how are made turbo collector fan and/or leaf vacuums fan?
Posted October 24, 2011 - 10:29 AM
I tried finding pictures of the impellers but had no luck so far.
Posted October 31, 2011 - 11:26 AM
This machine works quite well but the conception is really bad. Looks like it was assembled with a bunch of parts without ever thinking about maintenance, durability or useability. At least it does vacuum properly and DOES shred to small pieces.
I had to repair it a bit so I disassembled it completely.
Here is the "blower housing"... quite simple!
Even more simple is the impeller
So, nothing fancy about the conception and it does the work properly. Easy to copy and that's what I will do to be able of installing a similar vacuum behind my MF 1655 but PTO driven.
I hope it will help someone.
Edited by MacWorld, October 31, 2011 - 11:31 AM.
- Lovintractorin said thank you
Posted October 31, 2011 - 09:48 PM
Look at your furnace blower how it is designed, it is designed to move air. then look at your wife's vacuum cleaner and look at it impeller. A yard vacuum is about the same in design, but needs to be build properly or you will have part flying all over the place. Ouch
having a spiraling blades can help the air flow and things that are in the air flow. but they are hard to make out of steel. plastic impellers have to be hard for impact but also be flexible so that they come apart.
so I would save a lot of time a buy an impeller and make the housing.
remember that rocks and other things have mast and will break things, so make your bag or box the stand up to it.
to see several different design for impeller do a Google search for "impeller design"
Posted October 31, 2011 - 10:12 PM
Posted November 01, 2011 - 08:12 AM
I am not too much afraid of the balancing, worst case there is machines to do that. You might be aware that for performance gasoline car engine it's frequent to remove weight on the flywheel and balance it again. Those things are balanced for 8000 - 9000rpm. My guess is that this method would be fine for a small impeller.
As for plastic I doubt it would last long with small branches and rocks hitting it. Also, the concept of this impeller is so simple I can copy it pretty easily since I know how to weld and bend metal to shape.
The speed is quite easy to find if I copy the impeller and the housing on a scale ratio of 1:1... The same RPM as the 5hp engine! I simply have to find the RPM of this engine and use proper pulleys to adjust my PTO RPM to something near that.
Alc: the point of making a copy of it is to keep the current machine useable. I found it to be pretty efficient in removing leaf under my cedar hedge (I hope it's the right term) and mounted on the tractor I could not use it for this purpose.
I also do not want to have the loud 5hp engine running behind the tractor. I will get this thing running off my 1655's PTO. I will look at the possibility to make a "quick connect" to use the impeller and housing on the machine or on the tractor but I am afraid this would require major modifications and a complicated-for-nothing mechanism.
Posted November 01, 2011 - 11:17 AM
Posted November 02, 2011 - 08:00 AM
About how fast should it turn?
Almost all 4-cycle leaf vacuums and leaf blowers have the impeller attached directly to the engine crankshaft, so the impeller turns at engine speed. .....For best performance, the engine should run at 3600-3800 rpm, which is pretty much the maximum rpm the engine should run at for long life.
If you drive your impeller through the PTO, you will probably want to increase the rpm above the PTO speed to obtain good results. (I am not familiar with the PTO speed of your MF tractor.) .....If you are belt-driving the impeller from the PTO, you should be able to use pulley ratios to get the impeller rpm where you want it.
A properly-designed, larger impeller may operate satisfactorily at lower speeds, but impeller design requires considerable engineering. .....Strength of materials, inertia, and blade-tip speeds all need to be considered as well as balancing, which you are already aware.