There was a thread here a few weeks back about powered soil sifting. Here is my version if you are interested.
So, how much are you selling them for?
Ha! This is a one of a kind.
A whole host of safety issues before it could go on the market and numerous details of the design that could be better to say nothing of the 400 v single phase ac supply concocted from various transformers! Nearly everything came from the scrap box or designed around bits bought off ebay.
Still, it does the job!
Bob
What a wonderful example of British ingenuity!
The Effin Softy people would have a fit mind you....
interested.http://s115.photobucket.com/albums/n313/9fingersphotos/Soil%20Sifter/> I have a very stony garden. about 1 sq metre of soil dug to a couple of
Bob ... very interested in this ... have you made a set of drawings for this ? ...... (or is that being to cheeky)
interested.http://s115.photobucket.com/albums/n313/9fingersphotos/Soil%20Sifter/>> I have a very stony garden. about 1 sq metre of soil dug to a couple of
Not at all cheeky just naive! LOL
I just made everything to fit from what materials were to hand.
Started with a tray for the sieve unit that fitted some wire mesh that I had lying around. Then a frame for that to sit in with a few mm clearance all round. This is hung on four short wooden arms each partially bored at either end with a 35mm hinge bit. 35mm diameter ballraces set in each end. 8 in total. Then I made a static frame and hung the oscillating frame in it off the
4 arms. The crank was made adjustable to give a throw of between a few mm and 50 mm. The motor is a 3 phase 6 pole unit run from an inverter for variable speed. The con rod was made the same way as the arms but longer. same 35mm bearings. Bought a pack of 10 off fleabay - stupidly cheap. Even the pillow blocks for the crankshaft were less than a fiver each.No design here!! I just fiddled with the throw and the motor speed until it sifted OK Do it too slow and it does not sieve, too fast and it walks all round the garden!
6 pole motor does 950 rpm from 50Hz, I ended up with 40Hz so that means the motor runs at 760 rpm. Toothed belt drive is 22 tooth driving 72 tooth wheel. So the crank is doing 232rpm or just under 4 rps.The fixed stand was dimensioned to allow a wheel barrow to fit under it and to suit some beech I happened to have around and cross braced with some 18mm ply scrap.
I hope this has given you some ideas to work from.
A few simple metal components turned up on the lathe and basic woodwork
- job done.
If you are anywhere near Southampton then you can drop in and see the beast!
HTH
Bob bobdotminchinatntlworlddotcom
I've got lots of working electric motors lying about. Commercial hat on:-)
regards
>
I rather like that expression. Can I pinch it?
Dave
Please do.
care to give any away ?
this sounds like a project I need to build.
Bob ... thanks for that, the crank seems to be the biggest troublesome item .... wood work side no problem, but I no longer have access to a lathe.
I'm assuming the somewhat complex motor arrangement was just to use what you had ? ... A suitable 1/2 hp 1ph induction should do the job, key would be getting toothed belt step down ratio correct. Thinking here that a cement mixer motor would have enough ooomph.
Or do you find variable speed is needed ?
Did you get the bearing supports of ebay as well ? ..
Hi Rick,
The most common motors are 4 pole 1425 rpm. I found that a crankshaft speed of 230 is rpm seems about right. so that means more than 6:1 speed reduction. Vee belt would need at least 2" pulley for the motor to get a good grip for the belt and then a 12-13" driven pulley!! I opted for toothed belt drive for grip but 22 was the smallest pulley that would fit my motor and would need about 135 teeth - blooming expensive. My 72 tooth was the dearest item I had to buy from RS even with trade discount. If you can find a 6 pole (950 rpm) or even an 8 pole (720 rpm) this will help a lot. Yes I just happened to have a 3 phase motor and an inverter as I collect such things when I see them free/cheap on the bay. Once I got the speed right, I've not needed to change it but the inverter does give me a soft start over 5 seconds so i can load up the sieve and then switch on (starting loaded without a soft start might be a bit vicious)but I suppose i could always start empty and load once it was running. Using the variable speed and the adjustable throw crank just meant I did not have to get everything spot on. Yes the pillow blocks can from ebay. Joanne at JBenterprises (or something like that) will sort you out for those.
Cheers Bob ... I'll look on eBay. Did you use a standard mesh ...from steel suppliers, or buy in something ?
The mesh was some stuff i had around for years originally liberated from work scrap bin.
2" mesh 1/8 wire welded and each junction. I used two layers offset by half a square in each axis to give 1" mesh. I wanted to leave some stones in for drainage but for choice I'd go for 3/4" another time. it is quite surprising the size of stones that find a way through 1" mesh. I should have realised as normal concrete ballast is 20mm. Wonderful thing hindsight!Dont underestimate the load taken by the mesh. My sieve holds two full shovels of dirt and stones. Ordinary chicken wire wont last. Most of the mesh in the garden centres or B&Q was rubbish You could do worse than one of those galvanised foot scraper come doormat things like ebay no 310058046303.
Regards
Bob
In message , Rick Hughes writes
Scrap value?
Actually, there is a single phase geared drive which was the stirrer motor for our bulk milk tank. Probably too slow. Most are in the range
0.5 to 3hp and 4 pole. Previous uses were grain augers, feed mixers, fan drives etc.regards
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.