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longer CF arms

Posted: Mon Oct 05, 2015 11:44 am
by stonewater
in my never ending desire to make things better, I decided to purchase a bunch of parts from Brian, I already had the CF arms, so I got the trucks and his new effector mount, I just could not afford a new set of longer CF arms along with my other purchases. I went back to the delta arm blues thread and did some reading, and looked at a bunch of the Kossel deltas to see what people were using to make CF arms. I do not like the solid CF arms though.... I figured I might be able to whip something up.

the traxass ball rod ends mentioned were a bit different, but I found the correct ones at amazon http://www.amazon.com/Traxxas-5347-Holl ... B000BOLVJY 8.68

I found the CF rod inserts at Cabela's - carbon express arrow point inserts, they are 10 bucks

I found the carbon tubing at Tap Plastics http://www.tapplastics.com/product/plas ... _tubes/582 4.30 each needed 3 pieces.

I found a ball rod end jig I could print out from thingiverse (cannot find the link right now, its in the delta arm blues thread)

I found 6/32 screws would work for the threads. I ran the screw in from the bottom of the insert, threaded on the ball rod end and put a bit of red Loctite on the threads. then I backed the screw out till the rod end was flush with the insert and cut the screw head off with a pair of dykes so it would fit in the CF tube.

I mounted the ball rod end jig on my work bench at 325 mm - yes I know its not exactly 325 but its within .25 of a millimeter and I know I can dial that in by printing parts and modifying the diagonal rod length. I used 2 part 3500 pound Loctite epoxy from home depot. the only way to get it apart is to destroy the CF arm with a set of pliers crunching the rod off the insert. so I know its not going anywhere.

just thought I would share.

Tom C

Re: longer CF arms

Posted: Wed Oct 21, 2015 3:11 pm
by acaldwell01
Can you elaborate on where you modify the diagonal rod length?

I just built my rostock recently and put on the 300mm arms from Tricklaser. Now I'm trying to dial in the axis to get this printing true to size rather than significantly oversized and struggling a bit.

Re: longer CF arms

Posted: Wed Oct 21, 2015 3:31 pm
by Tincho85
acaldwell01 wrote:Can you elaborate on where you modify the diagonal rod length?

I just built my rostock recently and put on the 300mm arms from Tricklaser. Now I'm trying to dial in the axis to get this printing true to size rather than significantly oversized and struggling a bit.
With the firmware, under configuration.h
#define DELTA_DIAGONAL_ROD

I think that EEPROM supports that feature too.

Re: longer CF arms

Posted: Wed Oct 21, 2015 5:20 pm
by Eaglezsoar
stonewater wrote:in my never ending desire to make things better, I decided to purchase a bunch of parts from Brian, I already had the CF arms, so I got the trucks and his new effector mount, I just could not afford a new set of longer CF arms along with my other purchases. I went back to the delta arm blues thread and did some reading, and looked at a bunch of the Kossel deltas to see what people were using to make CF arms. I do not like the solid CF arms though.... I figured I might be able to whip something up.

the traxass ball rod ends mentioned were a bit different, but I found the correct ones at amazon http://www.amazon.com/Traxxas-5347-Holl ... B000BOLVJY 8.68

I found the CF rod inserts at Cabela's - carbon express arrow point inserts, they are 10 bucks

I found the carbon tubing at Tap Plastics http://www.tapplastics.com/product/plas ... _tubes/582 4.30 each needed 3 pieces.

I found a ball rod end jig I could print out from thingiverse (cannot find the link right now, its in the delta arm blues thread)

I found 6/32 screws would work for the threads. I ran the screw in from the bottom of the insert, threaded on the ball rod end and put a bit of red Loctite on the threads. then I backed the screw out till the rod end was flush with the insert and cut the screw head off with a pair of dykes so it would fit in the CF tube.

I mounted the ball rod end jig on my work bench at 325 mm - yes I know its not exactly 325 but its within .25 of a millimeter and I know I can dial that in by printing parts and modifying the diagonal rod length. I used 2 part 3500 pound Loctite epoxy from home depot. the only way to get it apart is to destroy the CF arm with a set of pliers crunching the rod off the insert. so I know its not going anywhere.

just thought I would share.

Tom C

Thanks for the write up Tom, I appreciate this do it yourself kind of tips. Could I ask what tube size did you order (ID and OD) or if they were solid. A picture would be grand also.

Re: longer CF arms

Posted: Thu Oct 22, 2015 12:38 am
by stonewater
Eagle,

I don't know what the tubing id and od is....... the tubing is hollow, I took the arrow head threaded inserts I bought and walked into tap plastics. they had several carbon fiber tubes of various diameters. I just hunted thru the stock until I found a tube that was a snug fit. they look EXACTLY like the tricklaser arms....

here is the printable jig

http://www.thingiverse.com/thing:37306

Tom C

Re: longer CF arms

Posted: Thu Oct 22, 2015 12:57 pm
by Eaglezsoar
stonewater wrote:Eagle,

I don't know what the tubing id and od is....... the tubing is hollow, I took the arrow head threaded inserts I bought and walked into tap plastics. they had several carbon fiber tubes of various diameters. I just hunted thru the stock until I found a tube that was a snug fit. they look EXACTLY like the tricklaser arms....

here is the printable jig

http://www.thingiverse.com/thing:37306

Tom C
Thanks Tom for the link. I can measure the ends with a micrometer to get the inside measurement of the tube.

Re: longer CF arms

Posted: Fri Oct 23, 2015 11:45 am
by stonewater
20151008_223903.jpg
here is what 325 mm arms look like on the rostock

Re: longer CF arms

Posted: Fri Oct 23, 2015 6:35 pm
by teoman
One question comes to mind. The seemecnc longer arms and the new carriages OR the tricktrucks and lanoger cf arms. Which would be better?

Re: longer CF arms

Posted: Fri Oct 23, 2015 6:55 pm
by Eaglezsoar
teoman wrote:One question comes to mind. The seemecnc longer arms and the new carriages OR the tricktrucks and lanoger cf arms. Which would be better?
The new ball arms from SeeMeCNC are great. If I need to make arms similar to Trick Laser I would make them myself from the carbon tubes and the Traxxas connectors.

Re: longer CF arms

Posted: Fri Oct 23, 2015 7:39 pm
by Earthbound
teoman wrote:One question comes to mind. The seemecnc longer arms and the new carriages OR the tricktrucks and lanoger cf arms. Which would be better?
I have two machines. A one year old RMV2 that is mechanically stock that works well, and a RMV2 based hybrid under construction. The hybrid is getting Trick Trucks and CF arms built from a TriD kit. I have been waffling on what to do for its effector and hot end (Prometheus v2) mounting. I just bought a set of the new ball arms and carriages to update the stock machine. Since the SeeMeCNC ball arms come with a new effector, I think the old effector will go to the hybrid build.

I hope to be very pleased with the SeeMeCNC ball arms. One thing against the CF arm solutions that use Traxas joints is hassle when you need to separate an arm from the effector or tower. That is one place where magnetic joints seem like a great idea, but I am not a fan of them.

Re: longer CF arms

Posted: Thu Jan 28, 2016 1:41 pm
by TFMike
stonewater wrote:
20151008_223903.jpg
here is what 325 mm arms look like on the rostock

What are you using to mount the arms to the trick trucks? They don't look like the stock mounts. Nice work btw

Re: longer CF arms

Posted: Sat Jan 30, 2016 6:38 am
by Eaglezsoar
I can understand going to 300mm arms but what advantage is the 325mm arms?

Re: longer CF arms

Posted: Sat Jan 30, 2016 11:37 am
by stonewater
@TFmike,

the metal effector came with mount for the trick trucks. so they are from Brian.

@eaglezsoar

I was reading thru a few threads, particularly the one where we were discussing longer arms. JFettig had mentioned he would take 300 or 325 mm arms , the longer the better. as I understood his reasoning, the lower one of the towers carriage gets to horizontal the slower it has to move, and the less precise as the effector moves thru the spot directly opposite the tower, with the arms horizontal, there is a point where it cannot draw an arc. I wanted to be able to use the full diameter of the bed without having to slow the print down. I can print a full diameter perimeter circle .6mm wide at speeds above 50.... I could not do the full diameter OR anything close at speeds above 25... I don't make things very tall, I am more concerned with build diameter.

Tom C

Re: longer CF arms

Posted: Sun Jan 31, 2016 12:33 pm
by Eaglezsoar
stonewater wrote:@TFmike,

the metal effector came with mount for the trick trucks. so they are from Brian.

@eaglezsoar

I was reading thru a few threads, particularly the one where we were discussing longer arms. JFettig had mentioned he would take 300 or 325 mm arms , the longer the better. as I understood his reasoning, the lower one of the towers carriage gets to horizontal the slower it has to move, and the less precise as the effector moves thru the spot directly opposite the tower, with the arms horizontal, there is a point where it cannot draw an arc. I wanted to be able to use the full diameter of the bed without having to slow the print down. I can print a full diameter perimeter circle .6mm wide at speeds above 50.... I could not do the full diameter OR anything close at speeds above 25... I don't make things very tall, I am more concerned with build diameter.

Tom C
Thanks for the great explanation!