motor pan and belt cover issue

[terrydowning]

I have a 1955 Mark V with an A head stock.

These models did not come with tiinnerman clips for fastening the screws that secure the belt cover and motor pan. Just tapped aluminum. Unfortunately after almost 60 yrs of regular removal for lubrication and maintenance some of the holes have become stripped. I have drilled and re-tapped by going up a size but these holes are now starting to strip as well and I don't think there is enough meat left to tap up another size and have any kind of lasting improvement. I have heard of the tinnerman (speed clips) on other models but have never actually seen them installed. Can someone post a pic of the tinnerman clips It may be time for me to use tinnerman clips to secure the belt cover and motor pan.

If there are other suggestions for better securing the belt cover and motor pan I'd love to hear them. Preferably something that removes quickly. Unscrewing all those screws every 10 hrs of operation is becoming a real "labor of love" (PITA).

P.S. I'm not interested in drilling the access hole. I have large hands and they're not going to fit the hole that will fit under the existing medallion. I also want to keep the original medallion installed.

[dusty]

If I had your task, I would first fill in the existing holes with JBweld and then redrill as required for the tinnerman clips.

There are several different kinds of clips that could be used. I don't know if all of them go by the name tinnerman or not but they all do essentially the same thing. They replace or eliminate the need for threads in thin materials.

I would use the style shown on the right in the first two images.

[ATTACH]20674[/ATTACH]

[ATTACH]20675[/ATTACH]

[ATTACH]20676[/ATTACH]

[terrydowning]

Are those the SS version?

I'm thinking about those 1/4 turn fasteners as a possibility.

Please include screw size, and clip size as well.

[dusty]

Are those the SS version?

I'm thinking about those 1/4 turn fasteners as a possibility.

Please include screw size, and clip size as well.

No. These are clips in my parts bins that have been collected over the many years. The clips that are on my Mark V are like the ones shown in the center.

The screws that are used on my Mark V are sheet metal screws (I don't know what size). The clip that I would use mate with machine screws (have a threaded receptacle).

[dusty]

Are those the SS version?

I'm thinking about those 1/4 turn fasteners as a possibility.

Please include screw size, and clip size as well.

The use of 1/4 turn panel fasteners is more work than I want. We used them a lot in airborne communications gear. They work but they are a lot of work both to install and to maintain.

Here is a catalog that shows some of what I envision when you say 1/4 turn fasteners. It takes a while to load.

[billmayo]

If I had your task, I would first fill in the existing holes with JBweld and then redrill as required for the tinnerman clips.

There are several different kinds of clips that could be used. I don't know if all of them go by the name tinnerman or not but they all do essentially the same thing. They replace or eliminate the need for threads in thin materials.

I would use the style shown on the right in the first two images.

[ATTACH]20674[/ATTACH]

[ATTACH]20675[/ATTACH]

[ATTACH]20676[/ATTACH]

I drill the "A" heastock motor pan and belt cover holes with a #10 drill and use the tinnerman clips. The motor pan will not fit snuggly againest the headstock but is close enough.

[billmayo]

If I had your task, I would first fill in the existing holes with JBweld and then redrill as required for the tinnerman clips.

There are several different kinds of clips that could be used. I don't know if all of them go by the name tinnerman or not but they all do essentially the same thing. They replace or eliminate the need for threads in thin materials.

I would use the style shown on the right in the first two images.

[ATTACH]20674[/ATTACH]

[ATTACH]20675[/ATTACH]

[ATTACH]20676[/ATTACH]

I drill the "A" heastock motor pan and belt cover holes with a #12 drill and use the tinnerman clips. The motor pan will not fit snuggly againest the headstock but is close enough. I use #10 SS screws on all headstocks.

[allsas]

Trouble w/Timmermann nuts is that they get knocked off, down into the motor pan. Recovery is difficult and IF you can (the wires to the switch) tilt the pan, the items don't slide out of the motor pan. They can't be fished out with a magnet because of all the other metal in the pan/motor.

Consider JB weldingcrown nuts to the casting and using machine screws. There is enough room for a end of the machine screw - ie the pointed tip of the pan head screw. The crown washer on the nut holds the nut while it hardens and allows you to center the nut in the hole. The Motor Pan should fit flush because the nut is welded to the inside of the casting. The crown nuts should be available in hardware stores.

You won't have the convenience of the point of the pan head screw, but the hole in the casting will help orient the machine screw to the nut. You need the length of the screw ( now the machine screw ) to start pulling the motor pan to the casting. You may have to leave on side loose and start the other side before the gap on the second side needs too much pressure to start the machine screw.

From, newby at the time, who has lost timmerman nuts in the motor pan for MONTHS and found collections in the bottom of motor pans.

[dusty]

Trouble w/Timmermann nuts is that they get knocked off, down into the motor pan. Recovery is difficult and IF you can (the wires to the switch) tilt the pan, the items don't slide out of the motor pan. They can't be fished out with a magnet because of all the other metal in the pan/motor.

Consider JB weldingcrown nuts to the casting and using machine screws. There is enough room for a end of the machine screw - ie the pointed tip of the pan head screw. The crown washer on the nut holds the nut while it hardens and allows you to center the nut in the hole. The Motor Pan should fit flush because the nut is welded to the inside of the casting.

You won't have the convenience of the point of the pan head screw, but the hole in the casting will help orient the machine screw to the nut. You need the length of the screw ( now the machine screw ) to start pulling the motor pan to the casting. You may have to leave on side loose and start the other side before the gap on the second side needs too much pressure to start the machine screw.

From, newby at the time, who has lost timmerman nuts in the motor pan for MONTHS and found collections in the bottom of motor pans.

Hmmmm, JBWeld again. Thanks for the idea, allsas. I'm going to consider JBWeld on the tinnermans the next time I have a lose one. You know, the size of the tinnerman that you use is a function of intended screw size and the thickness of the material to which the tinnerman is attached. You also know that after a tinnerman has been in place for a few years, it loses its spring tension and normal maintenance procedures call for "replacement".

JBWeld just may be a reasonable substitute for good maintenance practice.

[terrydowning]

Trouble w/Timmermann nuts is that they get knocked off, down into the motor pan. Recovery is difficult and IF you can (the wires to the switch) tilt the pan, the items don't slide out of the motor pan. They can't be fished out with a magnet because of all the other metal in the pan/motor.

Consider JB weldingcrown nuts to the casting and using machine screws. There is enough room for a end of the machine screw - ie the pointed tip of the pan head screw. The crown washer on the nut holds the nut while it hardens and allows you to center the nut in the hole. The Motor Pan should fit flush because the nut is welded to the inside of the casting. The crown nuts should be available in hardware stores.

You won't have the convenience of the point of the pan head screw, but the hole in the casting will help orient the machine screw to the nut. You need the length of the screw ( now the machine screw ) to start pulling the motor pan to the casting. You may have to leave on side loose and start the other side before the gap on the second side needs too much pressure to start the machine screw.

From, newby at the time, who has lost timmerman nuts in the motor pan for MONTHS and found collections in the bottom of motor pans.

This is one of the options I have been considering mentally. I've heard of the tinnermans on here and I'm looking for options and opinions.

IMO as the OP this is a brain storming session and nothing is off limits. I have a problem that others may/will have or have already conquered Thanks for your input. For those that conquered, what are your solutions??