Tormach Disassembly

 

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Moving the mill from the garage to the basement was a bit of a challenge, for several reasons.  First, only one path to the basement was possible - up three steps through a door between the garage and utility room, then a sharp turn through a doorway to the basement stairs, and then another sharp turn through another doorway into the shop area.  Aside from the issue of having to disassemble the mill into components, all of the doors measure about 29" wide at the frames which meant that clearance for wider parts would be a problem.  We live in a town home with a common wall between our utility room and the neighbor so another problem was rigging some sort of anchor in the utility room to lower heavy parts down the stairs.  A final problem was labor - a couple of friends offered to help but the vacation was over by this point and my work schedule is uncertain enough that it is tough to arrange help at the right time, especially as all of the friends are at least 1/2 hour away.  My wife and I decided to do as much of the moving and re-assembly as possible and in the end we were able to do the whole thing ourselves.

The Tormach manual has a short section on disassembly for moving and cautions that the warranty will be invalidated, but also invites owners to call for suggestions on how best to approach the process.  Of course by the time we were ready to start tearing the mill down it was a weekend and it was unlikely that tech support was available so we just dug in.  Because of the limited basement access it was necessary to tear the mill down into as many small pieces as possible.  A key factor in determining waht to remove was that I didn't want to disturb anything that would affect the alignment or fit of the essential mill components to each other.  A review of the Tormach documents and several fora on the web where Tormach mills are discussed suggested that it was feasible to break the mill down into these pieces:

  1. the stand
  2. the control cabinet
  3. the head
  4. the column
  5. the base, table and apron

After tear down was started it was decided to also pull the X- and Y-axis stepper motors, the one-shot lube pump, the spindle motor, and most importantly the apron and table as one assembly from  base.  The stepper motors and lube pump didn't make a huge difference in the weight, but removing them was easy and lessened the chance of snagging one in transport and breaking or cracking a casting.  Removing the spindle motor made it a little easier to get the head down the stairs.  Separating the table/apron from the base didn't seem feasible until the base was removed from the stand but it then looked doable.  Separating the base and apron/table proved quite beneficial as the entire table/apron/base assembly was just too bulky to get through the doorways in a safe manner.  More on that below.

The head is aligned to the column and the column to the base with pairs of taper pins.  That is a very nice feature since it means that those components could be re-assembled into essentially the same positions as they were in when received without having to fool with witness marks or time consuming re-alignments on re-assembly.

The easy parts were attacked first, starting with the one-shot lubricator, then pulling the wiring between the stepper/spindle motors and the control cabinet, the wiring from the X- and Y- limit switches, the wiring from the spindle access door interlock limit switch, and then the motor and cabinet.  The head was then pulled, followed by lifting the column off the base and then pulling the base/apron, and table as one unit off the stand.  The table and apron were then removed from the base.

Pulling the motor and limit switch wires

It seemed like the logical first step was to pull the wires for the spindle motor, stepper motors, and limit switches.  It was a nice to see that all of the wires inside the cabinet and most of the wires at the other end were all neatly labeled with unique tag IDs as that made it easy to keep notes of what went where.

The motor wiring is simple - just 3 labeled wires to the terminals inside the motor junction box and a ground wire to the case. A flexible tube similar to shrink fit tubing is used contain the wires from the motor to the side of the head.

 

 

A limit switch is used to act as an interlock to disable spindle operation if the head access door is open and the switch wiring must be removed to get the head off.  The switch is held to the back of the head with a couple of screws which were removed to gain access to the plastic "boot" that covers the switch terminals.  Here the boot has been popped off to reveal the labeled switch wires, which were then removed from the switch.  The switch was then re-attached to the head so it wouldn't get lost.

 

The wiring for the motor and the interlock switch on the head access door are routed into the column through this flexible conduit.

 

 

Wiring from the column to the control panel is run through mating holes in the column and left-hand side of the control panel.  Shown here are the cords from the spindle and stepper motors.  The wire tie that bundles these wires together has been cut just before the motor and interlock wiring was pulled into the control panel.

 

This is a view of the wiring inside the housing for the X-axis stepper motor.  As seen here the wiring at the stepper side terminates inside the motor somewhere and appeared to be inaccessible so far as pulling the wires from the motor side.  The other two steppers are similarly wired so it was decided to pull the stepper wires from the control cabinet back to the stepper motors and remove the X- and Y-axis steppers.  Removing the Z-axis stepper motor is not advised as the Z-axis stepper is only thing holding the head in position, through its coupling to the Z ball screw.  If the Z stepper is removed the head will just drop by gravity until the spindle hits something solid, like the table, or the ball screw nut hits the bumper.  Either occurrence is probably a Very Bad Thing.

A view of the stepper motor control boards for the X- and Y-axes inside the control cabinet.  There are six labeled wires from the motors attached to the terminal strip at the bottom left side of each control plus a ground wire from each that is connected to the ground bus plate in the picture below.  The wires are routed through plastic trays inside the cabinet down to the hole between the column and control cabinet.  Here a couple of the X-axis wires have been removed from it's control board. 

The ground bus inside the control cabinet.

 

 

A view of the Y-axis stepper showing the flexible conduit for the control wires between the stepper housing and the column.  A similar arrangement is used for the X- and Y-axis steppers.

 

 

The X-axis stepper wiring has been pulled from the control cabinet through the column and the conduit has been removed from its fitting on the column.  The steppers are attached to their housing with 4 metric SHCS, which have been removed to pull the stepper from the housing after loosening the coupling between the stepper shaft and the ball screw shaft.

 

Here the stepper wires have been pulled from the X- and Y-axis control boards and the Y-stepper with its conduit and wire bundle has been removed.

 

 

The terminal strip inside the control cabinet for the limit switches.  Again, all of the wires are neatly labeled with uniq wire tags.

 

 

The wiring for the X- and Y-axis limit switches pass from the control cabinet through a flexible conduit to a junction box which serves as a mount for the Y-axis switch as well as a pass through for the X-axis switch wiring.  On the right, the access door has been removed from the junction box and disconnection of the wires has been started.  The brown and red wires are the hot connection from the X-axis switch and were connected with a blind crimp connect (sitting on top of the junction box) which was removed so that the wires could be pulled through.  The blue wires are the switch commons and have the common from the control panel was crimped to a lug for the Y-axis switch with a second wire leading to the X-axis switch.  This crimp was also removed so the wires could be pulled.

The X-axis limit switch with its boot removed to expose the wires from the junction box.  During initial trials in the garage the switch got crunched during an X-axis traverse.  I'm not sure how, but assume that it had loosened during the long trip from China and stuck up far enough to get caught by one of the switch stops.  Tormach had another to me within a day and a half of my call to report the problem.  The X-axis switch, wire run and conduit were pulled as one assembly and set aside.  The Y-axis wire bundle and conduit were pulled back and tied to the control panel.

 

Mechanical Disassembly

Now for the fun part - pulling apart the main assemblies and getting them into the basement.  I wish that it had been possible to take better pictures of many of these steps as it would have proved amusing for the more experienced riggers if not educational for other hackers like me, but with just two of us to do the rigging and moving there were many times when there was no one free to snap a picture.  As major components were removed they were weighed with a bathroom scale to get an idea of what we would have to deal with down the stairs.

The lube pump is attached with three SHCS to the side of the base.  Here the pump has been removed and the way oil drained into a 1-pint glass jar through a drain plug in the bottom of the pump.  The tubing that distributes way oil to the slides and screws was then disconnected and drained.

 

Alas, this is the only picture of the control cabinet removal.  The cabinet consists of two sections attached to each other - an enclosure with gasketed door at the top and a sheet metal tray underneath that is spot welded and screwed to the enclosure.  The tray can be seen here just below the PCNC logo and provides space for the power cords for main mill power as well as the PC, coolant pump, accessory, and the parallel port cable.  The enclosure itself contains power distribution and all of the control circuits and electronic components.  The enclosure and tray must be removed as one unit and are attached to the column with 4 SHCS inside the enclosure and two Philips machine screws inside the tray.  The enclosure door must be open to gain access to the fasteners which makes removal a little tricky since the open door swing around changes the center of gravity of the box pretty quickly.  We blocked up the enclosure with wood spacers to provide some support (as seen here), completely removed the two Philips screws between the tray  and column and partially loosened the 4 SHCS.  Then I held the cabinet steady while my wife removed the SHCS, starting at the bottom and ending at the top.  I was able to steady it briefly as the last SHCS came out until my wife could get the door closed and assist with getting it lowered to the floor.  It weighed 115 lbs and we hand carried it to the basement.

The spindle motor was the next component tackled.  The motor is bolted to a plate, which is attached to the head with a SHCS through a bushing at the left rear (under the hex wrench) and an articulated clamping rod at the right rear.  The clamp rod was loosened to slide the motor forward about the pivot SHCS to slip the belt off the motor pulley.  The pivot SHCS, washer, and bushing were then removed, the clamp rod was unscrewed, and the motor was lifted off by hand and carried to the basement.  It weighed 45 lbs.

 

Now it was time to pull the head.  A manifold to distribute way oil from the lubricator to various lube points is attached to the back of the head with a couple of SHCS.  Lube comes in through the tube on the column into the manifold and then on to leadscrews and ways.  I decided to pull the tube from the column off at the manifold and then remove the SHCS to leave the manifold attached to the column via the clamps on the top of the Z-axis slide.  The removed tube was later pulled through to the inside of the column so it wouldn't snag.

 

 

 

Head Removal and Moving

The head is attached to the Z-axis slide with 6 SHCS and is aligned with two tapered dowel pins, one on the lower right side of the head and the other on the upper left hand side.  The Tormach manual advises that the taper pins be removed first and then the SHCS.  The pins are tapped for a jacking screw and here the right-hand pin is being jacked out with a metric hex screw through a piece of SS tubing with a washer to serve as a bearing surface and spacer between the screw head and the top of the tubing.  It would have been a good idea to put a washer between the head and the bottom of the tubing as the tubing dug into the paint quite a bit.  The right combination of tubing length and washer thickness is necessary because the pin is not tapped too deeply and you want to get enough threads engaged to avoid stripping them while providing enough unengaged thread to get the pin jacked out enough to extract it.  A fair amount of force is necessary to pull the pin and it was hard to tell if the screw had bottomed out or not.  I also found that the threads on the pins were a bit tight (or maybe had debris in them) and chased them with a metric tap.

Here is one of the head taper pins along with the hardware used to extract it.

 

 

The head looked pretty heavy, even without the motor attached so we decided lift it from above with the engine hoist.   There's a cavity through the head behind the spindle and square hole in the bottom of the head through which a rigging strap was inserted.  A large aluminum rod cutoff was inserted through the open strap loop at the bottom of the head an the opposite end of the loop attached to the hoist hook.

 

The load still looked tippy so a second strap was wrapped around the spindle and slipped over the vertical strap to help steady the head was it was free.

 

 

Here the 6 SHCS mounting bolts have been removed from the head and the head has been lifted free of the vertical slide on the column.  Several blocks of wood were placed on the table to protect it in case the head slipped or swung too low.  It was probably a little late in the day as I look pretty worn out here.

 

 

The head was lowered to the floor, strapped to a two-wheel refrigerator dolly and then moved to the "staging" area in the basement.  The head weighed about 140 lbs and it was pretty easy to lower it down the basement steps by myself, with my wife holding onto my belt as a backup in case the dolly started to run down the steps too fast.

 

 

 

Column Removal and Moving

Like the head, the column is attached to the base with 6 SHCS and aligned with two taper pins.  A similar arrangement was used to jack out the taper pins,  before pulling the SHCS.  Shown here is the set up for extracting the pin on the right hand side of the column, using a short piece of 1/2" conduit as a tube, several washers for spacers and a metric hex head bolt.  Note that the control cabinet is installed on this side of the head and that the cabinet must be removed to gain access to this pin.

 

Here the pin on the left-hand side of the column has been extracted.  The threads on the hole in the taper pin head were also a little rough and the threads on both of these pins were chased with a metric tap.

 

The engine hoist has been moved into position to lift the column off the base and stand with the hoist hook snapped onto the column lifting lug..

 

 

 

 

The SHCS have been removed from the column, the column has been lifted slightly free of the base, and the hoist has been partially backed away from the stand.  My wife backed up the hoist until the column was clear of the stand while I kept a hand on the column to keep it from swinging too much.  The wood blocks under the column were used to protect the base mounting area from dings as the column was pulled away.

 

 

 

The column has been lowered to the floor and strapped to a two-wheel refrigerator dolly in preparation for lowering it don the basement stairs.  The column weighed around 300 lbs and we decided that it was too heavy to lower it manually by the dolly handles.

 

 

Getting the dolly and column up three steps from the garage into the utility room proved too difficult for us to handle so we used this Harbor Freight 440/880 lb electric hoist ($80 or so on sale) to provide some help.  The hoist has been bolted to a 2x8 leaned against the inside of the kitchen door frame with a lifting strap looped through the dolly handles and attached to the hook on the hoist cable.  A piece of plywood was placed over the garage steps to form a ramp which made it easier to get the dolly into the utility room.   The door on the right, just outside the kitchen is the doorway to the basement steps.

 

 

The dolly has been dragged all the way into the utility room, placed upright, and an A-frame assembled to provide an anchor for lowering the dolly and column down the basement steps.  The A-frame was assembled for a previous job to move a (probably) heavier surface grinder base down the steps (see the KO Lee grinder page on this site) and it was a good thing we kept the parts.  The frame consists of a U-shaped section formed of 2x8s with the bottom of the U serving as a mount for the HF electric hoist and the open ends laid up against the basement doorway frame.  The angled arms are made from 2x6s that were screwed to the base at the bottom.  Notches were cut into the upper ends of the arms to fit under the upper part of the door frame and old towels were used as buffers to minimize damage to the door frame.

 

 

Once the frame was positioned, the hoist hook was attached to the lifting strap through the dolly handles, some of the slack was taken out of the hoist cable, and the dolly was tilted down and started by hand over the first step, with my wife on one handle and myself on the other.  This was a little tricky since if the dolly got away from us it would gain momentum on its way down the stairs until all of the slack was taken out of the cable, with a lurch that could damage the door frame.  We were careful (or lucky) and didn't have much of a problem there.  Here the dolly has been lowered part way down the steps and the trip the rest of the way was uneventful.

 

 

Base Removal and Separation of Table/Apron from Base

The base was lifted off the stand by sliding a couple of carbon steel solid rounds through the holes in the base and using a couple of lifting straps wrapped around the rounds and the engine hoist.

 

 

 

A close up of the base lifting arrangement.  The table was position along the Y-axis to help balance the load and provide clearance for the straps.

 

 

Once the base was lowered to the floor we started to think of how it could be moved to the basement.  We estimated the weight at something over 500 lbs which seemed a bit forbidding, especially since assembly is too wide and deep to fit through the three doorways it would have to go through.

A look through the exploded parts diagrams for the mill revealed that the Y-axis ball screw nut inside the base was aligned to the apron with 4 SHCS and aligned with two tapered dowel pins, which would be accessible from underneath the base.  We decided to flip the assembly on its back and check that out up close.  Here the hoist is being used to lift the base, apron, and table up with a rod through the holes on one end of the base in order to tip it over.

The assembly has been placed on a sheet of plywood and balanced on one end just before tipping it over.

 

 

 

 

Once the assembly started to tip over a 2x8 was placed on the hoist legs to support the table.

 

 

 

The assembly has been tipped upside down with the table resting on the 2x8.

The ball screw nut was inspected and it looked like it could be removed, which would then allow the base to be slid off the table and apron.  This would result in two components - the base and the combined apron/table - which would each be much lighter, smaller, and easier to get down the stairs than the complete assembly.

 

 

The taper pins were jacked out of the ball nut and the 4 SHCS were removed - this shows a close up of one side of the ball screw nut after screw and pin removal.

 

This view shows the Y-axis gib which is a tight, sliding fit between the apron and base dovetails.  It is necessary to remove the gib in order to slide the base and table/apron apart.  The gib is held in place by two flanged screws on each end of the slide, one of which can be seen here near the middle of the picture.  The gib can be tapped out after removing the two screws.

 

In order to separate the table/apron from the base we decided that the best approach was to lift the entire assembly up, slide a movers dolly under the upside down table, insert some wood blocks to elevate the table above the hoist legs, lower the table onto the wood blocks, pull the gib, lift the base enough to clear the dovetails between the base and apron and then slide the table and apron as one assembly out from under the suspended based.    Here, the table/apron are in the final stages of extraction from the base.  After the table/apron was slid out of the way, the base was lowered onto a plywood sheet over the legs and then tipped back up to a vertical position and strapped to the 2-wheel refrigerator dolly and transported down the basement steps/

 

Here the table and apron have been strapped to the 2-wheel dolly.  The assembly weighed in at about 310 lbs and was lowered down the steps with the dolly by hand.

 

The base weighed in at about 210 lbs and here has been strapped to the dolly.  It also was moved down the stairs by hand.

 

 

 

 

 

The stand was strapped to the two wheel dolly and lowered down the stairs by hand.  Though bulky, it just fit through the doorways and was relatively easy to move.

 

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Last edited: 03/08/2009

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