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How to rig Okamoto 820

mzh

Plastic
Joined
May 1, 2019
We just purchased an Okamoto 820 surface grinder and was wondering two things:

1 - Do you have recommendations for rigging and securing the grinder for moving? I am probably going to hire a rigging firm that I have used in the past to move it. With that said, I'd like to have as much information as possible prior to moving it.

2 - Do operator / parts manuals exist for these machines? I've attached the photo that the seller provided as reference.

okamoto.jpg

Thanks in advance for you help.

Mark
 
Got one just like that, a great grinder! I believe I got the manual from Okamoto. Can't remember how much, I don't recall being in shock over it so probably not too much.
 
Got one just like that, a great grinder! I believe I got the manual from Okamoto. Can't remember how much, I don't recall being in shock over it so probably not too much.

Does the manual specify lifting points for moving?
 
The four rubber caps on the left and right sides can be removed to install lifting bars for lifting with a crane or you can lift from the bottom with a fork lift.

There were shipping clamps supplied with the machine to prevent the the saddle and table from sliding during transport. The saddle clamp will still be on the machine. It is used for locking the saddle when grinding a shoulder. The table clamp is only used for shipping.
The table and saddle are held on to the base by gravity, There needs to be a strap to prevent the table from lifting up when going over a pot hole. This will require removing the splash guards.

Or one could hold the table in place with threaded rods attached to a shipping pallet. If it is a short move the shipping pallet is not needed. You need to drive slowly and remember that the table wants to leave the grinder. There is only room for one tight hold down strap between the table and column. One strap will work if there are blocks of wood nailed to the truck bed to prevent the grinder frame from sliding during truck starts and stops.

You should have a minimum of two straps coming off at 20 degree angles to safely secure the grinder to the truck bed. There is no way to do this effectively with this frame.

The alternative is to use chains instead of straps. The chains can be fed through the lifting holes on the frame and will provide a secure hold down to the truck bed. They will also chip the paint unless a rubber sleeve is used.

The holes are 2 1/4 " in diameter on the 1224 grinder. I do not know what the diameter is on the 820 grinder. The chain can be installed by placing a 3 ft long 2 " diameter PVC pipe in the lifting holes and then pulling the chain through with a wire.

The third method is to install a pair of 2" diameter 3ft long lifting bars and then wrap the two tie down straps around the bars and frame.

The hydraulic oil will slosh out of the four lifting holes during transport. You need to either empty the oil or plug the holes. You were planing on changing the oil anyway. You might as well empty the oil before the move.

The grinding spindle casting needs to be supported on a wood block to prevent damage to the lead screw and ways. The grinding wheel should be removed from the spindle to prevent damage to the spindle bearings during transport.

The grinder was supplied with lead feet that were fitted to the four leveling screws.
 
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Hello MZH:
My memory of what I did wrong on the Okamoto move has improved a bit.

When you load the grinder on the truck bed with a forklift the grinder is placed on two 4x4 wood standoffs to allow the forks to slide out. It is difficult to nail the 4x4's to the truck bed. My solution involved nailing a stack of 2x4's one on top of the other to obtain sufficient height to prevent the grinder from sliding off the 4x4's This arrangement does not holdup well on a rough road or a sudden stop. That is why I recommended using chains passing through the lifting holes for hold downs.

The forklift forks need to be close together to allow the grinder to be placed on the 4x4's at the edge of the base. The lift needs to be done slowly to avoid having the grinder tip over. A rope securing the grinder to the forklift mast is good insurance against a spill.

It is tempting to just use two straps on the grinder frame. One is placed between the column and saddle. The other is placed on the front of the saddle. The straps are pulled straight down by the strap winches. The first strap works well. The second strap on the saddle will cause the saddle to rock and lift off the ways when tightened. This strap can be made snug but it cannot be tightened as normal without damaging the grinder. The saddle strap will not be effective in holding the grinder in place on the truck bed.

The grinder table is held down by the spindle casting which is resting on a wood block. If you have the table clamp installed or there is oil in the hydraulic cylinder the table cannot slide. Additional straps on the table are not needed. The wings on the table are aluminum castings held onto the center cast iron section with two bolts. Putting a tie down load on the aluminum wings may cause them to break.

The table clamp is a rectangular plate with a slot and two holes. The slot engages one of the table stop dog rail standoffs. The two holes match the threaded holes on the left side of the saddle.

The saddle uses a ball screw. To prevent damage to the screw during the move the saddle clamp on the left side of the grinder needs to be tightened down.

The bolts holding the left and right hand magnetic chuck clamps also need to be checked. The accepted practice is to tighten firmly only one of the bolts to allow for thermal expansion of the chuck. When moving the grinder both bolts should be tightened down.

The grinder was sold with a blue tool box. Maybe 8"x10"x3" in size. The box will have the table hold down clamp, the wheel adapter wrench, a wheel adapter puller nut, the base adjusting screw wrench and maybe the lead feed for the adjusting screws.

Ask the seller if he has the balancing arbor for the grinder's wheel adapter.
 
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Thanks again

The seller didn't think his forklift was capable of the job so I hired a rigging company to move it. Got the machine in the shop yesterday, contacted Okamoto for a operators manual and they emailed my in under 10 minutes. I'm now trying to figure out the spindle assembly. He didn't have the puller and it looks like some of the other parts are not there either.

With that said, it's in great condition and I just need to figure out if I can get the wheel adaptors and puller from okamoto. Will try to snap a few picks and post in the next few days.
 
Another question - What is the small valve to the lower left of the vertical feed wheel?
20190618_092402.jpg

And here is a photo of the entire machine. Did a test run on Friday and all seems to be running well. Still need to test the fine feed.
20190618_092411.jpg
 
Another question - What is the small valve to the lower left of the vertical feed wheel?

The grinder has a automatic down feed operating mode. The amount of down feed for both manual and automatic operation is controlled by a small screw on the right of the hand wheel casting. The throttle valve on the lower left of the casting controls how fast the oil fills the piston which increments the down feed in the automatic mode. I penciled in a note in my manual years ago for the location of the valve in the hydraulic circuit diagram. The manual does not describe how the valve should be adjusted. Experiment and find out what best works for you.

You are missing the vacuum suction attachment that connects to the 2" diameter pipe on top of the wheel housing. A large wet operation vacuum cleaner should work as a substitute. It will not be as quit as the original 3600 RPM suction fan.

The aluminum table wings will act as expendable anodes for the cast iron table if you do not maintain the proper coolant concentration.

Try removing the diamond from the over the wheel dresser and coating it with anti seize compound. The diamond mount wants to do a permanent rust bond with the holder.

The underside of the magnetic chuck may need a bit of cleaning. See the previous posts on this forum on what to do.

There may be a compatibility problem with the way-hydraulic oil and the use of a full synthetic coolant. See the earlier posts on the use of Mobile Vacuoline and Mobile Vactra 1 ISO 32 oil

Remove the four socket head bolts that hold the plastic cap in place on the top of the column. Verify that the oil sump is clean and the oil wicks for the ways are in place. Remember to wait for the oil to fill the sight glass on the sump before moving the saddle or table.

Robert
 
If it's not a sore point, could you please elaborate?

I moved the Okamoto with the oil remaining in the base using two tie down straps with the base sitting on two 4"X4" X 4ft wood standoffs. There were nailed wood blocks to prevent the grinder from sliding.

This worked while driving on the highway. By the time I arrived at my access road the wood blocks and truck bed were soaked in oil. The oil had sloshed out of the four lifting holes even though they had plastic caps and were sealed with tape.

The access road is steep. rough and is 7 miles long.
The grinder was still on the truck bed when I arrived at the front gate. However the nailed blocks had pulled out and the grinder had slid 12 inches off the 4X4 's. No harm done.

The forces acting on the grinder while on a rough road at 5 miles/hour are not as severe as what would occur in traveling at highway speeds and being forced to brake quickly. That is why I recommended chains and emptying the oil from the base of the grinder.
 








 
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