Just wanted to share this weekend's side project. I had an old Dayton Speedaire compressor that had a bad electric motor. It was given to me, and just been sitting in my garage for years. I have a fencing project coming up that requires portable air to run a pneumatic fence stapler. So, a quick trip to Harbor freight with a coupon for a 6.5hp engine, and an order for a couple parts off Amazon and Boom! New life given to old equipment. And yes, I have the belt guards, I just haven't installed them yet as the mounting tabs don't line up anymore. They will get put on before I put this into service. Builds air to 130psi, unloads and drops to idle until air bleeds off to 90 psi, then kicks back to high idle and pumps back up. I didn't time my no-load recovery time from 90 to 130, but I will later. I'll put up a parts list later in case anyone else is interested.
So did you do a lot of calculating on pulley sizes vs. rpm from the electric motor to the gas engine? or go by the "that looks about right" method. Also curious how the idle down works. Thanks.
I had almost the exact same "Speedaire" 25 years ago, It was a freebie too. Put a 5 HP Honda on it and many years of good use out of it. The unloader I used didn't have the throttle kickdown cable but I found a little air cylinder (KW hvac I think) and made that work. I used a drive pulley the same size as the one on the electric motor, Electric was 3450 RPM and the Honda was 3600RPM.
I hope you're gonna treat the old girl to a coat of paint ......... Nice job though.
@crane operator Yes, I did calculate the pulley diameter. It's actually not that hard with all of the online calculators available. The numbers were the same as @RZucker said. That said, I did choose the same diameter pulley as they are readily available at local hardware, and I can just set the governor screw in a bit to run the engine slower to match the electric motor speed. @Nige - it's on the list .
There's a spring in the unloader valve. When it gets to max pressure it lifts, opening an exhaust port for compressor, and applies air to the pneumatic throttle to extend the cable. You just mount it so when contracted, the engine is at max rpm, and extended goes to idle position. I'll shoot a video later and share. I'm out plowing fields today (still...)
Wet spring? I guess it should really be wet summer by now. What are you hoping to plant to get to harvest? real short season soybeans? Best wishes for a late frost and 1st snow- you are going to need it.
Up here in Washington they have been planting dry beans and sweet corn just this last week as a double crop following the fresh peas that were just harvested. SOP in this country. Corn will be ready in September and the beans will be done in early October.
Not a farmer myself but seems like there are lots of fields around us that have not been planted yet. And the ones that have been planted on some of them the corn is only is only a couple inches tall! Seems that I remember most of these fields had corn around 18 to 24 inches tall by this time of the year. Even some of the fields that do have good growth also have washed out areas that are bare from the rain. The first cutting on the alfalfa fields next to our house the machine that picks up the alfalfa, forget the proper name for it, had to tow the trucks around the field due to how soft the ground was. First time I recall seeing that and we have lived here over 30 years. Most of these trucks have the super wide tires with the tractor type lug threads!
@crane operator - short season soy beans. We had a bit over 400 acres to cover, 25 more for tomorrow and we can put the planter away. Not gonna be a money maker, but should yield enough to pay the property taxes. @RZucker - double cropping rarely happens here. Not enough season, not enough moisture (usually) at the right time. @kshansen - our first alfalfa cutting went the same way. Fields were horribly saturated and crop was mature and needed to be cut. And we start cutting 2nd cutting alfalfa tomorrow.
Finding the right pulley is probably the most difficult part of this kind of project. Running the compressor a few hundred RPM slower than original is not a problem, though.
You may want to replace your large red air line, with a hard line, my experience is that the air coming off the compressor is too hot and will break down a rubber line. You could black pipe or copper, but I don't know how long the rubber line will take it.
Well at least it does have a foot or so of copper so that will help some. I might prefer a stainless steel braided hose with Teflon liner to alow for some vibration. As for rubber hose on compressor outlet, that reminds me of a WA600 Komatsu we had at the quarry. It can from factory with a black rubber hose right of the air compressor of the K19 Cummins engine. After replacing five of these factory hoses over over a six year span of time at a cost from the dealer of around $100 for a maybe 2-3 foot long hose I got fed up that BS. I had tried several times to source metric fittings to convert to the Teflon hose with no luck. Finally managed to find a fitting that I could bore out and braze to a fitting that would let me adapt to the piping on the machine. Not counting labor for the boring and brazing, maybe 30 minutes max, I was able to put together this hose for right around $50 or half the factory price. Best thing about it that half price hose was still holding strong at over 12 years of use when I retired in 2015. At the rate factory hoses were failing it would have cost over $1,200 in hoses not taking into account shipping and downtime costs if dealer did not have one on the shelf!
I was thinking about the hose too. Probably going to re-plumb it in soft copper (how it was originally). I did notice how warm that red hose got from what little bit of running I did.
The thing about copper is vibration cracks it. Might work for a few years on an electric motor powered compressor, but I suspect the one-lunger would beat it to death. What is the temperature rating of those teflon lined hoses?
If you have a old truck in the boneyard, you could steal the braided discharge line off of one of those compressors. No worry about vibration, might just need a couple fittings.
Just a quick look at Aeorquip Catalog on line shows this: Operating range of -100 to +500ºF that should cover it for most applications!!
I guess I shoulda considered they coat frying pans with the stuff....
Yeah. If it repels hot grease it ought to repel hot air, and let's face it there's plenty of that on this forum ........
You talking bad about this Yank the day before Independence Day?
If the cap fits ........
Well according to all the research I have done my mothers parents never left Manchester till the early 1900's, Mom's dad came over on the Lusitania, go here while it was still afloat! Dad's grand parents were a little earlier, late 1800's so to the best of my knowledge have no recitatives involved in that little disagreement back in the late 1700's