/cpi/ctaf/d ... mber=94076

If people are interested, even at regular price, they have good deals on those pistol handle style clamps. Always useful for building the PP. Last time, they had the smallest ones (4"), on sale for $1 each. So I stocked up on a few more.

-Kwok

 

It cuts foam fine, but it's not a tool that I expect to last very long. Who know if that's really the rpm. The rpm actually drops, like 50%, if I turn it upside down. Harbor Freight is one of my favorite stores, also. An ok tool is better than, no tool. That said, I was very impressed with the $50 drill press and $15 set of drills, I bought from them. Haven't had that feeling of precision and a tool that actually cuts instead of being forced through a piece of wood, in a long time.

-Kwok

 

These Proxon 12VDC rotary tools sound very much like the setup of a brushless motor and spindle:



http://www.proxxon.com/

The best one to me seems to be a MICROMOT 50/E, I've read a few reviews on it and everybody says it is really quiet...until you start cutting stuff

The interesting feature to me is the claim of hight torque at low rpms. Maybe the rotary pot on this could be wired into the stepper control and the spindle RPM could be adjusted via Mach 3? Maybe it would even be possible to shut the tool off during rapids between cuts? The tool requires a 12VDC power supply with at least 1A current capability.

Has anyone wired a dremel to the stepper control and mach3 to adjust spindle speed on a dremel? Attached files

 

I never seen one of those Proxon run before. But it only goes up to 20k rpm, so all things being equal, it better be quieter. Turning the dremel to low doesn't solve your noise problem? Or coveing up the openings?

Don't know about controlling the rpm with Mach3. But I do have (not used it yet) the solid state relay (from easy-cnc) that cuts the 115v ac power and is controlled by G Code. My original objective was just to have the dremel automatically turn off after the PP was done. Technically, you could edit the commands into your code to cut power to your demel at anytime during your cut, but I would think it be very confusing to do. For a better idea, I would look at the mod to cut the dremel off automatically when it is retracted. Uses a simple limit switch and relay.
viewtopic.php?f=12&t=123

No, I don't of "anyone who has wired a dremel to the stepper control and mach3 to adjust spindle speed on a dremel".

-Kwok