Thread: Random Orbital Sander Questions

Orbits Per Minute are not necessarily the same as Revelations Per Minute...

There are only a few sanders designed to cover the spectrum of sanding applications (eg. Metabo Duo). Many think that the only difference lies in the grit of the sand paper but more important, is the size of the orbit.

Finishing sanders only orbit 3mm while sanders designed to remove more stock orbit approx. 7mm.

If the anchor is connected directly to the sanding bed, the OPM will match the RPM. If the connection runs over a gearbox, it is usually to enable an independence between the two.

There are rubber and plastic plate attachements for drills and angle grinders that allow for high-speed sanding. These are great for removing larger amounts of stock.

Triton make an attachment for an angle grinder that will remove copious amounts quickly. You need to be careful though, that you don't end up with a surface that is not flat.

Hi Damian,
So where do the 5mm ROS/OS sanders fit in. (eg. the Festool ETS150/5 ROS and the Rotex OS/ROS.)? I find with the Rotex I can achieve a finish almost, if not equal to the ETS150/3mm and I can take timber from rough sawn all the way through to a high finish and in less time. The Rotex uses a 5mm stroke either in Orbital mode for rapid stock removal and then random orbital mode for fine sanding. Example below. Rough Jarrah sanded through from 50g to 4000 grit with a ROS150. The timber on the left is the same stuff and has been oiled at 400g.

Regards,

Rob

Originally Posted by LGS

Hi Damian,
So where do the 5mm ROS/OS sanders fit in. (eg. the Festool ETS150/5 ROS and the Rotex OS/ROS.)? I find with the Rotex I can achieve a finish almost, if not equal to the ETS150/3mm and I can take timber from rough sawn all the way through to a high finish and in less time. The Rotex uses a 5mm stroke either in Orbital mode for rapid stock removal and then random orbital mode for fine sanding. Example below. Rough Jarrah sanded through from 50g to 4000 grit with a ROS150. The timber on the left is the same stuff and has been oiled at 400g.
Regards,

Rob

What he said. The Rotex is the general answer. You'll be disappointed if you count on a finish sander to take off stock agressively. Angle grinders are not the answer; just makes grooves that have to be smoothed. Listen to Rob. He knows. I have spent the arvo in the shed with both the Rotex and the 150/3. Rotex for stock removal and then settle down.

Originally Posted by LGS

Hi Damian,
So where do the 5mm ROS/OS sanders fit in. (eg. the Festool ETS150/5 ROS and the Rotex OS/ROS.)? I find with the Rotex I can achieve a finish almost, if not equal to the ETS150/3mm and I can take timber from rough sawn all the way through to a high finish and in less time.

Mmmm... I guess it fits in between 3mm and 7mm? A nice allrounder if you don't have the dough to buy two. (Well a ETS150/5 costs more than two normal name brand sanders anyway ) Festool - while trying to sell more tools - are the first people to tout taking off stock with a 7 and finishing with a 3...

When my sanders grow up they're going to be Festools...

Hi Damien,
Very true about their claim for 7mm stroke, but I've seen one of their large belt sanders at work (with the frame) and you could, in my opinion, run one of those over the surface to 120g then go straight to a finishing sander. The thing I like about the RO150 is the flexibility and speed and the table top in that photo is not finished with anything other than oil and sanding. The timber is as smooth as..
I also must admit that I am a great fan of the Platin 2 pads, which will fit any 150mm hook and eye sander. For final "sanding" at 500, 1000, 2000 or 4000 they are just the ants pants.
I now have a DTS400 and find that to give excellent results at 320g with a 2.5mm stroke. I must admit, for smaller projects an ETS150/3 would be nice. See no reason for the 125mm diameter jobbie though. As for price, yes they are pricey, but the finish.......!!

Regards,

Rob

Originally Posted by damienhazo

There are only a few sanders designed to cover the spectrum of sanding applications (eg. Metabo Duo).

Do You have a Metabo Duo? Ive seen them for sale over here (Japan) and was wondering how good they are?

Hi! Thanks all for the answers, I think I understand now

Finally I keep going with hand planing yesterday, until I got the tabletop super flat, and then I'll keep going now with the finishing sander in random orbital mode, just to turn smooth a surface that it's now flat but roguh.

Best!
Mariano

Originally Posted by underused

Do You have a Metabo Duo? Ive seen them for sale over here (Japan) and was wondering how good they are?

I have one and it is very good. Only seen Festool in the shop so I have no idea about them (other than propaganda from the Festool sub forum) but the duo has been reliable and I have not needed separate sanders (I have them but don't need them in the technical sense of the word need). I wish it had been my first sander - robust, great dust extraction, good removal on large orbit and glassy smooth on fine orbit.

Pusser

Originally Posted by underused

Do You have a Metabo Duo? Ive seen them for sale over here (Japan) and was wondering how good they are?

Na mate but it's on me wish list...

Thanks for the feedback Pusser. I've heard some reports with the duo selection switch failing... I'll have to get one soon and see for myself...

Originally Posted by LGS

Hi Damien,
I now have a DTS400 and find that to give excellent results at 320g with a 2.5mm stroke. I must admit, for smaller projects an ETS150/3 would be nice. See no reason for the 125mm diameter jobbie though. As for price, yes they are pricey, but the finish.......!!

Regards,

Rob

Alright, alright. We believe you Festool owners. Now settle down or be banished back to your sub-forum...



Damien

I'm sorry not going down the shed to find out the modle number of the belt sander....its an electric portable belt sander all I know is its a big blue Makita one....needs two hands to hold it touch the wood and it nearly gets air-bourne...one like chippies use for taking edges back on doors & archatraves...etc...oh boy does that chew up & spit out wood.....then come in with the orbital sander when the first 1/4 inch has gone....lol

Cant be with out my Festo....but have learn the Festo pads do the best job....horses for course...right tool right job.....but don't be afraid to bring in some big gun to clear the jungle a bit first.....Now I'm going fishing for that person who posted the two pieces of jarrah....before & after shot....I'm gunning for you( in a good way)...so if you read this PM me...I need some critical imformation regarding oil/sanding etc....
regards KEKEMO

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