Portable Boring Bar stand / table build

[Gearhead88]

A couple of months ago I bought a nice old Van Norman 944 boring bar , complete and in great shape. I'm no stranger to this type of equipment , my reason for purchasing this is , as a career and as a hobby , I rebuild engines , primarily motorcycle engines , rather than outsource cylinder bore work , I've decided to equip my workshop to do this in house. In addition to the Boring bar a couple of months ago , in 2020 I bought a used Sunnen Honing machine and have been outfitting it since then to equip it for doing several types of bore sizes , bushings , rod fitting etc.
In the past I've worked at a few shops that do engine machining , re-bores , valve & seat work , crank rebuilding , at those places , I was the guy that did much of that kind of work . I'm semi retired at this point and over time have been equipping my home workshop to expand my capabilities to include precision cylinder boring & honing . When boring motorcycle cylinders , most of those engines have removable cylinders that need to be mounted in a stand or fixture of some kind and a portable boring bar is then used to re-size the bore . Smaller , more compact cylinders can be bored out using a bench mounted boring bar such as a boremaster , I've worked at a couple of shops that have those machines too.

I have been trying to find a used boring bar stand for a few months now , knowing that this was not going to be easy to find , my back up plan was to build one , so that is what I am going to do.

I started by finding a slab of steel , 15 1/2" X 15 1/2" X 1 5/16" thick , it was torch cut on two sides but roughed in to the size I wanted as a top for the table.





I used one of the milling machines at work to square up & surface the "chunk"

View attachment IMG_1261.MOV

At this point I could take it home to finish it on my smaller machines , I have a mill / drill and a small knee mill . The mill drill can be run slow enough to bore a hole with a hole saw , don't laugh guys , some of you are not gonna believe this but I used a hole saw to cut two 4 1/4" holes and a 4 1/2" hole in this plate , which is now , after being surfaced on both sides , is 1 1/4" thick . I took my time ( lots of it ! ) and I wasn't cheap with the cutting fluid . The hole saws survived ! and can be used another day.








I moved over to the knee mill for the next bit , which consisted of , drill and thread two holes for the jacking mechanism that will be below the table , drill three holes and thread them , for the hold down / anchor bolts that hold the boring bar to the table , and then drill / counter bore the four corners to attach some legs.









As of today , Jan 1st 2022 , This is where the project is . I've prepped some pieces and I have to buy some more steel tubing for the base .
I've got some pieces of 1 1/2" x .188" wall tubing cut for legs , there are going to be some 1" square stock pieces that will be drilled and threaded then welded into the tubes that make up the legs . Those will be bolted to the bottom of the table with 1/2" socket head cap screws , where I have counter bored the table on the four corners.
I'm still finalizing the design for the base and the clamping arrangement that will hold the cylinders up against parallels under the table .

All of this is a work in progress and I will be updating this thread as I proceed with the project over the next few weeks.

 

[Gearhead88]

I should also mention , I have an Asian 12 X 36 lathe that is down right now , I'm working on trying to get it running again .
I'm gonna need this machine running again to finish my Bore table.

Here's the deal with that , I bought it new in 2004 , a very short time later the motor failed and I replaced it with a warranty replacement motor , it's run great ever since . About three weeks ago , I was in the middle of making a shop tool on the lathe and it crapped out on me . When you try to start the motor it just hums and will not turn unless you help it with your hand to get it turning , I never finished that project , the lathe has been down since then. I assumed it was the motor again and ordered a new one . It took a few weeks and $360.00 and I had a new motor . I was pretty disappointed when the new motor didn't want to start either . The booklet that came with the lathe when new is poor at best , is translated to Chinglish and does not have a proper wiring diagram , it has one but it's not all that great , making trouble shooting a bit of a challenge. I found a few other 12 x 36 lathes that are very similar and being sold through other stores such as PM & Grizzly , I downloaded the manuals for those machines and saved them to my computer . Now I have an actual wiring diagram , maybe not exactly the same as mine but close .......... I can now see how it all works , there are three contactors , a thermal overload relay and a transformer to step down the voltage for the control circuits to 24 volts AC.
I'm not sure which of the components is at fault here but I am pretty close to finding out , I need some more time to poke around . I ordered two of the contactors off ebay . I think it's the thermal overload relay that is the root of the problem but I'm having a difficult time finding one that is exactly the same. Here's some pics of the electrical box.........







This is the drawing inside the door , it's a simplified view but is not real easy to follow.

 

[Be_Zero_Be]

It sounds like a loss of one of the phases.
I assume that the lathe will not run in forward or reverse.
If so, the overload is the likely problem.
I assume that you have pushed the red button on the overload to reset it.
If it still won't start, remove the overload fron the contactor and connect the motor directly to the contactor.
If it runs, the overload is bad.
The replacement does not have ot be physically exact.
So long as it is the right size with the right current range it should be fine.

 

[Gearhead88]

It sounds like a loss of one of the phases.
I assume that the lathe will not run in forward or reverse.
If so, the overload is the likely problem.
I assume that you have pushed the red button on the overload to reset it.
If it still won't start, remove the overload fron the contactor and connect the motor directly to the contactor.
If it runs, the overload is bad.
The replacement does not have ot be physically exact.
So long as it is the right size with the right current range it should be fine.

Thank's
It will not run in forward or reverse , I'm with you on the " the overload is bad " comment .
Due to this machine being close to twenty years old , I'm ok with the replacement motor I ****** away $ 360 on , I'm also ok with having a couple of spare parts on the shelf . I have two of the contactors coming , new , on ebay , they are less than $30 each for the exact same part as what the machine came with . I've looked for the overload relay , have not had success finding an exact match , the one I have now has a setting range of 8.5 - 12.5 A. I've found similar ones but not exact and if I order one it's probably gonna be on a slow boat from China .

 

[Gearhead88]

The Stand I'm building is similar to images others I've found while searching , here's a couple of examples .................

 

[Firstram]

Awesome, looking forward to updates!

 

[Z2V]

That sucks $360 bad. Have you removed the covers of the contactors and checked the contacts. After 20 years they might be a bit toasty. Remove the power first!! You have ordered new contactors but you might just need the physical contacts. Just a thought

 

[Gearhead88]

That sucks $360 bad. Have you removed the covers of the contactors and checked the contacts. After 20 years they might be a bit toasty. Remove the power first!! You have ordered new contactors but you might just need the physical contacts. Just a thought

I haven't looked inside any of the contactors , what I did notice is there is some arcing inside the one in the middle when you energize it , I believe that one is for forward , the one to it's left , I believe is reverse , it also has the overload relay connected to it , the one to the right of center gives a solid click when you power up the lathe. There isn't a power switch on the control panel , I use the circuit breaker in the sub panel in my garage and I unplug the lathe when I'm not using it too , there's only one 220 outlet in my garage so whatever runs 220 is plugged in when I'm using it , my little knee mill , the lathe or my welder. I added a 110 volt outlet on the side of the lathe back when I first got it , for a work light ,this lathe didn't come wired for a work light or coolant system , if anyone is wondering why I have three wires and the ground coming on the supply line . This lathe has been discontinued and then updated to a different model by the distributor here , that model has provision for an optional brake , a work light and a coolant system. Funny thing is , I looked online for the manual , found it and there isn't a wiring diagram included in that manual , the manual is the same crappy version that was included with my lathe. Here's a picture of the control panel . Also , what is a pain in the arse is I don't have room to stand behind the machine to work on it , I've bolted it down to the floor and it's close to the wall , repairs are a bit inconvenient to make happen.

 

[Z2V]

The arching could be the root of your problem. They arch, they burn and pit and don’t make good connection. The repair sounds like a challenge being up against the wall. Mine is the same way.
Good luck

 

[Gearhead88]

The arching could be the root of your problem. They arch, they burn and pit and don’t make good connection. The repair sounds like a challenge being up against the wall. Mine is the same way.
Good luck

I may just unbolt it and move it out a bit , it's one thing to stick your hand with an I phone back there to take a pic , a whole different matter getting in there to tinker with wiring .