The Red Fox

would be a cool end

I've decided to bolt the frame together, for ease of maintenance. The rails are thick enough to tap for bolts, so I shouldn't need many lock nuts

how big will the bolts be? Do you think i could do that with mine too?

I'm gonna be using a lot of the original mtd bolts... mostly 5/16 16 tpi.

whether or not YOU can do it this way depends on the thickness of your steel, and the # of threads per inch. A good rule of thumb is you need at least 3 threads in the hole. so if you tried 1/8, with a coarse 16 threads per inch, you would only get about 1 and 1/2 threads... not enough. fine thread, like 32 tpi will work fine.I just oversize the hole and use a nut for thin stuff... but with thick plate or beams, threading the hole means one less fastener (nut) and no need for a second wrench to hold the nut.

here's the update vid, Featuring my older peacock about halfway through, he strutted though like a boss


BTW, for a sense of scale, his tail feathers are 4 feet long

o ok, thanks

I like your rod oven. Im gona have to come up with something like that at some point too.

I posted that specifically for the stick welders among us... a candy thermometer stuck through the door and a dimmer switch will allow you to control the temp

Aintchya done yet lawren?

GRRR... That's my line!

Yea Aintcha done yet lawren? lol

The Question has come up as to the top speed of the red fox when completed. Here's what the math says:

max rpm for the onan is 3900 rpm. Final drive ratio on the rear axle is roughly 3 to 1

1st gear for the ford 4 speed is roughly 3.65 to one... top speed with 14 inch tires is

(3900 / 3.65) / 3= roughly 356 rpm's at the rear wheel. That = 2 (feet diameter) x (PI) 3.14= 6.28 (circumference) x rpm's

6.28 x 356 = 2235.68 feet per minute

now to convert it to hour, multiply that by 60 minutes

2235.68 x 60 =134140
now convert to miles per hour, divide 134240 by 5280 = 25.4 MPH

in first gear

4th gear is easy

3900/3 = 1300 rpm at the rear wheel
1300x6.28 circumference= 8164 feet per minute
x 60 minutes = 489840 feet per hour / by 5280 feet in a mile = 92.777 MPH

Thing is, this is math... an ideal world
in reality, the onan may not be able to achieve 3900 rpm pulling the heavy fox, there will be drivetrain losses in power, tires may not be EXACTLY 24 inches... etc
Math says it's possible, experience says it aint likely... I'll be happy if I can hit 50, so I can reasonably drive it on the road.

I really think you're going to want to gear that down by a factor of at LEAST 2. Now... How will you be connecting the engine to the transmission? That's a potential reduction point right there. 25 MPH in first gear suggests to me that you're going to have a tough time in low gear manoeuvring in tight spots or yanking a load. Since idle is typically about 1200RPM at the lowest, that suggests a maximum wheel speed of of about 8MPH right at idle. This is too high, IMO. Kiss whatever clutch bye-bye.

Idle speed on the onan is 1000 rpm ungoverned. (per the onan manual) I'm keeping the actual automotive type clutch in the tranny, and bolting a flywheel to the back of the motor. The stock 9 inch clutch was designed for a much heavier vehicle, so I doubt there will be a problem there. I agree that I want to gear it down, I don't EVER want to go that fast in a claptrap rig like this. I'm not sure how to gear it down further without a gear reduction behind the tranny, or a different rear diff. I would LOVE to find an old courier axle, with 4.55 to one rear... that would be ideal, but I mat have to get a vw bus gear reduction unit and mate it to the tranny output shaft.

Smaller tires would help, but if I go too small, it wont look right. Ive seen folks use auto parts to make a tractor, but not many using tractor parts to make a TRUCK. It ought to be interesting no matter how it turns out. I'd like to be able to use the cast iron 1200 that moose is sending me, I'd need to lengthen the axles and housing, but it would give me a lot more reasonable gearing. If I need to, I can ditch the stock clutch, cut away the bell housing, and run belt and pulley reduction from the motor to the tranny.

In all honesty, I'll probably just put it together, test it, THEN see how I need to mod it.

Ahh- I didn't realize you were using a (superior) disc-type clutch. I can't argue that it's better, but it does kill the possibility for reduction there.

Interesting that the Onan idles so low, idle spec on most OPE engines start at 1200 and go up from there.

genny standard is 1200... when on a tractor, the specs called for 1000

I think the disc clutch and flywheel is gonna make or break this build... Slipping the clutch will allow it to pull the higher gears, particularly since the Fox is much lighter than the vehicle it was designed for... Light for a car, but dang heavy for a lawn tractor. Almost every piece of the original tractor will be present in the final product... just reshaped, and repurposed.

Whoa, no way you can trail with that gearing. Max speed is around 4 mph in first on ours, and many times we idle first gear. You could belt drive the drive shaft, from the transmission, for an easy reduction.

Not done yet Lawren, and ya starting on speed calculations      

hey TD, someone asked... Seems someone ELSE posted sumthin about 92 MPH too... Without bein done



yeah stretch, I know, and agree. Gonna have to work the gearing angle. I may be able to incorporate a gear reduction in the ragb going into the rear axle... an additional 3 to one there would help a LOT. Right now, the drivetrain is geared almost identical to the average passenger car... I need some lower gears for trail riding. something like the High Low on a 4x4 tranny...hmm..

Depending on what transmission you have, you can swap out the tailhousing and bolt on a transfer case. Nothing says you have to hook up the front output on it. That would solve the low range, and still have high range for driving.

Many transmissions and transfer cases bolt together, junkyard is probably full of them. Maybe one out of a Geo tracker, they have transfercases, and lightweight transmissions.

yeah, that was the HMM thought at the end... could always add a front drive later then too

I love how you and TD bicker like the grumpy old men... makes me feel young again  bahaha

mrkadage wrote:

I love how you and TD bicker like the grumpy old men... makes me feel young again  bahaha

I don't bicker, I'm just pointing out facts in a weird way   

He cant help it. His last name is Bickerson. It comes from eating too much Lutefisk as a young man. That'll sour anyone's disposition!

I HAVE managed to get the frame rails mocked up and start the drilling process for the holes... I have been steadily working between rains to remove the rear axle for placement of the spring hangers. The cast steel front axle beam needs to be sectioned, and a foot taken out of the middle, as well as a rebuild /rework of the spindles

well, I did some more work on the golf cart axle, found some numbers, and found that the rear axle has a

13 to one ratio on these 'lectric jobs

here's what it looks like INSIDE



this changes the speeds for 1st to around a quarter of the first estimate... much more lawn tractor speeds.

I still have a problem with converting from side input (splined input shaft) to 90 degree shaft input. Finding the correct RAGB for that particular task is gonna be fun!

I AM gonna fill the diff carrier with lead, alla old timey locker (like Mainmudmowers zinc locker) just to show it will work. The diff carrier in this axle is similar to the MTD FNR tranny's, and has c clips. I'm thinking about using the old FNR as a right angle gearbox... I'll have to play with that idea for a bit.

Yook off the electric motor and SURPRISE!   

MY variant does NOT have a shaft, it has a helical gear on the MOTOR shaft. GRRR! so I'm going to have to cast an aluminum carrier for a homemade right angle gearbox using the gears from the MTD FNR to drive the helical input gear

On the plus side, I have springs, shackles, axle, shocks, anti sway bar, and dual mechanical drum brakes... it may be worth the effort.