Drum Chipper RPM

[Greg Moore]

Anyone happen to know the actual drum (typical) RPM on a Asplundh style 12" chipper? I've searched and found a ton of engine RPM but that's kind of useless without the drive and driven pulley sizes. The one I'm fixing up used to have a Ford (owner said V6 but not possible given its age) but they swapped in a 305 Chevy without a governor.

I'll be setting it up with a governor and am quite happy running the engine anywhere from 2500-3500 so no issues there. The original pulleys give me about a 25% overdrive so I'm thinking 2800 at engine, 3500 at drum. I just want to make certain I'm reaching an efficient blade speed without launching the blades into the woods.

If you actually know what RPM your drum runs and have a similer machine, thanks in advance for your input!

 

[Knobby57]

I’ve seen lots of 300 in line fords in older chippers . They sure arnt a rever of a motor .

 

[Greg Moore]

No but their service RPM is between 2500 and 3200 depending on application. Most gas engines will run in that range as work engines.. I also found that almost all Hoof governors of that era were designed to run at 2800 ideally and usually were pullied 1:1 with the motor so unless I can dig up something elsewhere will target 2800 at the motor..

I also verified the owner isn't too smart.. He sold it as originally a V6 and a 12" chipper. Actually got the blades out this weekend and they didn't look 12".. It's a 16" and judging from some of the original bits and pieces was a V8 not V6 (which would have made the move to 305 easier).. Probably a 332 FE Ford as the chipper is late 50's to very early 60's

Guess no one knows the speed their drums run at

 

[Greg Moore]

Just in case someone finds this via a search I thought I'd post what I've found out.. In my case this girl is as old as the hills. I've been reading some patents and got most of this info from there. There's essentially 2 setups out there in drum style. One will have a smaller flywheel (20-22" diameter), a smaller pulley on the drum than is on the motor and probably no secondary fan on the shute. This is mine.. The normally newer ones will have a larger diameter flywheel, 24" up to 28", will have a helper blower on the shute and either equal pulley sizes (if diesel) or larger pulley on the drum than on the motor (gasers)..

The first typically older style like mine will be made to run 2500rpm to over 3000rpm at the drum.. Later on Asplundh patented a quieter chipper (Whisper) by increasing the flywheel size to allow the drum to run a lower RPM, typically 1500-1800 at the drum. They had to add the blower to help clear chips because at this speed the chips didn't travel fast enough off the blades to make the trip up and out the shute into the back of the truck.

For me it means I want to turn a little under 3000rpm at the drum.. For someone with say a 30" diameter flywheel, this could be catastrophic for the flywheel and anyone nearby!