Along with the times, the availability of fossil energy is decreasing, especially natural gas and coal, before using fossil energy, humans have used biomass as an energy source. Indonesia has many plantation commodities, one of which is coffee which is the fourth largest coffee producer in the world. Coffee grounds are the main waste produced by coffee shops and are usually only thrown away. The main ingredients in this study were arabica coffee grounds and robusta. By using robusta composition 60% arabica 40%, robusta 50% arabica 50% robusta 40% arabica 60%. In addition, briquettes are tested for hardness by making points on the surface of the briquettes using a durometer shore A tool of 30 points, then a calorimeter bomb test is carried out to obtain the calorific value content. The result obtained from the highest hardness value is briquettes with a robusta mixture of 50% arabica 50% with a value of 23.7 HA, while the highest calorific value is found in a robusta mixture of 60% arabica 40% with a value of 4526.85 cal / gram.

Briquettes are a type of alternative energy whose raw material source comes from agricultural waste such as coconut shells. Coconut shells are converted into charcoal which has a higher calorific value through the pyrolysis process. The aim of this research is to determine the effect of comparing particle size and printing pressure on the length of burning time and burning temperature, so as to obtain a briquette composition that is durable and produces high temperatures. In this research, the raw material used was shell waste with a drying process of 400°C and the particle size variations used were mesh 30, 150 and 250 mixed with 12 grams of starch adhesive. The briquette molding process uses 3 kg and 5 kg pressure, which are then dried using an oven at a temperature of 750°C for 3 hours. Tests were carried out on burning time, burning temperature, water content and ash content. From the research results, it was found that for the highest temperature, briquettes with a particle size of 250 mesh were produced with a pressure of 5 kg at 312°C, and the flame duration of the briquettes was 240 minutes.

The primary function of mobile robots is to transport various loads, including their own weight and additional cargo. Ensuring adequate torque in the wheel motors is crucial for effective load-bearing and movement. This study investigates the load-carrying capabilities of the TT DC gearbox motor, a popular and cost-effective choice for small robots. A mobile robot equipped with four TT DC gearbox motors and employing skid steering locomotion was constructed for this purpose. The robot featured a container designed to carry sand, and its load capacity was tested by gradually increasing the weight until the robot could no longer move. Experimental results showed that the maximum load the robot could carry on a flat surface was 4000 grams, which corresponds to 1000 grams per 5 cm diameter wheel, driven by a stall torque of 0.08336 Nm (0.85 kg.cm). This finding is consistent with the motor's specified stall torque of 0.8 kg.cm at 6V. These results suggest that the maximum load of a mobile robot can be predicted using the motor's stall torque specification and the wheel radius through the total tractive effort (TTE) formula. This study offers valuable insights into estimating the performance limits of DC gearbox motors used in driving mobile robots.

One of the reasons the Sugar Factory failed to meet its sugar production target was due to damage to the machine components, particularly at the milling station, where the milling rollers are located. The milling rollers play a crucial role in extracting juice from sugar cane, separating the juice from the bagasse, and measuring the raw juice before it enters the purification process. This unit is designed to maximize raw juice yield while minimizing the amount of bagasse. The milling rollers are arranged in a triangular configuration of three mills, with a milling path between the front and rear rollers that can move forward and backward. Several common issues affect the milling rollers, including surface wear, damage from excessive loads, and wear from repeated friction between the rollers and the sugar cane. Sugar cane itself contributes to roller wear due to its composition, which includes water, sucrose, cellulose, lignin, hemicellulose, ash, and silica. These substances are highly corrosive, even to stainless steel, and act like abrasives against the rollers. The usual remedy at the factory is to weld stainless steel onto cast iron rollers. However, this method has only been moderately effective, as the rollers continue to experience wear after a short period. Based on field observations and literature reviews, some suggested solutions include more frequent cleaning and applying a tungsten coating to the roller surfaces.

Abstrak
 
Kegiatan pengabdian pada masyarakat berupa pelatihan dan pendampingan masyarakat RT 31 RW 06 Pandanlandung Wagir Malang. Masalah yang dihadapi masyarakat adalah bahwa kesadaran penggunaan energi alternatif terbarukan yang ramah lingkungan, kebutuhan listrik yang penting, biaya listrik yang mahal, dan lisrrik PLN sering mati. Kegiatan yang dilakukan ini adalah membuat Pembangkit Listrik Tenaga Surya (PLTS) sebagai  penghasil listrik. Pelatihan ini memberikan pemahaman, sosialisasi, dan penyuluhan agar warga RT 31 bisa membuat dan menghasilkan energi listrik. Beberapa langkah yang dilakukan adalah sosialisasi/penyuluhan pembuatan PLTS serta Pembuatan, Pelatihan dan Pemahaman Pengoperasian dan Pemeliharaan. Sosialisai/penyuluhan  PLTS berisi tentang: Fisika dasar, Matahari sebagai sumber energi, Pembangkit listrik tenaga surya (PLTS), Potensi PLTS di Indonesia, Aplikasi Teknologi PLTS: On-grid dan Off-grid dan Pedoman Perancangan PLTS. Pembuatan/perakitan PLTS ditunjukkan proses dan pemanfaatan penghasil listrik, langkah-langkah pengoperasian dan pemeliharaan. Prosedur pengoperasian PLTS yang dilakukan antara lain: persiapan pengoperasian, pemeriksaan awal, pemeriksaan tegangan keluaran, dan pengoperasian. Paska pengoperasian PLTS   dilakukan pemeliharaan dengan memperhatikan prosedur yang dilakukan.Hasil luaran yang dilakukan adalah pertemuan, handout sosialisasi/penyuluhan  PLTS, Panduan Pengoperasian dan Pemeliharaan dan pemanfaatan untuk penerangan Balai RT 31 RW 06 Pandanlandung Wagir Malang.
 
Kata kunci: listrik, pelatihan, panel surya,
 
 
 
Abstract
 
The community service carrying out were training and assistancing in the use of solar panels as an electricity producer at RT 31, RW 6, Pandanlandung Vilalge, Wagir District of Malang. The problem faced by the community is the ignorance of the use of the renewable alternative energy that is environmentally friendly. The need of electricity is important, but the cost of it is expensive, while the electricity managed by PLN often goes out. The activity carried out was to make a Solar Power Plant (SPP) as a producer of electricity by giving counseling and training to the residents about the construction, operation, and mantainance of PV mini-grid. They were also given knowledge about basic physics, the sun as an enery source, solar power plants, SPP potentials in Indonesia and its applications: On-grid and Ogg-grid, as well as SPP Dsign Guidelines. The process and utilization of electricity generators steps were also shown tho them. The output of this activity was the handout for SPP socialization and maintanance guidelines and utilization for lighting.
Key words: solar panels, electricity producers, training