Author Topic: Skill chalenge  (Read 2614 times)

Offline chipenter

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Skill chalenge
« on: July 08, 2019, 10:24:13 AM »
I have been given three castings for a universal dividing table , these will be a challenge for me to finish , the drawing is a copy of a copy and non to clear , I started with the middle casting took over an hour to set up  and five minuets to skim to size , because of the 6" angle plate got in the way I had to lift the dividing head , cutting the groove with very little of the end mill in the collet to get the depth required light cuts , to cut the t slot the cutter threads were turned off , and a very slow feed got the job done .
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #1 on: July 09, 2019, 02:44:11 AM »
My t slot cutter is 5/8" and the parallels are 1/2" , and wouldn't fit without damage so I had to make a 1/2" cutter to knock the corners off the slot , cut the corners off and managed to fiddle the cutter int and cut the t slot , flipped the casting around to index the end but kept loosing count , after turning the fist attempt off got it done on the second go , next is the base .
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #2 on: July 11, 2019, 03:55:51 PM »
Squared the base and tried several set ups to machine a 1 29/32" radius , without hitting the 1 2 3 blocks or the clamps finished set up is to high and not as setting secure as I would like , used a slitting saw this allowed me to lock the table and cut top and bottom at the same setting .
Jeff

Offline Pete.

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Re: Skill chalenge
« Reply #3 on: July 11, 2019, 04:15:09 PM »
Nice work Jeff. A great show of inventiveness.

Offline chipenter

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Re: Skill chalenge
« Reply #4 on: July 15, 2019, 02:15:11 AM »
I have to drill and ream three interconnecting holes ,as I don't have a vice big enough and dividing head was mounted on the table that was used again ,  I set the dividing head to zero and used a parallel to bolt the angle plate to the faceplate , set the dividing head to 45 degrees and drilled and reamed for the clamp shaft , back to zero and drilled and reamed for the clamp lock and retainer .
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #5 on: July 16, 2019, 06:18:34 AM »
First mistake I only removed the skin of the base casting , making it 1/16" over size and the same on the top thicker is stronger right , making the hole for the clamp rod off centre by 3/32" and 3 degrees  , to get it to clamp the plate is asymmetric but now works , hopefully I will learn from this . 
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #6 on: July 17, 2019, 11:47:04 AM »
Started on the table turned to size bored and reamed one morse taper , plain turning no photos as my hands were black with the cast iron dust , mounted in the dividing head and stated to index it , photo shows my method to index so I can walk away when I get bored ,
4 nuts and a piece of steel held in a toolmaker clamp , move a nut after a cut after 4 cuts remove the piece of steel and cut the longer one , put the piece of steel back and I am back where I started repeat 72 times to get all the way round .
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #7 on: July 28, 2019, 04:10:32 AM »
Not had a lot of time lately to hot over 40 degrees in the shed , got all the way round 360 indexes moved the dividing head 90 degrees and milled the slots 5/16" 1/2" deep , but when I came to mill the tees the table spun and damaged the surface , the er40 collet nut undid probably due to heat expansion  , I am not turning it down and starting again I will try to file off the damage , tightened up moved the slots out of alignment so I couldn't use the index holes that I used for the slots , and cut the tee slots with a VERY slow feed , clamped the centre casting and drilled and taped 8mm for the clamp bolt , next I have to cut a slot to allow the casting to flex and clamp the table .
« Last Edit: August 01, 2019, 04:39:13 PM by chipenter »
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #8 on: July 30, 2019, 02:58:45 PM »
My ER collet nut is almost the same size as my 1/8" slitting saw so I made a 20mm arbour , and cut the slot from both sides , conversely clime milling was quiet and conventional milling resonated loudly , the small diameter was just the right size to go between the hole and the side of the casting without touching , making the arbour took longer to make than cutting the slot .   
« Last Edit: August 01, 2019, 04:37:19 PM by chipenter »
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #9 on: August 02, 2019, 02:24:44 PM »
Made a holder for stamping the numbers on the ark , milled a 1/2" slot to take 1/2" square with a 1/4" slot for the punches , the idea being that the 1/2" slot will help to hold it square to the face , held in by a small t nut worked fairly well but I was 5 lines short , also made a threaded ring to hold the table with a slot and bolt to clamp in position , sorry the last photo is dark , still trying to work out a way to stamp the table .
Jeff

Offline chipenter

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Re: Skill chalenge
« Reply #10 on: August 03, 2019, 02:51:02 PM »
Numbered the table today , used a 1morse collet with a piece of 8mm bar threaded 8mm , to hold my much used clamping jig in place , held the whole thing in the vice to stamp the numbers , just have to mark the zero positions now , I have acquired an unfinished rotary table kit from a friend , it's unindexed but has a 60 tooth worm wheel so I may be able to put a Vernier on as there is no worm , that will have weight until I finish the rotary table .
Jeff