RXB250L Pod Filter Adapter

zero_dgz · 02-02-2022, 10:55 PM

And other 3D Printable Parts!

I am hijacking my own original post to add additional items, information, and also update the links to the .stl files. Latest addition: I made a printable replacement for the rubber bumpers that go on the bottom of the stock seat. My bike came missing one. Now it isn't.

Air Filter Adapter For 40mm Pod Filters
- Easily adaptable to other neck sizes.
- Updated V2 design uses less material and prints faster, relocates filter slightly higher to aid in installation.

.STL File - Preview

Gasket For Air Filter Adapter (Printing in TPU required!)
- Should also fit stock air filter cartridge.

.STL File - Preview

10mm "Tall" Seat Pan Bumper (Printing in TPU required! Supports recommended.)
- Can replace middle and rear row bumpers which are easily lost.

.STL File - Preview

Original blathering below...

A while back I was messing around with my new 2021 RXB250L and the subject of its weird air filter came up. Here it is again, just for grins. What the heck, you say. Me too. The plastic flange and end cap do not come off. The whole ensemble is glued together so it has to be replaced as a unit. It's pleated paper, too, so it's not cleanable. Lord only knows what it is, part number wise, and while I found a fair few on Alibaba and suchlike that appear similar, well. Who knows without waiting for the slow boat from China to find out.

The other thing I noticed is that there's no kind of gasket on this thing as it comes from the factory at all. It's just a plastic on plastic junction, and while there's a ridge on the air box that I guess is meant to meet up with the inner face of the groove around the plastic flange but this does not fill me with much confidence vis-a-vis fine dust getting sucked in through the gap. I'm not entirely certain it's actually tall enough to make contact, to be honest with you.

I tried and failed to find a correctly sized O-ring at any of my usual sources. So enough already. It's time to get out the big guns.

So I drafted this, which I can 3D print in flexible TPU and use as a gasket. Here it is, riding neatly in the groove of the stock filter. The top hat shape and the screw hole lobes are probably not strictly necessary. Actually, a flat ring maybe 1 or 1.5mm thick the same dimensions as the groove in the filter flange would probably work just as well but this design gives positive proof that the gasket is in place and not kinked or twisted.

The next logical step was to just make an adapter flange plate that mounts to the airbox the same as the stock filter, but terminates in a neck for a pod filter. The trouble is, the paper filter is really short. 64.5mm tall, just about 2.5 inches, which is shorter than most of the foam pod filters I could find. I got my hands on a pack of Uni PK-52 filters at my local parts outfit (with chrome endcaps, no less, which no one will ever see) which allege a 3" length but seem to measure out a hair shorter in real life. The endcap presses against the little step molded into the airbox for the factory filter but it seems to be close enough for government work. You might be able to make one of the longer 15 degree angle filters mount, too, like the UP-4182AST since the bottom of the airbox is sloped towards the back. The bad news with the ones I've got is, $42. But the good news is you get two of them. I can keep one oiled and ready to swap in after a trip, same as I do with the filters for my big bikes.

Here is the entire ensemble in the flesh (and the stock filter for comparison) and assembled. I got the groove wrong on my first test print because I forgot that a radius is half of a diameter (somehow...) but with that corrected it bolts right on like it's factory. I printed it in ordinary PLA, and time will tell if this turned out to be a bad idea. I have ABS available if I need a more heat resistant material, but I really can't imagine the airbox area getting all that hot.

Maybe the red means it will be high performance.

OffRoadToad · 02-03-2022, 08:40 AM

That's pretty sweet! Love when guys get all ingenious like this!

What year is your 250? Mine is I think 2020, and it's a standard basket KTM style filter.

tknj99 · 02-03-2022, 08:52 AM

Good stuff.. but just a note for my Xpro Titan DLX brethren.. this does not apply to us. We have the previous model equivalent foam filter setup found in older RXB250L with the 5-speed

zero_dgz · 02-03-2022, 09:53 AM

Quote:

Originally Posted by OffRoadToad

What year is your 250? Mine is I think 2020, and it's a standard basket KTM style filter.

Mine's a 2021 and they changed the airbox to this for whatever reason. I would have much preferred a foam dirt bike style filter. In addition to the engine change, the plastics are also different. The frame is very similar to the 2020, but without having one nearby and naked to compare to I can't tell for sure.

zero_dgz · 02-16-2022, 04:38 PM

So while I was doing this I noticed that one of the rubber bumpers on the underside of my seat is missing. When did that happen?

Rather than go through the rigmarole of trying to source one of those (or get one from Orion -- ha!) I found it much easier to just 3D print a replacement. I recently got a spool of TPU filament and it's somewhat flexible and rubbery, though not quite as squishable as the OEM rubber bumpers.

I guess this makes it a knockoff of a knockoff? Original on the left, printed on the right. The design was super simple to reverse engineer (it's just a gussied up cylinder, really) and it works just fine, but I've already made a version 2.0 which has a different shape to the mushroom end and has a cross in it to facilitate getting it stuffed through the hole. I had to use a little silicone on the v1.0 widget to get it to pop through.

Here it is.

Printing it with supports is definitely recommended since there's a significant, and important, sharp overhang on it. There actually appear to be two types of these, as the two bumpers on the front are shorter than the middle and rear ones.

I'm consolidating all of my 3D printable stuff in the top post on this thread for the 0.0002% likely scenario that anyone in the future will have one of these bikes or one like it and need any of this stuff. Including the .STL file for this object.

02-02-2022, 10:55 PM	#1
zero_dgz Join Date: Jan 2020 Posts: 257	RXB250L Pod Filter Adapter And other 3D Printable Parts! I am hijacking my own original post to add additional items, information, and also update the links to the .stl files. Latest addition: I made a printable replacement for the rubber bumpers that go on the bottom of the stock seat. My bike came missing one. Now it isn't. Air Filter Adapter For 40mm Pod Filters - Easily adaptable to other neck sizes. - Updated V2 design uses less material and prints faster, relocates filter slightly higher to aid in installation. .STL File - Preview Gasket For Air Filter Adapter (Printing in TPU required!) - Should also fit stock air filter cartridge. .STL File - Preview 10mm "Tall" Seat Pan Bumper (Printing in TPU required! Supports recommended.) - Can replace middle and rear row bumpers which are easily lost. .STL File - Preview Original blathering below... A while back I was messing around with my new 2021 RXB250L and the subject of its weird air filter came up. Here it is again, just for grins. What the heck, you say. Me too. The plastic flange and end cap do not come off. The whole ensemble is glued together so it has to be replaced as a unit. It's pleated paper, too, so it's not cleanable. Lord only knows what it is, part number wise, and while I found a fair few on Alibaba and suchlike that appear similar, well. Who knows without waiting for the slow boat from China to find out. The other thing I noticed is that there's no kind of gasket on this thing as it comes from the factory at all. It's just a plastic on plastic junction, and while there's a ridge on the air box that I guess is meant to meet up with the inner face of the groove around the plastic flange but this does not fill me with much confidence vis-a-vis fine dust getting sucked in through the gap. I'm not entirely certain it's actually tall enough to make contact, to be honest with you. I tried and failed to find a correctly sized O-ring at any of my usual sources. So enough already. It's time to get out the big guns. So I drafted this, which I can 3D print in flexible TPU and use as a gasket. Here it is, riding neatly in the groove of the stock filter. The top hat shape and the screw hole lobes are probably not strictly necessary. Actually, a flat ring maybe 1 or 1.5mm thick the same dimensions as the groove in the filter flange would probably work just as well but this design gives positive proof that the gasket is in place and not kinked or twisted. The next logical step was to just make an adapter flange plate that mounts to the airbox the same as the stock filter, but terminates in a neck for a pod filter. The trouble is, the paper filter is really short. 64.5mm tall, just about 2.5 inches, which is shorter than most of the foam pod filters I could find. I got my hands on a pack of Uni PK-52 filters at my local parts outfit (with chrome endcaps, no less, which no one will ever see) which allege a 3" length but seem to measure out a hair shorter in real life. The endcap presses against the little step molded into the airbox for the factory filter but it seems to be close enough for government work. You might be able to make one of the longer 15 degree angle filters mount, too, like the UP-4182AST since the bottom of the airbox is sloped towards the back. The bad news with the ones I've got is, $42. But the good news is you get two of them. I can keep one oiled and ready to swap in after a trip, same as I do with the filters for my big bikes. Here is the entire ensemble in the flesh (and the stock filter for comparison) and assembled. I got the groove wrong on my first test print because I forgot that a radius is half of a diameter (somehow...) but with that corrected it bolts right on like it's factory. I printed it in ordinary PLA, and time will tell if this turned out to be a bad idea. I have ABS available if I need a more heat resistant material, but I really can't imagine the airbox area getting all that hot. Maybe the red means it will be high performance. Last edited by zero_dgz; 02-16-2022 at 03:29 PM.
	1

02-03-2022, 08:52 AM	#3
tknj99 Join Date: Oct 2020 Location: Central VA Posts: 1,259	Good stuff.. but just a note for my Xpro Titan DLX brethren.. this does not apply to us. We have the previous model equivalent foam filter setup found in older RXB250L with the 5-speed __________________ 2024 Zuma Storm 150 DLX 2019 Beta 430 RRS 2018 VStrom 1000 XT Former China Bikes: Tao DBX1, Brozz 250, CSC RX4, Titan DLX, Templar X
	0

02-03-2022, 08:40 AM	#2
OffRoadToad Join Date: Jul 2021 Location: Florida Posts: 21	That's pretty sweet! Love when guys get all ingenious like this! What year is your 250? Mine is I think 2020, and it's a standard basket KTM style filter.
	0

02-16-2022, 04:38 PM	#5
zero_dgz Join Date: Jan 2020 Posts: 257	So while I was doing this I noticed that one of the rubber bumpers on the underside of my seat is missing. When did that happen? Rather than go through the rigmarole of trying to source one of those (or get one from Orion -- ha!) I found it much easier to just 3D print a replacement. I recently got a spool of TPU filament and it's somewhat flexible and rubbery, though not quite as squishable as the OEM rubber bumpers. I guess this makes it a knockoff of a knockoff? Original on the left, printed on the right. The design was super simple to reverse engineer (it's just a gussied up cylinder, really) and it works just fine, but I've already made a version 2.0 which has a different shape to the mushroom end and has a cross in it to facilitate getting it stuffed through the hole. I had to use a little silicone on the v1.0 widget to get it to pop through. Here it is. Printing it with supports is definitely recommended since there's a significant, and important, sharp overhang on it. There actually appear to be two types of these, as the two bumpers on the front are shorter than the middle and rear ones. I'm consolidating all of my 3D printable stuff in the top post on this thread for the 0.0002% likely scenario that anyone in the future will have one of these bikes or one like it and need any of this stuff. Including the .STL file for this object.
	0