Grading Broke an 1845 Mower Blade

[Charlie_Iliff]

Re: 1845 temperature

John:
Your experience was similar to mine <font color=red>full load on the mower, grass on a 90 degree day over the weekend and the temp gauge topped out at the highest number, 240 </font color=red>. So, this evening I gave it a test. I raised the deck to its highest level, left the finish blades on and hit a pasture with air temp at 90. I mowed for an hour and a half. With the deck high, it threw significantly less dust and shreds out the front, but enough so I had to wear a mask. After 1/2 hour, the temp was stable at about 220. From there, it gradually climbed until at the end of 1 1/2 hours it was at about 235. It didn't peg the needle. I have no doubt that I will find at least a little dust, etc, covering part of the cooler. Outside temp at end of the test was 88.
My problem is that it is a mile by road from where I keep the PT and do most of my mowing to the shop where we have a compressor. Oh, well, if I get another compressor, I'll be able to get an impact wrench and change blades at home, too.

 

[Sedgewood]

Charlie:

<font color=red>My machining skill is nil. We have a Grizzly vertical mill, but no bit that will put a one inch hole through the hardened blades. I'll have to get one. Anything special I should look for?</font color=red>
My machining skill isn't much more than nil. I'd be surprised if a drill wouldn't cut the blades. If not certainly carbide end mills would. You'll still have to step up incrementally to 1 inch just as you would with drill bits. I would put a stop on the vise so you can swap blades easily and do all the holes in one size before moving up to the next size. Its still just as many swaps but they are easier and quicker I find.

<font color=red>(We also have a huge old lathe, but haven't gotten someone knowledgable to help us mount the chuck so it runs true. It is a WW II vintage barrell making lathe with turret -- heavy.)</font color=red>
Wow. Just what I need to drill and tap a coupla holes in the ends of a 1-1/4 square bar. I picked up the other day a spring tooth cultivator I'm looking to make a grapple with for the small bucket. The cultivator springs mount on the square bar and if I drill & tap it for 3/4 bolts I'll have a pivot when bolted through a couple of brackets I'll mount on the bucket.

<font color=red>Mine hits 220-240 regularly. One time it pegged the needle, power wound down and it wouldn't take throttle. But no alarm went off. Although the Deutz book mentioned an alarm, I didn't know we actually had it. Mine obviously doesn't work. Do you know where it is located and wired?</font color=red>
It uses the same beeper as the oil pressure alarm. Seems to be triggered through a resistor on the temp guage if I read the schematic correctly. I have no idea where the thing actually is located. And I didn't hear it myself until I dismounted for another reason and then only faintly through my Pro Ears. Which were turned off. I turned them on briefly to see if I could hear it better and it disappeared entirely. At least I think so unless it stopped sounding because the temp had dropped by then. I wasn't paying enough attention to be sure. I was going to try it again later with the key on before starting the engine to see how the oil pressure alarm sounded but forgot to do it. It may be that the active suppression/compression of the Pro Ears blocks it.

These engine are running a tad hot in my estimation; I wonder if the air flow in the engine compartment is sufficient. And also I'm a bit surprised to be running at full load so much with the mower. My INT 484, which is I think about 40hp, hardly breaks a sweat with the five foot Bush Hog in full grown hay. Just what is a roughcut mower designed to cut anyway?

 

[Charlie_Iliff]

After 6 weeks of drought, our first good soaking rain hit just when I scheduled to test the Power Trac finish blades against my custom blades. I cut Gravely high-lift offset blades in half, and ruined a supposedly hard bi-metal hole saw trying to cut 1" holes. I took them to a pro, who did a beatiful job, but took almost two weeks and charged $80 for 12 blades. I guess I'll have to spring for a $50 one-inch bit if I want to stay in the blade modification business.
So, now I have 12 swiveling finish blades and plan to cut a few passes with the factory rigid set, and cut the next few with mine. It may be the weekend before I can manage it, however.

 

[Charlie_Iliff]

Re: 1845 Engine temp

Sedgewood: re your post <font color=red>BTW, I was out mowing tall, full load on the mower, grass on a 90 degree day over the weekend and the temp gauge topped out at the highest number, 240</font color=red>
I have now paid pretty close attention for three mowing sessions. The grass has nearly stopped growing, so my mowing is spaced out - finally.
With the finish blades, which throw more dist than the rough-cuts, I can mow in dry conditions for about an hour and a half, in outside temps up to 93, with the engine temperature at 200 to 220 (factory gauge). It gradually climbs. When it has gotten to 240, removing the oil cooler panel reveals about the front 20% to 33% of the cooler to have dust caked enough to restrict flow. Blowing it out solves the problem.
Since it requires backing out the two bolts and blowing out with an air hose, I have added a portable air tank to my list, that already has a rear carry rack rising to the top. I'm afreid to fill my old portable tank.

 

[Sedgewood]

Charlie: <font color=red>I cut Gravely high-lift offset blades in half, and ruined a supposedly hard bi-metal hole saw trying to cut 1" holes.</font color=red>

BTW, I was at Home Depot a coupla weeks ago and saw that they have universal blades in various sizes that come with a 1 inch hole and a collection of spacers.

Sean seems to have forgotten to send me the dozen spacers I so recklessly requested so I think I'll order up a length of that Aircraft Spruce thick wall you mentioned and make some.

 

[Charlie_Iliff]

<font color=red>"BTW, I was at Home Depot a coupla weeks ago and saw that they have universal blades in various sizes that come with a 1 inch hole and a collection of spacers.</font color=red>
When I looked at Home Depot, I didn't see any that looked adaptable. but I'll look again. Everything they had was about 1/8" thick, like the ones Power Trac cut up to make their finish blade set. The Gravely blades I got are 1/4" thick and hardened.

 

[duane]

Re: 1845 Engine temp

Charlie,

When you say that your guage hits 240, is that the engine oil temperature?. How high of an oil temperature (or the temperature that you are measuring) are you allowed to achieve prior to having to shut down

Duane

 

[Charlie_Iliff]

Re: 1845 Engine temp

Duane:
I haven't looked for the oil temp sensor, but the 240 is the top number on the scale. Once, I really cooked it, and got some strange performance - it was sluggish and wouldn't take throttle. I don't know what was going on, but there was no auto shutdown or alarm. Sedgewood says his has an alarm. I have a beep that sounds when the engine isn't running, but the switch on, which I assume is for oil pressure, but haven't heard it when it's hot.
The 240 is my shutdown point. The engine book is a bit unclear, since it doesn't reference the type of gauge that is on the PT. The PT book is pretty useless. But, as long as the gauge is working, I know to watch it and shut down before it cooks itself.