Making your own grinding, mandrel
For those of you who like to make your own things here is a look at how to make a 4 inch grinding mandrel. First get, 4 inch bolt, 3, ½ inch washers, 3 inches of tubing-1/2 min. i.d. x 5/8 or more o.d. and ½ inch nut.
Everything has to be trued off the shaft of the bolt. First step is to turn the threaded end down to 3/8 x .650 long, file burr off threads. Second step true the inside face of the bolt remove as little as possible also make a 1/64 under cut where the bolt face meets the shaft
Third step true both ends of tubing to 2 inches .375. When using thin grinding discs use a washer between bolt head and disc, one between disc and spacer and one between spacer and nut. Snug nut down do not over tighten. There will be a bit of run out because of the difference between holes and bolt sizes this should not effect grinding. Thick discs may also be used but use only one washer between nut and spacer. Approximate cost, bolt,
Washer, spacer, nut at local hardware $3.oo, gas to and from $1.50, labor and trouble $7.oo per hr. x 2 = $14.oo, total aprox. $18.50. If your drill press is so worn out and wobbly it won’t even drill correctly this ain’t going to work, also don’t even think of buying a bolt with out making it true and sticking the stuff in your drill press. As a matter of fact don’t even fool around with it just buy one from Lindsay.
Disclaimer, I do not recommend anyone doing the above, go see a professional!
Carl Bleile
Southwest,Ohio
Last edited by carl bleile; 02-28-2009 at 03:38 PM.
Reason: wrong number
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