Micromotor vs flex shaft

[pmace]

I want to add details to my champleve enamel work that I can’t get with saw and solder laminating. Engraving the outline gets the details I want but the background is way too deep. I have a cheap Dremel flex shaft that I use with some carbide burrs that works ok. I’ve never seen a micromotor but I imagine them to be a souped up Dremel tool. Which offers better control and which is less tiring to use under a scope? When the better half asks what I want for my birthday this year I want to be prepared with an answer.

 

[dogcatcher]

This is from a woodcarving forum, I think the discussion will answer your questions.
https://forum.woodcarvingillustrate...g/power-carving/45442-micromotor-vs-flexshaft

 

[pmace]

Great, thanks. That answers the question. Now I have to get some small burrs that can reach in and get the detail I want.

 

[Chujybear]

diference will be torque (sorry if thats what the article i already saying, i couldnt open it)

flex shaft is better for drilling, higher torque, micro motor is more control, higher speeds.

 

[tdelewis]

I have a flex shaft Dremel. There is a slight oscillation that will brake my stone setting drills every time. It is not noticeable except under high magnification. Maybe it is just my Dremel but I would stay away.

 

[pmace]

I have a flex shaft Dremel. There is a slight oscillation that will brake my stone setting drills every time. It is not noticeable except under high magnification. Maybe it is just my Dremel but I would stay away.

The wife gave me the dremel flex shaft years ago and I thought I’d try it out just to see how a rotary tool works in this application. In my case it may have more to do with the quality of burs. The set I got from Rio Grande has maybe 3 or 4 flutes. I see some of the higher quality burs have like 8 or 10 flutes on the same size bur. That may help with control.

 

[monk]

the dremel has its place. the dreml tools fall short because there's too much slop in the shaft. the micromotors are much better. the one i have uses fg burs, and has a .125 chuck for the larger bits.

 

[pmace]

the dremel has its place. the dreml tools fall short because there's too much slop in the shaft. the micromotors are much better. the one i have uses fg burs, and has a .125 chuck for the larger bits.

Thanks Monk. For the work I’m doing I need a pretty good looking relieved area since you can see through the transparent enamel. The dremel and flex shaft work ok but I can see they won’t last very long. I think I’m better off with the micromotor since it has better control and I don’t need the torque of the flex shaft.

 

[farmer57]

Paul, curious to hear what you decided in regards to the tools.
I do fair bit of champlevé in silver (and less so on copper) and I engrave 'bottom' details (instead of the more popular silver fusing or even acid etching techniques). On occasion, I also combine engraving with cloisonne wires. I found there is so no one tool that is 'magical' for the bulk of the material removal. I like the old tried technique of initial engraving of the outlines with either fine onglette for straighter lines and small round for tighter curves. Depending on the size of the work, if small or tiny - I will just keep going with flats and squares and rounds (as in traditional methods) but if it is larger piece - I will go with my foredom for the parts that are away from the 'walls' and with micromotor in the areas that are closer to the 'walls'. This is where the extra torque for deep removal is nice.
I like dental burs for all of this (both high and low speed), the carbide burs will remove material in cleaner fashion but diamond burs tend to be slightly smoother and I will often go over the 'bottom' with diamond burs to make it less bumpy. As I get deeper - it is harder to keep your bottom flat when using the rotary tools. I found going over with nice polished flat graver gives it best and flatter finish (on occasion I will stipple flat). If I am going to engrave deep and tightly spaced patterns - then it is not so crucial to have it super flat.
I like the foot controlled Foredom jeweler tool for the initial bulk removal but it is too slow to control well as I get deeper. Micromotors are very good but also have their limitations and are not great for nice clean 'bottom' lines or textures that are continuous lines or repetitive symmetry patterns (good for dots though) - engraving gives me much nicer results and there is less danger with slip-us. As I am sure you know, with champlevé, the more shiny and clean those bottom cuts are - the better the results with enamels covering.
There are number of very good air turbine style tools out there such NSK or GSR, I use Vortex F5 Carver (I think it is capable to go around 400K rpm - much like the rest of the better ones out there). It is a good tool but can only accept standard high speed dental burs. I actually like using dental low speed burs in my Foredom for rough removal - these are short thus easier to handle through the scope. As you mentioned - the more 'flutes' will be smoother but I often find these don't remove enough material yet fewer 'flutes' are harder to control.
Another thing, when using micromotor - I find it can be tricky with the standard short dental burs to get the right angles as you dig deeper, even with 'flame' shape burs since rounds can star bogging down at such sharp angle. Don't know what you use for material but my work is usually with 16-14 gauge silver so I can get a good 'dig' going at times. I don't think I would want to use any 'rotaries' in thinner than 18 gauge.

 

[pmace]

I wound up with an NSK air turbine and a Foredom flex shaft. The air turbine is good for doing backgrounds for engraving and fine work too small for the flex shaft. The flex shaft is great for hogging out the volume you need for champleve. I may invest in a micromotor some day but honestly I don’t see a lot of benefit in one. The NSK with needle diamond burs can do the details you can’t get to with a graver or the Foredom. I do the outline with gravers, hog out with the Foredom, finish detail with the NSK and then clean up the bottom with flat gravers and ceramic stones. Mostly copper, some sterling. Thanks for the advice.

 

[monk]

about 3 weeks ago i bought an "ata"brand air turbine for working on metal sculpture. it's 70k rpm. out performs any other rotary i have. no foot pedal, it's pneumatic, with the control on the rear of the "pencil". rather pricey, but it worx !

 

[Dave London]

You can make your own burrs from ones that got Dull by shaping them into a three or four sided triangular or pyramid shape
Tim Wells sells a jig to make them. Link on Steve Lindsay’s site under graver sharpening

 

[Victorvile]

Micromotor is not as robust as flex-shaft.Needs frequent cleaning.Overheats easily.Cheap brands have electronics with short life-span. I think that apart form american Foredom ,that probably now is made in China too,the old european brands like KAVO or Reco don´t produce flex-shafts anymore,only micromotors.Old Kavo or reco will outlast everything else.

 

[Dave London]

NSK not cheap but the best MTC YMMV

 

[Jim Disbrow]

I use an NSK Emax EVOlution. Kind of expensive, but does a great job. I've only been engraving for about 6 or 7 years and I'm not a jeweler and I've never worked ewithnamel but I cannot imagine needing a flex-shaft.

 

[papart1]

nsk best price on the planet...........UtahHandpiecerepair.com

 

[farmer57]

I wound up with an NSK air turbine and a Foredom flex shaft. The air turbine is good for doing backgrounds for engraving and fine work too small for the flex shaft. The flex shaft is great for hogging out the volume you need for champleve. I may invest in a micromotor some day but honestly I don’t see a lot of benefit in one. The NSK with needle diamond burs can do the details you can’t get to with a graver or the Foredom. I do the outline with gravers, hog out with the Foredom, finish detail with the NSK and then clean up the bottom with flat gravers and ceramic stones. Mostly copper, some sterling. Thanks for the advice.

Great, sounds like our setups are quite similar. When working on copper, I never seem to get the same level of 'shine-reflection' as I get on fine silver - sterling is better but not as consistent as on fine silver. I guess many colours seem a bit duller when over flux on copper - unless we go with foils etc.
I can usually get away without flux on fine silver with all but light reds, pinks and some yellows.
Do you use non or leaded enamels?
I do both, leaded have so many more transparent colours - especially transparent reds. Thompson's unleaded reds really are not very good (and only couple to choose from), probably not so bad over copper but over silver I prefer to go with Japanese enamels. WG Ball in UK has very nice unleaded greens and blues and many others but reds are again very poorly represented - I think they cannot produce the reds in similar choices as with leaded.

I know what you mean by trying to texture in very tight spaces and it is difficult to get the clean 'shiny scoupout' with the graver. Sometimes, if the design allows, I will just void entire area and engrave the textures and then use cloisonne wires to separate areas with small details - it works well when you're in a pinch, probably similar in terms of time but I find it easier overall.

You mention ceramic stones for the bottom clean up, how small are those?

Using tiny burnisher (well polished and flat bottomed) also can work well for tight areas. Broken dental drills are good for that application.

 

[monk]

You can make your own burrs from ones that got Dull by shaping them into a three or four sided triangular or pyramid shape
Tim Wells sells a jig to make them. Link on Steve Lindsay’s site under graver sharpening

dave: does that geometry prove useful for stippling ?

 

[monk]

The wife gave me the dremel flex shaft years ago and I thought I’d try it out just to see how a rotary tool works in this application. In my case it may have more to do with the quality of burs. The set I got from Rio Grande has maybe 3 or 4 flutes. I see some of the higher quality burs have like 8 or 10 flutes on the same size bur. That may help with control.

for me, the diamond burs give better control. i use carbide first, then finish off with diamond. the diamonds i use are imports (drat), but hold up reasonably well even in ss & mild steel.

 

[Dave London]

Monk
yes just don’t sharpen to a needle point, just a tad blunt