diff --git a/application/config/form_validation.php b/application/config/form_validation.php
index 5cb8bfd..26a7dee 100644
--- a/application/config/form_validation.php
+++ b/application/config/form_validation.php
@@ -255,6 +255,11 @@ $config['trials/create'] = array(
 				'label' => _('Program'),
 				'rules' => 'required|alpha_numeric|trim',
 		),
+		array(
+				'field' => '3dmodel',
+				'label' => _('3D model'),
+				'rules' => 'file_allowed_type[obj]',
+		),
 );
 
 /* End of file form_validation.php */
diff --git a/application/controllers/trials.php b/application/controllers/trials.php
index f2f01d5..399c062 100644
--- a/application/controllers/trials.php
+++ b/application/controllers/trials.php
@@ -35,7 +35,6 @@ class Trials extends CI_Controller {
 	public function __construct() {
 		parent::__construct();
 		$this->load->library('form_validation');
-		$this->load->library('upload');
 		$this->load->model('parameter');
 		$this->load->model('program');
 		$this->load->model('project');
@@ -63,55 +62,65 @@ class Trials extends CI_Controller {
 			$parameters[$program['id']] = $this->parameter->getAll($program['id']);
 		}
 
-		if ($this->form_validation->run('trials/create') === true) {
-			$config = array(
-				'upload_path' => '/tmp',
-				'allowed_types' => '*',
-				'max_size' => 64*1024, // set maximum file size to 64 megabytes
-				'file_name' => 'default',
-			);
-			$this->upload->initialize($config);
+		if (is_null($project['default_model'])) {
+			$this->load->config('form_validation');
+			foreach ($this->config->item('trials/create') as $rule) { // restore old rules
+				$this->form_validation->set_rules($rule['field'], $rule['label'], $rule['rules']);
+			}
 
-			if (!$this->upload->do_upload('3dmodel')) {
-				$this->messages->add(_('There was an error while uploading the selected 3d model.'), 'error');
-			} else {
-				$data = array(
+			$this->form_validation->set_rules('3dmodel', _('3d model'), 'file_required|file_allowed_type[obj]');
+		}
+
+		// run form validation
+		if ($this->form_validation->run('trials/create') === true) {
+			$data = array(
 					'name' => $this->input->post('name'),
 					'description' => $this->input->post('description'),
 					'program_id' => $this->input->post('program_id'),
 					'project_id' => $projectId,
 					'creator_id' => $this->session->userdata('user_id'),
+			);
+
+			$data['trial_id'] = $this->trial->create($data);
+
+			if (isset($data['trial_id'])) {
+				$this->load->helper('directory');
+				$trialPath = FCPATH . 'uploads/' . $projectId . '/' .  $data['trial_id'] . '/';
+				mkdirs($trialPath);
+
+				$config = array(
+						'upload_path' => $trialPath,
+						'allowed_types' => '*',
+						'overwrite' => true,
+						'file_name' => 'default',
 				);
+				$this->load->library('upload', $config);
 
-				$trialId = $this->trial->create($data);
-				if ($trialId) {
-					foreach ($_POST as $key => $value) {
-						if (preg_match('/^param-[0-9a-z]+/', $key) && !empty($value)) {
-							$param['parameter_id'] = substr($key, 6, 16);
-							$param['value'] = $this->input->post($key);
-							$this->trial->addParameter($param, $trialId);
-						}
+				if ($_FILES['3dmodel']['tmp_name'] != '') {
+					if ($this->upload->do_upload('3dmodel')) {
+						$model = $this->upload->data();
+					} else {
+						$this->messages->add(_('The selected model could not be uploaded.'), 'error');
 					}
-
-					$this->load->helper('directory');
-					$trialPath = FCPATH . 'uploads/' . $projectId . '/' .  $trialId . '/';
-					mkdirs($trialPath);
-
-					$model = $this->upload->data();
-					if (!copy($model['full_path'], $trialPath . $model['file_name'])) {
-						$this->messages->add(_('The selected 3d model could not be copied to trial path.'), 'error');
-					}
-
-					$program = $this->program->getById($data['program_id']);
-
-					$this->load->library('program_runner', array('program_driver' => $program['driver']));
-					$this->program_runner->createJob($trialId);
-
-					//redirect('trials/detail/' . $trialId, 'refresh');
-					redirect('projects/detail/' . $projectId, 303);
-				} else {
-					$this->messages->add(_('The trial could not be created.'), 'error');
 				}
+
+				// save parameters to db
+				foreach ($_POST as $key => $value) {
+					if (preg_match('/^param-[0-9a-z]+/', $key) && !empty($value)) {
+						$param['parameter_id'] = substr($key, 6, 16);
+						$param['value'] = $this->input->post($key);
+						$this->trial->addParameter($param, $data['trial_id']);
+					}
+				}
+
+				// TODO: Don't start jobs automatically
+				$program = $this->program->getById($data['program_id']);
+				$this->load->library('program_runner', array('program_driver' => $program['driver']));
+				$this->program_runner->createJob($data['trial_id']);
+
+				redirect('/projects/detail/' . $projectId, 303);
+			} else {
+				$this->messages->add(_('The trial could not be created.'), 'error');
 			}
 		}
 
diff --git a/application/views/trial/new.php b/application/views/trial/new.php
index 0a2f53e..34cf425 100644
--- a/application/views/trial/new.php
+++ b/application/views/trial/new.php
@@ -21,29 +21,28 @@
 					</li>
 					<li>
 						<?=form_label(_('Description'), 'description');?>
-						<span class="req">*</span>
+						<span class="req">*</span><br />
+						<label class="note"><?=_('A description is useful if you want to share this trial with co-workers.');?></label>
 						<div>
 							<textarea name="description" id="description" rows="6" cols="60" class="textarea"><?=set_value('description');?></textarea>
 							<?=form_error('description');?>
 						</div>
-						<label class="note"><?=_('A description is useful if you want to share this trial with co-workers.');?></label>
 					</li>
 					<li>
 						<h4><?=_('3D model');?></h4>
-<?
-	if (file_exists(FCPATH.'uploads/'.$project['id'].'/default.txt')):
+<?php
+	if (!is_null($project['default_model'])):
 ?>
 						<div class="notice">
 							<strong><?=_('There is a default model set for this project.');?></strong><br />
 							<?=_('If you want to use a different model for this trial, you can upload it here.');?>
 						</div>
-<?
+<?php
 	endif;
 ?>
 						<div>
 							<input type="file" class="file" name="3dmodel" value="<?=set_value('3dmodel');?>" />
 							<?=form_error('3dmodel');?>
-							<?=$this->upload->display_errors('<span class="error">', '</span>');?>
 						</div>
 					</li>
 				</ul>
@@ -52,30 +51,30 @@
 		<div class="box">
 
 			<h3><?=_('Application-specific parameters');?></h3>
-<?
-	if (isset($defaultconfig)):
+<?php
+	if (!is_null($project['default_config'])):
 ?>
 			<div class="notice">
 				<strong><?=_('There is a default configuration set for this project.');?></strong><br />
 				<?=_('This form contains the default values. You can adjust them for this trial.');?><br />
 				<?=_('The default configuration will not be modified.');?>
 			</div>
-<?
+<?php
 	endif;
 ?>
 			<h4><?=_('Application to use for the computation');?></h4>
 			<input type="hidden" name="program_id" id="program_id" value="<?=set_value('program_id');?>" />
 			<?=form_error('program_id');?>
 			<p>
-<?
+<?php
 	foreach ($programs as $program):
 ?>
 				<a class="button" href="javascript:void(0);" onclick="$('.program-parameters').hide();$('#<?=$program['id'];?>-params').show();$('.button').removeClass('locked');$(this).addClass('locked');$('input[name=program_id]').val('<?=$program['id'];?>');return false;"><?=$program['name'];?></a>
-<?
+<?php
 	endforeach;
 ?>
 			</p>
-<?
+<?php
 	foreach ($programs as $program):
 ?>
 
@@ -91,7 +90,7 @@
 							</tr>
 						</thead>
 						<tbody>
-<?
+<?php
 	foreach ($parameters[$program['id']] as $param):
 ?>
 							<tr>
@@ -111,14 +110,14 @@
 								</td>
 								<td><?=$param['unit'];?></td>
 							</tr>
-<?
+<?php
 	endforeach;
 ?>
 						</tbody>
 					</table>
 				</p>
 			</div>
-<?
+<?php
 	endforeach;
 ?>
 			<p>