Best material for a barrel spider ?

[Shrek]

I'm going to make both a front and rear spider for my lathe as my first ever project on my lathe. I plan to buy a D1-4 plain back plate and true it up on the lathe and cut it as thin as possible. Then mount the spider to it. I'm wondering what material to make the spiders from. Aluminum or steel and what particular type aluminum or steel ? I plan on 5/16th fine thread bolts with a ball bearing between the bolt and an aluminum block. I want to have the diameter such that the the heads are flush in counter sunk holes when backed out clear of the center hole so there is no danger from bolts catching fingers and such.

 

[Hal]

You might check around and see if they make a thick back plate, and use it to make a spider.

Hal

 

[Danny1788]

this will save you a lot of time, just mount it to a spare back plate. http://bullets.com/products/Aluminum-Spider-Plate-5-Diameter/BE1125

 

[Shrek]

Danny1788 , I have two of those that I was going to use with the Logan I own and they won't work very well for what I want. First thing is the bolts stick out the outside diameter which I don't want and trying to make the pre drilled mounting hole work with the D1-4 mounting looks to be a pita and sloppy looking. I want to build my own that are exactly what I want rather than try to make something off the shelf work. This will be a fun learning project.

 

[Shrek]

The question I'm trying to answer is what type of metal, 6061 , 7075 , 4130 , etc. I know what I want to build but I know squat about the actual material to order and where to order from.

 

[ridgeway]

Get a back plate(thicker) for an adjustable chuck and machine a stepped nose on front so you can drill/tap for brass tipped screws.

 

[shortgrass]

The question I'm trying to answer is what type of metal, 6061 , 7075 , 4130 , etc. I know what I want to build but I know squat about the actual material to order and where to order from.

Good ol' 1018 should work just fine. Or, you might use Inconel.

 

[jdh47]

You could make it out of C1018 HR but Al. is good. 6061 is fine. I would make the bolts 1/2-20 though. Copper or brass inserts work fine. The plate will need to be around 1.1" thick and you might have to thin down the backplate register a little for clearance. The hole needs to be no bigger than the hole in your spindle which in your case is 1.5". You will have a long way to tap to hide the bolts but it can be done. If you use Al. WD40 is a good coolant.

Joe

 

[tac284]

Good ol' 1018 should work just fine. Or, you might use Inconel.

Inconel. Love it!

 

[bapayton]

I made two front spiders for the d1-4 I use. One was from scratch, 6061 round bar I drilled/tapped for camlocks and 4 set screws. It's not the best but it works for me on barrels down to 20".

The second one I made using a backplate I got off eBay. I drilled the backside & countersunk/tapped eight 1/2" bolts into 6061 bar stock. It's much higher quality and also a little thicker. I can use it for barrels and a second set of holes allows me to do receivers as well.

I think the set screws are 5/16 brass tipped. I probably need to go bigger but haven't taken the time yet.

Hope all that makes sense!

 

[Cloudrepair]

Inconel sounds like a good time waiting to happen

I've been lucky and had some 4140 drop that I've used for my outboard and a quick front one I could hold in a non adjust true chuck.
Then I just used a
d1-4 back plate for a adjust true chuck that is thicker so I could drill and tap the holes for the jack screws in the flange the adjust true screws ride on.
The 4140 is great and I used 3/8-24 screws that seem like a good size for my 12-36 lathe

 

[Shrek]

This is what I have in mind. I can get a plain D1-4 backplate off eBay that comes 1 1/8" thick that I would thin as much as I could and then put the spider chuck on it. @ 1" thick @7" diameter. I am thinking 5/16" fine thread bolts would give plenty of beef for threads in aluminum.

 

[Rich S]

Below us a link to a thread on Benchrest Central. One of the post is a spider made with the thicker backplate. Looks like the way to go if you have to purchase a backplate. I also have a D1-4 and was going to use the Bald Eagle spider for convenience but didnt like how close the mounting holes would be to the lugs. I already had a backplate and a piece of cast about the correct size so used them. The fine grain cast works fine. If had to purchase material I'd use carbon steel or an alloy such as 4140L. I used brass tipped bolts inboard and ourboard and that works fine. The bolts on the outbord spider came from McMaster Carr and have smaller brass tips. I believe that helps prevent bending. I may convert to the ball arrangement in the future. For rigidity, I think it is best to keep the ID as small as you can for you mounting arrangement. Attached is a picture of mine. 6 1/4" OD and 4 3/8" bolt spacing.


http://benchrest.com/showthread.php?96423-Ultimate-front-spider/page2

 

[Someoldguy]

Inconel. Love it!

Mine is a double spider made of Unobtanium.

 

[Shrek]

I keep seeing people use 1/4-20 bolts. I was thinking that a fine thread would give better fine adjustments. If you have used both what do you feel worked best ?

 

[Cloudrepair]

I keep seeing people use 1/4-20 bolts. I was thinking that a fine thread would give better fine adjustments. If you have used both what do you feel worked best ?

I think you mean
1/2-20 I believe
1/4-20 is to small a screw.
My adjust true buck chucks have 1/2-20 screws that work great for it but I prefer my spiders with
3/8-24 screws, not because of the screws but because mine is a better setup. The finer thread probably helps though.
If you want to see pics of it they are in that thread @ BRC that was posted earlier in this thread. I guess I have been lazy or just to busy to do what I have to post pics here.

 

[jfseaman]

this will save you a lot of time, just mount it to a spare back plate. http://bullets.com/products/Aluminum-Spider-Plate-5-Diameter/BE1125

Having made my spider I have some advice. Just buy this one. It will be faster, cheaper than a DIY.

 

[carlsbad]

I make mine from aluminum bolted and pinned to the backplate. I use heavy long allen set screws with brass tips. No exposed capscrews to catch you.

for the rear (or left) spider I use aluminum and thread it to match the spindle. Many chinese spindles are M50x1.5 thread.

FYI, I currently have a set for sale, D1-4 and M50x1.5. PM if interested. Maybe I'll get them listed this weekend.

--Jerry

 

[butchlambert]

I use 1/2x20 set screws with "copper tips". My catheads are aluminum. Ain't no stress on the backplate or alum. cathead, unobtainium not necessary.

 

[Rustystud]

Butch how about putting them on with oar locks or sky hooks.