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FabianRW

ArboristSite Member
Joined
Jun 10, 2021
Messages
54
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Location
Polstead Heath, Colchester, CO6 5BA, UK
I have been looking at Honda gx engines for a unique new DIY mobile bandsaw mill build.

Non-trailer so I will design it to be moveable in two or three wheeled/lifted pieces by one person.
I've designed the basic system; it's just two rails that secure at each end of the log, at each corner there are feet that drop down to prevent movement, so the log and rails become one sturdy mass, then the bandmill part simply wheels on to start milling.
Simple farm jacks are then used to quickly raise and lower each end of the log if need be, I already do this while chainsaw milling.

Still want to cut up to 1.2m cuts in hardwoods at reasonable speed so I'm needing at least 22HP if not more.
Because I'm on a budget new engines are not an option.

Would it be possible to simply use 2X identical (used) honda gx340 engines with the throttles linked?
For that matter why not have 3X or 4X engines, why is it that nobody seems to ever pair up engines like this for more power on machinery instead of one heavy lump?
I'd run identical v pulleys and belts from both to one shaft, using the generic gx 2:1 clutch gearboxes that bolt straight on.

Slightly decreased power to weight and efficiency compared to 1X engine, for example a GX690, a little complexity too but despite that surely someone has attempted it?

I'm grateful in advance for anyone willing to share constructive knowledge and insights, or even experience of this.
 
Cheers, that was my thought with the synchronization of them, got no answers from looking online though.
I would link the throttles and match absolutely everything running in and out of them but dunno if it's really that simple, if one misfired for example I'm thinking it may lead to engine damage but then the v-belt should just slip a little instead in theory.
 
“I'd run identical v pulleys and belts from both to one shaft, using the generic gx 2:1 clutch gearboxes that bolt straight on.”

that'll do it. When both are clutched, you can drop either one in or out.

will you get 2x, I doubt it, but you’ll be close enough for government work…lol
 
Cheers, that was my thought with the synchronization of them, got no answers from looking online though.
I would link the throttles and match absolutely everything running in and out of them but dunno if it's really that simple, if one misfired for example I'm thinking it may lead to engine damage but then the v-belt should just slip a little instead in theory.
Synchronization isn’t that big of a deal, they never will synchronize 100% of the time. The ’slop’ will be taken by the more powerful motor dragging the weaker motor along via the belt connecting them and both will be less than rated power, that why I said you’ll never get exactly 2x, but your HPs will be additive on the shaft…
 
I see 2X used gx340's adding up to half the price of just 1X used GX690, I'm thinking it might be worth it. I only see a couple of gx690's even for sale for a lot of money, may as well but a new one of them for what they go for used (which I cannot afford) whereas there's tons of the smaller ones about cheap.
Put into context £500 total for 2X gx340's and around £800+ for a gx690.

I'm just hoping a cheap 24hp+ Briggs vanguard or something decent like that will eventually come up but I've been looking for months now and they're all vertical or knackered.
 
I did consider them too but found that every so often people came across a dodgy one where one major part fails and I'll be running this engine for long hours on tough hardwoods.
I see a lot of honda gx's cheap enough but only up to the gx390 then it gets really pricey, not powerful enough for what I need even if modded unfortunately.

I worked out 20HP was a minimum, I really need around 24HP up to 28HP able to work all day.
 
You could put these on your motors to help synchronize motors under load. I use this on my 24 hp Vanguard on a HUD-Son mill. There are cheaper versions, but these have worked good for years.
 

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You could put these on your motors to help synchronize motors under load. I use this on my 24 hp Vanguard on a HUD-Son mill. There are cheaper versions, but these have worked good for years.
Cheers!

What will your 24hp mill cut in terms of max width and how fast in hardwood, say oak?
What blade?

I considered that kind of v-twin engine first, but have seen none for sale second hand yet under £600 which is my absolute max budget for the engine, they look just right though.
 
Cheers!

What will your 24hp mill cut in terms of max width and how fast in hardwood, say oak?
What blade?

I considered that kind of v-twin engine first, but have seen none for sale second hand yet under £600 which is my absolute max budget for the engine, they look just right though.
I do 30 inch width oak with 23 hp with 1-1/4 inch blades. I have no problems. You will have to put in a blade cooling system, I turn mine up with that width but even that works good.
 
Sounds good, that's the average diameter log I cut at the moment at 30". 1-1/4" sounds sensible to me, maybe 3tpi skip.

I may just use the old 076 chainsaw mill for wider cuts and stick to a max cut width at 30" and 22-24HP for the bandmill.

Thanks for the knowledge 👍

I do 30 inch width oak with 23 hp with 1-1/4 inch blades. I have no problems. You will have to put in a blade cooling system, I turn mine up with that width but even that works good.
 
I have been looking at Honda gx engines for a unique new DIY mobile bandsaw mill build.

Non-trailer so I will design it to be moveable in two or three wheeled/lifted pieces by one person.
I've designed the basic system; it's just two rails that secure at each end of the log, at each corner there are feet that drop down to prevent movement, so the log and rails become one sturdy mass, then the bandmill part simply wheels on to start milling.
Simple farm jacks are then used to quickly raise and lower each end of the log if need be, I already do this while chainsaw milling.

Still want to cut up to 1.2m cuts in hardwoods at reasonable speed so I'm needing at least 22HP if not more.
Because I'm on a budget new engines are not an option.

Would it be possible to simply use 2X identical (used) honda gx340 engines with the throttles linked?
For that matter why not have 3X or 4X engines, why is it that nobody seems to ever pair up engines like this for more power on machinery instead of one heavy lump?
I'd run identical v pulleys and belts from both to one shaft, using the generic gx 2:1 clutch gearboxes that bolt straight on.

Slightly decreased power to weight and efficiency compared to 1X engine, for example a GX690, a little complexity too but despite that surely someone has attempted it?

I'm grateful in advance for anyone willing to share constructive knowledge and insights, or even experience of this.
I have been looking at Honda gx engines for a unique new DIY mobile bandsaw mill build.

Non-trailer so I will design it to be moveable in two or three wheeled/lifted pieces by one person.
I've designed the basic system; it's just two rails that secure at each end of the log, at each corner there are feet that drop down to prevent movement, so the log and rails become one sturdy mass, then the bandmill part simply wheels on to start milling.
Simple farm jacks are then used to quickly raise and lower each end of the log if need be, I already do this while chainsaw milling.

Still want to cut up to 1.2m cuts in hardwoods at reasonable speed so I'm needing at least 22HP if not more.
Because I'm on a budget new engines are not an option.

Would it be possible to simply use 2X identical (used) honda gx340 engines with the throttles linked?
For that matter why not have 3X or 4X engines, why is it that nobody seems to ever pair up engines like this for more power on machinery instead of one heavy lump?
I'd run identical v pulleys and belts from both to one shaft, using the generic gx 2:1 clutch gearboxes that bolt straight on.

Slightly decreased power to weight and efficiency compared to 1X engine, for example a GX690, a little complexity too but despite that surely someone has attempted it?

I'm grateful in advance for anyone willing to share constructive knowledge and insights, or even experience of this.
When I built my mill I got a 22hp predator motor from harbor freight . It was very economical and has done a great job I would definitely buy that engine again .
 
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