[Claytonc]

I'm currently using a craftsman router on my home built machine. It is double insulated so I am unable to use the auto zero feature without attaching a clamp to the bit. I see that many people are using the Bosch routers. I'm wondering two things about these routers. One, is it double insulated? and two, what is the diameter of the bottom 1/2 part of the router. I'm hoping its about 10cm so it will fit right in my current mounts.
My machine is currently down while I wait on my Gecko G540 to arrive. Thanks for any info!

[groswald]

The Bosch Colt *is* double insulated. I have the same problem having to attach a clamp.

I don't know the diameter right off.

Randy

[Claytonc]

Well shoot... Is there any routers out there that are not double insulated anymore? I would really like to get around this having to clamp the bit thing... Anyone know if there is anyway to modify a double insulated router so I can have this feature?

[groswald]

I saw one thread where the author had attached a ground wire to the upper bearing mount in his Colt. I may try that.

[RomanLini]

You can make a simple Z height sensor that will work without needing any electrical connection to the router, for instance if your router is double insulated or if you are using a ceramic or diamond cutting tool (that does not conduct).

There are a couple of threads on Z height sensors, and I even designed one that can be cut in simple 2D from a common piece of 12mm acrylic sheet;
http://www.cnczone.com/forums/cnc_wo...ll_router.html
(see post #18, probably on page 2)

[Claytonc]

WOW! Man you are one creative guy! Since this is breaking the circuit instead of closing it what do you use for zeroing the bit to the material you are cutting?

I love the tool change / height sensor idea. I am going to cut one of these tonight. Actually, I guess I need two variations of it. One for zeroing to the material and one for tool change.

Thank you for this awesome idea!

You can make a simple Z height sensor that will work without needing any electrical connection to the router, for instance if your router is double insulated or if you are using a ceramic or diamond cutting tool (that does not conduct).

There are a couple of threads on Z height sensors, and I even designed one that can be cut in simple 2D from a common piece of 12mm acrylic sheet;
http://www.cnczone.com/forums/cnc_wo...ll_router.html
(see post #18, probably on page 2)

[RomanLini]

Hi Claytonc, my height sensor is permanently mounted so it tells me the exact height of the tool in reference to the table top itself.

So I can zero the tool, then put some stock on the table and tell it to "cut at 10mm height" and it will face the stock down to exactly 10mm thick.

If you made a similar sensor and had it movable, you could place it on top of the stock and it would tell you the distance between the tool and the top of the stock.

If you are making a movable one you could change the design to make it shorter in height. As long as it has a solid base, solid top contact (both needed for accuracy) and bendable part so the arm can deflect and spring back.

Obviously you need to know the height of the sensor unit itself, but that is just one initial calibration and won't change after that, as there is nothing much to wear out there.

[Claytonc]

Yup, I got thinking the same thing after I posted. Using your idea this is what I've come up with. I'm cutting it out of 1" thick plexi so I can cut it all from the top. Instead of the Plexiglas flexing I’m using a ½” x 1” lite spring in the large hole. The lip on the left is to help keep the flat bar from shifting from side to side since it will basically be floating on the left screw.. I will probably redo the movable one to be thinner like you suggested.
fficeffice" />>>
Thanks for this awesome idea!>>
>>

[ger21]

Well shoot... Is there any routers out there that are not double insulated anymore?

I don't believe the Porter Cable 690 is.

[Drools]

Claytonc, when you are done building your zero-setter I would like to see it in action.
Thx

[Claytonc]

Will do Drools. I'll be working on it tonight. Well, maybe... I finally got my G540 today as well so I need to get that installed and configured. I'm also working on mounts for the router, a dust collection system (with lights and all lol). Hopefully I'll have Sunday to knock a bunch of it out.

[tpworks]

Well shoot... Is there any routers out there that are not double insulated anymore? I would really like to get around this having to clamp the bit thing... Anyone know if there is anyway to modify a double insulated router so I can have this feature?

Typically any motor that has a 2 prong plug is double insulated, the 690 has a 3 prong plug, I checked it on one of mine and there is continuity between the housing and the shaft.

[tpworks]

Well shoot... Is there any routers out there that are not double insulated anymore? I would really like to get around this having to clamp the bit thing... Anyone know if there is anyway to modify a double insulated router so I can have this feature?

Typically any motor that has a 2 prong plug is double insulated, the 690 has a 3 prong plug, I checked it on one of mine and there is continuity between the housing and the shaft. I believe that double insulated has to do with the armature windings and core are seperated from the shaft with a non conductive sleeve therefore if your motor has a metal housing on the lower end it should be conductive with the shaft through the bearing.

[Claytonc]

Typically any motor that has a 2 prong plug is double insulated, the 690 has a 3 prong plug, I checked it on one of mine and there is continuity between the housing and the shaft. I believe that double insulated has to do with the armature windings and core are seperated from the shaft with a non conductive sleeve therefore if your motor has a metal housing on the lower end it should be conductive with the shaft through the bearing.

Thank you for that bit of information! If my touchplate doesn't perform well I will look into this router.

[RomanLini]

Yup, I got thinking the same thing after I posted. Using your idea this is what I've come up with. I'm cutting it out of 1" thick plexi so I can cut it all from the top. Instead of the Plexiglas flexing I’m using a ½” x 1” lite spring in the large hole. The lip on the left is to help keep the flat bar from shifting from side to side since it will basically be floating on the left screw.. I will probably redo the movable one to be thinner like you suggested.
fficeffice" />>>
Thanks for this awesome idea!>>
>>

Your design looks pretty good Claytonc, the metal bar with floating screw should still work fine provided it always breaks the contact at exactly the same height.

Just watch out for 2 issues;

1. you need the wire to the bar to be secure, so maybe the wire needs it's own electrical screw to the bar. That's easy enough.

2. to ensure a repeatable point where the contacts open you need to make sure the right (contact) side of the bar pushes down to open the contacts, but the left (screw) side needs to be fixed so it can't push down. I think you can do that easy enough if the bar sits down hard onto the left side (so it can't press down on the left), and you make the "float" part above the bar and under the screw head like a wave-washer or rubber o-ring.

Still thinking about it, it might still be easiest just to cut away some material on the left so the plastic can flex (but not push down), based on mine it only pushes the bar down the tinyest amount so it only needs a tiny bit of flex in the plastic there. It does solve those other 2 problems.

I did a rough edit to your block below, the slot allows plenty of flex without any downward movement of the left side, and I moved the spring hole to the right under where the contact movement will be.

[Claytonc]

Well.. I've already got them made so I'm going to see how it works out. I just need to attach the wires and I'll be able to test them out.

I made two of these. On the movable one the spring is very close to the screw that holds the long contact bar. A 1" x 1/2" spring works really well here. On the stationary one the spring is a little closer to the center because of the mounting screw holes. This makes the tension much greater. Im going to cut the spring down a bit to make it easier to push down before I mount it.

Looking back at the original design it looks like it would have better repeatability. I should have just went with what worked and not try to fix something that wasnt broke... Well, since I've already made them I'll give mine a shot and see how it works. If I can hit the same spot each time it should be fairly accurate. This will probably work fine with the stationary plate but would not be so easy to hit the same spot with the movable one... hmm...

[RomanLini]

I think they will still work great provided the bar can only move downward at one side. That's pretty much all there is to it.

As for "hitting the right spot" I don't think it's that critical as ANY downward deflection of the bar opens the contacts, so the threshold is extremely accurate.

On mine I zero to within 0.01mm and it's the same every time I zero, so accuracy is better than 0.01mm. Then once the router is warm after 10 minutes cutting I re-zero and it easily picks up the 0.03mm or so downward growth as the tool and router shaft have expanded when warm.

To get that accuracy it "double" zeros, so it moves down quick and gets the first reading, then lifts the tool a couple mm and comes down real slow (maybe 0.5mm per second) to get the accurate reading.

[Pplug]

My quiet Hitatchi 12vc works with an aluminum height plate

[Claytonc]

I've got the touchplates made and installed but I'm having other issus (in another thread) with my router mounts. Once I get that worked out I will be able to test it for real but it seems as though its going to work just fine for my applications

[Claytonc]

I've gotten my spindle mounting issus worked out and finally took the time to record the touch probe/plates in action. I'm not sure how to test repeatability but they seem to work pretty darn good from what I can tell.

[ame=http://www.youtube.com/watch?v=HRXZYaPufJM]new touch probe - YouTube[/ame]