Slightly Over-engineered Homemade Gravel Trommel

I've got three yards of gravel to separate. A 2x2 hand screen wouldn't cut it.

Category:

Howto & Style

Tags:

• trommel
• compost
• gravel
• rotary screen
• sifter
• soil seperater
• compost screen
• sieve

[MrDhammon]

What size v-belt are you using?

[wardomon]

@MrDhammon I'm pretty sure that I went with the larger 5L. Getting the length right was another thing. Two tries to get the motor to drive shaft correct and three to get the drive shaft to drum. It's a good thing that the Fleet Farm is only 7 miles away. You said that you're using 22" rims. I had a pair of 27" that I salvaged from an old bike and picked up the 3rd from a bike shop for $6. If you aren't too far along, see if you can build a larger drum.

[wardomon]

Thirty six inches. I got a roll of 36" hardware cloth (1/4" mesh galvanized screen). The drum is more than 7' in circumfrence. I think I had to buy 10'. Get fencing wire to lace the screen to the rims. Sew it on. Out one spoke hole, in the next. Once I had it laced, I twisted "Z" bends into the wire on the outside of the rim. You'll have to fudge around with pulley sizes to get the drum speed into the 24 - 30 rpm range.

[MrDhammon]

How long is your drum? You state that you have a 27" diameter drum. I'm collecting parts now. I have rims that would make a 22 1/2" diameter drum.

[wardomon]

@MrDhammon I found a pulley calc here: blocklayer.mobi/pulley-belteng­.aspx

1725 rpm motor w/ 2" pulley to a 12" pulley = 287rpm

345 rpm on a shafted 2" pulley to a ~22" drum = ~25rpm

Keep the speed under 30rpm or you be "spin drying" the dirt rather than sifting it.

[MrDhammon]

@wardomon I need to get the v-belt, pulleys and small wheels for the drum to ride upon. I have the frame, and drum completed. I guess one could say that all I have left are the mechanics...

[wardomon]

@shexdensmore : Funny! I used so many screws I had to get more.

[shexdensmore]

@wardomon

Well you can still draw up a plan of how it is built. Just take it apart. lol

[wardomon]

@winkdogg : Thanks. I thought about an magnets to get the nails and bottle caps but I had to hand sort wood chips, bones and shards of glass from the mix anyway. It didn't seem like it would be worth the effort. Look at the other video I posted. I used a fan to blow light organic material (grass and roots) out of the gravel.

[wardomon]

@shexdensmore : Thanks. It's all 2x4's & 1x4's combined with hardware from a big box store and mechanics from the local surplus dealer. I really should have drawn up plans as I built it.