# DIY 4 stroke Chainsaw Mill



## Chas0218 (Sep 24, 2018)

So I have been looking around for ideas of a 4 stroke CSM. It seems like it could have the benefits of a BSM minus the almost constant adjusting, bearing issues, and blade wander. Now I'm not saying all these happen every time so please don't flame me too much. But for my needs I feel like a CSM would work best and be a lot easier for me to maintain and house. I was going for the carriage setup where it sits next to the log instead of the carriage straddling the log. I'm not against doing it one way or the other but for an unsupported end that seems most logical.

So I have been researching and have come to the conclusion I need to get some insight before I start spending a lot of money. For my mill I'm looking at using a 15hp kohler paired with a 42" bar from what I understand that should allow me to cut trees 30" or better when using support at both ends (if I go that way). Realistically I probably won't be cutting much over 24" until I get a tractor to help with moving the large logs.

I plan on using V-belt pulleys to get the correct rpm for turning the chain, I wanted to run the chain around 10,000 rpm to get a better quality of cut or process the logs faster. I'm not looking to win any races but would like something close to the speed of a manual BSM.

I'm still in the drafting stage when it comes to attaching everything. Most likely going to mock up the carriage then start mocking up the motor and build my way out to the bar. I guess the biggest concern is going to be keeping chain tension. Maybe build a setup where I can push/pull on the back of the bar with some adjusting nuts.

If anyone has some pictures or threads I could reference it would be greatly appreciated. I tried a search but when it came to pictures or build threads I couldn't find much. The below video was something I was going for replacing the electric motor for gas.


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## Franny K (Sep 24, 2018)

You would want to work in feet per minute of the chain I would think.

Thanks for posting the video. Looks like someone with a band mill could make a carriage assembly to deal with logs too large, just put beside mill. Could also build off the existing carriage but log would be farther out most likely.

fran


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## Sawyer Rob (Oct 25, 2018)

Chas0218 said:


> So I have been looking around for ideas of a 4 stroke CSM. It seems like it could have the benefits of a BSM minus the almost constant adjusting, bearing issues, and blade wander. Now I'm not saying all these happen every time so please don't flame me too much.


 OK, I won't flame you too much... lol BUT, what gives you the idea that BSM's require constant adjustment, have bearing issues and lots of blade wonder???

I have NOT found that to be true, since I started milling with BSM's in 1998...

My current BSM that I bought new in 2003, has all the original bearing in it, including guides!! I never replaced any bearing in the previous mill either... Same with constant adjusting... What constant adjusting?? What kind of junk have you been running?? lol Most of the constant adjusting "I" have seen, comes from home built mills... Low end early Hudson's and HF mills!

Then we come to blade wonder... I can see why folks keep repeating that one, over and over... It does happen BUT, there are reasons why it happens and it's easy to deal with...

IF you get blade wonder, you have to STOP and deal with it but most operators think, I'll just make a few more cuts, and then the same thing happens, just like when you have a dull chain in a CSM. 99'9% of the time, putting on a fresh band fixes the problem.

IF you hit dirt or an imbedded stone, if you hit metal in the log or hit a log post you forgot to but down! it's going to instantly dull the band, just like if you did the same with a chainsaw chain! You have to stop and deal with it!

As for keeping bands sharp, you can sharpen them your self or let someone else do it. I do sharpen them myself, but I found an Amish guy that does it for $7.00 ea., and they come back like new! So, I have now got lazy, and I let him do them... My brother uses a Dremel and sharpens his own, they come out pretty good for him, so like sharpening chain saw chain, you either learn how to do it, or let some one else do it....

I really don't care what anyone buys, but I'm having trouble sitting here reading the same ole bandsaw BS being repeated over and over. I just figure, some one with "up tp date" first hand experience should set the record straight.

BYW, you can already buy 4 stroke CSM's, but they aren't cheeeep...

SR


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## Chas0218 (Oct 25, 2018)

Sawyer Rob said:


> OK, I won't flame you too much... lol BUT, what gives you the idea that BSM's require constant adjustment, have bearing issues and lots of blade wonder???
> 
> I have NOT found that to be true, since I started milling with BSM's in 1998...
> 
> ...


I understand, and figured I would catch some flak. Unfortunately I have very limited funds but not the knowledge to build my own mill. For me the BSM will cost significantly more for me to build vs the CSM.

Build wise, the wheels (blade wheels) and guides for the BSM carriage alone will cost me what the bar and chain will run. The pillow bearings will be the same price no matter which way I build the carriage. I have a 20hp vertical shaft I was planning on using for the CSM, if I went with a BSM I would need to somehow acquire a horizontal shaft motor for the BSM. The rails isn't an issue I have an old boat rail system I'm hacking up to make a set of rails and can source metal cheap. I don't have to worry as much about wander with dull chain just need to touch it up every so often. I'm not against learning how to sharpen blades just not sure I can do as nice a job as others can with a sharpener. I don't plan to go to commercial scale just fill the void of needing wood for woodworking and being able to source it from my own property will be an added bonus. No need to pay the middle man and the quality of wood will be much better. The store bought stuff makes me just cringe at the quality of the wood and the money they are asking. I want something I can use for slabbing some smaller stuff (around 24"+) and for a BSM to do that I get into a lot of pricey mills.

Unfortunately the only BSM I would be able to afford to buy new would be something along the Timber Tuff or HFT and they are junk no doubt about that. Do they work? yeah but if I'm going to buy something new I'm in no way going to buy something for $2k dollars just to throw another $1k at it to get it running right and to replace the junk parts. I don't have anything against BSM's just a CSM will meet my requirements much better at a fraction of the cost. Granted I will need to replace the bar but for the amount of cuts to the replacement it would be just a tad more expensive than replacing blades. From what I have read there have been people milling with their CSM for an absurd amount of bd.ft. before replacing the bar where as bands seem to be replaced much more often to keep it cutting true.


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## Sawyer Rob (Oct 26, 2018)

You are comparing "bars" to "bands"? Nothing on a BSM compares to a chainsaw bar...

The chain compares to a band and I can sharpen my bands at least 10 times, and one band typically last through several logs, (without touch up) IF the logs are clean.

I don't care what anyone buys, I just want to keep the BSM info accurate and help folks who don't know about them, accurately informed...

Happy milling!

SR


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## Chas0218 (Oct 26, 2018)

Sawyer Rob said:


> You are comparing "bars" to "bands"? Nothing on a BSM compares to a chainsaw bar...
> 
> The chain compares to a band and I can sharpen my bands at least 10 times, and one band typically last through several logs, (without touch up) IF the logs are clean.
> 
> ...


Good to know, thank you for correcting me. I am new to all the milling and hope to get as much info before building my own or purchasing a mill. No matter what mill the tree needs to be clean in order to have true milled lumber. I'm not knocking BSM's I am just relaying information I have gotten from friends that have ran BSM's and CSM's My experience is limited to the Granberg CSM which I am currently running. The biggest advantage to the Granberg style CSM is portability. It can be transported in the backwoods/hills that would be inaccessible by a large BSM.


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