Milling machine quill deadstop

[springcrocus]

Mill deadstop

One of the things that this hobby mill is missing is a deadstop for the quill. Industrial machines usually have these on the front of the quill housing and come in very useful when repeat drilling or milling to a set depth. Our hobby machines appear to rely on using the simple DRO to get to a depth and it's very easy to make a mistake and go too far, ruining the workpiece. I've now made a quill deadstop to help overcome this problem.

I dismantled the safety guard and interlocking switch the very first day I got the mill so decided to make use of the guard mounting holes. A pair of blocks were milled up from some 30mm x 12mm flat steel bar and a counterbored hole put in each to take M5 cap screws. A 5mm hole was also drilled to take the vertical rod. With the blocks screwed to the machine, it left a gap of 55mm between them and the maximum travel on the quill is a tad under 50mm. A pair of knurled rings were made from 7/8" dia bar, drilled and tapped M5 and parted off at 4mm thick. A length of M5 allthread was used to make the rod.



To connect to the quill, I would have prefered to make a collar with connecting bar but couldn't find any suitable material. Therefore, I replaced the flimsy, plastic block connecting the DRO tail to the quill with a more substantial block of steel and used a length of flat bar to connect this to the bottom of the stop-rod. I also had to make a new quill-locking screw but, not having any 12mm hex material, made an extension instead. This ensures I don't trap my fingers or skin my knuckles when using the lock (got the tee-shirt).



It's a little "spongey" in use but, combined with using the DRO, certainly speeds up jobs like multiple plunge-cuts. This took a couple of hours to make but well worth the time. When a suitable chunk of material appears, I will make a quill collar and dispense with the current connecting bar.

Because of the need to dismantle the safety guard, I can't recommend that others copy this exactly but a more able mind than mine may well find an alternative method of mounting the deadstop and keeping the guard.

Regards, Steve

[steamlaser]

What a great idea!
I have the same model of Mill and also found that there is a "lack of feel" when try to cut to a required depth.

[cplmickey]

I need to do something for my Lux mill as that doesn't have a depth stop. Think there might have been something originally but I haven't got any bits with the machine so something like this will do the job nicely. Ian

[jon38r80]

I have the same sort of machine (except its painted green) and like you I removed the so called safety guard before I even used it . Not only was the cut out limit switch in it a joke , I couldnt see through it and it got in the way when using the mill as a drilling machine. More dangerous than a safety feature. Also like you I find the chopped up electronic caliper depth guage unreliable for repeat depths. I would like to make a depth stop but there is very little of the quill extending below the bottom of the bearing housing making it harder to find a way to fix an arm.

I think if you could make a beefier arm to connect the electronic depth guage and used a thicker arm to connect the stop you would find it less spongy. you have a pretty long lever arm twisting the guage and its held on with a couple of pretty long bolts that aren't very far apartso it will twist quite easily. On drilling machines thr depth stop is always a pretty beefy threaded rod , I wonder if that would make any difference?

Having said all that I'm quite envious, it must make drilling to depth and repeat settings for milling a great deal easier.

[timb]

A neat solution Steve, well done.

I keep meaning to make an 'educated nut' for my Bridgeport, but I have so little time in the workshop at the moment, any time I get I try to move one or the other of the models along.

Tim

[Gary L]

Feb 19, 2022 19:48:08 GMT jon38r80 said:

I have the same sort of machine (except its painted green) and like you I removed the so called safety guard before I even used it . Not only was the cut out limit switch in it a joke , I couldnt see through it and it got in the way when using the mill as a drilling machine. More dangerous than a safety feature. Also like you I find the chopped up electronic caliper depth guage unreliable for repeat depths. I would like to make a depth stop but there is very little of the quill extending below the bottom of the bearing housing making it harder to find a way to fix an arm.

I think if you could make a beefier arm to connect the electronic depth guage and used a thicker arm to connect the stop you would find it less spongy. you have a pretty long lever arm twisting the guage and its held on with a couple of pretty long bolts that aren't very far apartso it will twist quite easily. On drilling machines thr depth stop is always a pretty beefy threaded rod , I wonder if that would make any difference?

Having said all that I'm quite envious, it must make drilling to depth and repeat settings for milling a great deal easier.

It’s a great machine, but I only half agree about the guard. I removed one of the mounting screws, so that the guard pivot axis can be moved off the vertical; specifically upwards towards the user. This makes it much more useful and less in the way. I use the guard to stop the mill instead of the stop switch- it is much closer to hand and you don’t need to take your eye off the work.

Maybe one day I’ll get around to making a depth stop too!

Gary

[springcrocus]

Feb 26, 2022 0:31:30 GMT Gary L said:

It’s a great machine, but I only half agree about the guard. I removed one of the mounting screws, so that the guard pivot axis can be moved off the vertical; specifically upwards towards the user. This makes it much more useful and less in the way. I use the guard to stop the mill instead of the stop switch- it is much closer to hand and you don’t need to take your eye off the work.

Maybe one day I’ll get around to making a depth stop too!

Gary

I don't know if you have the same motor controller as I have but stopping the machine in this fashion, similar to just flicking the switch to off or hitting the e-stop, is not recommended. The instructions specifically refer to winding the speed back to zero before stopping to protect the electronics. However, I don't know enough about electronics to decide whether that is sound advice or they are just covering their backs against warranty claims.

Regards, Steve

[Gary L]

Feb 26, 2022 8:54:14 GMT springcrocus said:

Feb 26, 2022 0:31:30 GMT Gary L said:

It’s a great machine, but I only half agree about the guard. I removed one of the mounting screws, so that the guard pivot axis can be moved off the vertical; specifically upwards towards the user. This makes it much more useful and less in the way. I use the guard to stop the mill instead of the stop switch- it is much closer to hand and you don’t need to take your eye off the work.

Maybe one day I’ll get around to making a depth stop too!

Gary

I don't know if you have the same motor controller as I have but stopping the machine in this fashion, similar to just flicking the switch to off or hitting the e-stop, is not recommended. The instructions specifically refer to winding the speed back to zero before stopping to protect the electronics. However, I don't know enough about electronics to decide whether that is sound advice or they are just covering their backs against warranty claims.

Regards, Steve

Well… it does say that, but the novelty soon wore off. I never stop it (or start it) in the approved manner. So far, so good…?

Gary

[springcrocus]

Gary, you must have a different controller to me because mine does not remember the previous speed. Regardless of whether one hits the stop switch or wind it back and then stop, it always starts at the lowest speed and has to be wound up to the required speed. It's not a standard potentiometer because the dial winds round and round continuously, it never comes to the end of it's travel.

Regards, Steve

[Gary L]

Feb 26, 2022 12:22:25 GMT springcrocus said:

Gary, you must have a different controller to me because mine does not remember the previous speed. Regardless of whether one hits the stop switch or wind it back and then stop, it always starts at the lowest speed and has to be wound up to the required speed. It's not a standard potentiometer because the dial winds round and round continuously, it never comes to the end of it's travel.

Regards, Steve

Hi Steve

That's interesting. Mine has a normal potentiometer to set the speed, and it is independent of the stop-go switches, so you always go back to the set speed. It's an AMAT25LV (AKA Titan TM25V). I had a AMA25LV previously, but this one has removed all the weak points of that version and added DROs on all axes, so I'm well pleased with it. Maybe yours has a later version of the electronics, specially designed to prevent awful people like me doing terrible things with it?

Gary

PS Note to others: AMA just signifies Amadeal, though I don't think anybody else imports this precise model, with or without the blue paint job. Last time I looked, Amadeal no longer listed the DRO version either.

[GWRdriver]

Aside from it's other shortcomings, which I live with, my mill very much needs to have a new, or revised, quill stop. My stop is identical in basic design to Steve's machine, a pair of knurled jamb nuts on a threaded rod. The problem on my machine has been the nuts can't be counted on to securely lock each other and stay put, at least with finger strength, resulting in always having to be careful to watch for over-travel to creep in.

The new stop nuts (or rebuilt existing ones) may have spanner flats, holes for a small tommy bars, or possibly secondary thumbscrews.

Another project for the (long) List.

[GWRdriver]

To quickly follow up . . . my mill is a 1980s vintage Taiwanese which means that overall it was a valiant attempt, but always fell short in some details, one of those being the quill stops.

Disassembly and inspection showed they were turned from mild steel and after engraving (they incorporated a depth dial in .001") were plated in frosted chrome. I saw immediately that the mating, ie "jamming", faces of the nuts were roughly finished, and were only partially plated, so they were making only a fraction of their intended full facial contact. I dated a young woman some years ago and had the same problem with her . . . but I digress.

I chucked both nuts and put a very fine turned finish on both mating faces, which in the process skimmed off the spotty chrome plating.

This has done the trick. The result is the nuts jam each other much more positively than they did, given the same amount of finger torque. There is also clearance enough to install a few small tommy bars on the nuts to allow a bit more torque to be applied, if I need to take that step.

I may have to do something beyond this, but even so this modification has made a significant improvement.

An even more significant improvement would be to devise some sort of quick-indexing stop which could be disengaged and moved quickly up or down the rod, rather than have to spin the nuts to get them into place. I've seen these for drill presses.

UPDATE: Before re-installing the stop nuts I stoned the mating faces and this produced a wringing fit (well, almost), which may now REQUIRE me to install a couple of tommy bars to get them apart.