Building/modifying An Atlas Th42

[great white]

Made a mount for the baldor 3/4 hp DC motor and mounted it on the TH42.

Installed the reversing switch in the control head.

With any luck, it will be wired up and running tomorrow. It's been two days without a running lathe now and I feel......."exposed".



Gotta say, that Baldor DC motor absolutely dwarfs the 1/8 hp ac motor that the lathe came with.

Trying to decide where to put the slap kill switch.

Seems like somewhere on the left side somewhere (as you look at it) makes the most sense to reach it with either hand. It's also where the work is going on (ie: headstock) so most likely to be close to it.

 

[schor]

Made a mount for the baldor 3/4 hp DC motor and mounted it on the TH42.

Installed the reversing switch in the control head.

With any luck, it will be wired up and running tomorrow. It's been two days without a running lathe now and I feel......."exposed".



Gotta say, that Baldor DC motor absolutely dwarfs the 1/8 hp ac motor that the lathe came with.

Trying to decide where to put the slap kill switch.

Seems like somewhere on the left side somewhere (as you look at it) makes the most sense to reach it with either hand. It's also where the work is going on (ie: headstock) so most likely to be close to it.

Pictures or a video or it didn't happen. Congrats on getting er done.

 

[great white]

Pictures or a video or it didn't happen...

okey dokey. Not much to look at though.

Motor:



The motor is a flange mount and sealed unit. Bolted at the pulley end and and sitting on a rubber isolation block at the other. It's more than strong enough in this application and I've captured 3 of the mount bolts. I still have to clean up the mount bracket to look like something other than the 90 degree bend piece of Al that it is. Prob just radius the corners and call it good. The data plate looks a little "distressed" because it's previous life was industrial use in a paper mill. You can still see some paper residue on the face in the picture below (still have to give it a final cleaning). Brushes checked out good and the commutator is smooth and clean. Motor should pretty much outlast the lathe in this application. I'm looking forward to not having the motor drag down to nearly stall when I put tool to surface. It may only be a 3/4 horse, but it's going to out torque that little 1/8 Hp AC motor all day long.

Wiring in progress:



Reversing switch installed in control head next to tach display:

 

[great white]

Got the dc motor and cycletrol up and running:

I didn't bother with wring up the reversing switch. I don't need it for anything right now and I didn't feel like running the extra wiring. It's going to have limited use anyways since my spindle is the "thread on" type.

I'll probably sew up the cover for the lathe tomorrow and leave it at that for a while. I've got stuff to do around the house and the motorcycle projects are falling a bit behind schedule.

The lathe is up and running again, that's good enough to be able to use it again.

 

[Round in circles]

Started the dro installation:



I did the big one first as it was going to be the most trouble.

I took a cheap caliper apart and modified the slide to fit a piece of al holding the sensor strip. Drilled and tapped two 1/4 holes in the bed and bolted it up.

The bracket to hold the head turned out to be messier than I wanted. I did one leg and when I found that it allowed the head to cock and stick I had to add the second one. Works smooth as silk now and I at least have a template to make a nicer one in the future.

It's got a 24" travel (limits of the carriage) and a .001 error when I run it from one end back to the other.

I don't use coolant, but a nice little bent al cover will protect it fine. That's why the bracket goes down and under the head and track.

Next up will be building cross slide and tail stock measures but they will be easy as I can just use the cheap calipers "as is" without making a sensor strip.

Yuri's dro and my nexus 7 tablet will pull it all together into a usable readout while I'm working.

GW,
How do those sensor strips work ? Is it by a wiped electrical contact on a resistance or via an ultrasonic measuring system that bounces a signal off bars in micro widths of reflective material set in the strip & then uses micro chip processing to count them .

I ask because I'd like to know if they are affected by oil or grease on them & if not why ?

 

[great white]

GW,
How do those sensor strips work ? Is it by a wiped electrical contact on a resistance or via an ultrasonic measuring system that bounces a signal off bars in micro widths of reflective material set in the strip & then uses micro chip processing to count them .

I ask because I'd like to know if they are affected by oil or grease on them & if not why ?

Capacitance measuring as far as I know. here's a pdf with some info on them if you would like to veiw it:
http://www.lima.com.tr/BasicTiger/Applications/PDF/appn_066e_Reading out a digital vernier caliper.PDF

They won't get getting anything on them in my particular application as they will have a shield over them once it's all done.

 

[great white]

was sitting here thinking about how much the DC conversion cost me.

$85 for the Baldor 3/4 hp Motor and it was 35 bucks for the cycletrol (the one I used). $18 for two 16 foot lengths of 14 gauge extension cord to wire it all up.

The rest was leftover bits I had lying around.

So, just shy of $140 for the whole shebang.

Not bad for an "industrial quality" drive. Not too bad at all!

 

[great white]

Went looking for a slightly shorter belt for the motor as it was a bit loose due to the change in motor size.

Original belt is a 4L390. I needed a 380 and no one in this one horse burg had one.

I finally found one at an auto parts store a ways up the road. I returned home thinking I would pop it on and all would be good.

Nope. The 380 had some weird defect that caused it to half twist on the pulley at the same point every time. No big, I had also grabbed a 370 from the same store just in case the 380 was still too long.

I pull the 370 out of the sleeve and try to install it.

No joy here either. The parts guy had given me a frikin 350!

That was enough of that. I went out and bought some longer bolts and some fender washers. I spaced the middle pulley assembly up about 1/2" and that gave me enough additional adjustment to take up the slack in the belt.

While I was at it, I reshape the clip guard and a few other bits that were allowing the motor to make more noise than it normally would.

The motor runs pretty much quiet now and the lathe even is running quieter.

 

[mattthemuppet2]

I didn't bother with wring up the reversing switch. I don't need it for anything right now and I didn't feel like running the extra wiring. It's going to have limited use anyways since my spindle is the "thread on" type.

looking really good, you'll love the variable speed! As for not needing reversing, it's super useful when doing metric threads if you don't have a metric lathe. Keep the halfnuts engaged, do cut, wind out, reverse lathe, wind in, do cut etc etc. If you don't have reverse you either have to reverse the spindle by hand with a crank or be very careful to re-engage the halfnuts at exactly the right spot on the bed and the threading dial. Trust me, I have a 618 and a reversible DC motor and cutting a 32x1.5mm thread for a collet nut was a breeze.

 

[great white]

looking really good, you'll love the variable speed! As for not needing reversing, it's super useful when doing metric threads if you don't have a metric lathe. Keep the halfnuts engaged, do cut, wind out, reverse lathe, wind in, do cut etc etc. If you don't have reverse you either have to reverse the spindle by hand with a crank or be very careful to re-engage the halfnuts at exactly the right spot on the bed and the threading dial. Trust me, I have a 618 and a reversible DC motor and cutting a 32x1.5mm thread for a collet nut was a breeze.

Thanks for the gen info.

I am planing to wire up the reversing switch, just haven't done it yet. I was aware of how easy it makes metric threading on a "non metric" lathe, which is something I will eventually get in to as I build metric motorcycles.

The boys in the machine shop told me reverse is also useful when cutting a snap ring or o-ring land inside a cylinder. Just run the lathe backwards and you can cut the "back wall" of the cylinder, making it easier to watch as it cuts. That will be useful for me as I often need to do that operation as well. Well, haven't done it yet but I sure can use it.

I'm already liking the variable speeds. Makes it very easy to adjust for cutting speeds "on the fly".

Next project is to get the spindle tach wired up. Even though the DC motor is rated the same speeds as the old AC (1750), I'm pretty sure it's fast enough that it might be overspeeding the lather on the highest setting on the cycletrol.

Spindle tach will also make it easy to get the SFM "in the ballpark" and then a little tweek to improve the cut.

Yep, DC motor and the speed control are a nice step up for me so far!