Rotisserie Spit Tip

[NRM]

I am trying to figure out the best way to make a tip for my rotisserie and have come up with a couple of options. The spit is 304 SS 1” Sch 40 pipe 6’ long and am planning on making the tip out of 304 SS 1.25” round bar. I would like the tip to be 3” long and turn the backend down to fit into the pipe and secured with a set screw. My thoughts are:

1. Find a pre made tip like a water well drive point and cut it to match the pipe diameter and weld in round bar to secure it. Problem is I can’t find any SS only MS
2. Use 304 SS 1.25” round bar and grind down a tip. Will take some time.
3. Turn the 304 SS 1.25” round bar in the lathe. Will take some time and have a learning curve.
4. Cut the 304 SS 1.25” round bar with and TCT/Abrasive saw to get the rough shape, then grind it smooth.
5. Have a fab shop do it. $$$$.

What do you think will be the most time and cost effective way? Any other suggestions?

[Brian Ski]

I am not a metal pro, but I sure have made pounds of metal shavings. Stainless is pretty tough, but I have used a 4 1/2" high speed grinder. It really seems to take metal off. I wonder if you can turn it fairly slow and get a rough shape with one of those. If you do not have one I think they are a really nice investment for a metal worker. Not the bigger 6" ones get the smaller high speed one. Nice to pick up a box of the cheaper replacement discs from Harbor Freight. BTW mine is a Craftsman and it has held up very well.

Good luck, Sounds like a neat project.

[jakeru]

Have you considered cutting the away portions of the tip of the schedule 40 pipe leaving a series of triangle pieces, pinching or hammering the triangle pieces together, TIG weld together, and grind / finish as needed to make your own tip?

Of course, it won't look as "perfect" as a lathe-turned tip would, (because it will be done by hand not machine) but you could actually make it look pretty good if you put in some time and patience. You could even grind it smooth and polish it if you wanted.

PS - if the stainless work hardens on you, just heat up the area that needs to be annealed/softened with the TIG arc. It gets real ductile and workable again.

[DaveO]

Have you considered cutting the away portions of the tip of the schedule 40 pipe leaving a series of triangle pieces, pinching or hammering the triangle pieces together, TIG weld together, and grind / finish as needed to make your own tip?

Not to hijack the thread but it reminds me of a clever solution to a problem- as a kid I remember my Dad wanted to run some electrical wiring to the far side of a driveway. So he did this triangle cut-away thing that Jake mentions, using steel pipe: closed off the end, then welded and ground to a near-perfect bullet shape. Threaded the bullet end onto a 4-ft. section of pipe, and we dug holes on both sides of the driveway, one hole deep and long enough to swing a sledge hammer, the other hole just big enough to see the pipe emerge at the other end. Kept the pipe level and straight, started sledging, and threaded on more pipe as we made progress. The bullet end emerged as planned (it had drifted only a little), then Dad unthreaded the bullet and ran the electrical wire through.

[Brian Ski]

I have done similar... I used a piece of 3/4 emt conduit and would run a trench next to the drive. Then hook it to the end of a garden hose. The water would run the conduit right under the drive. Worked pretty well unless you hit a big rock. Little muddy though.
Probably not the way to do it with a pig on a stick!!!!

[Bigwilly01]

Not to hijack the thread but it reminds me of a clever solution to a problem- as a kid I remember my Dad wanted to run some electrical wiring to the far side of a driveway. So he did this triangle cut-away thing that Jake mentions, using steel pipe: closed off the end, then welded and ground to a near-perfect bullet shape. Threaded the bullet end onto a 4-ft. section of pipe, and we dug holes on both sides of the driveway, one hole deep and long enough to swing a sledge hammer, the other hole just big enough to see the pipe emerge at the other end. Kept the pipe level and straight, started sledging, and threaded on more pipe as we made progress. The bullet end emerged as planned (it had drifted only a little), then Dad unthreaded the bullet and ran the electrical wire through.

Your story reminds me of my late Grandfather. He was a farmer by trade and a fabricator by necessity. If he needed something he would go to the shop and build it. If it was a great idea he would build them for friends and family.

[NRM]

Jake - I was also thinking about doing that, however I didn't think I could make it look very nice and some spots would be a lot thinner than others. Some may find this ridiculous but I want it to look good and work well. I’m kind of partial to my number 4 which is to do some rough cuts with an TCT/Abrasive saw first then grind it smooth.

[NRM]

I finished the two spit rod tips I wanted to make. First made some calculations (they were wrong turns out) about how long the round stock should be then put it into the lathe. I drilled a 3/8” hole on the back end so I could spin it in a ½” drill chuck to get the tip smooth after turning it on the lathe.


Next cut the shoulder to fit into the spits ¾” and 1-1/16” both by 1”. Flipped the stock around putting the neck into the chuck jaws and started cutting the tip. Forgot to take pictures but here is a drawing.

Once the tip was rough cut inserted it into the spit found center and drilled a 3/16” hole. Pulled the tips out cleaned up the tips and the spits and inserted the 3/8” shaft into the tips and drilled a 3/16” hole in the shaft. Attached to the drill had a friend hold the drill and spin the tip and went at it with the grinder.


Finished with some fine paper in the lathe and the final product was what I wanted. There are things that didn't turn out as I expected like the shoulder to the neck is not exactly 90 degrees and the ends of the spits aren't either, but it will turn what I need.

[Rambozo]

Why didn't you just turn the angle you wanted with the compound on your lathe?

[Rodsmachineshop]

i have a cross feed on my lathe makes it easy to do angles when doing stuff , the tips turned out nice looks good to me

[NRM]

Using a lathe is new to me and I'm not quite sure how to do it that way. I know you have to turn the rest to the angle you want and start there. Then move the rest and cross slide but I'm not sure how to calculate the travel. Any help/explanation would be great.

[Rambozo]

Using a lathe is new to me and I'm not quite sure how to do it that way. I know you have to turn the rest to the angle you want and start there. Then move the rest and cross slide but I'm not sure how to calculate the travel. Any help/explanation would be great.

No problem. You simply rotate the compound rest to the angle you want to cut, and then use the compound to feed the cutter across the part. You can use the cross feed to advance the cutter for each pass. Sometimes it helps to lock the carriage to keep it from moving. There is a book that South Bend has been printing since the dawn of time (early 1900s) that you might want to get. It’s called “How To Run A Lathe”. You can find online scans and I think you can even buy a current printed version from South Bend. Without a doubt a lathe is one of the most versatile machine tools you can own.

Here I have the compound rotated to about 30° to make a 60° point on the end of some stock.
Start here…


And end here, by advancing the compound feed.


And of course YouTube is filled with all kinds of stuff, too.
http://www.youtube.com/watch?v=P6Q7VTdZVfw

[NRM]

Rambozo thanks for the pics and the video. I learned how to use a wiggler from watching a youtube video from Tubalcain (think that was his alias). That is what I kind of thought but I was not sure how to calculate the angle and have the length of round stock match. If I make another one I will defiantly use the rest. I do have to figure out how much travel the rest has. Thanks again.

[Rambozo]

Rambozo thanks for the pics and the video. I learned how to use a wiggler from watching a youtube video from Tubalcain (think that was his alias). That is what I kind of thought but I was not sure how to calculate the angle and have the length of round stock match. If I make another one I will defiantly use the rest. I do have to figure out how much travel the rest has. Thanks again.

For something like what you’re doing, I would probably just eyeball the angle. However, if you wanted something precise, it’s not hard to calculate the exact angle to use. For your large tip, the pipe OD is 1.32” and you mentioned that you wanted a 3” long point. So that will be a right triangle with the radius (.66”) as the short side and 3” as the long. Do the trig or plug those numbers into a handy online trig calculator like www.carbidedepot.com/formulas-trigright.asp and you get an angle of 12.4°. You can do it in sections if the travel on your compound isn’t long enough, but I think on an SB9 you should be pretty close.

[NRM]

Rambozo thanks again for the information and help. That is a great link and it will help with my project this weekend.