Bellows Dry Washer Build

I have started my Covid Bellows Blower, the build is with 2mm aluminum, similar to Dave63's but different .
The top grizzly tray is almost complete and now ready to start on the riffle tray.
The bellows will be 180mm wide x 750mm long.
The riffle tray has 7 holes 140x40mm in front of and aligned the front edge of the riffles, 2 front riffles will be 30deg forward and approx 15mm high, the other 5 (might be to many) will be 12.5mm x 20mm angle 12.5mm high. Underneath the riffle tray will be stretched Calco supported by 15mm square mesh
A question are the holes in front of the riffle about the correct size?
Are 7 riffles to many?
Appreciate any comments.

Here are some photos of the started project, the top hopper (grizzly) and the riffle tray. The riffle tray 3rd riffle I have changed to be the same of the first two as that still leaves me with four vertical riffles.
The riffles on the mesh in the top hopper are to help break down any clods of heard dirt.

Today the dry blower had its first test run in the shed, not quite finished as yet however it should be finished tomorrow. I am looking forward to getting a couple of bucket loads of soil / gravel and see how it runs. I have taken advice from forum members including Nightjar on many little aspects including setting up the riffle tray at 21 deg and having a caravan spirit level on zero, so the unit will be pre-set at 21 deg when taken out.
Once out on a test run with soil and gravel I will video and post.

https://youtu.be/zyN_CW3Y7Ms

Now that Covid restrictions allow Regional Victoria to drive around, I went out to a spot that has had some old time gold diggings and put 6 buckets of soil and gravel through the Dry Blower. I was impressed with the performance of the blower I need to get some experience at using it, mainly to allow the right amount of soil to flow over the riffles. At the end I worked any soil down onto the calico and finally ended up with just under half a gold pan of soil, I washed this with some detergent and found one small spec of gold that I needed a snuffer bottle to pick it up. So I guess it works, I am yet to test pan some of the soil that has gone through the blower checking for gold that went over the riffles.
I sieved the soil down to 1/4 inch and used a wooden mullet break down the clods of clay which was very time consuming.

Cheers

https://www.youtube.com/watch?v=VVExulxGauY

I put some more soil through the Dry Blower this morning, tried a few different things.
Also placed some small pieces of lead cut from a sheet, one per bucket to see if the lead stayed there for the 3 buckets. The pieces were from the size of a decent 12 gauge pellet to larger.
First up I slowed the bellows down to 45 pumps per minute, there was not enough puff to keep the soil moving so I then put a 50mm piece of timber under the back legs increasing the riffle box to around 25deg but this still didn't fix the problem.
So back to the 100 pumps per minute, this made a difference but however the soil gets bogged down, if the soil is running from the top box okay the Blower likes it more, it loves to work hard.
I have worked out why Nightjar's riffle tray has 2 sets of holes above the riffles, one just in front to catch the gold and the other back a little. I am sure the holes in the riffle tray that are back from the riffle keep the soil moving, so that will be my next move but unfortunately that will not be for another week at least.
I tipped the riffle tray out on to a sheet of plastic to pan each riffle, the first riffle caught the 3 pieces of lead no gold unfortunately. All other riffles panned with no gold.
I checked the bucket sieve / clod breaker thread and that could be my next project to supply soil to the Dry Blower.
Cheers

Highway1 said:

Today the dry blower had its first test run in the shed, not quite finished as yet however it should be finished tomorrow. I am looking forward to getting a couple of bucket loads of soil / gravel and see how it runs. I have taken advice from forum members including Nightjar on many little aspects including setting up the riffle tray at 21 deg and having a caravan spirit level on zero, so the unit will be pre-set at 21 deg when taken out.
Once out on a test run with soil and gravel I will video and post.

https://youtu.be/zyN_CW3Y7Ms

Click to expand...

good on you , by the way thats a nice rhythm your machine has going there , my missus just popped her head in the door to see if i had sneaked a young lady into the shed.

Thank you CreviceSucker, yes the blower has a rhythm going and it is not really loud so it is not to invasive while you operate it. I am happy with the way it going.

There is a good video worth watching with good tips, it seems I cannot post links yet but search on youtube for
"DIY Power Vibrating Classifier for Gold Dirt, Drywashing Thompson Drywasher, Freinds"