We are up to 44. Hopefully we’ll reach 50 next week, and I’ll be able to put in an order. I’m going to investigate the most cost effective method for shipping. I expect to purchase these with my own personal credit card. I’ll be asking teams to send a check ASAP after the order is placed so I can pay the bill when it arrives. My statement date is the 28th of the month, so I’ll shoot for placing the order around the end of the month to give as much time as possible to collect checks.
I’m curious about how you guys could go about interfacing this piece into a design?
Would you pop on a chain and use this as an idler, or perhaps just design to gear it in?
- Sunny G.
What 192 plans on doing is connecting the shaft of the encoder to one of the shafts in our gearbox using a flexible shaft coupling. The coupling doesn’t have to be flexible but it’ll just make our lives easier. I saw this set up on the gearboxes of a few teams this year, namely 1717 and 118. 118 had a very nice set up with a 3D printed mount for the encoder that spaced it making room for the coupler, we plan on doing something similar.
This year, we used stock ballshifters, so we used the sub-optimal encoder setup with which those came.
Next year, I plan to incorporate the encoder mount into the first stage of our (custom) gearbox by extending the shaft out of the bearing, boring a slip-fit hole for the encoder shaft into it, cutting a ‘x’ pattern with a band saw, and then using a shaft collar to clamp the shaft in place. The top of the encoder will probably be held by a 3D-printed mount.
What was sub-optimal about it?
The delrin gear to which the encoder gear was connected was press-fit into the ballshifting shaft. Over time, it started slipping, which required us to superglue it in. It was also very difficult to center an S4 in the encoder mount.
Here are some photos taken while scouting the dc regional. Our cad team is modelling a bracket which will be printed on our makerbot. The shafts can be connected by a short piece of surgical tubing, used as a shaft coupling.
https://picasaweb.google.com/109992844858216450198/130511EncoderMountIdeas
Team 237 is in for 6 of the S4s. Please send me a PM with your contact information so we can get a check to you.
Do the prices that you have been quoting include the appropriate cables/connectors? If not, it would be nice to order those in bulk too.
Is anyone on this thread using C++? My team often has visions of awesomeness but comes up short with the coding to make it happen. If we had some C++ support I would feel more comfortable commiting to an order of 6-8.
Let me know.
Thanks for doing this!
Have you placed the order?
When you have please let us know the price and where to send the check to
All,
We have reached the magic number, so the order is a go. I’ll shoot for placing the order next Monday, June 3rd. The cost per encoder will be $48.60 each, with a small fee to cover re-boxing and shipping. Price does not include wiring or connectors. I’ll PM the poster who made the order commitment with my address so checks can be sent. I’ll keep everyone posted on the status of the receipt of the bulk order and the status of team orders. Team orders will be sent out upon receipt of checks.
Here is the updated list of order commitments:
2363: 8
696: 4
192: 8
4063: 4
1836: 8
1912: 8
2175: 4
237: 6
2590: 5
total: 55
Feel free to increase your quantity, or get in on this group-buy until the order is placed.
Then, I expect we’ll have a nice CD thread about how to mount, wire and program using the encoders. I received a PM from team 1323 recommending McMaster Carr P/N 71335K52 wire.
Can we please get pre-assembled cables with connector along with the encoders? I’d like a 3 foot wire length. Anyone else want cables too?
Along with the encoder quote, I got a quote for encoder cables. They quoted $7.30 each for part number CA-MIC4-W4-NC-2. (2 feet)
AndyMark sells CA-MIC4-W4-NC-1 for $6.30, and the CA-MIC4-W4-NC-3 for $10.
In the past, our team has taken the AndyMark cables and spliced on enough wire and the appropriate connector to run the encoder lines where they needed to go. We aren’t interested in the cable directly from US Digital unless there was a significant cost savings.
I just called and got pricing on the 3 foot cables (part number CA-MIC4-W4-NC-3). For 1-9, $7.80. For 10-49, $7.30. For 50-100, $6.67.
It’s not my intent to compete with AndyMark with this group-buy. I’m doing this for free as a service to the community. AM has employees they need to pay. If anyone wants CA-MIC4-W4-NC-3 cables, I would be happy to add them to your order. (If it turns out that the cables add lead time to the order, I would omit them. I don’t want the ordering and payment process to go past one credit card billing cycle.)
Put 3081 down for 2, unless you hear differently from Steve.
(if it is still possible to add to the order)
what cpr?
The S4-120-250-N-S-B is 120 CPR.
why not go with the 360?
Team 2175 would like 4 of the 3ft long encoder cables if they are available.
We are looking at using them for high speed velocity control (encoder attached to shooter wheel, for example). For a given sampling period, a 120 cpr encoder can be used for speed control on a wheel spinning 3X as fast as one on a 360 cpr encoder.
For controlling our drivetrain, the 120 cpr encoder gives .105" resolution on a 4" wheel directly coupled to the axle. If we need better than that, we’ll attach to an intermediate gearbox shaft or use a mechanical multiplier.
You can put me down for 4 of the CA-MIC4-W4-NC-3 cables to go with my 4 encoders.