Thread: FELDER RL200 and RL250 question

My system is 8" all the way to the cyclone with a about 1m vertical lift before it enters the cyclone, as far as regular dust goes I've never had a problem with the airflow not being enough to lift the dust up this length of pipe, I do have an issue with smallish blocks/bits that are too heavy and they fall out and sit in the bend at the bottom of this lift, I don't have accurate enough figures to quote how much airflow I do have but my gut feeling is it is below the 1000cfm which then means I am also below the 4000fpm, I'm not far off tho.
Not much help but something to add to the mix.




Pete

Originally Posted by pjt

My system is 8" all the way to the cyclone with a about 1m vertical lift before it enters the cyclone, as far as regular dust goes I've never had a problem with the airflow not being enough to lift the dust up this length of pipe, I do have an issue with smallish blocks/bits that are too heavy and they fall out and sit in the bend at the bottom of this lift, I don't have accurate enough figures to quote how much airflow I do have but my gut feeling is it is below the 1000cfm which then means I am also below the 4000fpm, I'm not far off tho.

Pete, thanks for chiming in. LuckyD he has a 2.5m lift from his 500 mm wide thicknesser which is a fairly big ask. I suspect his DC is OK and even though his thicknesser has a 140 mm port it may still not be getting enough air. He may need a bypass port to help add the required air to the ducting to help carry the dust.

Thanks Pete,
Like most things, I've found the more I learn the more I have to learn! I'm guilty of just thinking my extraction is good enough! The forum, and knowledgeable guys contributing to threads, show how hard it is to get enough airflow. I've got to work on my ports and go from there.

Is is there a particular reason for you to stay with 8"? I wonder what would. Happen if you reduced it to 6"?

Cheers, David

Originally Posted by LuckyDuck

Thanks Pete,
Like most things, I've found the more I learn the more I have to learn! I'm guilty of just thinking my extraction is good enough! The forum, and knowledgeable guys contributing to threads, show how hard it is to get enough airflow. I've got to work on my ports and go from there.

Is is there a particular reason for you to stay with 8"? I wonder what would. Happen if you reduced it to 6"?

Cheers, David

Yes, and we are never too old to stop learning,
The 8" was left over from a job back in another life, it followed me home one day and became my main ducting throughout the workshop, 8" is up towards the large end of size for the typical home shop but I won't be changing it anytime soon, I think what you are asking me is What would happen if I changed my ~1m of lift from 8" to 6", from a practical standpoint that 1m is made up of a transition from square to round,and two bends so I'm not about to change it, but Would I have less large pieces fall out of suspension if I did? maybe maybe not, based on some static pressure test I have previously done.....
100mm 4.JPG112mm 4.5.JPG72mm 2.83.JPG
......my fan is down the low end for pressure, this is a function of fan wheel diameter but the difference between the tests tells me that I have good flow despite the low end pressure and this is a function of pipe size (and the system restriction as a whole) a bit serendipitous that I have the 8" so my low fan pressure may not be able to overcome the increase in restriction from the 6" of 1m lift to then produce an increase in air speed to maintain the larger chunks in suspension, however your DC would have a better chance due to it having a higher operating pressure (larger diameter fan wheel) given the same scenario, I think you said 7".


Pete

Here is something you can do with 8" ducting

If you don't want to cut holes in your planar/thicknesser, add some extra air into the ducting immediately after the thicknesser connection.
So adding either an opening at B or ducting at A.
The arm at A is not directly over the table but behind the thicknesser fence so it would not get in the way of any work pieces
Neither A or B are completely open but would have a blast gate that you would closer down a bit otherwise the sawdust would not be drawn away from the thicknesser as easily.

The best place is as close as possible to the thicknesser outlet (e.g. B) so the air mixes with the sawdust as soon as the dust is formed.
B also has the added ability of helping with any blockage in the vertical section i.e. open up the blast gate and sticky something up there to help it fall out.

In terms of fine dust control position A because would be better as this is closer to the source of escaping dust.

You can also try this with 6" trunk and 4" ducting at A or B.
It won't be as effective but it is worth a try.
With a powerful enough DC you could add both A and B.

Originally Posted by BobL

Here is something you can do with 8" ducting

If you don't want to cut holes in your planar/thicknesser, add some extra air into the ducting immediately after the thicknesser connection.
So adding either an opening at B or ducting at A.
The arm at A is not directly over the table but behind the thicknesser fence so it would not get in the way of any work pieces
Neither A or B are completely open but would have a blast gate that you would closer down a bit otherwise the sawdust would not be drawn away from the thicknesser as easily.

Bob, this is a very interesting suggestion. Thank you for taking the time to post the diagram. A couple of guys on other forums suggested a very similar set-up. I would love to take measurements at the thicknesser port in order to check the effect on airflow opening and closing gates at position A or B would have.

Someone else suggested position B as a good alternative, which could then be incorporated into a floor sweep, which means the extra ducting is not "wasted".

Food for thought.

Thanks.

Just a comment to reinforce BobL's thoughts on where most of the losses come from.

The data from my installation confirm Bob's comment. The biggest losses come from machines and shrouds. Often (like my thicknesser) the problem is getting enough air to flow through the machine.

I get good dust extraction on my drum sander, but I noted that the airflow is lower than it is on my linisher, which is much further away from the cyclone. The problem is the shroud around the drum, which positions the outlet a bit too close to the drum. So, I have a 6 inch port (upgraded from 4 inches), but don't get the full benefit of the bigger duct because of this restriction. That shroud was not a restriction when it carried a 4 inch port, but it is became a restriction when I upped it to a 6 inch port.

BobL is right. Focus on getting enough air through the machine and its port/shroud. Then keep your velocity in the ducts high enough to stop blockages.

Have fun!

John

Originally Posted by LuckyDuck

Thanks BobL:

You may well be right about my "over" focus on the DE (highly likely) but I certainly will not be neglecting the ducting side of things. I should have attacked my machines years ago but this time I'm convinced that I must. I have intentions to modify the TS, BS and thicknesser to ensure that enough air moves through them. I had thought I would use 200mm mains and a vertical to my three biggest machines, leave it at 200mm for the thicknesser, and split off to 160mm and 120mm for both the TS and the BS. I'm assuming this would work, and work well, with enough airflow.

If I've understood you and BP correctly, I'll need to rethink these sizes, or else move up to the RL250. ?

Interesting, I just had a good read of the Clearvueoz site and noted two things. First, are cyclones really 90dB? The RL200 is "supposed" to be 70dB. I wonder if these figures are accurate and how they are measured!? Second, I note that the Clearvue cyclones have a 4kW motor. The RL200 has a 5.5kW motor. Even if all other aspects of the two units are the same (which is undoubtedly not true!), the presence of the filter on the RL unit shows why it is not oversized at all. I imagine that the extra kilowatts are more than offset by that filter...

I'm really tying my knickers in a knot over all this! I thought I was implementing an excellent dust solution when I bought the RL160, but it was/is underpowered, and while I installed 150mm PVC ducting, I did not go through with modifying my machines. This time I want to do it right. I'm committed to modifying my machines, and getting the ducting sized correctly. So, is it the RL200 or the RL250... hmmm

Cheers,
David

Hi David

Did you endup with RL250?

I am about to upgrade my dust extractor sometime in future.

was thinking about either Micronair or RL250 or Donaldson Torit Unimaster 250 (Donaldson is the most expensive)...

what you rekon?

Originally Posted by Albert

Hi David
Did you endup with RL250?
I am about to upgrade my dust extractor sometime in future.
was thinking about either Micronair or RL250 or Donaldson Torit Unimaster 250 (Donaldson is the most expensive)...
what you rekon?

Hi Albert:

Yes, I bought the RL250, and I love it...but read on. Before giving you some, perhaps useful feedback on the RL unit, in answer to your questions, I must say I don't know much at all about the Micronair so I'm no help there, and the Felder Owner Group (USA) reckon the Donaldson Torit machines are hands-down better than the Felder RL units. However, the price difference is enough to warrant serious consideration of pros and cons. But at least I can tell you about my experience with the RL250.

1. I find the RL250 surprisingly quiet compared to my RL160. Yes, there is more noise from large airflow in ducting, but not much more noise. I am quietly (ha ha) happy.

2. I have used Felder ducting; the QLD rep has been exceptionally generous and flexible in the sense that he has offered to let me change various bits and pieces of ducting to suite my perverse desires to get the ducting as good as can be. This is one of the reasons why I went with Felder in the first place -- I like the QLD rep as he has provided me excellent service, past and present.

3. I followed the principles of Pentz and others, re. maintaining airflow by watching cross-sections, and minimising resistance through ducting and machines. Thus for example, BobL was spot on in saying that the table saw cabinet has to be opened up to allow for airflow. The angle-grinder has made a huge difference and was not all that hard anyway.

4. The same people harp on (rightly) about the enormous resistance which comes from using undersized ducting and flex-work. Like many, I figured surely duct size did not make that much difference? IT DOES! Indeed, I don't have any instruments to measure, but I can say that there is a demonstrable (subjective) difference in suck between 160mm ducting, 120mm ducting, and 100mm ducting.

5. To reiterate point 4, I can say that ducting smaller than 100mm is next to useless when it comes to decent airflows. There is not enough pressure to increase airspeeds on the smaller ducts... I have a 100mm flex which reduces to little over 70mm ducting for my table saw guard. Rubbish suction in my experience. I have three times 120mm ducts on my bandsaw. While much better, I am not that impressed with the suction I get from 120mm. Compare that (again subjectively) with what I get from 1 x 160mm duct and 1 x 140mm duct to my cut off saw. AWESOME! Those two ducts simply have a lot more airflow. Again let me reiterate that this is experiential and subjective, but that ought to count for something. I think only my cut off saw has the right ducting solution. I intend to massively increase the size of my table saw guard ducting (which requires a saw guard rebuild), and increase the over table ducting on my band saw to 160mm, I think.

6. I was told by more than one source that the RL units do not have enough pressure to keep chips/dust moving vertically up a duct larger than 160mm and that 200mm drops or larger are not advisable. I don't have hard data, but I can say that 200mm ducting seems to have no trouble sucking up chips/dust. I wish I had instruments to see what the airflow actually is. I used 200mm vertical ducting to my cut off saw. Again, it is my best ducting solution.

7. It has been stated that the horsepower rating of the RL250 is not an indicator of how much airflow it is able to move. I respectfully disagree. I have an 80A dedicated 3PH supply to my shop, and 20A circuits to my main machines, including the RL250. The RL250 has a 5.5kW motor, which Europeans various describe as 7.5HP (S1) or 10HP (S6). I'll leave it to others to tell me why they have different HP ratings depending on the duty rating? The motor says S1 on it. My point is this. The star/delta start motor trips the 20A circuit from time to time, and the lights dim on start-up (different circuit to the RL unit but sharing the 80A main supply). I don't understand how this motor is not considered to be vastly more powerful than the motors I hear are being used on ClearVue units?

8. I like the controls on the RL250. I have it permanently attached to an air compressor so the auto-pulse cleaning cycle kicks in as necessary. It works as expected. I haven't hooked up the fire suppression system yet, but intend to. One guy over in the US saved his shop through the auto-suppression when he was cutting some palm wood which was so pitchy that the chips caught alight and he had a fire going inside his RL unit. Scary stuff, although it seems to happen but rarely.

9. My old RL160 has side-by-side bins which are nice to empty because they are both close, but fill unevenly. The chips used to go to the far bin and skip the close bin which was frustrating. On the RL250, the bins are oriented front and back so that they fill more evenly. This is a great improvement, although it could be better still. Chips still try to fill up the far side, but it is a lot easier to open the bins when they are half full and even out the level in each bin (RL250), than trying to scoop chips from one bin to another (RL160). Something to keep in mind.

10. With my current ducting, I have to keep quite a few extra ducts/ports open to ensure that I maintain a 250mm cross-section airflow throughout my ducting. This seems to work fine. A lot of general air scrubbing is happening here, as I only use one machine at a time. Indeed, the exhaust from the RL250 unit is significant, significant enough so that it works like a giant fan in my shop, which is welcome when I get a sweat up feeding the jointer some slabs of timber...

11. I have an auto-start and contractor setup which turns on the dusty with each machine, and delays by 10 seconds when turning off. However, BobL and others has suggested that we should leave on our dusty for quite some time after the last "dust making activity" to ensure that any airborne dust is reduced/eliminated. I am convinced that this is a good move, so I have installed several remote switches around the shop so that I can turn on the dusty and leave it running for a while after turning off a main machine. This works well for me.

Mate, that's about all I can think of at the moment. Please feel free to come back to me if you have any more specific questions about the RL250 or my ducting setup. And I would love to know what you end up buying and how you find it suits your purposes...

Thanks, David

Hi LD,
Just a thought on point 8, make sure the air from your compressor is oil and water free, oil/water and dust don't make for clean filters.

At a guess you will have a pressure reducing valve inline which will incorporate a water trap which will trap some oil and water, note some, a charcaol filter for oil removal and there are a few ways of removing water, refrigeration being one.

Also drain your reciever tank periodically. I have known of them being half full of water

Cheers for now


Pete.

Hi David

Thanks so much for the detailed response!

I have 250 main duct (Danish product by JKF), only one machine will be used at a time for now, I want the capability to have 2 machine working at the same time, I may hire a helping hand, my workshop is only 9m x 6m, so its about half of yours, the ceiling height is 2.7m (yes my workshop is my garage), the big user is a wide belt sander (930mm), it has 160mm dust hood, the "worst" dust hoods are on my Robland combi, they are 100mm, not ideal but thats what I have.

The power to my workshp is only 60A, extreme case of the power I will be using is when I use the extractor (4kw) + compressor (7.5kw) + sander (11kw), the circuit was designed and installed to run bigger motor than what I actually use.

The rep from Donaldson Torit paid me a visit yesterday, I was very impressed with the knowledge and advice given, I asked about cyclone, told me probably not what I want if I want to stay off council radar, other than council regulations the fine dust will settle on metal service, wood dust is slighty acidity, when mixed with water + time, there wil be rust on metal surfaces. ie, bonnet of car, and yes, I do have this problem....

For a Donald Torit UMA 250, 5.5kw, 23m2 filter, the cost is $15k NZD + tax, no need for compressor, has its own auto shaker motor to shake off the dust when switched off, has its own explosion relief panel (no need to hook up sprinkler), can place outside the shed in the weather, placing the extractor outside is my ultimate goal and its probably the best practice... my neighbour wont mind as I am in a semi rural area.

Here is the fan curve of the UMA 250, G8 fan is 5.5kw.
Unimaster Fan.jpg

Here is the fan curve of the UMA 450, K11 fan is 7.5kw, a UMA 450 is $18k. 42m2 filter.

unimaster 450.jpg

For a Felder RL250, 5.5kw, 50m2 filter, the cost is $17k NZD + tax, need to hookup to a compressor (not a biggie I've got a 7.5kw hydrovane compressor but then I will need a dryer which is another cost), designed to be used in door - occupy valuable shop space.

I am not sure which is better...

the workshop is only to be used 2 hours a day max, I dont think I will clog up that filter that quickly if it has auto shaker when switched off, I think the shaker is a bit more effective than compressed air blowing at the filter? there is a thread on Sawmillcreek about a RL160 owner who commented the compressor blowing unit is not as effective as he expected.

so I am leaning a bit towards Donaldson Torit's dust extractor...

Originally Posted by LuckyDuck

7. It has been stated that the horsepower rating of the RL250 is not an indicator of how much airflow it is able to move. I respectfully disagree. I have an 80A dedicated 3PH supply to my shop, and 20A circuits to my main machines, including the RL250. The RL250 has a 5.5kW motor, which Europeans various describe as 7.5HP (S1) or 10HP (S6). I'll leave it to others to tell me why they have different HP ratings depending on the duty rating? The motor says S1 on it. My point is this. The star/delta start motor trips the 20A circuit from time to time, and the lights dim on start-up (different circuit to the RL unit but sharing the 80A main supply). I don't understand how this motor is not considered to be vastly more powerful than the motors I hear are being used on ClearVue units?

The difference between the start up on your machine and the CV is that the CV has a soft start that rises relatively slowly and maxes out at 16 amps for about 5 seconds and then falls back quickly. A CV Max using a hard start would trip circuit breakers just as the Felder does. One way of monitoring duct flow behaviour is to use an amp gauge, they can be had off Ebay for about $10 and are very nice units.

Originally Posted by Chris Parks

The difference between the start up on your machine and the CV is that the CV has a soft start that rises relatively slowly and maxes out at 16 amps for about 5 seconds and then falls back quickly. A CV Max using a hard start would trip circuit breakers just as the Felder does. One way of monitoring duct flow behaviour is to use an amp gauge, they can be had off Ebay for about $10 and are very nice units.

Hi Chris:

The RL250 has a star-delta start, which, I thought, was designed to reduce the Amperage spike on start up? I would like to get said gauge to measure Amps though!

Warm regards,
David

Originally Posted by pjt

Hi LD,
Just a thought on point 8, make sure the air from your compressor is oil and water free, oil/water and dust don't make for clean filters.

At a guess you will have a pressure reducing valve inline which will incorporate a water trap which will trap some oil and water, note some, a charcaol filter for oil removal and there are a few ways of removing water, refrigeration being one.

Also drain your reciever tank periodically. I have known of them being half full of water

Cheers for now


Pete.

Hi Pete:

Thanks for the reminder on this. All good points!

Warm regards,
David