Thread: Rotary Quill Movement

Hi Dean,

I'd forget your first idea, wont the "seperate piece" be relying on the crest of the thread for location? Can't see that lasting long. Maybe M10 all thread with a 7mm hole in it and a pin made to suit with a tee head would work better?

I've see guys using these on tailstock dros.
I'm sure you could get tham out of china on ebay for almost nothing but my search doesnt seem to be working so well ATM.

http://www.hobbyking.com/hobbyking/s..._2pcs_bag.html

Stuart

Originally Posted by Stustoys

Hi Dean,

I'd forget your first idea, wont the "seperate piece" be relying on the crest of the thread for location? Can't see that lasting long. Maybe M10 all thread with a 7mm hole in it and a pin made to suit with a tee head would work better?

I've see guys using these on tailstock dros.


http://www.hobbyking.com/hobbyking/s..._2pcs_bag.html

Stuart

Yes the seperate piece would be relying on the crest of the thread. That was sort of my reason for the question actually. I did have doubts.

Maybe M10 all thread with a 7mm hole in it and a pin made to suit with a tee head would work better?

The tee head being inserted from inside the quill bore? Sounds like it would work. I should be able to remember how to remove the quill after replacing the bearings. The slot is about 3mm deep. I was trying to think how I could use a tee shaped piece like that but did not join the dots like you.

What steel should I use for the tee head part? I bought some M10 X 80mm HT hex head bolts today for the all thread part although it may be overkill. I will cut the head off and turn a thread on that end for a locking nut. I have yet to use my threading tools in anger. Would the bolt head end work ok to be machined down for the Tee head?

I've see guys using these on tailstock dros.
I'm sure you could get tham out of china on ebay for almost nothing but my search doesnt seem to be working so well ATM.

I was avoiding that sort of arrangement because I thought it would effect the accuracy too much. If this would work ok then it would be a much easier solution. Once I have reduced the quill movement as much as possible then I will have a go at this arrangement. It is only the single dimension I have movement in (to all intents and purposes) so a simple pivot top and bottom should work. I want to fit the DRO's so that I can get an accurate poisition to locate the ball handle that Michael gave to me. That is the first job after this is finished.

I have been having lots of fun with new toys. Computer toys. It seems harder to setup new computer / network systems than metalworking machinery.

I have bought a new highish end notebook, router, HDD enclosures, nas and just received a UPS today for the nas. I am thinking about running my entire computer system off the UPS when the power goes out, using a big battery which I will switch in as needed. If I can't work in the shed I can use the net for a few hours anyway. It can handle 750w for as long as the battery lasts. I have had hude headaches getting it all setup but the notebook is totally stunning compared to the old one. Much faster internet download speed for some reason. Faster computer / Gigabit Ethernet? I also picked up an 8 port Gig switch from Big W a while back for dirt cheap. Handy since my new Audio Visual Receiver and Blu-ray Player both have ethernet ports which I want to use for streaming, and that requires more ports than the router has.

Dean

Originally Posted by Oldneweng

.................................
Any other suggestions about how I could improve on my ideas. The main reason for doing this is to reduce any sideways movement transferring thru to the DRO scale. I would like the rod that transfers the quill vertical movement to the DRO read head to be as solid as possible for accuracy, but this means that the head and scale will be subject to sideways force from the rotary movement. Is there any way to allow movement in the connection without sacrificing accuracy. The scale is a magnetic type so not super accurate.

Dean

Hi Dean,

My mill is different from yours, its a Sieg X3. But I had to overcome the same problems with the quill when fitting my DRO. You may or may not like my solution, as there are many ways to skin a cat. But it may give you some inspiration. Also, I use these very cheap Chinese scales you can find everywhere, copies of the Swiss Sylvac scales of the 80's. I actually use the sum function to add two such scales, the quill scale and the vertical column scale, to display on the DRO as if both were one (Z=Z1+Z2). I found this extremely useful, no matter if I move the quill or the entire mill head or both, I always see on one single Z display where the tip of my tool is. Not all DRO's have such a sum function, I use the Shumatech DRO550 wich is a kit DRO to assemble yourself, with open source software.

Anyway, here some pics on how I made sure this quill cannot rotate and exert side pressures onto the scale:

x3_3.jpgx3_2.jpgx3_1.jpg


I made that plate out of 12mm thick Aluminium sheet, it clamps around the quill body. Attached to it is a ground 12mm diameter steel shaft. This shaft slides through an oilite bushing pressed into a rectangular Aluminium body. This body is attached with two bolts to the side of the mill head. This body also has four grub screws at each corner to adjust such that the oilite bushing and the ground shaft perfectly line up, without causing any binding to the quilll motion. At the top of the ground shaft you can see a red cap and a clamp. This is a bonus feature, its an adjustable quill downfeed stop.

The contraption has proven itself over many years as being very functional and useful. Chris

Thanks for showing me your setup Chris. That is certainly something else to consider.

Dean

Hi Dean,

It never occurred to me to have a look at mine till you mentioned it. Mine has some rotational slop as well. I recall from when I did the metal gears that the peg that locates the quill was quite sloppy and that I used a blob of grease to stop it falling out whilst I put the quill back in. I'd be interested in how you sort yours.

Hi Dean,

I had never really worried about the rotational slop in my quill. I'm not saying it shouldn't be considered I'm just saying it's something that I have (happily) overlooked. I have had a DRO scale on my quill for about 3 years now and it has performed without issue. I must admit that I only ever run my spindle in the one direction though, so once it takes up on the locating dowel pin, it's not really going to move anymore.

CBA, that's a mighty fine setup you have made. that would have taken a fair amount of alignment for smoothness.

Edit: those Chinese DRo scales are held firm with a brass strip inside the sliding scales under slight compression to maintain their sliding position. There is a bit of play in those which is probably enough to allow me to get away without doing anything about it.

Simon

It never occurred to me to have a look at mine till you mentioned it. Mine has some rotational slop as well. I recall from when I did the metal gears that the peg that locates the quill was quite sloppy and that I used a blob of grease to stop it falling out whilst I put the quill back in. I'd be interested in how you sort yours.

I was aware of some movement in the quill already and it was automatic to look at fixing it. The DRO that I have, has the scale fixed and the head sliding. I knew that the quill movement would be pushing against the DRO. I did not think having the DRO acting to control this movement itself was a good idea.

At this stage my intention is to recut the all thread I am using now with a closer fitting diameter end. As I said before this already had a turned down end and it was a tiny bit too small to clean up properly and is slightly small. It has enough length to do it again. Once this is done I will fit the DRO. I started with the Z axis, but I really want the Y axis to centralise the balls of the 3 ball handle. When I have finished the ball handle and anything else urgent I will follow Stuarts idea. I have been thinking about how to do this. The head of a HT M10 bolt will be the rectangle piece that slides in the slot and about 20mm of the shaftwill locate inside the adjusting screw which will be another M10 bolt sans head with a length of thread for locking purposes turned on the other end. I need to make a tiny boring bar. I can bore my soft lathe jaws to hold the bolts to turn the head to length and a 7mm diam shaft etc. I can then use this boring bar in my new boring head to bore a hole in an ali block, 7mm diam in the mill. This will hold the 7mm shaft section for milling the sides with my new 30mm indexible milling cutter, to fit the quill slot. Predrilled and tapped holes and grub screws will clamp it so the ali block does not need to be moved unless I want to check it for fit. The boring bar will also do the 7mm bore in the adjusting screw.

I think I will make a connecting rod for the DRO using a home made pivot similar to in the link Stuart put up. I only need single dimension movement so a ball joint is overkill. I will have a simple pivot at each end using HDPE with a firm fit. Hopefully it won't need to move anyway.

I also like Chris' idea at least for the stop.

I don't have any pictures at the moment. Actually I have about 2000 sequentially named pictures (00000001) to go thru at some point, from my cameras. I have found some great ways to sort out pictures. I added a column in Windows explorer showing the camera model, as an attribute so to speak. This also listed manufacturer. Choose one from my camera, click on column heading and all my camera pictures can be easily selected and moved. Do this with the SLR and then my other halfs camera. Hopefully you get the idea. The 32,000 Jpeg's I recovered from the crashed HDD are now much better sorted.

As I was saying, my mill has a cast section on the bottom of the quill which has the tapping adjustment shaft mounted in it. There is enough thread available from this mount to fit a plate for the DRO connecting rod and hopefully a setup like Chris', but without the precision control. Just a depth stop.

I had never really worried about the rotational slop in my quill. I'm not saying it shouldn't be considered I'm just saying it's something that I have (happily) overlooked. I have had a DRO scale on my quill for about 3 years now and it has performed without issue. I must admit that I only ever run my spindle in the one direction though, so once it takes up on the locating dowel pin, it's not really going to move anymore.

I have used mine a bit for tapping. I did think about the one direction thing, but I would like to tap with it.

Edit: those Chinese DRo scales are held firm with a brass strip inside the sliding scales under slight compression to maintain their sliding position. There is a bit of play in those which is probably enough to allow me to get away without doing anything about it.

You hope! lol After years of procrastinating I have finally forked out for DRO's and even if they only cost $180 total, I don't want to mess them up.

I have started the DRO installation, just. I am taking pictures. I was eventually planning on doing a thread on that. I was holding off because of the issues with the forum. I have had very little chance to get on lately. It seems to be fixed now tho. Maybe in the next few days.


Dean

Originally Posted by simonl

.................
CBA, that's a mighty fine setup you have made. that would have taken a fair amount of alignment for smoothness. ............
Simon

The slightest misalignment will cause binding. So yes, careful alignment could take half an hour or so. But its a one off job. I never had to redo it. Movement is perfectly smooth.

Was using my mill yesterday and thought id check my rotational movement by hand. None that I could notice. That would be why I never considered it. Its not a high end machine, a 45 size Chinese mill but I must have got lucky with the quill. I needed attention in other areas though!

Simon

A quick update to say that as of yet there has been no action. I have been flat out catching up with the backlog of jobs that need doing. Dean

Hi Dean,
On my Jones & Shipman drill the downfeed gearbox has a long key sliding in key way to select gears.This long key helps to eliminate the play. Most of the key is below the key way height. Would a similar long key fit in your key way and be held in place by having a threaded hole near the top and bottom. A pair of bolts through the cast housing picking up the threaded holes to keep the key in place.
Bob

Originally Posted by krisfarm

Hi Dean,
On my Jones & Shipman drill the downfeed gearbox has a long key sliding in key way to select gears.This long key helps to eliminate the play. Most of the key is below the key way height. Would a similar long key fit in your key way and be held in place by having a threaded hole near the top and bottom. A pair of bolts through the cast housing picking up the threaded holes to keep the key in place.
Bob

This could work. The key is only about 7mm wide so plenty of opportunity for me to miss it drilling thru. There is about 60mm of cast to drill thru to the quill bore. I will have to think about it.

Dean

Dean,
That is not a very wide key and 60mm of casting is a fair way to drill through. Could you make a dog legged drill guide jig that is located in the actual key way and around the quill and securely clamped to the quill.?
Bob

Originally Posted by krisfarm

Dean,
That is not a very wide key and 60mm of casting is a fair way to drill through. Could you make a dog legged drill guide jig that is located in the actual key way and around the quill and securely clamped to the quill.?
Bob

Are you suggesting a guide that has a keyway sized foot that fits in the quill keyway when it is lowered? (Keyway is not full length) Raise the quill to get the drill guide to line up with required hole position on the outside of the casting and clamp the drill guide in this position around the quill?

Given the small size of the keyway I don't know if this will be rigid enough. The rigidity should come from the quill clamping (thinking as I type) but will need to be precise enough to be clamped without moving. I will have to think further on this.

I will need to do some work on the quill soon as it has started being hesitant to turn again. Not as bad as last time. I think I just need to back off the bearings a bit. Cold weather? It runs, but has a quick think about it first.

Dean