today we learnt about estimates and quotes and what they involve.
we learnt that giving a quote means a solid answer and that the customer only has to pay that even if other problems or cost occur. therefore giving an estamite is better as u can give a price range and a not a set deal. giving an estimate is the best kind of pricing on a deal as if a problem or extra damge occurs during the repair the customer can be notified and they can pay extra for that repair.
Wednesday, October 26, 2011
26 october , class reflection
quotations and estimates
avarage automotive hourly rate
$70-$130
making an estimate or quote:
identify what it needs
parts
materials
outwork
miscelanious( cleaning matterials , spare bolts , small amount)
oil, anti frezze
labour
avarage automotive hourly rate
$70-$130
making an estimate or quote:
identify what it needs
parts
materials
outwork
miscelanious( cleaning matterials , spare bolts , small amount)
oil, anti frezze
labour
marine gearboxes
explain the diffrent types of gear selection types found in
outboard gearcases and sterndrive:
the gear selector system in a gear case is quite simple only having a forward and revers. forward and revers are selected by a dog clutch. this clutch has three big teath on either side and are used to grab hold of either the forward or revers gear.the dog clutch is located inbetween the two gears. the dog cluth has movement as it is needed to lock in one gear. in order to lock in the gear the shift rod needs to be minoverd ( pulled up or pusshed down). doing this shifts the dog cluth on its slide locking its teath into the teath on the inside of a drive gear. this is also the same in a stren drive but in a bigger scale and slightly more heavy dutey equipment. forward and revers can either be selected from the controll pannel in the boat or on the out board depending on the size of the engin or design of the boat.
inboard marine gear selectors:
gears are selected either by hydrolic or cable systems wich can be controlled from the main controll pannel. the reason why an inboard has this system compared to an outboard is because the engin is under the floor and would cause problems having to go down to the engin and back to change the gear, also inboard gearboxes are alot more heavy duty and there for need more pull to change. instead of a dogcluth system like a outboard it has a cluth pack wich is sevral clutch plates and spacers.when a inboard gear box is shifted it locks a sertan shaft or gear wich makes outside gears or plantintry gears rotate a spacifictway selected by the oporater.
what type of gears are used in outboards and strenlegs? give an explanation of why manafactures choose this types of gear.
there are two types of gears in a gearcase and stern leg, those gears are a pinion gear and two drive gears, theres only a forward revers and neutral because having more than one forward means that more moving parts need to be made, housed and mounted so they work smothly. doing this would make the gear case harder to service. also there would have to be a type of clutch installed and a bigger gear case would need to be made bigger wich would cause more drag in the water making fuel econimany alot worse .
duo prop
a duo prop is basicly two props on the same drive shaft on one gear case. the shaft that holds the two propellers is designed so one prop spins the opposite direction to the other propellor. the reason for the props spinning opposite directions is to remove thrst and disturbistance in the water. the propellor shaft that the two props run off is made so one end is fixed an one rotates the opposite direction on bearings.
jet unit vs surface drive unit:
a jet unit drive system is used by drawing water in and pushing it out at a high pressure through a smaller hole it came through. jet units re used quit alot on small race boats wich are not on wavey surfaces. a surface drive unit is designed so two out of three blades on the prop are under water and the other out above the water. having a surface drive can work to some advantages on diffrent types of boats. boath these types ofdrive systems dont realy work well on wavey or ruff surfaces as if the boat leaves the water just slightly all power and drive stops as there is no water to be driven off. there for these types of drives are used on heavy boats or for boats on flat water for full power. i would chosse a jet unit over surface drive because how simple the system is and how much power can be created.
outboard gearcases and sterndrive:
the gear selector system in a gear case is quite simple only having a forward and revers. forward and revers are selected by a dog clutch. this clutch has three big teath on either side and are used to grab hold of either the forward or revers gear.the dog clutch is located inbetween the two gears. the dog cluth has movement as it is needed to lock in one gear. in order to lock in the gear the shift rod needs to be minoverd ( pulled up or pusshed down). doing this shifts the dog cluth on its slide locking its teath into the teath on the inside of a drive gear. this is also the same in a stren drive but in a bigger scale and slightly more heavy dutey equipment. forward and revers can either be selected from the controll pannel in the boat or on the out board depending on the size of the engin or design of the boat.
inboard marine gear selectors:
gears are selected either by hydrolic or cable systems wich can be controlled from the main controll pannel. the reason why an inboard has this system compared to an outboard is because the engin is under the floor and would cause problems having to go down to the engin and back to change the gear, also inboard gearboxes are alot more heavy duty and there for need more pull to change. instead of a dogcluth system like a outboard it has a cluth pack wich is sevral clutch plates and spacers.when a inboard gear box is shifted it locks a sertan shaft or gear wich makes outside gears or plantintry gears rotate a spacifictway selected by the oporater.
what type of gears are used in outboards and strenlegs? give an explanation of why manafactures choose this types of gear.
there are two types of gears in a gearcase and stern leg, those gears are a pinion gear and two drive gears, theres only a forward revers and neutral because having more than one forward means that more moving parts need to be made, housed and mounted so they work smothly. doing this would make the gear case harder to service. also there would have to be a type of clutch installed and a bigger gear case would need to be made bigger wich would cause more drag in the water making fuel econimany alot worse .
duo prop
a duo prop is basicly two props on the same drive shaft on one gear case. the shaft that holds the two propellers is designed so one prop spins the opposite direction to the other propellor. the reason for the props spinning opposite directions is to remove thrst and disturbistance in the water. the propellor shaft that the two props run off is made so one end is fixed an one rotates the opposite direction on bearings.
jet unit vs surface drive unit:
a jet unit drive system is used by drawing water in and pushing it out at a high pressure through a smaller hole it came through. jet units re used quit alot on small race boats wich are not on wavey surfaces. a surface drive unit is designed so two out of three blades on the prop are under water and the other out above the water. having a surface drive can work to some advantages on diffrent types of boats. boath these types ofdrive systems dont realy work well on wavey or ruff surfaces as if the boat leaves the water just slightly all power and drive stops as there is no water to be driven off. there for these types of drives are used on heavy boats or for boats on flat water for full power. i would chosse a jet unit over surface drive because how simple the system is and how much power can be created.
Saturday, October 1, 2011
gear boxes
in class we pulled apart and inspected a toyota 4 speed gearbox. the gear box was for a rear wheel drive (north south) engin. the gear case was in ok condition and had small wear and chips. bolts and threads were in ok condition.
inside the gear box there was a input and out put shaft ,revers idler and driver shaft.
on the driver shaft there were 5 gears that were all part of the shaft and alwasy spin at the same speed as each other.there were 4 helical cut gears that were 1,2,3 and forth gear. the fith gear was a straigh cut gear and was revers gear . these gears were all in good conditon and so wear the roller bearings inside on the shaft.
out put shaft
the output shaft held the all the gears except forth wich is on the input shaft. the out put shaft also holds two sychro units wich are used to select the gears when changing gears. these gears were all in good condition ,well lubricated, bearings were good and not lumpy or worn. when i put the gears back together i checked the play and clearinces to see if a spacer or washer is needed to close the clearinceto reduces play wich can cause extensive wear.
HELLICAL
a hellical cut gear is a long cut gear wich is alot stronger than a straight cut gear. the hellical cut gear is used manly in forward drive gears (not revers). altough some older gear boxes had first and sometimes sceond gear with a straight cut gear. this has changed as manifactures have wated to improve durablitiy and overall strength of of the gear boxes.
STRAIGHT CUT
a straight cut gear is a straight tothed gear wich is mostly used in the revers system (driver ,driven and idler) . the problem with straight cut gears is that the weight of the drive is pressed on a small straight surface wich isnt as strong as a long offset cut like a hellical cut. the most common issue with staright cut gears is knocking a tooth off or shreading teath wich creats excessive noise slippage and further damage.
SYNCRO UNITS
a syncro unit is a system that helps with the selction of gears. inside a sysncro unit is a straight cut gear wich slots into a houseing. two circlips are inserted with 3 small metal spacers locking the spacers in. having these small metal bars alowws the gear housing to slide backwards and forwards selcting the gear needed.the gear inside the houseing slots into teath on the output shaft wich makes it fixed to the out put shaft.having a faulty syncro unit or a a syncro unti assembeled wrong can make cahnging gears extremly hard if not impossible.
SELECTOR SHAFTS AND SYSTEM
changing gear involves a few diffrent mechanisims. the gear leaver ataches to a selector shaft wich hooks on to sevral other selector shafts wich are attached to the syncros and revers system. on the toyota gear box i did there were 3 selector shafts. there were also 3 tic tacs wich slotted between the selector shafts to prevent selecting to gears at once.
BEARINGS
the bearings inside the toyota gear box were mostly roller bearings some caged and some like the input shaft into the output shaft were free roller berings (without cage). also there were oil groves were the gears sloted onto on the out put shaft wich act like beaarings as the pump oil in and around the gear to lubricate it. on the gear box i did some bearings needed to be replaced as some rollers were missing and some were lumpy and worn. the out put shaft ran on a caged roller bearing wich was ok and not lumpy. when re assemberling i lubricated all the bearings to ensure as little wear as possible.
inside the gear box there was a input and out put shaft ,revers idler and driver shaft.
on the driver shaft there were 5 gears that were all part of the shaft and alwasy spin at the same speed as each other.there were 4 helical cut gears that were 1,2,3 and forth gear. the fith gear was a straigh cut gear and was revers gear . these gears were all in good conditon and so wear the roller bearings inside on the shaft.
out put shaft
the output shaft held the all the gears except forth wich is on the input shaft. the out put shaft also holds two sychro units wich are used to select the gears when changing gears. these gears were all in good condition ,well lubricated, bearings were good and not lumpy or worn. when i put the gears back together i checked the play and clearinces to see if a spacer or washer is needed to close the clearinceto reduces play wich can cause extensive wear.
HELLICAL
a hellical cut gear is a long cut gear wich is alot stronger than a straight cut gear. the hellical cut gear is used manly in forward drive gears (not revers). altough some older gear boxes had first and sometimes sceond gear with a straight cut gear. this has changed as manifactures have wated to improve durablitiy and overall strength of of the gear boxes. STRAIGHT CUT
a straight cut gear is a straight tothed gear wich is mostly used in the revers system (driver ,driven and idler) . the problem with straight cut gears is that the weight of the drive is pressed on a small straight surface wich isnt as strong as a long offset cut like a hellical cut. the most common issue with staright cut gears is knocking a tooth off or shreading teath wich creats excessive noise slippage and further damage.SYNCRO UNITS
a syncro unit is a system that helps with the selction of gears. inside a sysncro unit is a straight cut gear wich slots into a houseing. two circlips are inserted with 3 small metal spacers locking the spacers in. having these small metal bars alowws the gear housing to slide backwards and forwards selcting the gear needed.the gear inside the houseing slots into teath on the output shaft wich makes it fixed to the out put shaft.having a faulty syncro unit or a a syncro unti assembeled wrong can make cahnging gears extremly hard if not impossible.
SELECTOR SHAFTS AND SYSTEM
changing gear involves a few diffrent mechanisims. the gear leaver ataches to a selector shaft wich hooks on to sevral other selector shafts wich are attached to the syncros and revers system. on the toyota gear box i did there were 3 selector shafts. there were also 3 tic tacs wich slotted between the selector shafts to prevent selecting to gears at once.
BEARINGS
the bearings inside the toyota gear box were mostly roller bearings some caged and some like the input shaft into the output shaft were free roller berings (without cage). also there were oil groves were the gears sloted onto on the out put shaft wich act like beaarings as the pump oil in and around the gear to lubricate it. on the gear box i did some bearings needed to be replaced as some rollers were missing and some were lumpy and worn. the out put shaft ran on a caged roller bearing wich was ok and not lumpy. when re assemberling i lubricated all the bearings to ensure as little wear as possible.
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