Thread: Homebrew Slotter project !

Hi Guys,

I've been looking at some old document files that I have hanging around on one of my backup discs and found an article detailing making a stand alone slotter ! I was actually looking for something else when I came across this.

Slotter.jpg

Sorry about the picture quality, I lifted the picture from the article which itself was a copy of a copy !

I wonder what the collective think ?

Is it worth having a go at building one, obviously I would have to put my own slant on this since I don't have any ability to make any castings, so would have to fabricate all the parts needed. Whilst I can slot key ways on the lathe, I think that it would be good for making gears and the like.

The ram is based on a piece of square stock running in a slot with the tool bit secured in the bottom. The stroke is 100 mm with a 100 mm throat. An X-Y table is used to position the work.

Comments please

I think you should make two and send one to me.

If you could find yourself an old arbor press, you would have the main casting ready to go.

Michael

I wonder if one could make something like this as a removable attachment for an arbor press?
I'm thinking like using the existing motion mechanism with an adjustable stroke, so you could use it for progressive forming, vibrashear style, as well.....
Food for thought.

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Originally Posted by BaronJ

Hi Guys,

I've been looking at some old document files that I have hanging around on one of my backup discs and found an article detailing making a stand alone slotter ! I was actually looking for something else when I came across this.

Slotter.jpg

Sorry about the picture quality, I lifted the picture from the article which itself was a copy of a copy !

I wonder what the collective think ?

Is it worth having a go at building one, obviously I would have to put my own slant on this since I don't have any ability to make any castings, so would have to fabricate all the parts needed. Whilst I can slot key ways on the lathe, I think that it would be good for making gears and the like.

The ram is based on a piece of square stock running in a slot with the tool bit secured in the bottom. The stroke is 100 mm with a 100 mm throat. An X-Y table is used to position the work.

Comments please

best simple one i have seen was on YouTube where a cheap chinkese electric motor 1/3hp mounted to right hand speed reduction gear box which are available cheap on ebay ,home made conrod and ram conected to reduction gearbox pto, this was then bolted to a milling machine head, great idea for a slotter with a slow speed

I think it's a worthwhile project.

Simon

Sent from a galaxy far far away

Hi Guys,

Whilst collecting material for this project I've picked up a cast iron bar bell weight, 7.5" inches in diameter, 1 inch thick with a 1" inch hole through it.

I'm looking for ideas on how to hold this for turning on a 3.5" CH Myford ?

I want to machine the edge for a multi "V" belt and clean up at least one face. I also need to bore the centre for a ball race.

Thanks Guys.

Does your lathe have a gap that will accommodate the pully diameter?

Do you have a boring head for your mill?

If the answers are yes and you don't have a chuck that that you can use , you will probably have to use a mandrel.

You maybe able to fly cut both faces on your mill first, then bore the centre to the desired size with boring head.

You can then make a suitable mandrel to hold the disc so you can machine the OD and your face.

Hi Peter,

Originally Posted by pipeclay

Does your lathe have a gap that will accommodate the pulley diameter?

Do you have a boring head for your mill?

If the answers are yes and you don't have a chuck that that you can use , you will probably have to use a mandrel.

You maybe able to fly cut both faces on your mill first, then bore the centre to the desired size with boring head.

You can then make a suitable mandrel to hold the disc so you can machine the OD and your face.

Thankyou for your reply.

Yes the Myford can swing 9" inches in the gap, just ! It hadn't occurred to me to fly cut the face using the mill, though I am going to mill a slot across one face for the drive pin mounting.

I must admit that I would rather bore the centre for the bearing on the lathe rather than using a boring head. I've never been able to get a parallel sided bore using the mill.

I'll have to take some pictures as I go.

You may have to mount the disc to a face plate for the bore.

1) As Peter says, a faceplate is probably the traditional way, if you have one which is big enough.


2) Now that I have a mill, I would face it on the mill, then bore/drill/ream the centre out, then mount it on the lathe for machining the periphery and the Vs.


3) I have machined a weight plate on my Hercus with just the Pratt 4" chuck, and a length of threaded rod through the spindle. However, it was only a 5lb weight. If your weight is 7.5lb or 10lb, I wouldn't trust your little chuck.

3.1- Grab weight by the hole in the middle of the weight, with normal jaws tightened out into the hole

3.2- Machine a step around the middle

3.3- Turn weight over, grab around the step, and use threaded rod through the middle to bolt securely to chuck & spindle.

3.4- Machine periphery, Vs, and most of the face

3.5- Remove threaded rod, carefully finish facing, and bore middle out


3.1 thru 3.3 are photographed here: https://metalworkforums.com/f189/t20...03#post1985803



If your chuck is reasonable, you could carefully do the boring in two halves (before and after flipping the weight), before using threaded rod to secure weight to chuck.

Hi Nigel, Guys,

Nigel thank you for the link to your earlier post, I do remember that one and the difficulty you had getting the runout down.

I promised some pictures earlier. These are of the work that I've done so far, as you can see I have used the Myford face plate, its actually about 8 mm smaller than the 5Kg bar bell weight that I want to machine.

04-02-2022-001.jpg 04-02-2022-002.jpg

These two pictures are of the barbell weight and the Myford faceplate. The barbell weight is thicker than the faceplate at 1" inch! Mine is the 7.5" inch one, but Myford also made a 9" inch faceplate.

04-02-2022-003.jpg 04-02-2022-005.jpg 04-02-2022-004.jpg

Since the 7.5" inch Myford faceplate is slotted with eight 12 mm wide slots and the faceplate is very slightly smaller than the barbell weight, I marked out and drilled two diametrically opposite holes and threaded them M10. Using a pair of hex head bolts and washers allows the faceplate and the barbell weight to be fastened to each other, and since the bolt holes go right through I can mount the weight from either side.

I've yet to fit the faceplate to the lathe, fasten the barbell weight to it then true it up. I haven't made up my mind yet whether to true up on the rim or the bore ! Though I doubt that the bore will be accurately centred. I propose to machine the rim to accept a five rib multi "V" belt so I will have to find the correct sizes for machining those grooves.

Hi Guys,

Today I swapped the lathe chuck for the faceplate. I found that there wasn't enough room in the gap to fit the faceplate with the barbell weight fastened to it, so I had to fit the faceplate and then mount the weight/work piece to it. This made it very difficult to centre it up properly. I got it within about 30 thou or so.

I also found that the weight was bowed, rocking, and didn't lay flat on the faceplate, so I cut a piece of cardboard to fit between the weight and faceplate, I didn't want to distort the faceplate when I tightened the bolts. As I guessed the centre hole was miles out. I did try a pipe centre using the tail stock to get it true, but the centre hole was much further out than the edge.

05-02-2022-002.jpg 05-02-2022-003.jpg

This is the workpiece mounted on the faceplate ready to be centred and tightened up.

05-02-2022-006.jpg 05-02-2022-005.jpg

There were several hard spots where the casting had been chilled. If you look at the picture on the left you can see where the lathe tool has been deflected.

05-02-2022-004.jpg 05-02-2022-001.jpg

I took several cuts on the rim but didn't manage to get rid of the hard spot, even after changing to a brazed carbide tipped tool. There was also a hard spot near the centre which resulted in causing the lathe tool to dig in.

Anyway I now have a flat surface to fasten to the faceplate in order to machine the other side and bore the centre hole. I had originally thought about putting a ball race in the centre, but I think a bronze bush would be better since it wouldn't have the looseness that a ball race would have.

Hi Guys,

I've found that I need a lathe tool that I can use to cut several 40 degree "V" grooves into my cast Iron pulley ! Its doubtful that a HSS bit would last very long being used to cut five or six "V" grooves into cast Iron. Does anyone know if there is a suitable carbide insert that would have a 40 degree angle that I could use ?

Thanks Guys.

Originally Posted by BaronJ

suitable carbide insert that would have a 40 degree angle

Closest I have seen is the 35° V series. e.g. VNMG.

Plunge in with that, and if you are worried about the fit not being perfect, a few extra passes with the compound set +/-2.5°