Planer blade and gib bolt help

[Sam Layton]

I was wondering if anyone has this problem with their planer. I have a General 130, 14" planer. I have never changed the knives. I purchased the planer new. I removed one knife, and no problem. When I tried to remove the second knife, the gib bolts were really tight. On about 4 gib bolts, some of the threads were fragmented. Little portions of the threads were broken upon removing them.

I was just wondering if anyone has had this problem with their planer. Also, where can I find new gib bolts?

I really appreciate any help, Sam

[Tom Davis]

Sam -

I habve the same planer and I purchased the screws from General. Looking at the parts schematic, it says that these are 1-1/4" X 1/2" screws, so they may be easily found locally. I have not had the problem that you describe.

Tom

[Mel Fulks]

Sam,I used a good number of machines and seen that only once. It was a planer that had its own knife grinder and was bought used by a friend .Right or wrong ,I blamed it on grit getting into the threads. We had no trouble finding new ones from local hardware but they were just a little too long and needed a little grinding .

[John TenEyck]

If/when you buy new bolts, it would be good to buy high quality ones, like Grade 8 or something similar. You don't want a bolt failure in that application.

John

[Sam Layton]

Thank you everyone for your response.

Tom, I will call General on Monday and see if I can order new bolts. Tom, what type of knives are you using, and where do you get them?

Mel, yesterday I found bolts from a local screw and bolt place. However, they were to long as well. Before I grind them I am going to continue to look.

John, good point regarding the grade. In most structural things I always look for grade 5 or 8 depending on the application. However, it this situation I did not even think of that.

Thanks again everyone for your input, Sam

[Bruce Wrenn]

Put some anti-seeze on the threads of the bolts. Makes them a lot easier to go in and more importantly, get out later. You might want to take a bottoming tap and clean out holes.

[Ronald Blue]

I am guessing these are allen head style bolts. If so they are automatically grade 9. They are alloy steel and stronger then the same size hex head. If i understand your description correctly sections of thread were broken on the bolts you removed. That sounds like a cheap bolt that the heat treating made the threads brittle. Look for a quality brand like Holo-Krome. Good luck.

[pat warner]

Don't wanna be grinding set screws.
Their (probably cup points in your case) ends need to be used as punched. SO get the right length from the get go.

[Mel Fulks]

The ones that I had to grind were evidently a proprietary special size as catalogs do not list them. Only removed a little metal and I don't consider gib bolts high stress . I believe the ones we replaced were original. Hope you can get the right size without special order.

[Mel Fulks]

Sam ,I just reread your post .The proper way to change knives is to remove and replace one knife before removing another one. Cutter heads are distorted slightly by the knives. Since you had no problem with the first knife I'm wondering if that distortion could have put more stress on the second set of bolts. For example ,a four knife moulder head with close tolerances will sometimes not slip on to the spindle if only two knives are being used unless two blanks are used in the other spots to equalize the stress. If you have all of the knives out I would put all the new ones in with lightly tightened bolts then tighten the two center bolts on one knife ,the two center bolts on second,and third . Then the next two centermost all around .And so on. Then check all bolts all around. But regardless of what the problem turns out to be,next time just remove and replace one at a time.

[Sam Layton]

Bruce, that is a good idea regarding the anti seeze. I did purchase a tap to clean things up.

Ronald, they are square head bolts, 1/4 x 20. You are correct, as I removed them the threads were fragmented, and, or chiped away. The bolts are the origional ones form General.

Pat, I agree regarding the grinding. I will try to find the correct one. Monday I am going to call General. They are not cup pointed. The pressure is against the square head when they are tightened.

Mel, I removed only one knife, cleaned things up, and reset the knife. All was fine. All of the gib bolts were in new condition. When I removed the second knife, is when I had the poblem. On 1 bolt, I tried to loosen it, and it would not unscrew. With a little more pressure it did unscrew. However, many of the threads were broken, and jamed against the gib threads. Upon getting the bolt out, it looked like the threads were very brittle and broken. I think 3 others were framented a little, like maybe one or two threads had chips in them. I have heard about not removing all of the knives at the same time. I have not removed the third knife yet, because I want to get the second one in first. I decided not to reset the knives. I ordered new ones and hopefully they will arrived next week. I now need to get the proper gib bolts.

Thanks everyone for your help. I really appreciate it. Sam

[joe maday]

I would get a new set of gib bolts from general or a parts supplier like ereplacement, other planers might use the same or similar gib bolt. I would not use a regular macine bolt because the heads on gib bolts (at least ones on the machines I have are slightly domed, to create a snigle point of contact. This stops the bolt from moving the gib from side to side as it is tightened. If need be you could cut down a longer bolt, but only if it is a gib bolt of the same thread diameter. addionally some gib bolts have different thickness of heads, some thinner for more clearence and some are thicker to provide a stonger "purchase" on the gib. Patience is needed to get the right bolts. Clean up the threads on the original bolts and cutterhead make sure nothing is left to gall the threads and like above posts use anti-seize (sparingly).

[Bob Wingard]

One method I used a long time ago ... since the gibs tighten in reverse, and push the blade into tightness, I took a handful of 1/4"-20 setscrews ... screwed them into the threaded holes in the gibs until they JUST broke the back plane ... stone or file away any excess that peeks out the back of the gib and Loctite them all in place. Set the knife and newly prepared gib in place, and measure/mark all of the setscrews. Trim them until they are JUST long enough to let the pieces slip into place. Thread either square nuts or heavy nuts onto the studs several turns ... slip everything into place ... start the normal tightening sequence, only now, you are turning the nut ... NOT the screw ... the screw is stationary and Loctited in place. In this scenario, the threads in the gibs and the threads of the screw that are engaged in the gibs are never at risk of wearing or strippng ... AND ... you will ALWAYS have full engagement of threads between those two pieces ... the ONLY part that can ever wear is the nut, which is easily replaced.

[Sam Layton]

Joe, Thank you for the information on the bolts. I called General today, but they were closed. I will call them first thing in the morning.

Bob, Thank you for the information as well. If General does not come through, and I can't find the correct bolts, that sounds like a very good idea.

Thanks again, Sam

[Steven Satur]

Hey Sam, I was looking at those planers for years but the price kept creeping up until it was out of the ball park. I would not put anything on the bolts. You want then tight, that is just my opinion. As for General being closed today, you do know they are closed up in Canada the last I heard, General Canada is done which is a shame. Good luck with them helping you.

Steve

[John Lifer]

If you can get from general. And they won't be grade 8 or 9 they are usually much softer than that. You want the head to deform and bolt should be softer than the knife

[Bob Wingard]

bolt should be softer than the knife

??? Most bolts will be softer than the knives ... what is the correlation there ???

[Sam Layton]

Steve, I have heard that General is closed. I called General International, and they had the gib bolts. I purchased new gibs and gib bolts. I also purchased a new gear box gasket to have it on hand.

Thanks everyone for your help. Luckily I was able to order the correct parts form General International.

Sam