Quill Rod

[sgkent]

Have a Craftsman 536.797430 lawn edger. Quill has broken again. This will be the 2nd time it has been welded. Hate to get rid of it because it works perfect otherwise. The quill is the part that holds the blade, It has a shaft thru two bearings and some nuts and bolts. The original part number was a mtd part I think, 338070 which became 740039. Both are NLA. Fleabay doesn't have any. Unfortunately over the years threw the broken ones away so no spares either. Anyone have a good one out there or know a new part number cause I can't find one. I attached a photo online of the later part number.

 

[bertsmobile1]

The quill is wrought
A weld is a casting
inch for inch the casting at best will be 1.2 as strong as the wrought rod the quill was made from
Welding is OK to build up a work spot , repair a broken out key way and occasionally a thread .
But if the shaft has broken then then welding is not the answer .. replacement is the only option .

 

[sgkent]

The safety shield bolts to the plate. The plate eventually succumbs to the vibration breaks off the tube that holds the bearings. If I could find a new one I would buy it. They come from the factory with one small weld between the plate and tube. This one broke there about five to seven years ago, a professional welder made 3 welds and they all finally failed. There is too much mass in the shield and it vibrates and wobbles during edging. I am pretty sure it is was a high failure item because the part used to be readily available then it upgraded to a cheaper made part then it went NLA. This quill has a bend in the shaft, the new ones are shorter and less massive, which probably cuts the vibration down but I have no idea if they can be made to fit. This is like a 1997 model. I called my go to weld guy today but he has retired so I have a call into another welder I know. Hopefully he'll take the job. Most of the good welders around here don't want to be bothered with small jobs like this. I've already cleaned it up for whomever welds it.

 

[bertsmobile1]

Grind the old welds off
Get a machine shop ( or friend ) to make a flanged boss
Weld the boss to the quill and bolt the plate to the boss
In my shop the flanged boss would be a sleeve of heavy walled tube with an old blade welded to it
So it would like like a bar blade boss on steroids
then if it needs to be removed I would bolt the backing plate to it or weld the backing plate to the old blade if it did not have to be removed
Doing a butt weld thin sheet to tube is never a good idea
I make a lot of stuff from old bar blades & am seriously thinking about getting a small charcoal forge as I end up with a lot of them and the foundry I used to sell then to has now closed down because their two major clients have outsourced to China and they also lost the car parts when Ford & GM closed their Aust plants
Where is the new Pontiac coming from ?

 

[sgkent]

found my good welder guy I used before his dad retired. He has his own shop now - 25 miles away but it is what it is. Just wish I could find someone with some of these new or used. The old part 338070ma lasted a long time before it broke. The replacement part 740039ma has more wobble in it. Can't change the past but I sure wish I had hung onto the old parts to repair them.

 

[sgkent]

the quill housing has been welded. I've ordered a new shaft that I think will fit. The measurements seem the same and it is coming from a mower shop that took the measurements. Will know in a couple days. In the meantime I am keeping my eyes open for a new or used quill, or a broken edger cheap enough to pull one from.

 

[sgkent]

shaft came in, perfect fit except the woodruff key is deeper so I have to find one. It is a standard 1/8 key and McMasterCarr has them but only in a package of 100. Will have to hit the local hardware store tomorrow. Maybe take recycled aluminum and copper on the same trip. Have been putting it off.

 

[sgkent]

weld done, used demel to clean up for bearing, pressed new bearings and new shaft in. Had to get a slightly taller woodruff key and trim it, Reassembled and tested. Just like new. Will keep an eye open for a spare quill. Makes edging so fast. Project complete.