3pt. snowblower paddles.

[PILOON]

Jerry/MT;
A turbine is a whole lot higher RPM than a snow blower, i.e. 550 rpm!
A bird strike will totally demolish a turbine while stones and chunks of ice repeatidly tossed by a blower will show not even a slight wobble.
I, for one, strengthened my blower blades by adding 1/4" X 1.5" X about 6" welded to each fan blade as the origionals were mere 'heavy tin' so to speak.
I hacksawed each to the same pattern and stick welded those braces as close as possible to same locations.
Believe me the stick welding alone was enough to unbalance as access was not easy.
I fired her up and not the slightest indication of concerning vibrations, and I run my blower at 750 rpms.(shoots farther)
I also intend to close up my gaps and probably will simply weld extensions to the fan blades as they do indeed wear back some due to gravel and sand etc.
Heck my fan corners have nice radius wear corners, about 1" or so and I guess the blades are worn back to about a 3/8 gap.
I'd like tha to be a 'paper tin' gap!

 

[scesnick]

I'd like tha to be a 'paper tin' gap!

Speaking of the gap between fan blade and the housing, what distance would you guys suggest? The extensions you can buy can pobviously be put on with any gap the buyer would like.
Should they be put on and actually touching the housing ( since they are rubber they would just wear down accordingly.) or, should there still be a bit of a gap, say 1/16th or so. ??

 

[Jerry/MT]

Jerry/MT,.

I hear what your saying but the plastic lining in the housing just wears out too darn quick. I don't think the fan is moving fast enought o cause a major failure. From what I have read many many people have used this technics for years with no issues.
I would ultimately like to just replace the fan with a new one but my blower is an older model and to be honest I don't think Ber-Vac is evewn in business any longer.
I discussed the unbalance issue with the maker and he said he has never had an issue with it.

I do have feet on the blower but with 2.5 miles of uneven road it is next to impossible to not get gravel n the blower.

The maker of that kit has used a lash up for small snow blowers. If he breaks something on one of those, the weight of material is small and the kinetic energy is low. If you break something it'll be heavier and have a higher kinetic energy.
Use some conveyer belting material on the static structure to reduce the clearance between the fan tip and the casing or go to a fab shop and have them make a ring for you that you can insert (maybe in three peices). Just stay away from the rotating machinery.

By the way, Ber Vac is still in business. Rad technolies 1-800-338-1615 or radtec@radinter.com

 

[Jerry/MT]

Jerry/MT;
A turbine is a whole lot higher RPM than a snow blower, i.e. 550 rpm!
A bird strike will totally demolish a turbine while stones and chunks of ice repeatidly tossed by a blower will show not even a slight wobble.
I, for one, strengthened my blower blades by adding 1/4" X 1.5" X about 6" welded to each fan blade as the origionals were mere 'heavy tin' so to speak.
I hacksawed each to the same pattern and stick welded those braces as close as possible to same locations.
Believe me the stick welding alone was enough to unbalance as access was not easy.
I fired her up and not the slightest indication of concerning vibrations, and I run my blower at 750 rpms.(shoots farther)
I also intend to close up my gaps and probably will simply weld extensions to the fan blades as they do indeed wear back some due to gravel and sand etc.
Heck my fan corners have nice radius wear corners, about 1" or so and I guess the blades are worn back to about a 3/8 gap.
I'd like tha to be a 'paper tin' gap!

Most of the fans on a snow blower have step up gear boxes I believe. If that is so, the rpm of the fan is higher than the pto rpm.

"...while stones and chunks of ice repeatidly tossed by a blower will show not even a slight wobble." Believe me; if a blade comes off you'll know it.

Birds strikes on aircraft engine take out the fans that run at about 1200-1400fps tip speed at max power. The turbines are usually damaged by the resulting overtemperature. So yeah fans on airplane engines run at higher tip speeds than snowblower fans. My point is that the engine is designed to contain those failures. I doubt anybody has analyzed these modifications to see how capable the sructure is in those circumstanaces.

When you alter the fan you change the stresses that it is operating under and the material properties of the fan. Holes make for stress rises, unbalance adds a different stress distribution, and welding changes the material properties. Adding weight at the tip increases the root stress. Just because it hasn't broken or come apart yet doesn't mean it's a safe modification. All you can say is you're running an experiment and you have X hours of running time without a failure.

 

[scesnick]

Using the conveyor belt to line the housing is an option I did not think of.

 

[Scooby074]

Using the conveyor belt to line the housing is an option I did not think of.

id use uhmw in the housing and chute. its slick as snot

 

[TOMDUALLY]

I'd add your impeller extensions to regain your correct clearance, then I'd add a couple of skids to the bottom edge keep it up out of the rocks about an inch or so.

 

[Jerry/MT]

Using the conveyor belt to line the housing is an option I did not think of.

And it's a lot safer!

All you're trying to do is reduce clearance between the tip of the fan and the casing. if you halve the clearance that will be an improvement. What you use to hold it in place will probably dictate your achievable clearance. Depending on the belting thickness, you maybe able to use countersink fasteners.

 

[studor]

The amount of weight you are putting on the blower vanes is not enough to cause a serious out of balance condition. I too have a six foot Bervac and this spring it is due for a good sandblasting and repaint. I am sure that the blades are not in balance as it is, given the rocks it has eaten on my 1/4 mile drive
I used UMHW pieces on another blower I had as an experiment a few years ago and set the gap at a 1/4 inch from the nearest point -- worked like a charm. I plan to do the same thing to the Bervac.
Lining the housing strikes me as a bad idea since it would be tough to fasten the material to the housing properly versus bolting it to the blades. I do plan to use a slick paint on the housing and chute. JMHO