# Powered head adjustment-Chinese Mill



## Brian Rupnow (Nov 15, 2009)

I have a CT129 Craftex mill from Busy Bee and the handwheel that I have to turn (in pink circle) to adjust the height of the head is high up at the rear of the mill. This happens to be right in the quadrant of movement that really bothers an old tendon injury in my right shoulder. Last night I was thinking of adding a power adjustment to the head. What immediately came to mind is the motor and gearset off an old barbeque rotisserie.---Trouble with that is that I doubt the motor is reverseable. Has anybody made a modification like that to their mill?----Brian


----------



## chuck foster (Nov 15, 2009)

brian, i wonder if you could use a windshield wiper motor or a power window motor?
i think they have lots of power and they will revers very easily, only drawback is you would have to have a d.c. power supply to run it.

chuck


----------



## Toyman01 (Nov 15, 2009)

Try these people:https: www.surpluscenter.com/home.asp

They carry an assortment of gear motors as well as chain and sprockets that could be used to hook it all up.


----------



## Brian Rupnow (Nov 15, 2009)

Aermotor--I actually did think of that as well.--Hmmm---Could use the 12volt Bass boat battery and my 12V charger---It wouldn't be used all that frequently---


----------



## Artie (Nov 15, 2009)

Not a power actuator but I have seen a version of my mill with two stainless cables running from the head over two pulleys down to two large tension springs (sort of like a roller door has), this takes all the 'load' off the handle when its unlocked. Ive been thinking about it for mine for ages..... trouble is I dont 'need' to do it (yet)....

Cheers Rob


----------



## Brian Rupnow (Nov 15, 2009)

Something like this--Remove top handwheel, put sprocket in its place, mount smaller sprocket on output shaft of some kind of gearmotor--connect with roller chain. My model shows gearmotor mounted on wall behind mill---in actuality I would probably build up support brackets off mill column.


----------



## Brian Rupnow (Nov 15, 2009)

The more I think about it, the more logistics are involved.---Would either need limit switches as both "extremes" of travel, or a friction "slip clutch" in one of the sprockets.---or---a motor you could temporarily "stall" without danger of burning it out.


----------



## Kanuck1958 (Nov 16, 2009)

Brian
Automotive power window motors are electrically protected so when you stall them they temporarily open. They are reversable as well.


----------



## Brian Rupnow (Nov 16, 2009)

Thanks for your input guys. I am now researching a more manual approach using a set of bicycle sprockets and chain and a right angle drill adapter to move the handwheel into an easier to reach position. The tendon injury in my right shoulder only bothers me when my arm is at full extension and angled up at about 45 degrees.


----------



## black85vette (Nov 16, 2009)

I would think a potential problem would be driving the spindle assembly downward and the possibility of tooling and materials coming in contact long before you got to the lower limit of travel.

The early C4 generation (84-96) Corvettes headlights used a set of switches internal to the motor. They used a worm gear with springs on both ends. If the torque was too high caused by a stall or jam the worm gear would push against the switch and shut down the motor.  

They moved to a solid state circuit by about 1988 (not sure) that sensed a current spike caused by a stall and shut down the motor. I converted my 85 over to the newer headlights and control system. The Trans-AM used the same control module for its headlights. I paid $5 for a used module at a junk yard.


----------



## Brian Rupnow (Nov 16, 2009)

So---This morning I went scrounging!!! First, down to the bicycle repair shop, where I scrounged a pair of small sprockets and a length of chain. (I actually paid for a new master link.) Then over to one of my fabricators where I begged 3 pieces of mild steel round bar to make hubs, out of there shorts rack. (Had to promise they will get to quote on the next job I design (IF I EVER GET ANYMORE FRICKIN WORK!!!) Then up to BusyBee Tools, where I actually had to PAY $25 for a right angle gear box. (actually its a 90 degree drive adapter for a 3/8" electric drill.)


----------



## Brian Rupnow (Nov 16, 2009)

Well, this gets the handwheel for adjusting head height down to a much more comfortable position for me to reach. Two small bike sprockets and a peice of bike chain. ---And I don't have to worry about limit switches or power supplies.


----------



## tel (Nov 16, 2009)

Looks like a good idea so far Brian, but where, in the great scheme of things, does the right angle drive come in?


----------



## Brian Rupnow (Nov 16, 2009)

Tel--I had so many tentative plans in my head this morning when I got up, and the right angle drive was one of the potential scenarios, powered with a dedicated 3/8" reverseable drill. The fabricator I went to beg the steel from has his shop utterly and completely on the far side of town from where I live---In fact he couldn't be any farther away and still be in the same city. And it just so happens that Busybee Tools is almost beside that shop. I figured that sooner or later, I was going to need that right angle gear set-up (for something) and as it was on sale for less than $20 I thought "Better buy it anyways and save a trip." The plan I'm working on mightt still morph into a powered set-up---to do that I would drop the lower sprocket even farther, hook the right angle drive onto it, and bring a shaft out below the table to a dedicated 3/8" drill.


----------



## Artie (Nov 16, 2009)

Brian, thanks for starting this thread because it pointed me towards a problem that I had in past identified, but never put any real thought into. I had seen the above mentioned cable and spring design but at the time, thought it 'looked' messy. Probably worked ok but I didnt like the business of the result.

Your problem is much different to mine. Physically Im ok its just that my mill is large and lifting the head up takes a bit of effort.... not too much but enough for me to think bugger that would be nice.. etc etc..

Enter the 'solution'...... I have several of these laying around 'new' from a previous life so... a no cost 'fix' at least for me.... these things arent necessarily cheap and junkyard units are normally just that ... junked.....

Head is in the 70kg range and these will support 30kg (approx ea) so 2 required.

Cheers Rob (not 'my' idea... I 'sourced' it from another site ;D


----------



## Brian Rupnow (Nov 17, 2009)

Yesterday afternoon I made the hubs for the two sprockets. Nothing spectacular here, just simple turning. I will weld the sprockets to the hubs with my mig. Today I actually got a new engineering contract HOORAY!!! ------- so didn't do any work in my toy shop.


----------



## black85vette (Nov 17, 2009)

Congrats. Glad you got some work to do.


----------



## ozzie46 (Nov 17, 2009)

Congrats on the contract Brian. Eating is more important than playing. Darn it anyway. :big: :big:


  Ron


----------



## Brian Rupnow (Nov 17, 2009)

Fellows, its been a long, hungry year!!! Going through my invoice book last week, I see that I have worked 3 months out of the last 10 1/2. I have been through these recession/depression cycles about 4 times since I started working in 1965, but I was always working for big companies at the time, and as big companies don't like to lose their engineering staff, I was always protected. This is the first one I've rode out since I registered my own company 10 years ago, and all I can say is that I'm damn glad my kids are grown, my house is paid for, and my wife still works.


----------



## lathe nut (Nov 17, 2009)

Brian, you must not watch much television, they say things are going to be great, jobs created and on and on it goes, course that is not going on where I live, I work in the oil field and its real bad and not hope in sight, we have worked all our lives what else shall we do, hope it gets better soon for you, Lathe Nut


----------



## Maryak (Nov 17, 2009)

Brian,

Congratulations on your contract. Now you can afford a new roundtuit :

Best Regards
Bob


----------



## Deanofid (Nov 18, 2009)

Brian, it looks like a real arm saver, this thing. Whyn't you make it easy on yourself and double, or treble the size of that top sprocket? 
Ten years from now, you'll thank me...

Dean


----------



## Brian Rupnow (Nov 21, 2009)

I made some more progress today on this project. Both hubs are finished and welded to the sprockets. I didn't realize it, but the sprockets appear to be made from some type of sintered metal.--I'm not sure how good the welds are going to be because of this, but I will take a "Try it and find out" attitude. I also finished the shaft for the bottom sprocket, and got the keyway cut in it to key it to the relocated handwheel.


----------



## coldte (Nov 21, 2009)

Hi , just read your post and thought i might contribute to it,I too have a large mill and the handle is on the right behind the drilling handles(very inconvenient ) plus the head is heavy to raise .After a while i removed the handle and installed a chain sprocket and used a 24vdc motor from a childs scooter running on 12vdc.
after a few weeks noticed that something was amiss ,on investigation found that the spur gear had parted from the feed screw alignment. this caused major problems in refitting it (2 days on back under mill) . Decided to alter tack and after trolling the net found someone who had installed a Gas strut -liked the idea and purchased two off flea bay for £10 delivered.Installed both and had to remove one as it made it impossible to wind down but could wind up with your finger,it is now fine about the same up and down. I mentioned the first as a cautionary tale to would be modders (especially chinese machines).
regards coldte


----------



## Brian Rupnow (Nov 23, 2009)

Well, there we go. Project is finished. Everything worked out pretty well as I anticipated, and it IS in a much more comfortable position for me to reach that handwheel which raises and lowers the head. Of course, the "proof of the pudding is in the eating" and I will have to try using it this way for a while before I am really sure that I have indeed improved the machine, ergonomically. One good thing about a project like this, it didn't really cost anything other than my time, and if I don't like it, then it is very simple to return to its original condition. As I said in an earlier post, power would have been nice, but then you get into limit switches, power supplies, and all the logistics involved. This way its a lot simpler, and hopefully an improvement over what it was.---Brian


----------



## lathe nut (Nov 23, 2009)

Brian, that is a nice fit, again, copy and paste time, did you put bearing in the two block, is that a 43 chain, how about a close up shot while I am asking, thank again for the great ideas and projects of improvement, Lathe Nut


----------



## Toyman01 (Nov 23, 2009)

Nice! Very professional looking. :bow:


----------



## ariz (Nov 24, 2009)

very neat solution Brian, and a well done work indeed :bow:


but I wish to know something more about the gas strut from coldte (I emailed him to not go off topic, but no reply till now)


----------



## Brian Rupnow (Nov 24, 2009)

FOR LATHE NUT AND OTHERS





View attachment ASSY OF MILL WITH SPROCKETS ADDED.PDF


----------



## Brian Rupnow (Nov 24, 2009)

View attachment BLOCK TO SUPPORT LOWER SHAFT.PDF


----------



## Brian Rupnow (Nov 24, 2009)

View attachment LOWER SPRKT AND HUB ASSY.PDF


----------



## Brian Rupnow (Nov 24, 2009)

View attachment NEW HANDWHEEL SHAFT.PDF


----------



## Brian Rupnow (Nov 24, 2009)

View attachment SUB ASSY--LOWER SPRKT AND HANDWHEEL.PDF


----------



## Brian Rupnow (Nov 24, 2009)

View attachment TOP SPRKT AND HUB ASSY.PDF


----------



## lathe nut (Nov 24, 2009)

Brian, thanks again and again, copy paste and saved to file for hope this winter project, that must be nice to be able to draw thing out before doing them, your good to us, thanks again, Lathe Nut


----------



## Davo J (Nov 28, 2009)

Hi, 
I dont own a bench top machine, but thought I would let you know that the tiltadoors and panel lift doors on garages are operated off a bike chain as well. I know around here the roller companies throw the old units out when instailing new doors, most still have good motors on them. I dont think it would be much trouble to incorparate a 3rd sprocket for power feed using one of those motors, thats if you or the others wanted to go that way in the future.
Just a thought,
Dave.


----------



## lathe nut (Nov 29, 2009)

Thanks for the tip Dave, will be looking for them now, Lathe Nut


----------



## Davo J (Nov 29, 2009)

It might be worth a trip down to a roller door company and ask them. I know the company here lets you get them out of the scrap bin.The instailer fellows bring them back on there trucks after fitting new doors.
Dave


----------

