Progress Report Series No
0 
2 March, 1944
AGRICULTURAL EXPERIMENT STATION
of The Alabama Polytechnic Institute, Auburn, Ala.
M. J. Funckess, Director
USE OF A HAMER MILL TO HULL AND SPITFY
LESPEDEZA SBriCEA SEED
D. G. STUKIE, Agronoist
F, A
0 
KU11YER, Associate Agricultural Engineer
it is necessary to hull and scarify lespedeza seri"a seed to get
satisfactory germination
0  
Because regular scarifying machines are rela
tively uncommion in rural communities and because farmers must bear the
expense of shipping their seed for such treatmentthe Alabama Agricultural
Experiment Station in 1941 began to explore the possibility of using hammer
mills for hulling and scarifying&-lespedeza sericea seed
0
At standard speeds, it was found that the hammer mill crushed too
many seed, However
9 
by reducing the surface speed of the hammers to.7,000
to 10,,000 feet per minute9 a hanmmer mill would hull without breaking over 5
per cent of the seed and germination would be increased
0 
Only 11 Per cent
of the unscarified seed germinated, whereas 84-per cent of the seed scarified
with the regular scarifying machine germinated, and 50 to 68 per cent of the
seed put through a speed-adjusted hanfier nill germinatedThe seed run
through the hamner mill do not have as IiW-,9i a cermination as those treateu
in a scarifyinj achiie
0  
ile, the regular scarifier is more efficient from
the standpoint of yielding a higher percentage of germinating seed the gain
may be offset by shipping and commtercial scarifying costs.Therefore,
farmers who d10 not have access to scarifying machines would be justified in
using their hammer niills or mi'lls in their neighborhoods
0
,
The tests showed that-the hamrmer Mill" has two advantages over the
scarifying machine.; namely, (1). It will hull and scari~fy trashy seed in one
operation, whereas the seed must-be cleanied before ' it is put through a
saifier; and (2) it will hull the seed much faster
0
minute if prop er pulleys are available
0
If tractor power is used, it wIll be necess , to change t!-illey
size on the mill, because the tractor pulley cau-ioDbe changed
0  
In the case
Reprinted September.,l1%8
(2)
where the mill is to be driven by an electric motor, it may be simpler to
replace the pulley on the motor with one of proper sizeo
The following information is needed to calculate the pulley size
in order to obtain the recommended operating speed:
(1) Pulley speed of power unit: For tractors, this information is given in
the. insltruction book, or it may be obtained from your implement dealer;
for electric mot=or the speed is stamped on the name plate of the motor,
(2) Diameter of pulley on power unit (tractor pulley or motor pulley).
(3) Recom mended speed of pulley on hammer mill (given in accompanying table
for each make of mill)o
Two exnmples are given to ilisIr.,te how the proper pulley size for
the recommeni.e d surf.ce. speed may be foundo
Example 1. A tractor is used and the pulley on the hammer mill is to
be changed to obtain the recommended speed given in the accompanying table.
(1) Speed of tractor pulley is 600 revolutions per minute (from tractor
book or dealer)o
(2) Tractor pulley diameter is 14 incheso
(3) Recommended speed of hammer mill pulley is 
1,900 to 2,100, or a 2,000
ro p, mI average (from accompahying table)o
(4) The diameter of the hammer mill pulley is determined 
as follows:
Tractor pulley speed (times) tractor pulley diameter Diameter
-------------- (divided by) ------------- ammer mill
Recommended hammer mill pulley speed pulley
600 x 14 = 4.2 inche , (Use 4-inch pulley on hammer millo'*)
2,000
Examp~le 20 The mill is driven by an electric motor
0  
In this case
it may easier to change the pulley on the motoro
(1) Speed of motor is 1,750 ro po mo (from name plate)o
(2) Recommended speed of hammer mill pulley is 1,900 to 2,100, or a 2,000
ro po mo average (from accompanying table)o
(3) Diameter of pulley on hammer mill is 5 inches
0
(4) The diameter of the hammer mill pulley is 
trmined as follows:
Diameter, hammer mill pulley (times) recommended speed /Diameter
---- =-- (divided by) -- - ----- equals motor
Motor speed pulley
5 x 2,000 = 507 inches (Use 6-inch motor pulleyo*)
1,750
*Always select nearest smaller or nearest larger size pulley
0
OPERATING SPEEDS OF HAMMER 1MILLS FOR HULLING AND SCARIFYING LESPEDEZA SERICLA SEED
Trade name Dia. of Recommended Trade 
name a
0  
o eomne
and model of cylinder: speed of pulley 0 and model 
of OCylineapedo*ple
hammer mill.-.. on hammer mill 
o hammer mill
Inches R. P
0
-oMItoInce 
0 
.
AloaO- '-1t -2l50-2400 Gehi rt7tt4125 10
Akp
2  
K 19-1811 ~1900-2100 Gehl t' 10 t? 24145 
10
Algoma 0=K 1110--..2'___ 1700-1900 Gehl t110"t Comb, 
24 10
Al !4l oma = K "t 12- -4!'24 1425-100 Gel115"1 24145 60
AlgornaC K "l24" ~ ehl 
1"15" Comb
0 4 T ' l b
Belln "10-40" 23 1500-1650 Glea___co"A 5 1 90 20
Bell NI'o,,1 lodern 12285 03200 fOGle.aco "A 5 
PB" 1 90820
Bell I-To
0 
2 I. dern 12 28 %_3200 Gruendler_"Ze ni th" 
18 90 20
Case "G 10" 22,?,5-1725 Hci
6
Valley !?F? 22=12 '210
Case "G,141f 22 157'5,-1725Hummner 113"823
Cocksbutt No. 1 12-1 4 225 300Hummer 
11112H 23250 lO
Cockshutt No
0 
2 12=1 4 2825-3100 JayBeeCracker 
Jack 15230 50
CockshufttI, o
0
c,3 26 1325-1450 
"3Be15H2300 255
Dellingr 6 6 17-1 2 19'751-2175 LI"n k Gr 
a in BustOer102_______
Del1ingrer "73" 2 1500-1650 Link 
jr. 10,12 375 30
Dellinger. "73 T" ___23_____________1,I1assey arris 1"21"- 
133_45
Deliner "48 A" 2 -1 2 -1300-1450 
asrars"3"2125 40
De11inf er "20"Al2o.1 2 1300-1450 
IVcC.-DeeriniZ Vo. 21325 145
Dellinger 44" 26-1 2 1300-1450 
Ic C -De 1 23_______________
D el11ti,27e r It"46" 2 -1/2 1300-1450 I1 eacows 
Gold I d al1 "10"' 22155 72
DlingTe r 
t
1l_"2 b"d-12 13"0-1450 
1 eado-vvs Go ld P,.e dal T"20" 25140 
52
John Deere"10 A 2502400,. 17cado--s Gold 
("I TedJ 30 25 40 12
Ls"3 61122 1575-1725 I ol.a( if.,.Is 
Go _l(Id al"50" 25140 52
arlW22 1575-1725 
YMi2nn
0
=Iol0ine IMiC24145 60
Fair b ci Is T, o rse "1140" 13-1 2 2525-2'00 M3Fords 
'12" 2 60 10
Faibans orse "375" 24 1425100 rM- S F c)r d""2 15 
8
Fairbanks = orse 1"430'" 2=1 l00 4b = Fcs 6A" ll 5 1 0
: Far b F7 nks ore11 o",0110140Nelson 
Jumbo M"23 10 T5
Fairbanks -To r se " 00" 26 2 1300=1450 
Pa 2,c"X" ______________27________
r
Operating Speeds of Hammer llills for Hulling and ScariyingLsedz eIcaSe
TrYade name Dia, of Recomnmendied Trade name Dia,,f J~cmmne
and mi-odel of cylinder-, speed of pulleyGO and.mod el of c~ne~pe fple
hammer mill10 
on hamer mill hammer 
mill o amrml
Inchies Ro P
0 
M. Inchel
0
P
Epec "0'27 1275 -1400 Soe '93" 1 10 20
Papec .113" 27 1275 _1400 Viking Jr1
0  
1 40 20
Papec l3R~
t
^7 175 100Viking IVMIa s t er 20C 70 190
Papec MS 27 1275- 1400 H'estern TBearcat li3 AEB; 21 60 10
paJ e C 27 1275- 1400 4estern Bearcat "7 All 21 160 10
Por t Huron No,, 3 13-12 2525 -2800 Vestern Bearcat '12 A ~ 21 i60 10
Port Huron No. 4 18 1900 -2.100 .Ve.stern Bearcat % At'21 15 5
Prater Blue Streak f.W 31 1100 1225 7.iestertn IBearcat "l AS"? 213 0 10
PrUte r Blue Streak C20l 3792 I( 
;33"1 250 20
Pcalkzer Blue Streak 1120-1,31 1100 Y ? 1101,1 25 30
Prater Blue Streak 113Qtt 37 925 15 1900i2100
Standa rd Steel %4" 41570 508fpl 1??15E 90 20
Stau nd ar d Steel IIGpIv 40 550 950 1 1 ~8 24" 24 145 
60
Stover 857 12 2550 3200 W-W 'IF 22 12 250 30
Stover 1188"1 16 2150- 2400 WAN fF 
24:4,18 190,10
Stover 1.91 A" 1.6 2150- 2400 vV--7l" F 26i?1 190 20
Stover tt66tf 14 2450- 2700 W-14 ItF 27 AT t?1 
190 20
Stover 6'7Y 14 2450- 2700 WVT-- "F 28-Y," 15E 90 20
Stover t"9211 16 2150- 2400 Wietmore Clipper> 100 10
Note This list is based on specifications-of farmi hammer mills from ?The Tractor FieldBok19994
publ-ished by Farm Implement News Coo, Chicago,, Illinois
0