From 5e2e135ea16d68d70f9592a457d00e3ee844ea18 Mon Sep 17 00:00:00 2001
From: daniel watson <ozzloy@gmail.com>
Date: Thu, 15 May 2014 11:15:11 -0700
Subject: [PATCH] update bill of materials

* includes change in suppliers and prices for some parts
* removes misleading out-of-date BOM
---
 bill-of-materials-rev-b.ods | Bin 6696 -> 0 bytes
 bill-of-materials.rkt       |  90 +++++++++++++++++++++---------------
 2 files changed, 53 insertions(+), 37 deletions(-)
 delete mode 100644 bill-of-materials-rev-b.ods

diff --git a/bill-of-materials-rev-b.ods b/bill-of-materials-rev-b.ods
deleted file mode 100644
index 58877f8021131951e4c934755c7519c90926574a..0000000000000000000000000000000000000000
GIT binary patch
literal 0
HcmV?d00001

literal 6696
zcmZ{Jbx@qm*X7{uZb3tEhd>DK5}d(;Gq?_eyM_P(f@`qg&R_}d?(Xgy+*$JbcI(}J
zzy12DuI_%i&h4sG_ufCwQBi<{M+N-Xpaz843WT%09{x_`*J)>E2ZDGwf{Yy<ZLLg=
zAyy9d?5_4^Y!1fGR?ch=jv#w82U8b2kUfOW*%1sfHgmQFfgmccG4TP2|A{~ic)%9I
zCxiz8axnpbzb`pMJZwSEZ0>fpM_PmShkV$}M0+B{=)dFNZU^v-$4BHyjcIBfBaPv|
zg=WhJ{xoScTwPa)?m`JhTUumG4Z*;&2<5gIA!m#>R1#WkQnO3O=Vhu#SWpo&>y*^W
z6?t(VakVsMA;j2G8zapq5;Oea`?#)J$4XmcO-JI%WNUtuq7Ds!bZ8Ks3h-m;YT%NY
zGX;2|nybl4Nre}gk0i8yAQnHUU9XDKY07)o$hUAea(Zo7ig7)1u_wK`xnQ)5#xUBc
z_lxh=%zb7cvd_SH5OCy?if6HrCyivInXuct>EzWkFTcFK-PtK|qO3};At5coYkAU4
z8mq3ftn$gge(>X6c=oD#b6p3b-XkXE1!}2oFRJ5HR`W_99_1k4mZ+C)oe-@q>HGq#
ze=L&P)}<uFs9w=Sfaztt?4mrCZ3N0NseFTnCwfSfxzWd%`M5giR-=*Y)OOM)S53%1
ziHP#MyImCD8T1RZ^>)nms)cxOCT6uoEjZ0k7>#vimZhADRWwVd^_s7(p7dPwEXRc-
zq%)j0Mzh}=J=foW^X(sNBhY*WnTsiYrPK2V>ypQuJ^X-~DOdK}=%Jhd+27b~MW9*O
z?{ejdq1J%1NXkmXwr~qwG}~4$oaHwtkj8HntYo!lX$5SA9jjER-P;VD4j$0n-;YK=
z+$Yqzukmd^4wR?wc%bhzhdhWGvC<}6wB=z!2(f_Il@0K}c5afJAiCnYZSK)Q)7r!#
zyhmAwCIq$!vTlx-bQp!oTNoGMF1L3ig<PTH!XMoRI`*x0U_$P@LZ2|Olk!r}z&aTM
zpk{CW{L9`b@9fVnDXF#{41`BY7kfNFq&Akjo>k|Dj6xvmW){|W`rNn1UM`C#147t+
znX(}$(8?i@>Lb2gkM-S#CH_}LFG|Jv@4VM4xh8s_S65Gy0bK>1{Ea1P%lgpHh}>;f
z^}`7JchqNLZ5_Q&l=HYMBv<n5QRd{C+eSn-#rNPY%N_1sl+bz8<p37#qR$fV%TxM)
zClL~RuKQ0C{wV9d_T8`0aZ5fjE|(A5GE?I=;&fbYHe@IYSg<uya{R+9k6~j#YjZ>U
zErl-&ue?7?jhCj4haNHYGx`yJ2;szSN4MNJ(X%Xg_YGus7dh(Z0n+{_!+32dHB#yN
zpcBmJ;Tk)n@a!yqcbd;NwQAx!^^UNKNU25*&3YS9)H<{?iNvq0N%G;fEUtTv2_y~B
zLMI*Nr85!~ym;<OvJ-<BqJ{^NkdF_oLX)lG;`<@{%^cF*!9?Qq*>W;LERwmVD}mr<
zCK;#K5^Sj(s^vMFzWo?wvjY^|u}N0V>gBcOeE<AJyF_k84o6#@iP$roGM&z6VeUEE
zb7f(tXmjOI|2_Z4T(&>`Sx|BE0SN$jd4U7`zuhD25IZ9W2LM=$1_01ryN9WRJ>+k@
z`P)A9y&N_ha9&zPTZ7hYBAT<N7DvmWeIG`476xhR=bM>T@R4+LOpQT<F<T$+t?qU1
z`#;cKW!d$|;&NXLdn0+#s%|;*U!<)&$~OC6aNHya;z}D-64#+?Ixw28!<W}LP}B+g
zG>JAR;&!{Qn}}$~7$1I@EPG$z_t<%8^x=w}%Ms3k_gw_BKs!ySA;N*4WDv2kH$yWj
zQ4m1JfJb{xAYgEWN;_8SeoU0%qmkVOTGPqz=y&nRqrF?y<qtfp%yksq(N~NXA>9Sb
z*sHU4DTxSt5z)#)zp+Flg;NpRuI_Mq-*D)a?zG<!W_~HtA!kQQb@lVBSkbe_Ua^*L
zU7ej<26CyC$0g{Mi)SW)DZbqXM_K<QDbCIV5tZBp2fHvroFeOQ@s<O$r{ho=bSIiU
z@IT&?%zx*mbtW%z9z_XaNbX_cklGZ_{*LtJc7X?ZmzlC&Nxdi|uri0y6&d_>Q>LIo
zAbTE!?GXb@U(-2*{IEiIDT;Msk0kf~*RIHpTg@^-ddQn=v^Tr6>+8V_HRtK2k~M#r
zFn2hHFijw!%j(t{OP4UQs{~w;?sVDwaO62rIU~13{-30S&!QTfU&@@hx|v0k6vnFb
z8ea??Kp8C7(~6ni<3LuOvi!}I3rtoC(Q=M!*?31BQ9Nn*2js3z!b)zkpNU);h&R**
zIYuPh+IfB|&sOO#M}l@aVQJTK_bzwH@M^=#nQWxpHS<C@k#3PDMSTowL3p<?qCHq2
zyxG{)2DIC!J3yDXY*w8>{M#RTYILC^Vkm72nLNfI!7_){z!c8vrcuHNp6t2{I_oqH
zZ-M47q`4<?p89ar){!{JP)sE(BBRg~avb%s9c}qzgyyKWl=iHnw{ArO*ZmTntpNkv
z?@KssPo1}%*_zT_uep0p=e4Ja?=T<C;D6GlM=j?|@{oC0!zOb`t@r`z?+1r!%(W&_
z(M~~ulBayww6sLqNt+CZ6GDINE!JF=VMRI}*QFO0s~2^?=mgLUCGMP=aY^oS4F%xZ
zks(FC<A=%1S6iD=fd1L!!)sUk`MavqaL8T5UUTLu(in}O5xyJBp}jn!w%O{x4_ctw
z?0PnGuNX+yl4k9!to8qeaB<=+(JswTa69pk(p8bffN1z#knC-PMHkx7!Z@Z)&*?z_
z<E$u=!F+?E__En{QY;`RMTfCX_!F`;Mk;7Fm&6q=`Gw2G`tYpxxW98Hc+@OYqn!Br
zYDjdB&Osr5<Vm98GcQ^uo~;CB??ap6FcCJF?3r!@Ln;jRlbr0C1rIeg2#}C9*`~2#
zbPnf|<u&@vq7$fP=l0t(dK7hSG39;bQF~o1GX8O#VyDJ~k3>BN=F+mcS>mVun~_fv
z$CundzMcFG%<-NY$5XRZYvuYyWs1w{`4V(4FQ7;PbUrKTlirPzx!!R-Yp3mdYIc^%
zGmeJUF|r1l1HM^rPp3rwdTBwoEiD{lm^YQrvMhLCnC)@V9JA{_p$}d@p-Af8N8sq^
zJSkHx_%bT>Hp~Hj0yw`=@u7_4uEx><KNymdfoZ!Cbw1mzd5%x?VpH#Qv?1&ZUz&s&
zW_zp!W}HdjD<6>g6BCj7>zk#X_bJlO=#0fR{=rUB5}%1{^BH;$OEjWcwv?9jzE5>V
zhAqGh-m>z>m!iv${2G5rXbF@g#Hl=FbK|-j4qF>bp+<6-qbiNsDPfRy|8+^JN}lzg
z6Qek-wu;XaCDPXtM|eB65jp`El&PWkbYm7=q*yA1^o(1(g&>vk(q`l6fu1pne@E{B
zehWJevqrSH{N5;?`4CDvh4i8SaC7jz+$0Waf9zUvLnknUFzpf$X#>Jaok9XSR$PI|
z=O@Dg?&2g2_rpjiN*;a!VZP$&O2OpOgC&HGf62;eyrwvFa`^?on>;W-|B2wxKjB>l
z5LUgu{rs{ZdC1VFpYjarpyXW2IRA~8Wu)p5*+W7(!xwNG-n}bDN5{=zt+YXd1!^e`
zV^74@sgRxquqotxKEkkcI$A99iO9wde`wy?6N>n2Lc<7f#UOPIi(sf#o-}b=rJT->
zPWU7D^Cm~skBM2AkMn$B{P^Nu6N5+do<2ic<WV|PWD0;kED)^~8WrsUSTj}@f2S69
zo$=!)A0;H9HhrHFVXRf+C$TuG4kO&IaTe`rMbx3MQYBLUz;Sq|9PZTi=mrVG>M5O%
zH+lu)BmI*la%M>C^E=qBY+F1j#`**M2{c~3S8(V~w&Sq@t?GN1s_d*})E9RE?Kz0c
zU@Ym#Lpoh2x*p3na}IKy1&<vZJL{qPzL+W(aFt)E#wL(xrro1xSk;}YkNfM&S@TSM
zcBtO$NbN=(<rjVvVn4VGD3wMztlKu;HaOT`c<&lI&AYH}Fw@DtJEPtYFT%C=JDTU5
zP~;in?D`aUaQ~cUC<Ip4pKM*bJ9pp+O2@*O<cKVvKO|jdYb2GL<(T$UhUScnRP+S-
zVUCRWl6e0nAr7?y-O|^S^xw_~jqNWK=q`9!-^>T;A&1Q`*{knxZ&?jm&8albkm6Cn
z1=*|;iY_d8@a3_-#XIn7c_gYXoXY6eHXAVhp0}{fO9%?8?a!(50jmzv6jsbeP6YYW
zTi$t==6BW4Apl`5Tk@(Z<N)^ZCJ>kHT$wShGphPJ5@t!Fd_?P635A1WkmY{2^YB=b
zQm{SM7dW*GS^Vrnjxe|nH!>a~*q3nIPyQdbu-~$={!a1eavMk5pcxLFW{WEyhumkp
zA9TOH*gln;m=X91^^90`32ope9}dNjT+DFoP1(~YqhAc9^oWF~H+?rK!Ao`gLA?&#
zm!0>6RVpM|;vy{E=Q}zCU0-do`1_3yo~5+iaTB7cB|&Uq$xg)2P`4`3lJKvXj>HNW
z{|XNGLZ__CRq};+^0D~ViXEN<-kkF4^E9H^T=-q32Tw?l<@-Hdq=(@~+70egOp|4?
zQb8NyryonX5eD#pvcu*dAnoQl9ki_DD5Xn-#=}^!zc39Ao>V;Igtf>8$si{wYClY{
zQf-GDT|ideford&Uh}0_B-c9^v?{>`k2($20eb!EvY$!<OI#%wsf_(u`_?k2X^AVx
zKUY&qn)*wfcDHgcq1C8qoQF2z7ie>r2u7^_{4x&VKIk2IDh@r_Nq?&Cc0g&rxn+8I
zpG3MLD~vb;0-=*ioK!L>HHOG+_2#uMVTO=<*H#Cj`}v*FOgqI$-$gnfWUPd{c^L^4
zF5ha=rP58yN%7IdTyYVy{12MGb*w0f3&qn2UvY#RRhmjNl0x4>8DX;A7Z2o3G;7Ne
z%q(4|M_|qL{FjA(6?PIWTGNXli5>XR!CYQg{uzF-U#!E>zXOHnZ{t2pzC0yWe3Vi^
z|HT6V$v}{)upTeDjPY2V!i(iwF@$as87j)Dq+wRP>gca>wH3H~-tz!5ni@e7)~eMA
zUV%hslzR9V>0#Xk`=n`!)hMcb)C2So6hi-NbP|iOD~yaUF{lJNnbHpKuu~j92c!8)
znL(8IbWd_Ww#R(4dhmV>!rFz^0tH)Z#-P0|*fm&nVehWJ@V-h59XFBEv~uQ0dc7m!
zN<Q!IfMO^4BBjI+q*Gf+Y|<go=C<`x)4ln*hAdZmGVrx_@mJoqQC&&A*;EzvUDJYI
zkhmeqLD<uZct(pWW}5pi;jkWW*0jJGsxOQ>bJ;a^ayF(uyocBH$~{kU5l7~X`YK}F
ziQZMolfyngq1>QA)4nBNZ~4_(51sTkK>tr6d`s0+)}Z{5R2<!UkD!yfiZN0K+5#v2
zS}HRtUoPH-`0el6HoLrpLD~u6!r?&BVJADCjhwFAdktnAuQ+y736Wog?L@jV+;!d<
z)+;Yp+EYt~+1o1l^VrkCb8CX6DaVz=Pwf;WhzyW#Bt!LG@m0qDd<sSbTG>NxMO@64
zji~41sr|O!zcceK6ATTQIHtK8IooK;{Z`5*Q!yP%bE#+JGu!b~7wZj0sZJ)@8XnoH
znlXoHawOR^Fnu!>7I=bC!br7y)g&zWdB?I4qK}l*m6Ns$g&kK(dVqKDoaZ+7+#Rcb
z5dGmsjw7*!_Ywh;lIP%F_|2QQoSeshi3>;~_{^;dUEqG@0L2LAG+KeS+t-0<yU(A_
zBNsn_EAO#qj*E{<^Eq#>T0uRezs*vbV|cq=Sdp8kvi%m55c%1xFuxr8XvkN?5nYvi
zu8ESVBDh=G_p8*l!yKV01{bB(<9>SA+=V7NE9Hu}Kjcq+QsT12sqm7AaZ|^$#rfPx
zn<9qrT|$$_Z``V-xqQv)pgcr*x49oq1~ER9ok*g95Ej1_y_R6WMnPJAxI~%{ANCRH
zf+tl|LLX`uHQv7EBcK3xvhy1bOCDW{y2D-T?Zk(|59xP+yN1dpTmkngf5X|vD<eND
zuo01Hm}(>s)MC$^h)d(rx6$#d4{ZX0k}`D+MNo#-9qz+;48wd@+hZ}QfK|4|;J6bB
ze%0zCA_5-)v5tH8)ZoKkE{tdc@av{TXErbW5ZazRyjM8b6K*{9e<#D>3`^xU$IUl^
zn$_9?gQ&VdMD>>UOOIh8;$2G*#FWwJ1dNhiha3c?Vhl_=r5~o71t%!>Hv%ZMx>Ahi
znxdah7jMvd4cd$cHP_Iw&xrN6-;7{eyGKd-v=<A4W~NEkX*4Iq_tt4FJu2#(nPo#c
zi}6JKoxt8B2Y+IwIJTJbUBPjTrf{*w)|^s3;nQNKVSy*l(gcK<r5FirT8ZcEobqju
zyVX&`uqQ?Hq_Y)xzwQkj%%;drEc;p>>YhC@zu>X%lbqOhZeBM8)<FhLyQ>uAERVN&
z?rqa=@K~hD(M-Ivb{CkFTihj6g6HlOH)z|DN%I45Y2m)Yldt(m^L#G)9%8PSINb6a
zu##z$IL_IILEw~ow^>~!8G^@$n!)bmi4yW-_@%>Ylv*gIbTtj=WhM@*^ljK?ZJ^IY
zfwyaL0oA^^QbO}FzS_!GTv!Q%Pwd-p@NPt4aXm48IVQO_^BqsuJ?9<lD*O@&m@GIt
zRe!$+S?aCCXgm3JP=M0Rrd?M6diG;OrP_`B1p3Y`F&7`Tpydm?fUg;j8oTcv)!<`^
ziIot4p>uWkrct(J0K~8`sQ}YZK<kn21P8OzoY=rk-nb+tMRnV6OdOmlVyVOdiD)6`
zd6{c;4N9dKmE^535@Dcg>{|y?n6ldl|GYk`g?4(*|9JYuL6H_StQny$^iYD<7<Ow+
ztEWYUmWy%gBy{1uswX{wKn{pzTX$!93l;~jIy#kzmbrBs7!WF~wKZKqC#xGi7m0<)
z&>b5IGgRAxb7oh+vcy<w+7Kekypi1iUdi%KO~Hz>ru%o$hu2kwb_hBma8+3UK`FKk
zYcotV?eO1@{m5{t1>WRhkD&a$P;wn?MJ+IM)fU!{cQBFCYWz)gf5^{Foc^0m8FVdT
zue!lS#jtBHnK5_Hfw7>6o^Ez(17Blav9yJyk0ar&JJl3Sz-Lvh6bW61rs0?es_^Up
zmgd0CjbsJb)3^S9)d|^!#%vZa2ZL_P#Yh{n&N%RfIEk|!;`wP^)oYqf#4Bf<8NyNw
zv&&^0=uv^$OnhSrPzfFGs8ftikEOEOPuqs5B_*2YV-fm+Ct{HZQEt(4U=Db*?oQXl
zZoA)S(~hA%jV<K?z0jMI5584?%-X4O;IZiu8kpp@LSvH`r)byO_se4m<=L|j#K&7t
zB9#TXX9;#W;Dn~0lGL#u&AZdrG^%sHn|eB_+hSBENe=WZB2Xe3j8p*{m*t4M@@v7+
zj7)sp4^ORkkgJ0XUUv&u-_lF;b6v8Qj%;1~RFZNNxzP6*Hw%^c+SqQZjUOY}{d5<(
z5_s5}h^oi<$C4b&h3XH5qUJx^&XP5WUc}b9HARfgDXNUTcRyaUdJYsVA|CfIAd!&_
zY`M_bqFNn#XAtl$2*tOwS&Fy0Zxx#Qyp1>#-eQHhg*y>P^k@GC;Z>;l?^4baSDC~0
z>rFo_06_4%ev;A<W0g~qX16o8w=xGg|3}m*jcvE?<iM6Z4S5b4*9SW@)41+s2fUe3
zzlVvawTGXOcb}zxeqcfnJkEX_utax!W-dM9=^UQ@VWUl0H5a%erzxus{vk|uRkeCx
zp;-kGK>k{(idVf*6ODC<yyaz9b&<nFw*gu#bfQZ07t#w1v(1At(*BzIh9h_6&@ALt
zPh@)vcR)jyZ|z$7L>xFm^+kI608BpaF~+qWiv`APfn#(zpcS~FXnVZmO-F+7MUqs#
zx{6{^7v+0<ML84ru4r_VEK8q;@$ISNHwH(CpX_7c&KH+an2*a7zBj-9#vM)<J$=`i
zCD`w`>uU}FzeHgR@i|Jv0017ZMEysF2SJSg3SN<FjrN^X_{+>!lq|03T}2wSizN4R
z#cWnz?2+x&G|+L@_@5pY=9DHCDSqv`2&mX8mGwuh1-aHqvlKAEF=tG;8s^p?bGOLo
zgmo|(r-zXGNQkEGT<3!uGZNbp;`Gt@HVAY25V^^2;in5P5(RM}Yrq<8_xL4>Ha1+}
z{vAfo)JWiqX7rLmSuF2;<exSa0m#bM$m!Quc=Sj;#163ZSkrF5<%3K9jZfx{6mDfT
zi=4PB-|9sUO=#-&wW+6i9>uj$d&HjiMNXbu`|*ZNaag5`67=G1pRPRy$=J+7l3dp>
zbD$R_77_m0<I~E*L19SygoM01zD$|<2``Ybzrvj;uAhBff(J+=4$UcTtLb9?orh2m
zSux*h`<%qD`@%%rePrLr#Gji^5M(08%;m;c3r$b7P!`F%du8;$k`e}%^*>I;EBS!`
z?s@$E`_K444v31vU)2BXYW#!Hc-{Wvar_(iZ$0xLT<ohy@_(tD{|5fMdj0|G6aEji
l^zRV=&Z~bygc7}aJ^wq)R1^>p|K1?HepIiVofH2({V%Ztc5eUx

diff --git a/bill-of-materials.rkt b/bill-of-materials.rkt
index 4f3b74a..55e6c5e 100755
--- a/bill-of-materials.rkt
+++ b/bill-of-materials.rkt
@@ -4,45 +4,61 @@
 (module+ main
   (displayln total-cost))
 
-(struct item (description quantity unit-cost max-lead-days where-to-get))
-
+;; TODO: describe in detail what each field is
+(struct item
+  (description quantity unit-cost max-lead-days where-to-get note))
+(define (make-item
+         description quantity unit-cost max-lead-days where-to-get
+         [note ""])
+  (item description quantity unit-cost max-lead-days where-to-get note))
 (define bill-of-materials
   (list
-   (item "Arduino(tm) board"
-         1 21 8 (string-append "http://store.mp3car.com/"
-                               "Genuine_Arduino_Uno_R3_SMD_p/OPN-013B.htm"
-                               "?gclid=CKizyYOKsrkCFap7Qgod9kgAOQ"))
-   (item "USB a to b" 1 4 7 "https://www.sparkfun.com/products/512")
-   (item "wheel" 2 3 7 "http://www.pololu.com/catalog/product/184")
-   (item "motor" 2 6 7 "http://www.pololu.com/catalog/product/181")
-   (item "half BreadBoard" 1 5 3 "http://www.adafruit.com/products/64")
-   (item "jumper wire male/male assorted lengths"
-         1 6 3 "http://www.adafruit.com/products/153")
-   (item "jumper wire female/male" 1/5 6 2
-         (string-append "http://www.nexuscyber.com/"
-                        "7-premium-40-pin-male-to-female-jumper-wires"))
-   (item "small squares of double sided tape"
-         1/30 12 1
-         (string-append
-          "http://www.officedepot.com/"
-          "a/products/495242/Scotch-Permanent-Double-Sided-Foam-Tape/"))
-   (item "#4-40 Phillips 1 1/4 inch flat-head screws"
-         3 .1 1 "home depot, lowes")
-   (item "#4-40 hex nuts"
-         6 .1 1 "home depot, lowes")
-   (item "#4 lock washers"
-         3 .1 1 "home depot, lowes")
-   (item "Red LEDs"
-         2 .1 1 "evil mad science?")
-   (item "Yellow LEDs"
-         2 .1 1 "evil mad science?")
-   (item "Green LEDs"
-         2 .1 1 "evil mad science?")
-   (item "330 Ohm Resistors"
-         6 .1 1 "evil mad science?")
-   (item "motor controller"
-         1 (/ 5.2 5) 10 (string-append "http://www.ebay.com/"
-                                       "itm/like/180976411359?lpid=82"))))
+   ;; TODO: add solid core wires
+   ;; TODO: add male-female jump wires for connecting sonar sensors
+   ;; TODO: add 4x AA batteries
+   ;; TODO: add 4x AA battery holder
+   ;; TODO: add 3d printer filament cost for wheel, sonar sensor holders,
+   ;;       caster standoff
+   ;; TODO: add ball caster
+   ;; TODO: add angle bracket from evil mad science
+   (make-item "Arduino(tm) board"
+              1 16.98 8
+              (string-append
+               "http://www.colorapples.com/2012-new-arduino-uno-r3-board"
+               "-atmega328-with-usb-cable-p-89818.html#.U3Lz5nJKyzA")
+              "comes with USB A to B cable")
+   (make-item "motor" 2 6 7 "https://solarbotics.com/product/gm3/")
+   (make-item "transparent 400 point (half) BreadBoard"
+              1 5.95 1
+              (string-append
+               "http://www.jameco.com/webapp/wcs/stores/servlet/"
+               "Product_10001_10001_2123830_-1"))
+   (make-item "jumper wire female/male" 1/5 6 2
+              (string-append "http://www.nexuscyber.com/"
+                             "7-premium-40-pin-male-to-female-jumper-wires"))
+   (make-item "small squares of double sided tape"
+              1/30 12 1
+              (string-append
+               "http://www.officedepot.com/"
+               "a/products/495242/Scotch-Permanent-Double-Sided-Foam-Tape/"))
+   ;; TODO: get actual cost of #4-40 phillips 1&1/4" screws
+   (make-item "#4-40 Phillips 1 1/4 inch screws"
+              3 .1 1
+              "olander" "price is an estimate. can pick up in person")
+   ;; TODO: get actual cost of #4-40 hex lock nuts
+   (make-item "#4-40 hex lock nuts"
+              6 .1 1
+              "olander" "price is an estimate. can pick up in person")
+   ;; TODO: get actual cost of #6-32 3/8" screws
+   (make-item "#6-32 button hex head socket 3/8 inch"
+              12 .1 1
+              "olander" "price is an estimate. can pick up in person")
+   (make-item "motor controller"
+              1 (/ 5.2 5) 10
+              "http://www.ebay.com/itm/like/180976411359?lpid=82")
+   (make-item "sonar sensor hc-sr04"
+              2 1.39 7
+              "http://www.ebay.com/itm/161156018270")))
 
 (define total-cost
   (apply + (for/list ([thing bill-of-materials])
-- 
2.30.2