tri-power overhaul

[morbius]

Hi Folks,

Here goes my real first post. Been here a long time lurking and learning, now time to share and give back

Traded my old shoptask machine and got a tri-power with my cnc stuff refitted, ball screws and dro. I ended going that route since there was a couple feature I wanted that was on the new machine and the price was right. Yes I know there are some issues but nothing I can fix. Now I am going to set off on a project similar to what Bloy2004 did. Started stripping the machine so that every part can be cleaned (biggest problem I think with the machine is the mating surfaces are full of junk causing possible alignment issues), repaint correctly and re-assemble correctly. Change out the Nook 0.004 ball screws for the Nook 0.00015 version. And so on ...

I will try to keep a photo history like Bloy2004 and share my experience with the Tri-power. I like the machine, just need to get the accuratacy up. Like to chat with other tri-power users on tips, tricks, and ideas on what they did to their machines.

Cheers,
Roberto

[bicycleboy]

Roberto,
Hi, sounds like a big project. There are many things that need to be fixed. I have a late 2006 manual Tri-Power that I am in the early planning and procurement process of CNCing.

I plan on eliminating the y power feed during the conversion. The compromises made in order to make the y work are to limiting. Wonder what you think about this since you formerly had no power y. Actually, do you use the manual modes since you have CNC?

I made a DRO for the x axis that seems to work pretty good. Haven't done the others. Figured out the table rotates to much when changing x direction. Planning on making a removable plate that will be made to attach between the saddle and the tail stock base to extend the width to eliminate rotation. I will also be stiffening the fifth column and the horizontal plate to it and making a counter weight for the mill head.

I have some other silly ideas if anyone wants to hear them.

Mike

[morbius]

Hi Mike,

Yes, big project, but looks like a ton of fun ! Took a while to dismantle everything and notice a problem with the table. So I removed everything and noticed the table has a 1/2 inch bow. So in the process of fixing that and when I re-install the machine base, shims are going to be need to make sure the machine stays aligned. I will start posting pics at that point.

The thing I hated with my old machine was every time I wanted manual mode, I had to pull a bolt then put the bolt back and recheck everything. Drove me nuts ! I have not played much with this new setup, honestly it was something I wanted so only time will tell. I used my machine more in manual mode in the past to do little things here and there. Now I want to do more cnc and need precision hence the full tear down and rebuild.

No ideas are silly ! Lets hear them, the more we share and exchange ideas the better the machine will be and the more fun we can have

Cheers,
Roberto

[gerryv]

Wow are you serious, a 1/2" bow?

I just joined today, thinking of buying a manual/DRO system to start so this is kind of scarey. Is that pretty unusual, hopefully? Would it not be considered a manufacturers defect?

Thanks much,
Gerry

[morbius]

Hi Gerry,

Welcome aboard ! I should note if I did not already mention it, my system was damaged in transist. Fedex frieght (they are great but ...) destroyed the shipping crate, broke a couple a minor parts on the machine and bent up the table with the forklift. It almost looks like they dropped the skid at some point. There should be some upward crowning since the weight the machine will then flatten it out vs bowing the opposite direction, but was alot above that !

Nothing a little repair work can not fix real easy. Since I am tried of the yellow color and was planning changing it from the start, I noted the damages on the tag and John at Shoptask has been standing by with replacement parts if needed.

Cheers,
Roberto

Originally Posted by gerryv Wow are you serious, a 1/2" bow? I just joined today, thinking of buying a manual/DRO system to start so this is kind of scarey. Is that pretty unusual, hopefully? Would it not be considered a manufacturers defect? Thanks much, Gerry

[morbius]

Here is the start of the pics, please excuse the junk in the background. Limited on space and in the process of rebuilding my shop also ....

Here is the table, all cleaned, fixed and repainted:




Here is the bed installed. The support bars where put down with sealer behind them to seal the holes. All squared and level


Still some yellow to clean off ....


Lathe head installed. Required work on repairing the bushing that guides the gear for the tri-power x/y screws .... When I started, the gear could only be turned with a wrench and some serious force. Now it turns by hand, required shimming the back of the bush until square with the shaft.




The bed is fully level and square. The lathe top is squared, the lathe bottom is not and needed adjusting. Shimming the back corrected the problem .... 0.040 on the left and 0.044 on the right


More to come once new supply of shim stock arrives ...

Cheers,
Roberto

[morbius]

Hi Everyone,

More updates and work ....

The lathe head unit was so out of wack that it was easier to re-surface the base and make it square. Turned out we had to take 0.05 from side to 0.08 to the other side. Now the lathe head sits correctly on the bed and without shims is perfectly level (to 0.0005, the best my machinist level goes to or 0.00005 with my best dial !!) on the X and Y axis. Pinned it and torqued the bolts, waited 24 hours, re-torqued, waited 24 hours and re-checked, everything still in spec. The tail stock will have to be milled so that it sits correctly, now its too high.

BTW, if you removed bolts, REPLACE them. Here is what happened to me after torquing this one to 65 ft lbs. Others snapped ! Got replacements on everything from McMaster & Carr.


Once the correct bolts where used, the mill tower and swing arm where installed and torgue to make sure everything stayed level. It did


The swing arm is level along the X axis, off around 0.008 on the Y axis. With everything torque down and no bracing, the deflection max X, Y and Z axis is +/- 0.005, not bad, was counting on more.

Here are some pics of the lathe, motor box, and table drive in place.



The lathe gearbox was fully rebuilt and running very smoothly now. The bushings needed shimming and cleaning. The same applied to the table gearbox for the exception of de-burring the gears and shafts.

Now working on the bearings in the drive box. The belts and bearing are way too noisy and rough. They make the whole machine vibrate. New precision replacement bearing have been ordered and should be here in two weeks.


Once the motor drive box works smoothly and quietly without converting to VFD, I will tackle the tail stock and table. Will convert the table X and Y axis gibbs to a full floating version so no binding from the adjustment screws.

Cheers,
Roberto

[bicycleboy]

Hi Roberto,
Looks like your having fun! Great work and great pictures. I noticed the same issue with the bolts, see: http://www.cnczone.com/forums/showth...324#post271324
Did you re-tap the holes deeper? Some of mine are only about 3/8 in deep. Is it possible to drill them deeper and then re-tap without messing them up worse?

You mentioned that the deflection was +/-.005 in x,y and z. What load did you use for that deflection. Also what directions are x,y and z so we are talking about the same thing. I use x for right to left, Y for front to back and z for down to up. Don't know if this is correct for mach3 since I haven't finished adding CNC yet. I think I recall posts about changing the coordinate system between milling and lathe work.

Pushing the mill head for and aft is by far the least stiff direction. I plan on stiffening up the fifth column by bracing it for and aft and attaching it directly to the lathe bed in some fashion. By the way the quadralift locking lever that pinches one of the rods seems to have no effect on my machine.
I'd like to see any pictures you can take of the lathe bearing replacement as I'm sure mine will need that.

regards
Mike

[morbius]

Originally Posted by bicycleboy Hi Roberto, Looks like your having fun! Great work and great pictures. I noticed the same issue with the bolts, see: http://www.cnczone.com/forums/showth...324#post271324 Did you re-tap the holes deeper? Some of mine are only about 3/8 in deep. Is it possible to drill them deeper and then re-tap without messing them up worse? You mentioned that the deflection was +/-.005 in x,y and z. What load did you use for that deflection. Also what directions are x,y and z so we are talking about the same thing. I use x for right to left, Y for front to back and z for down to up. Don't know if this is correct for mach3 since I haven't finished adding CNC yet. I think I recall posts about changing the coordinate system between milling and lathe work. Pushing the mill head for and aft is by far the least stiff direction. I plan on stiffening up the fifth column by bracing it for and aft and attaching it directly to the lathe bed in some fashion. By the way the quadralift locking lever that pinches one of the rods seems to have no effect on my machine. I'd like to see any pictures you can take of the lathe bearing replacement as I'm sure mine will need that. regards Mike

Hi Mike,

Thanks and yes I am, great stress reliever

The direction I talking about is the same as the machine movement axis. The loads I was using was a static 200lbs. My main goal was to make sure that with additional loads on the swing arm and quill, the larthe head stayed put and no changes happened. So with a changing load on the quill, my test shaft in the lathe head stayed at 0.0000 .

The fifth column brace is still removed and will not be reinstalled until a couple strong backs are installed to make it even stiffer. I going to modify the fifth column big time. Working on a design that gives me the strength, stiffness, and no flexing so the it can move up and down via cnc automatically. More to come on that later ....

Yes, all the bolt hole where retapped and cleaned. I found a couple shallow ones and when investigating, found them packed with stuff and cleaned out really well.

My lathe bearing was in great shape and reused so I have no pics on that. Taking that gearbox apart is rather easy but the very large snap ring that holds the lathe gear in place is only removable when the the top plate is removed exposing a large hole at the top of the lathe head.



I will take more pics of the inside of the lathe unit when I take the swing arm off again for machining. Applied is a great source for the bearings, they have stock on a ever single bearing used on the tri-power ( http://www.applied.com ).

Cheers,
Roberto

[morbius]

Hi Everyone,

After a wait, finally got all the quality replacement bearing for the motor box. Spent some time installing the them and what a heck of difference !! Very very smooth and quiet. Still using the original belts, however replacement belts from Dayton have been ordered and waiting.





Once I have the new belts and the last of the lathe vibration removed, I can concentrate on finishing the tail stock, table, and saddle. Then all new wiring, the stock stuff is too light in size .....

Cheers,
Roberto

[asallwey]

Roberto,

Any chance of you posting the Applied #'s on the bearing and their cost?

Alex

[morbius]

Originally Posted by asallwey Roberto, Any chance of you posting the Applied #'s on the bearing and their cost? Alex

Alex,

More than happy to do so, have those handy at home, give me a couple days. One of the bearing I wanted Applied was out of stock and required a minimum order of 10 to get a back in stock and good deal. If several people combine their efforts, bearing costs can be reduced by $120.00.

For the group,

I installed new dayton belts from Graingers and what a hell of difference !! The machine had a nasty vibration when I started that would shake stuff off the table and now very smooth, almost like a heavy quality lathe. I did discover a slight vibration in the lathe motor that can dealt with in a couple ways. 1. Isolation pads so the motor is not directly bolted to the lathe unit (best way to do it) .... 2. replace the bearings in the motor (something that should be done no matter what .... 3. Do item 1 and 2 and do it right up front.

Side note, the dayton belt size for the 2 belts on the lathe motor are wrong and will have to get with John at Shoptask to correct that. If you use those sizes, you then have to run both belts under the idler pulley to get enough tension to work right. Otherwise you end up adjusting the motor so much that it hits the table and the belts still slip ....

Cheers,
Roberto