[4]

Ammco Shaper tool question...

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#1
So I have gotten far enough ahead on my other projects to allow me to finally play with this machine.
My intent is to cut internal key ways on a taper, yup gotta love a challenge.
So I have all aspects planned out, I will mount an $100 3 jaw chuck to a mounting plate so once I have it set I wont need to move anything. I will I will cut the key way at the bottom of the part so I do not have to make any movement other than up and down on the feed dial to cover the different size tapered holes and all the tapers are the same 5*.

So I made a 3/8 X 1 inch bar and silver soldered a 3/8 diameter rod to that on the business end I cut a notch on an angle and silver soldered a Cobalt bit on that end.
All went well as I was making cuts EXCEPT...ya one of those..

As the tool traveled forward the bit did not engage, even after turning the down feed dial to a point where it should have cut. And then all of a sudden it bit and bit hard and took the whole amount I have moved the dial at one time... My theory is this... the spring used to allow the tool to pick up when the machine is on the return stroke is weak and not holding the tool in the proper position during the power stroke.

My machine came with 2 springs in the position the are conical in shape. I think that putting a stronger spring there will result in proper function. I need to be that small on the tool as one of the parts I am making only has a .468 thru hole and I have to cut a 4mm key in that.

To test this I basically set up some flat stock and set the machine to take a cut with power side feed, it did the same thing, UNTIL I held the tool down during the power stroke. Once that was being done it cut just fine. So my long winded question is: What spec do I use for the spring, or do I just get stronger springs until it cuts properly?

I have attached a photo of the tool..
Shaper tool.jpg


Thanks

Richard
 

Bob Korves

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Jul 2, 2014
Messages
5,849
Likes
6,162
#2
The spring should not come into play at all during the cutting stroke. Perhaps you have something set up backwards in the mounting of the clapper box or in that area. The tool should be solidly supported during the cutting stroke and the spring should allow it to clear the work during the return stroke. There is also way too much spring in the tool. Anything cutting metal wants a rigid setup. If there was a triangular piece welded in, backing up the round tool bar to the flat bar for reinforcement, you would have a much more solid setup. Also, does the tool really need to extend that far to reach the work? Some pics of your setup would be a big help to figure out what you are doing and why...
 
F

f350ca

Guest - Please Register!
Guest - Please Register!
#3
When cutting keyways you need to lock the clapper down. The cutting edge is so far forward it wants to lift. You gave it enough force with the spring to get it started then the front rake on the tool made it dig in.

Greg
 

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#4
Bob,
I understand the spring part, that it only comes into play on the return and that the power stroke the tool should be rigid. That is what has me puzzled, gravity is just not enough to hold this tool down I think, and as for a brace, not possible as the bore of the smallest hub is .468 give or take a .001 or .002. Now for my key way,( 4mm ), to be proper it needs to be .078,( 2 mm ), deep, so take .375, ( diameter of the bar) + .078, (depth of key), that puts me at .453, leaving a gaping gash of .013 total clearance.

The clapper box, is untouched by my hand other than to check that it actually moves.

As for length of the bar, that current length leaves me .500 of tool to work with one each end of the stroke, so I start the tool. 250 before and stop it .250 after...

This is clearly the worst case scenario, as the other 4 hubs I make the bore is greater, it goes to .562 thru, so that would allow me .09 extra for bracing the bar.
 
F

f350ca

Guest - Please Register!
Guest - Please Register!
#5
My Logan had that spring too. Smaller shapers can be ran fast enough that the clapper won't fall on the return stroke, the spring keeps it down.

Greg
 

cjtoombs

Active User
Registered
Joined
May 10, 2012
Messages
582
Likes
170
#6
One of the problem with shapers is the backlash in the tool head leadscrew. You need to tighten the gibs on the toolhead to the point that it is a bit difficult to run it down with the leadscrew. What happens is that the toolhead falls down via gravity against the leadscrew, then the work pushes it back up against the leadscrew taking out the backlash. This can lead to hard hitting and rounded corners on the front side of a piece of work being surfaced. I suspect that you were running the tool down and it dropped through the backlash, which is why it dug in. Tightening the gibs prevents it from droping through the backlash and staying against the driving surface of the leadscrew when you dial it down.
 

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#7
good call, I will check that out tomorrow as it will be raining here and hey gotta make hay when ya can..


Thanks
 

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#8
good call, I will check that out tomorrow as it will be raining here and hey gotta make hay when ya can..


Thanks
 

talvare

Ted A
H-M Supporter - Gold Member ($25)
Joined
Apr 4, 2016
Messages
322
Likes
411
#9
I understand the spring part, that it only comes into play on the return and that the power stroke the tool should be rigid. That is what has me puzzled, gravity is just not enough to hold this tool down I think,
Another thing you can do to overcome the problem is to rotate your part 180 degrees so that you are cutting the keyway at the top of the part. Of course your tool bit has to be reversed also so that the cutting edge is up instead of down. This eliminates the problem of the tool lifting on the cutting stroke.

Ted
 

IanT

It's just a Hobby!
Registered
Joined
May 28, 2013
Messages
9
Likes
3
#10
Hi Richard,

Interesting job you've set yourself - and it's always a little difficult to visualise things from just a 'description' so I'll state my understanding first. I'm assuming that you are holding the work at the taper angle (of 5 degrees ?) such that the slot is uniform in depth. That the slot is 4mm wide and 2mm deep. You don't seem to say what width your cutting tool is but I'm assuming the same width as the slot. You are allowing 0.25 either side of the cut - front and rear - and cutting downwards, the clapper not being locked.

On that basis, the first thing I would suggest, is that you increase the length of stroke to allow at least 0.5" before the cut, as when slotting, there can be a tendency for the work/slot to hold onto the cutter a little longer on the return than with (for instance) plain surfacing. Although this mainly applies to deeper slots, it's not bad practice and although you maybe constrained at the back of the cut, I can't see why you would be so at the front, unless the taper length is very near the maximum stroke.

I fully agree with the point being made about the vertical head dropping because of backlash and tightening the gibs is one solution but will make 'ordinary' down-feeding more of a chore. If I think I'm having problems in this area, I sometimes use one of the gib adjusters to actually lock the slide between each feed (must get around to fitting a proper locking lever), which is slow but helpful. Slotting upside should also solve this problem and will (I guess) also effectively lock the clapper (I've not tried this myself but Stephan Gottswinter [search YouTube] has).

Final thought, I'm sure you been careful but when slotting 'to width' - side clearances are important - so it might be useful to check that your cutting tool is not very slightly angled. If it is, it will not only rub but may be contributing to the work 'clinging' to the tool as mentioned above...

Hope this helps but I'm sure you will find the solution anyway. Be interested to know what solves it for you.

Regards,

IanT
 

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#11
Yeah, I enjoy doing things differently, as for showing you folks my set up, I cant. As this is almost all theoretical the setup anyway, meaning, I do not have a 3 jaw set up, nor is it mounted to a plate as I envisioned.
The tool doing what it is doing is really happening.
Due to the length of the tool and the stroke limitations of the machine it is quite an interesting challenge to hold the part in the vise, which inherently leads to issues as I must hold the part in the vise with the jaw of the vise nearly completely open and spacers against the back jaw of the vise to mimic the proposed setup. Now the part is not moving but I think cjtoombs hit the nail on the head so I will try that this evening. I had also thought about turning the tip over and cutting at the top of the bore. I will reserve that for the last ditch effort.
As for my tool, I ground it to a with of .157 on my surface grinder with 1/2 degree side clearance on each side. I machined the groove in the holder to .158 so that thing would fit nice and snug with little slop. I see this first tool as nothing more than a proto tool to verify that I can do what my mind says I can and I will go from there. The info I am getting confirms my thoughts of potential issues. As for locking down the clapper, I see no means for that so something else to keep my mind going.

I will make a video of what I do have setup and post here soon, will also be ordering the chuck today as well.

Regards

Richard
 

Silverbullet

Gold
Registered
Joined
May 4, 2015
Messages
3,419
Likes
1,671
#12
I bet it's backlash on the compound and it just dropped .
 

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#13
Thinking I agree....will check tonight....
 

Reeltor

Active User
Registered
Joined
Nov 18, 2014
Messages
742
Likes
328
#14
I am very interested in your solution and look forward to seeing photos and maybe a video. Keith Fenner of Turn Wright Machine Shop on youtube posted a video of cutting a keyway on a taper. He built a very elaborate jig to hold his work. He eventually had to cut the keyway on the top to reduce bar spring. I posted the vid before, I think it is in the revent series
 

Richard White (richardsrelics)

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Dec 3, 2015
Messages
207
Likes
148
#15
Was he cutting steel or aluminum? I am doing aluminum....so hopefully I can get away with it...
 

IanT

It's just a Hobby!
Registered
Joined
May 28, 2013
Messages
9
Likes
3
#16
With regards to locking the clapper, some have drilled/tapped holes either side of the clapper box and fix a thick washer to hold the clapper box stationary when required. A simpler 'bodge' (that works on my 7" Acorntools - UK type Atlas) - is to use a long tool (or packing piece/tool-holder) in the tool-slot - and pack it at the top (above the clapper hinge) which also stops the clapper moving...

The former is the better solution - but would involve modding the machine in my case.....

Regards,

IanT
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,573
Likes
1,890
#17
So I have gotten far enough ahead on my other projects to allow me to finally play with this machine.
My intent is to cut internal key ways on a taper, yup gotta love a challenge.
So I have all aspects planned out, I will mount an $100 3 jaw chuck to a mounting plate so once I have it set I wont need to move anything. I will I will cut the key way at the bottom of the part so I do not have to make any movement other than up and down on the feed dial to cover the different size tapered holes and all the tapers are the same 5*.

So I made a 3/8 X 1 inch bar and silver soldered a 3/8 diameter rod to that on the business end I cut a notch on an angle and silver soldered a Cobalt bit on that end.
All went well as I was making cuts EXCEPT...ya one of those..

As the tool traveled forward the bit did not engage, even after turning the down feed dial to a point where it should have cut. And then all of a sudden it bit and bit hard and took the whole amount I have moved the dial at one time... My theory is this... the spring used to allow the tool to pick up when the machine is on the return stroke is weak and not holding the tool in the proper position during the power stroke.

My machine came with 2 springs in the position the are conical in shape. I think that putting a stronger spring there will result in proper function. I need to be that small on the tool as one of the parts I am making only has a .468 thru hole and I have to cut a 4mm key in that.

To test this I basically set up some flat stock and set the machine to take a cut with power side feed, it did the same thing, UNTIL I held the tool down during the power stroke. Once that was being done it cut just fine. So my long winded question is: What spec do I use for the spring, or do I just get stronger springs until it cuts properly?

I have attached a photo of the tool.. View attachment 243252

Thanks

Richard
When using an extension tool such as you show, the clapper box cannot be used, it must be immobilized; this is usually provided for by setscrews from the sides of the clapper that are dimpled into the clapper itself, and as other respondents have noted, the tool must cut at the top of the part being keyed. In my experience, internal shaping such as this is works poorly, as the tool drags on the return stroke, which tends to dull the tool. The tool needs to be as rigid as possible, that is, as large a diameter as possible, the one shown is too long for it's diameter; as with boring bars, a maximum ratio of 5:1 (length to diameter) should be adhered to, any higher ratio results in excessive springing and chatter. Excessive clearance can also cause problems; in this application, as with all shaper and planer tools, no more than a couple of degrees is advisable as it can cause excessive wear and digging in, so far as back rake is concerned, perhaps no more than about 10 degrees, more can cause digging in. The best tools for slotting on shapers is a tool held in an adaptor that holds it straight out in the hole where the tool post normally is situated, it has a nicely fitted hole in it's center that the slotting tools fit into and are clamped or held by setscrews; it projects straight out and cuts on it's end; I recently showed pictures of them on another thread relating to a milling machine slotting attachment, they may be seen there. I have also seen similar adaptors that have a integral "boring bar" projecting outward with a square hole for using with tool bits; these would work well also as well as the slotting type cutters, but just the same, you need to tie down the clapper and work on the top of the ID of the part.
 

Reeltor

Active User
Registered
Joined
Nov 18, 2014
Messages
742
Likes
328
#18
Was he cutting steel or aluminum? I am doing aluminum....so hopefully I can get away with it...
Keith was cutting steel, a very large key if I remember correctly it was 3/4".

My limited experience with the shaper would concur that the clapper needs to be locked while making keyway cuts.

When researching my 16" G & E I came across a patient for a small flat spring that is used to keep the clapper from excessive bouncing when running the machine at a high rate. I see pictures of large Cinci Shapers with a (coil) spring to keep pressure on the clapper, I assume for the same reason. The patient talks about running a shaper at 3-4 strokes per second. NOT ME lol
 

benmychree

John York
H-M Supporter - Gold Member ($25)
Joined
Jun 7, 2013
Messages
2,573
Likes
1,890
#19
Keith was cutting steel, a very large key if I remember correctly it was 3/4".

My limited experience with the shaper would concur that the clapper needs to be locked while making keyway cuts.

When researching my 16" G & E I came across a patient for a small flat spring that is used to keep the clapper from excessive bouncing when running the machine at a high rate. I see pictures of large Cinci Shapers with a (coil) spring to keep pressure on the clapper, I assume for the same reason. The patient talks about running a shaper at 3-4 strokes per second. NOT ME lol
My 20-24 G&E universal has that spring also, but it is broken, so I use a small coil spring wedged between the clapper box clamping bolt and the upper part of the tool holder. I have never heard of a shaper that ran at 3 or 4 strokes per second! The spring is necessary when running at normal speeds; if you let it hammer away without the spring, the shock tends to make the tool slide work it's way down and cut deeper, even with the lock screwed down tight.
 
[6]
[5] [7]
Top