Why are my error bars on my graph out of place? - r

Question

I have a graph that I'm trying to make with ggplot and gridExtra, but my error bars are out of place. I want the error bars to be at the top of each bar, not where they are now. What can I do to correct them?
Also, what ggsave parameters will generate a graph with the same pixel parameters that I am using with the r png base function? ggsave seems to work more consistently than this function, so I need to use it.
Data:
###Open packages###
library(readxl)
library(readr)
library(dplyr)
library(tidyr)
library(ggplot2)
library(gridExtra)
#Dataframes
set1 <- data.frame(type = c(1,
1,
1,
1,
1,
1,
1,
1,
1,
2,
2,
2,
2,
2,
2,
2,
2,
2,
3,
3,
3,
3,
3,
3,
3,
3,
3),
flowRate = c(24,
24,
24,
45,
45,
45,
58,
58,
58,
24,
24,
24,
45,
45,
45,
58,
58,
58,
24,
24,
24,
45,
45,
45,
58,
58,
58),
speed = c(0.563120137230256,
0.301721535875508,
0.170683367727845,
0.698874950490133,
0.158488731250147,
0.162788814307903,
0.105943103772245,
0.682354871986346,
0.17945825301837,
0.806637519498752,
0.599304186634932,
0.268788206619179,
0.518615600601962,
0.907628477211427,
0.144209408332705,
0.161586044320138,
0.946354993801663,
0.488881557759483,
0.497120443885793,
0.666120238846602,
0.264813203831783,
0.717007333314455,
0.95119232422312,
0.833669574933742,
0.450082932184122,
0.309570971522678,
0.732874401666482))
set2 <- data.frame(type = c(1,
1,
1,
1,
1,
1,
1,
1,
1,
2,
2,
2,
2,
2,
2,
2,
2,
2,
3,
3,
3,
3,
3,
3,
3,
3,
3),
flowRate = c(24,
24,
24,
45,
45,
45,
58,
58,
58,
24,
24,
24,
45,
45,
45,
58,
58,
58,
24,
24,
24,
45,
45,
45,
58,
58,
58),
speed = c(0.489966876244169,
0.535542121502899,
0.265940150225231,
0.399521957817437,
0.0831661276630631,
0.302201301891001,
0.78194419406759,
0.202331797255324,
0.192182716686147,
0.163038660094618,
0.658020173938572,
0.735633308902771,
0.480982144690572,
0.749452781972296,
0.491759702396918,
0.459610541236644,
0.397660083986082,
0.939983924945833,
0.128956722185581,
0.998492083119223,
0.440514184126494,
0.242917958355044,
0.350643319960552,
0.02613674288471,
0.71625407018877,
0.589325978787179,
0.649116781211748))
Code:
#Standard error of the mean function
sem <- function(x) sd(x)/sqrt(length(x))
#Aggregate dataframes, mean and Standard Error
mean_set1 <- aggregate(set1, by=list(set1$flowRate, set1$speed), mean)
mean_set1 <- select(mean_set1, -Group.1, -Group.2)
mean_set1 <- arrange(mean_set1, type, flowRate)
sem_set1 <- aggregate(set1, by=list(set1$flowRate, set1$speed), sem)
sem_set1 <- as.data.frame(sem_set1)
sem_set1 <- cbind(mean_set1$type, mean_set1$flowRate, sem_set1$Group.2)
sem_set1 <- as.data.frame(sem_set1)
mean_set2 <- aggregate(set2, by=list(set2$flowRate, set2$speed), mean)
mean_set2 <- select(mean_set2, -Group.1, -Group.2)
mean_set2 <- arrange(mean_set2, type, flowRate)
sem_set2 <- aggregate(set2, by=list(set2$flowRate, set2$speed), sem)
sem_set2 <- as.data.frame(sem_set2)
sem_set2 <- cbind(mean_set2$type, mean_set2$flowRate, sem_set2$Group.2)
sem_set2 <- as.data.frame(sem_set2)
#Graph sets
set1_graph <- ggplot(mean_set1, aes(x=type, y=speed, fill=factor(flowRate)))+
geom_bar(stat="identity",width=0.6, position="dodge", col="black")+
scale_fill_discrete(name="Flow Rate")+
xlab("type")+ylab("Speed")+
geom_errorbar(aes(ymin= mean_set1$speed,ymax=mean_set1$speed+sem_set1$V3), width=0.2, position = position_dodge(0.6))
set2_graph <- ggplot(mean_set2, aes(x=type, y=speed, fill=factor(flowRate)))+
geom_bar(stat="identity",width=0.6, position="dodge", col="black")+
scale_fill_discrete(name="Speed")+
xlab("type")+ylab("Flow Rate")+
geom_errorbar(aes(ymin= mean_set2$speed,ymax=mean_set2$speed+sem_set2$V3), width=0.2, position = position_dodge(0.6))
#Grid.arrange and save image
png("image.png", width = 1000, height = 700)
grid.arrange(set1_graph, set2_graph,nrow=1, ncol=2)
dev.off()