building a custom longtail. is a one inch shaft to big thats what my motor has if not then what size tubing to i need for the outer of the shaft and how to put bearings in the tube and seals i thought about having housings machined on the ends with sealed bearings in the ends good bad????

wow thats kinda heavy duty, but its whatever you can come up with i guess.
i'm making one myself i used a 3/4 shaft and 1 inch schedule 40 pipe. most long tail props i know of are 3/4 10.

Your motor shaft is 1 inch that's fine. Then you need a 1 inch u joint . Then a 3/4 10 6 foot drive shaft. That's gunna go inside a 1 inch tube. The 1 inch tube will be your frame. You need bronze olite bushings ( oil impregnated). Order them in 3/4 ID and 1 inch OD. You will have to ream them out a tiny bit in order to fit the 6 foot 3/4 inch D shaft through them. You want minimal play but the fit can't be too tight either or else you will build excess heat and vibrations will eventually break it. That's just a tiny bit of what I know hope this helps a little I summarized alot

I used 1.25 sched 40 pipe for the outer shaft and then threaded both ends so I could build caps and screw them on to hold the bushings and seals. I bought the bronze stock and milled them myself but you can go to a machine shop and they will make what you need. Your not building the landing gear for the space shuttle so dont try to over complicate it. take your time and do a lot of searching of the sites that have detailed pics and go devil has a service manual on there web site with a lot of good info in it. To save your self a lot of trouble stay with a 3/4 shaft and thread it with a 3/4 10 that is the most common bore for props that major suppliers carry. I built a longtail and now working on a small short tail. Its not rocket science but it is a lot of planning and trial and error, pipe and shaft are not that expensive, worst case start over . just be carful with the bronze that is not cheap if you have it machined.... good luck I always like it when someone says "where did you get that" and you can say I built that.....

yea just watch using pipe and dom tubing. O.D. on a sched 40 1 inch pipe is 1.300" with an I.D. of between 1' and 1.100". dom tubing is measused by O.D. and I.D. is determined by sidewall thickness you buy. just my .02 but its easier to buy and fabricate with pipe cause u can pick up most supplies at the hardware store.

it depends on what prop you want to run. The 10" GD props are 7/8" shaft.I believe the 31hp and up run 7/8" drive shaft.

thats SD props right? crawdads run 10" props theyre 3/4 arent they?

Mine is a longtail go-devil and it has a 7/8" shaft. I ordered a 10x8 tiger prop and it came in 3/4" shaft. Thats why it depends on what prop you plan on running.

thank you all its helpfull alot i be running a 16hp motor were can i find a u joint to go from 1 inch to 3/4 inch and bushings not bearings? i thought most ran bearings i been trying to find a housing to weld on or press fit on to put bearings and a seal into good bad?

i was going to build one awhile back. tractor supply had most all the parts in stock for the bushings/bearing. also, sd run with the motor on an angle. i was going to do away with the u-joint. they have a LOVE COUPLER, thats what i intended to use. it would get rid of the u-joint, but set the motor on a slight angle. ive under stand that the u-joint robs some power.

my idea was to use 1" pipe and steel couplers, not cast. a 1" pipe plug, oil lite bushings, and 2 seals, a 3/4" lock collar. put the coupler on the pipe, with the plug in. chuck it in a lathe and bore the center of the plug. the bushings they have would press into the pipe and the seals will fit inside the coupler. 2 seals in each end turned back to back. one to keep greese in and water out. the seals would need to be glued in to keep them in place and seal around the outer edges. the bored plug would hold it all together. the lock collar would take most of the trust once locked onto the shaft and ride against the face of the plug. was thinkin about a poly bushing between the two. water would lube it and shouldnt wear too bad.

so is that a GD thing? does any other manufacturer use 7/8th shaft? is there any difference in the props for the 7/8th shaft other than thread size?

thats what I did hunt4deer. I just put the coupler in a band saw and cut it down and welded a washer over one end and then chucked it up and bored the center to 3/4 ,my seal rides back behind the caps. You got the right idea , post some pics when your done. or during the build.

this is how i did it 1 inch coupler and a TCM 075192 TB2 is the oil seal number.
o.d. on the oil seal is 1.3752 so you can machine it or redneck it and grind a thou off a cheap uni bit and do it in a drill press. the electrical coupler. is it emt? works better cause its softer.

Damn garjacker next time I need some caps I am going to hit you up that looks a lot better than mine .

this is what we have used in the past, it is heavier duty than just schedule 40
1 3/8 OD x .188 wall thickness x 1 inch ID DOM tubing, cost is about 10.00 per foot
use 3/4 cold roll 1012 for the shaft, thread the end with a 3/4 x 10 die
you can get the u joint and yokes at tractor supply or driveshaftparts.com
3 bronze sleeve bearings 1 inch od x .75 id, have to smooth them slightly to get them to insert
5 shaft seals 1 inch od x 3/4 id
auto grease cup and then grease fittings, set screws etc.

we own a metal fabrication shop so putting it all together went fairly easy

hey brianb how are you straightening the 1012 round stock? does it come straight enough to use? i've been paying extra for the 1045 tgp. its almost double the price of 1012...

so far works fine, we lightly sand it due to 1018 (originally posted 1012 by mistake) having a tendency to corrode or rust easier than the etd 150 cold roll material, after we install it with the grease it has not corroded or rusted. we use that item for axles on other items we build so we keep it in stock and it was handy,we have been using the unit several days a week on catahoula lake since the beginning of the second split and no problems so far. i tried to find the etd 150 from our normal steel supplier but they did not have access to it so we used what we had

i did post a question about what type of vibration to expect out of a longtail and from what i gathered and also from my brother in laws go devil i am not experiencing any more vibration than what the factory models have. i also read the go devil manual and it stated slight vibration at idle was normal.