[wwendorf]

Hi all,

I was having a conversation about making a power drawbar for my Syil X3 similar to the one that Hoss made, and it was mentioned that it wasn't possible without locking the quill.

Can anyone tell me why? I'm a bit confused as to why it wouldn't work. Would that be because of the drill part of the mill where you can turn the handle to lower the spindle? I looked the X3 over a bit more, and on the front of the unit there is a handle for locking the spindle. Why can't this be locked and a power drawbar still used?

Thanks,
Wade

[iGG1e]

You're correct, the mill does have a quill lock. The only issue with the spring retention type as you listed is that you've got to make sure that lock is 100% effective. If it isn't, you're going to force the quill downwards when you want to do a tool change.

You might want to look at a means to lock the quill other than by the existing method. I decided to go with a small butterfly air impact wrench design for my draw bar as even though I do use the Tormach quick change system most of the time, I do swap other holders when I need to.

[wwendorf]

Have you heard of any other type of Quill lock that anyone has made for the Syil X3?

I really don't use any tooling than tormach, plus I want to build my own tooling rack, so the butterfly air impact wrench wouldn't work for me.

Wade

[wwendorf]

I'm still on my quest for a power drawbar, so I got to thinking about how the SX3 locks the quill. I looked on Grizzly's site and came up with the following pdf of the parts and pieces of the SX3.

http://www.grizzly.com/images/partslists/g0619_pl.pdf

It looks to me like the quill is actually locked against the Gear Shaft (Part #139 in the PDF) instead of the quill itself. That being said, it definately looks like putting 600 lbs on downward pressure on the top of the Drawbar bolt would be a bad idea. It could wind up stripping the toothed gears on the Gear Shaft.

I am still determined to figure out a method to lock the quill down so that I can add a power drawbar and ATC to my mill.

My main requirements is the ability to still use the quill as I want to be able to do tapping. But, if I can't do that, perhaps the quill assembly can be removed?

Does anyone have any thoughts?

Wade

[BobWarfield]

It worked great for Hoss on his X2. It has a quill too. Go look at what he did and copy it. You'll be fine.

Cheers,

BW

[wwendorf]

Actually, it will not work the same as on the X2. On the X2, the handle that raises and lowers it raises and lowers the entire head. I have an extending quill on the X3. It's an entirely different kind of assembly. As I said in my previous post, if I were to put 600 lbs of force on the top of the quill, I risk breaking the gears that make the entire quill assembly move up and down.

Not acceptable.

So, I need to figure out some sort of different quill locking system that will support 600 lbs of downward pressure.

Wade

[cjdavis618]

First, do you actually move your Quill up and down on your mill head?

As for the locking "mechanism", the bolt that goes through the front will put ample pressure on the spindle sleeve housing to keep it from going anywhere. The entire housing around the spindle sleeve clamps down on the sleeve as it is tightened. What I am more affraid of is the quality of the factory bearings. After seeing the quality of the ones that came out of my grizzly, I don't think they will last very long with that force. I changed my upper bearings to tapered as well.

On the other hand, maybe having the drawbar push down isn't the best option. What about finding the spring washers big enough to go between the spindle and the bottom of the spindle housing instead (Where the brass ring is). Then you could pull upwards to release.

[wwendorf]

Yes, I do move my quilll up and down in order to use the tapping feature.

Are you sure the bolt puts pressure on the spindle sleeve? It looked to me like it put pressure on the sleeve that controls the quill lever, in which case, the only thing that keeps the quilll from moving up and down is the gears on the quilt handle bolt meshing with the teeth on the back of the quill itself.

Regardless of that, Hoss was able to make a drawbar type system like this and he still used the stock bearing if I remember correctly.

Worse case scenario, I have to change out the bearings. Probably wouldn't be the worst thing anyway. I wonder how many hours of use is acceptable before a bearing replacement is necessary?!!?

Not sure what you mean by spring washers between the spindle and the bottom of the spindle housing. Are you saying inside the head of the mill itself?

Wade

[cjdavis618]

Ok then, what I suggested with the spring washers will not work then in your case.

I have taken my mill apart completely many times and looking at the structure, you have the spindle, which goes into the bearings. Then that Assembly goes into the Spindle sleeve.

That Assembly of - Spindle shaft, Bearings and Spindle sleeve - as a whole slides into the mill head casting. The hole that the spindle assembly fits into is slit down the side to the right. The bolt that you tighten for the Quill lock actually pulls the 2 halfs of the hole in the head casting together on that side to make a circular grip on the outside of the spindle assembly.

The Spring washers I mentioned would work like this..

If you look at your spindle from the bottom, you will see the Spindle that rotates, the spindle housing and then a brass ring that touches the head casting when completely pulled in. My thought was that if you do not use the quil as a drill head or tapping system, you could place the spring washers there for the drawbar tension (Between the Brass ring and the Casting). When not actuated, the springs are released and putting pressure on the collet to close on the tool. When actuated, you could pull the springs against each other from the top of the head, loosening the tension on the collet and releasing the tool. This will let the casting be the stop for the pressure instead of the opposite way of the spindle sleeve possibly being loose enough to slide down.

This would only work if you are not using the quill though. The Drawbar system would be a permanent change to the mill tool change system.

It is pretty easy to get the spindle assembly out. But as for the gear, it's only purpose is to move the quill up and down when released or loosened. The quill lock handle and bolt is the strength to lock it tight.

[wwendorf]

So, are you saying that you would still use the same type of system to press down on the drawbar from the top as Hoss did on his X2?

I'm liking this idea much more. I suppose I could use a stepper to run the spindle to do tapping similar to how Hoss did. It would likely be a bit better control than pressing the buttons.

I'll have to see if they make beleville springs in that size tho.

Wade

[cjdavis618]

Actually, I was thinking that pulling the spindle up would be the best option. I'll try to get a diagram of what I was thinking, but I am in the middle of a milling op at the minute. It may be tomorrow before I can post it.

[iGG1e]

Regarding the quill lock on the front, when you tighten it the force of the action causes the two bushes to squeeze together (these have been known to jam and you can't get the quill down when you want to!) and this puts pressure on the quill and locks it against the quil bore in the head. I have taken out the quill handle drive completely as I don't do anything manual on the mill (have a tapping head if I need to do lots of threads) and the quill is 100% locked by the front lock.

Whether is can withstand the force pushing down on it of the amount we're talking about...that's a tricky one to say. I wouldn't want to just rely on it myself. It could get awfully expensive on cutters if it came down even a small distance during a tool change and you're using a preset tool table.

It's difficult to get the best of both worlds. If I was going down the Hoss route I'd be machining a section of the quill to allow mechanical fastening of the lower quill section to the bottom of the head. In theory you could do something where under normal operation it was fixed by this mechanism and then unbolt it to allow tapping.

[wwendorf]

I felt that the qull lock did a pretty good job myself. What really would be the difference between using the beleville springs and just using the drawbar for tightening the collet? It seems to me that there is a lot of force no matter how you use lock the collet. Surely the bearings have to be adequate enough to handle it.

If I do indeed need new bearings, could you post what you bought and from where?

I wouldn't be adverse to just using a tapping head. Any recommendations on where to get one reasonably?

I guess my next step will have to be disassembling the head of the mill and figure out how to machine the quill to allow for the locking bolt. Unfortunately, that will put my project behind a little bit as I have a large project that takes precedence over anything else right now.

Any suggestions on what to machine and where? Perhaps from the side? Of course, I'd have to drill another hole in the head of the mill too, wouldn't I?

Wade

[wwendorf]

Nevermind the question about the tapping head. I'm now drooling over the Tormach Tapping Head system.

Wade

[wwendorf]

I had a conversation with Richard from Syil America today. He believes that the quill locking mechanism in the X3 is more than capable of standing up to the rigors of a belleville spring/air cyclinder type drawbar system. In fact, he's done that type of drawbar system on another mill that he owns which is strictly a friction lock system. He says the quill lock on the SyilX3 is beefier than the friction lock based one he modified and that one worked very well with that type of drawbar system.

I also asked him about bearings, and he said that they should be able to stand up to the rigors of that type of drawbar system for quite a while. While it would diminish the life of the bearings, the cost of replacing the bearing with new stock bearings is minimal, and... if someone wanted to, they could also go ahead and for under $100 someone could upgrade to really high quality bearings that would handle even higher RPMS like up to 9000 RPMS (ceramic bearings).

Any comments? I'm seriously considering moving forward on this drawbar system after this conversation.

Wade

[iGG1e]

Give it a go. Pushing the quill down from the top, if the lock doesn't hold really shouldn't harm anything. If it does move, then hopefully whilst you're doing the initial construction of the drawbar you can come up with a plan B in the event that it doesn't hold.

Given that the clamp in the quill lock is steel, you could possibly get a long allen cap bolt to replace the existing hand tightened one for an extra bit of hold. You can then use a small torque wrench to get repeated clamping pressure after you've used the quill. Pretty sure it'll do a good job of holding things in place.

[Crevice Reamer]

Go for it! I doubt the PDB will exert more force than when you currently bash the drawbar with mallet. I presently use three Bellevilles under SX3 MANUAL drawbar. If anything they have REDUCED the force on my quill. And since I have REMOVED all quill gearing, the only thing holding it IS the friction lock.

CR.

[devers6]

I have built an air-cylinder style power drawbar, and have used it for some time now. The quill lock works just fine to prevent the spindle from moving down from the force of the air cylinder.

My design is a little different than Hoss's - I chose to use a large diameter air cylinder (about 3 or 3.5 inches) directly over the spindle, so it pushes straight down with enough force at 100PSI to compress a stack of 5 belleville washers (same ones Hoss specified). I wanted to avoid the extra hassle of the lever arm. Every now and then I forget and leave the quill unlocked; and I get a nice surprise when the quill moves down and the handles rotate. Someday I'm going to go into the air cylinder and put in a travel restriction (it currently has about 1.5 inches of travel). I'll just put in some kind of loose-fitting bushing that will only let the cylinder travel a quarter of an inch or so, plenty enough for a tool change.

I mounted the cylinder on an aluminum bracket shaped like an 'H' with the two sides mounted to the head and a flat plate joining them that mounts the air cylinder. I made it so the assembly can pivot up on the back mounting bolts (I used two star-knobs on the front bolts) so I can move it out of the way if I ever need to put the standard drawbar back in.

But don't worry about the quill lock not handling the force - mine works great!

[wwendorf]

devers6,

Thank you for the confirmation!!! Would you mind posting where you got your air cyclinder from?

Thanks!

Wade

[devers6]

I used a Bimba FO-701 cylinder from Ebay - cost me about $35 if I remember correctly. This is a 3 inch bore, 1 inch travel I think. You could get by with much less travel - I have seen them as small as 3/8 of an inch which would probably be plenty. They are also easily taken apart and could be modified to reduce travel either by cutting down the cylinder body (and the mounting bosses), or like I intend to do by adding a bushing inside to keep the travel down. At one point I had a spring inside to push the cylinder back up when air pressure was removed, but I found I really didn't need it.

I have included a couple of Solidworks screen caps to show how I did it - not really much too it. The rear holes bolted to existing cooling holes in the top cover, the front holes I added (drilled and tapped 3/8-16) and I used a star knob with threaded stud.

The solenoid is a 115V unit from Surplus Center. Not shown on these screen caps is an aluminum plate I added to the front that holds a switch to actuate the solenoid, and a toggle switch that goes back to my Breakout board and Mach 3 to actuate the Z axis jog functions to raise and lower the head. Can't imagine living without either of these modifications now.