Question: GRS Ultra 850 rotary hand piece for removing background

[Arnaud Van Tilburgh]

As I’m looking for a rotary hand piece, I was wondering if any of you has a GRS Ultra 850.

I have several rotary hand pieces for a flexible hang motor I use for stone setting and making jewellery. I also used them to remove the engraving backgrounds but I don’t think my best Swiss rotary hand piece “Badeco 275â€￾ can be used continuous for ours to remove the background as it gets warm and I have to oil it to prevent it from being damaged.

So my question is if someone of you uses the GRS Ultra 850 rotary hand piece for removing background, as the Alexandre school’s engraver tools at Antwerp where I buy most of the GRS tools says it can only be used with dental burs for high speed as this hand piece makes 300,000 and 400,000 RPM.
Or what other rotary hand piece do you use to remove background?


arnaud

 

[vilts]

Arnaud, I have used it at Alexandre school during a class and it was a wonderful tool. Really-really smooth and worked well. Cutting metal with it was like scraping butter with hot metal, no pulling back or anything. I would have bought it for myself, but as I engrave in an apartment I was afraid it would stress my compressor and neighbours too much. So I bought 50k RPM electric rotary and it works like a charm too. Not as good (maybe correct is to say not as smooth) as the air one, but I can change the speed and it has more power. It does everything I need.

It should not be a problem to buy bits that handle 350k rpm, just check the specs. I think Fox carbide bits are the recommended ones. And you can later make punches from them etc

 

[Arnaud Van Tilburgh]

Thanks Vilts, I already have carbide burs starting at 0,2mm.
They are from Edenta and indeed when used I make punches of them. The recommended rpm is 500/50.000 so they can't be used.

So I 'm looking forward what others have to say about it, as it is quite a expensive handpiece, so I better be sure it works for background removal before I buy one

arnaud

 

[Tira]

Arnaud, I have the 850 hand piece and the NSK Emax system which is an electric motor system as well. Both remove background. I like the Emax better. It runs only up to 35000 rpm and I think it is easier to control. It is also very good for stone setting. The burs seem to wear longer in it as well. One other thing that is nice about it is that you can buy collets to hold 3 different types of shanks. It use it mostly with the dental size tools, but it also does the 2 sizes up from that as well. The only problem with it is the price.

 

[Sam]

I also have the 850 turbo and the Electer Emax. The 850 is 400,000 rpm and has very little torque, but removes metal very quickly and effortlessly. You must be very careful when using it. If you have a small air compressor you might not be able to use the 850 for extended periods of time. It's an amazing little handpiece.

The Electer Emax micromotor is much slower (and variable speed) but works great for background removal as well as drilling for stone setting. The cost is quite high, probably 3 times the price of the 850 turbo.

 

[Mario Sarto]

Hello Arnaud,
i thougt about the 850, too. Currently (the last eight years) i work with the "osada success 40", 40.000 rpm. It works well for very fine things and it is robust enough to remove a lot of background, too. I believe, the 850 is much faster...
Mario

 

[Marcus Hunt]

For some stuff the 850 is fine but for steel it runs too fast and with not enough torque for my liking, and hence it burns out burs very quickly. The Emax is a much better and far more controllable tool, in my opinion, plus it is far more versatile especially if you're a jeweller. If you're carving wood or egg shells the 850 is a superb piece of kit.

 

[Peter E]

Arnaud,
I have used Dremels and have had a Foredom flexible shaft Model "H" which at the time I bought it was the most powerful, and I also have the GRS 850.

I can't speak about the NSK emax as i've not used one, but I would agree with the opinions expressed so far.

The 850 removes metal with minimal resistance but as Sam mentioned, one slip and damage is done. I have the Silent-Aire compressor that GRS sells, and using the 850 taxes it and heats it up VERY fast. I therefore only use the 850 for short periods of time such as 10 -15 minutes.

That being said, the 850 removes material FAR quicker than other methods I have tried. It does wear out the burs quickly as mentioned, but you can easily improvise by using other worn out burs by grinding a point on a diamond wheel. There was a post about it on Steve Lindsay's forum.

Good Luck,
Peter

 

[Arnaud Van Tilburgh]

Thank you all for the feedback although I still don't know what to do.
The 850 uses an other size of burs, not the 2,3mm shaft so it ispropably not the best choice for background removal.
My Badeco works perfect for stone setting although it is a bit heavy to work with for ours at a time, that because of the flexible. It also does the background removal with perfect control, so I will probably using it until I can afford a Electer Emax micromotor

So what I also want to know is if one can use the Electer Emax micromotor for ours without ruin it? As the burs must stay perfect centred. Or does the Electer Emax micromotor also need to be oiled and is it getting warm after some ours?

arnaud

 

[Kevin P.]

Arnaud I have a NSK Emax micro motor. I use it for everything from wax carving to back round removal. I think it's one of the best tools I have.
Kevin P.

 

[Sam]

Arnaud: The Emax is an industrial quality machine and can used for hours and hours. The 850 can be too, but can be a strain on a small compressor.

 

[Arnaud Van Tilburgh]

Sam, my small but new oil less compressor makes 115 litre/min at 2bar I think this would work.
I also understand that the 850 cuts very fast when using the right burs, so one needs good control to handle it, I think I can use burs with good control, so the 850 is still an option, but also an expensive one if it doesn't do what I need it for.

But I think the 850 is light in the hand as the air tube has no weight, therefore I tought it was a good option.

I also ordered the piston upgrade V3 for the 901, so if I don't need a Monarch I could spend some money on the 850 that is more important I think.

An other question, which burs do you use with the 850, also the Fox carbide bits like Vilts suggests?

 

[Sam]

I use .4mm and .5mm carbide ball burs from GRS, but you can get them from a dental supply company. I'm not familiar with the ones Vilts uses.

Yes, it's very light and easy to maneuver.

Alexandre will probably let you test the 850. It takes some practice but can remove background very quickly. Also, the 850 has ceramic bearings and doesn't require oil.

 

[Christopher Malouf]

I use an 850 and it does the trick for fine work ... one of the best pieces of equipment I have. You shouldn't use it to get all of the background out anyway - just the bulk of the stuff so you can refine it with flats and squares easier/faster.

I also use a Foredom flexshaft for things that require less speed and more torque. The only dis-advantage is that the handpiece heats up after prolonged use.

Check out Foredom ... www.foredom.com

A less expensive alternative to the 850, which uses the same size bit, is the Turbo Carver. I've used it and it works well. www.turbocarver.com

Turbo Carver also sells a wide array of bits that are much smaller then the ones offered by GRS ... including needle burs and small polishing bits and fine Arkansas stones.

I find the dental catalogs to be overwhelming for choosing the right bits so I order the odd shaped bits I need from Turbo Carver even though they are a little more expensive. One of these days, I'll cross reference the manufacturer's numbers with those in the Darby Dental catalog and save some cash.

Hope that helps.

Chris

 

[Doc Mark]

If you want the best "dental" burs for background removal, order "High Speed 1/4 round" burs. The actual cutting head is 0.25 mm or in other words "1/4 of a mm round". By designating the bur as "High Speed" the manufacturer is stating that it fits a high speed handpiece, which is usually 1/16 shaft diameter. You can also get the same cutting head size in a longer shanked 3/32 diameter bur, which fits the electric handpieces. Now, having said this, I do not have an 850 handpiece, so I do not know which shank size that particular handpiece uses.

Mark

 

[fegarex]

The 850 uses the 1/16th diameter burs. Everyone has a preference but I also use the 1/4 round burs a lot. I also find the 1/2 round and #2 round handy for larger areas. The larger burs will last a bit better as there is more surface area. Still, they wear quickly and I replace them often. Using a dull one is a waste of time and money for the price. You can usually get them for around a dollar each in quanity from a dental supply place. Yuo may have to have to budy up to your local dentist as many dental supply companies will not sell to the general public. Some will but not all.

 

[JOSIAH HANLEY]

I get burs for my 850 from gesswein

 

[Arnaud Van Tilburgh]

Thank you all for the information.
I will ask Alexandre in Antwerp if I may test a 850 to be sure, but it seems a high precision hand piece and if it it able to remove background it is probably a good tool to do the job.

arnaud