Dewalt 735 Push separator

[brdad]

Hello all,
Over the past few weeks I have read about every post here and it got me inspired to make a unit for my new Dewalt 735 Planer. I was so impressed I thought the least I could do is post a few pictures that might help someone else out.

Since the 735 is designed with fan-assisted chip ejection I didn't need much more than a hose and a cloth bag to collect the chips, but I did not want to dump the bag to empty it, filling a plastic bag I could throw out made much more sense. A shop-vac is definitely not needed. This planer is capable of throwing chips clear across the room, far enough in fact the adapter for the machine has fins in it to slow the chips down.

So this is what I came up with. The lexan cylinder is about 12" diameter and 5" high. The outlet tube is about 3" diameter cut off peanut butter jar. It is very thin but quite strong and fits very snug. The baffle is 1/8 hardboard - As you can see in the pictures I added in a support halfway through the slot. The airflow was such that without it the baffle vibrated quite a bit. With the support in place it stays rock solid.

The unit hangs underneath the planer table but removes easily by moving some wooden latches I created. For the connection to the trash bag, I made a wooden ring and attached weatherstripping around the perimeter. The bag hangs from the ring , which is then clamped to the bottom ring of the separator, sandwiching the bag between the two.

Because it's a pressure system, when the planer is turned on, the bag inflates and actually had enough pressure to lift the separator up off it's mount, which I corrected with a few more pieces of wood. I feared it might have enough pressure to pop the bag, so I plugged the outlet and it seemed to hold up even with a cheap bag, so I think I am safe.

I don't have any filter on the outlet. I think I am safe since I won't be running a lot of wood through this at any given time. I also stuck a 12" X 12" square of duct tape about 6" above the outlet and ran several boards through it, and there was virtually nothing stuck to the tape afterward.

I also posted a short video to youtube: http://www.youtube.com/watch?v=2JIdejGQrY4

Thanks for this great design and all the information provided by the forum members.

[phil (admin)]

That came out great, brdad.

I know you looked for fine dust using tape (which isn't a bad method), but I wonder if it would be possible to adapt a shop vac filter to the outlet so you don't have to worry at all?

[brdad]

Thanks,
I contemplated that, but I only have about 4-5" of vertical clearance above the top of the hat. An option to get around that would be an air cleaner from an older model car. If I could get close to the right height, I could affix some weatherstripping around the circumference of the top of the air cleaner and the bottom of the table would seal the top. I may do that just to see how much does get through after extended use.

[phil (admin)]

Thanks,
I contemplated that, but I only have about 4-5" of vertical clearance above the top of the hat. An option to get around that would be an air cleaner from an older model car. If I could get close to the right height, I could affix some weatherstripping around the circumference of the top of the air cleaner and the bottom of the table would seal the top. I may do that just to see how much does get through after extended use.

In the interest of science, not a bad idea!

[alan m]

looking good brdad
the car filter should work.
im not familiar with the filters on your side of the pond but the ones you see on the tv in those big musscle cars . they look about 3 inchs high.


i would also look into some kind of filter you could put into the outlet

[brdad]

That's exactly the kind of filter I was talking about, Alan. And it would go on the outlet, right on top of the hat.

[brdad]

So I decided to look for a filter today. My clearance height measured out to be 4.75", which as I suspected, was just a bit to shallow for off the shelf shop vac filters. I looked through many automotive filters, and all of those available seemed to be less than 3" or more than 5" So, rather than using just one and making something make up the difference, I bought two about 2-1/4" high each and glued them together, then ran a strip of weatherstrip around the top and bottom. Worked like a charm. After planing half a bag's worth of shavings, I inspected the filters and found nothing visible in them, but there was a little fine dust on the clear plastic top. It'll be interesting to see what happens over time, but it looks like a worthwhile addition to the project.

[phil (admin)]

So do you run the filters INSIDE the separator, or on top?  I imagine you run them INSIDE, but I'm just curious.

[brdad]

No, they sit on top. The filter just sits on top and when placed into position, the bottom of the table seals the opening in the top filter and holds it securely. So the filter is actually working backward from it's intended use; air comes out of the separator outlet into the center of the filter and escapes through the outside.

Interesting thought about putting it inside. I would imaging it'd be more likely to pick up stray pieces of wood, clog sooner and possibly disturb airflow? My separator is totally sealed so I could not try them inside anyway, but I wonder how that method would work with a shop vac... (I'd better save that for another thread)

[phil (admin)]

Oh, I get it.  I wasn't sure how the top was sealing if it wasn't inside.

No, I'd leave it as-is.  Having the filter installed like that will make it easier to clean if the bag overfills, for example.

Very nice work.

[brdad]

Just an update to say this is working exceptionally well, but that I do need to make a shield of some sort around the trash bag. The planer produces enough pressure on the bag that while it does not burst under normal use, if anything remotely sharp touches the bag while it is running (end of a board, screwdriver, boot hooks), the bag will fail.