How to make a LoveJoy coupling

[chuckorlando]

Yea just move the table over to offset. But your right, if you dont adjust it becomes scrap on the back cut

 

[John_Dennis]

I am trying to figure out the angles and how to cut the left and right sides of each notch. I think I should cut the 4 right sides first using an end mill smaller than the narrow end of the slot and then move the table the width of the cutter and then cut the 4 left sides.

I do not know how to figure out the number of degrees to rotate the part. I don't have anything to measure the angle with.

 

[chuckorlando]

You have 8 sides if I am seeing it correct. 360/8 = *45

- - - Updated - - -

Correct me if I am wrong here but you dont need to find any angle. Just make a cut, rotate, off set cutter, make cut, rotate, off set cutter the other direction, make cut, repeat all that 3 more times.

 

[markknx]

I am trying to figure out the angles and how to cut the left and right sides of each notch. I think I should cut the 4 right sides first using an end mill smaller than the narrow end of the slot and then move the table the width of the cutter and then cut the 4 left sides.I do not know how to figure out the number of degrees to rotate the part. I don't have anything to measure the angle with.

You could mount the old part on the roto table edge find one side of the slot, Zero the table and rotate to the other side of the slot. Record the angle. replace it with the new part and mill these slots every 90*. Mark

 

[chips&more]

The left and right sides intersect the center of the coupling. Simply cut on center with the side of an end mill. Choose an end mill smaller than the narrow portion of the angled opening. Set it up on your super-spacer with 90° indexing. You will be doing 4 cuts with this same positioning. Then rotate part 45° and cut the other 4 sides. Do not cut all the way through, cut each tab/ear and then index to the next. So, you will index a total of 8 times to complete the job…Good Luck.

 

[Andre]

If teeth are too complicated, you can use inserted pins.

 

[kd4gij]

Here is how I would do it. Turn and bore on the lathe. Then using a rotab or indexer. Center rotab to quill using 1/4" endmill move y axes .125 back take first cut to center, index 90deg #2 cut, 90deg #3 90deg #4 cut. 45deg table forward .250 5cut, index 90deg,#6 cut,90 deg cut#7 90deg cut #8. all cuts outside -in so as not to climb mill. Then just go back and clean out the slots. Hope that helps

 

[dwdw47]

It sound like you are not very experienced. Turn a piece to the diameter you desire and bore the pilot size.
Hold the machined piece on the pilot, hold the machined piece tight and with a bent scriber mark each dog! remove and put in your mill and align the lines with a straight edge to the table 90 degrees, milling all 4 sides to the line and the 90 degree line to it. Then rotate to line the facing line to the same 90 degrees to the table mill the same. The drive dogs are there.
Hope this makes it easier.
dwdw47

 

[springer]

i actually just did this yesterday for the exact same reason. i'm new and it was pretty easy. i don't have a rotary table, so i had to drill holes and use pins to index it around, but you could just rotate the work. find the center of your work, offset 1/2 the diameter of the cutter, make a straight cut across. rotate 45*, make another straight cut, do it two more time. the reason you only move 45* vs 90* is because you are cutting both sides with one straight cut.

here is what i did yesterday. more pics are in the "project of the day" thread.