02-26-2016, 10:30 AM
Ok off we go again.
We now have all the details we need .
From this we can now find the amount we have to remove to cut the cam, the valve must be open for 117°so 360 minus 117=243° To cut away.
OK into the work shop and make the blank, then on to the mill.
I try to keep things simple when machining. I have a job to remember what I have taken off without plus or minus extra's. so when I use the rotary table I prefer to always work from zero.
My RT has a extra fiducial mark 90° from the original one to help when the table is used vertically this mark is also adjustable . in the past I have used temporary stick on marks for this type of job.
Right we know the relationship between the two cams is 107° so set the RT to 107° then set the adjustable
mark to 0°
Set up the blank on the RT with a tail stock centre or a machinists jack to keep it firm, set the RT to the new zero,
Use a end mill with a diameter about one and a half times the width of the cam and bring it down to just touch the blank of the exhaust cam with front one third of the cutter. add a little feed to the Z and rotate the RT to 243° Then return to zero,
Back away the Y feed add more Z then bring the cutter back to position. turn the RT when you reach 243° you will need to move the cutter forward to flatten the flank of the cam. Repeat this untill you get to your desired lift. Mic the base circle as a double check .
Now back off the cutter , move it over the inlet cam blank, Move the RT so zero is at the original mark and repeat the operation from the original mark.
When finished a nose radius is put on with a stone . Remember your cam may go the opposite way depending on if it is belt or gear drive. just reverse the order and start on the other mark.
I hope this answers your question Pete.
Brian.
We now have all the details we need .
From this we can now find the amount we have to remove to cut the cam, the valve must be open for 117°so 360 minus 117=243° To cut away.
OK into the work shop and make the blank, then on to the mill.
I try to keep things simple when machining. I have a job to remember what I have taken off without plus or minus extra's. so when I use the rotary table I prefer to always work from zero.
My RT has a extra fiducial mark 90° from the original one to help when the table is used vertically this mark is also adjustable . in the past I have used temporary stick on marks for this type of job.
Right we know the relationship between the two cams is 107° so set the RT to 107° then set the adjustable
mark to 0°
Set up the blank on the RT with a tail stock centre or a machinists jack to keep it firm, set the RT to the new zero,
Use a end mill with a diameter about one and a half times the width of the cam and bring it down to just touch the blank of the exhaust cam with front one third of the cutter. add a little feed to the Z and rotate the RT to 243° Then return to zero,
Back away the Y feed add more Z then bring the cutter back to position. turn the RT when you reach 243° you will need to move the cutter forward to flatten the flank of the cam. Repeat this untill you get to your desired lift. Mic the base circle as a double check .
Now back off the cutter , move it over the inlet cam blank, Move the RT so zero is at the original mark and repeat the operation from the original mark.
When finished a nose radius is put on with a stone . Remember your cam may go the opposite way depending on if it is belt or gear drive. just reverse the order and start on the other mark.
I hope this answers your question Pete.
Brian.
