Sealed encoder group buy?
 

One of the lessons we have learned over the past two years is that our team is not capable of using the open frame US Digital encoders reliably. We have gone through handfuls of them, and no matter how careful we handle them, they always go bad at the most inopportune times. Looking through past posts, other teams seem to be having similar experiences. Doing some research shows that the best teams have switched over to using the sealed versions of these encoders, with ball bearing supported input shafts. As a summer project, we are going to try this out.

I just got a quote from US Digital for their S4 encoders. In small quantities, they are nearly twice as expensive as the E4P encoders if purchased from AndyMark. Like most electrical components, increasing the quantity ordered decreases price rapidly. We're looking at getting part number S4-120-250-N-S-B. I'm hoping I could put together an order of at least 50 of them, which would get the price down to $48.60 each. Would any other teams be interested in going in on a group buy of these encoders?

Re: Sealed encoder group buy?
 

We've used the "H" series this year an in previous years with good success.
It also appears that the S4 is no longer available, or looks like it's being replaced.

I want to ask however, when you got your price quote did you tell them you were a FIRST Team?
They do give a discount to FIRST teams, but you have to ask for it.
IIRC the discount was about 25% on the encoders only.

Re: Sealed encoder group buy?
 

The discount was moving to the next price-break, so depending on quantity, the discount percentage varies. I was pleasantly surprised the last time we put in an order, but yes, you need mention you're a FIRST team to get the discount.

Re: Sealed encoder group buy?
 

I'm in for four.

Re: Sealed encoder group buy?
 

There are many options for encoders once you decide to spend some money. Is the US Digital The best buy. What CPR would most teams want to use. I'll Throw this out for thought. CUI makes the AMT102 and AMT103 encoders. Digikey link hear.
http://www.digikey.com/PTM/PTMPartLi...ng=en&ptm=5586
Now they are meant to mount on a shaft like the current US Digital that Andy Mark sells. The big difference is that they can be set to many different CPR up to 1024. You can turn these into a sealed unit with shaft. We made a base plate out of polycarb in the shape of the AMT102 base. In the polycarb base we mounted 2 precision ball bearings for a 1/4" stainless shaft. The programmers played with them last fall and they seamed to work well. We have not used them on a robot or really given them a test. Other teams have posted that they worked well. Could a run of base plates be done to add shaft capability to them? Then all that is needed is some shaft and bearing. I believe the bearing were about 5$ apiece. Is this an option?

Re: Sealed encoder group buy?
 

I did mention that we are a FIRST team, and the discount is to move up to the next price break point. So if we order 50 units, we are getting the 100 unit quantity discount.

Re: Sealed encoder group buy?
 

We're interested.

Re: Sealed encoder group buy?
 

We'd be interested too

Re: Sealed encoder group buy?
 

We're interested in 8

Re: Sealed encoder group buy?
 

Thanks, Joey.

Everyone else, it would be very helpful if you could edit your posts and add the quantity you are looking for. When we reach a total of 50 units, I can make arrangements for placing the group order.

Re: Sealed encoder group buy?
 

All,
I got a PM suggesting we take a look at the Grayhill encoders, as well.

The equivalent Grayhill encoder seems to be the series 63R.

There are two advantages of the US Digital S4 series over the Grayhill Series 63R:
- Max RPM. S4: 15,000 63R: 5,000
- Size. S4: .85" dia x .50" thk 63R: 1.25" dia x .50" thk

Please note that the US Digital S4 encoders are enclosed, and have a ball bearing mounted 1/4" dia input shaft. These are NOT the E4P encoders sold by AndyMark. The E4P series are the ones we have had problems with.

Re: Sealed encoder group buy?
 

Team 4063 would be interested in 4 of them.

Re: Sealed encoder group buy?
 

Here is the current total of committed encoders.

2363: 8
696: 4
192: 8
4063: 4

Total: 24

That gets us down from the single part price of $70.36 to $53.97 each. Almost halfway to the next price break.

Re: Sealed encoder group buy?
 

The S4 is currently listed on the US Digital website as:

They won't let you build a part number or order online like they will with their other products. Any idea what the future plans are for this item? I was considering using one, but don't want to pick something that will be obsolete soon.

Re: Sealed encoder group buy?
 

1836 will take 8

Re: Sealed encoder group buy?
 

1912 will take 8

Re: Sealed encoder group buy?
 

Also you wouldn't want to use something that isn't considered COTS anymore.

That being said, we've been pretty invested in the S4's and have a decent backcatalog of them. It's a great product, I just wonder what they're doing with it.

Re: Sealed encoder group buy?
 

All,
I'll call US Digital again today and see if I can get a fuller explanation of the cryptic statement on the webpage.

In the meantime, updated order commitments:
2363: 8
696: 4
192: 8
4063: 4
1836: 8
1912: 8

Total: 40

Re: Sealed encoder group buy?
 

Hi, I am Peter from the Fighting Calculators, team 2175, and we would like 4 of them. Thank you for doing this!

Re: Sealed encoder group buy?
 

Just talked to the customer support rep at US Digital. She said the message comes up because the stock on the modules is limited at this time. She assured me that there are no plans for the S4 or E4P encoders to be discontinued. They are working to resolve the inventory issue, but plan to continue to supply them to FIRST teams.

I get the feeling that they might not be able to support an order of the magnitude necessary for the module to be incorporated into a consumer product with volumes of tens of thousands, but have no trouble supporting our small quantity orders.

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

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?

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

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/1099928...oderMountIdeas

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

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!

Re: Sealed encoder group buy?
 

Have you placed the order?

When you have please let us know the price and where to send the check to

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

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?

Re: Sealed encoder group buy?
 

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.)

Re: Sealed encoder group buy?
 

Put 3081 down for 2, unless you hear differently from Steve.

(if it is still possible to add to the order)

Re: Sealed encoder group buy?
 

what cpr?

Re: Sealed encoder group buy?
 

The S4-120-250-N-S-B is 120 CPR.

Re: Sealed encoder group buy?
 

why not go with the 360?

Re: Sealed encoder group buy?
 

Team 2175 would like 4 of the 3ft long encoder cables if they are available.

Re: Sealed encoder group buy?
 

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.

Re: Sealed encoder group buy?
 

You can put me down for 4 of the CA-MIC4-W4-NC-3 cables to go with my 4 encoders.

Re: Sealed encoder group buy?
 

3081 is in for 6. This is 4 more than Evan posted earlier.

S

Re: Sealed encoder group buy?
 

Order will be placed on Monday. Here is the latest list. Teams, please check to be sure the numbers are accurate. A few people dropped out, so we are just over the min quantity for the group buy.

encoders
2363: 8
696: 4
192: 8
4063: 4
1912: 8
2175: 4
237: 6
3081: 6
1251: 4
(total: 52)

cables (3 ft)
2175: 4
696: 4
(total: 8)

Re: Sealed encoder group buy?
 

All,
Order has been placed with US Digital. It should ship tomorrow, UPS ground. I'll send out PM's to team contacts with my address and amounts for your checks.

Re: Sealed encoder group buy?
 

All,
The shipment arrived yesterday. I just sent out PMs with the order amounts and my address. Please check your inboxes.

Re: Sealed encoder group buy?
 

Shipments to teams 237, 4063 and 696 go in the mail tomorrow.

Re: Sealed encoder group buy?
 

Got them in the mail today!

Thanks for the opportunity and all of your hard work Todd!

Re: Sealed encoder group buy?
 

i put a check to you in the mail today. if you got my pm, great, but to me it looked like it did not send.

Re: Sealed encoder group buy?
 

Did anyone ever find out why US Digital discontinued the E4P? I got an email from them confirming that they don't recommend using the E4P for new designs, but suggested using the E5 instead (much more $$$).

Re: Sealed encoder group buy?
 

Sounds like they aren't discontinuing them but do have limited stock.

Re: Sealed encoder group buy?
 

Found this interesting URL:
http://www.avagotech.com/pages/us_di...ross_reference

Hmmm... interesting that Avago was supplying the parts for US Digital, and now they are not.

Re: Sealed encoder group buy?
 

Status:
237: order shipped 6/29/13, check cashed
4063: order shipped 6/29/13, checked cashed
696: order shipped 6/26/13, check cashed
2175: order shipped 7/20/13, check cashed
1912: order shipped 7/20/13, check cashed
1251: check cashed, PM me a mailing address unless I should send you package to the school board address, which was the return address on the check.

Need payments from 192, 3081.

Todd F.

Re: Sealed encoder group buy?
 

3081 check went in the mail today.

Re: Sealed encoder group buy?
 

1912's arrived yesterday, thanks

Re: Sealed encoder group buy?
 

Status:
237: order shipped 6/29/13, check cashed
4063: order shipped 6/29/13, checked cashed
696: order shipped 6/26/13, check cashed
2175: order shipped 7/20/13, check cashed
1912: order shipped 7/20/13, check cashed
1251: order shipped 7/27/13, check cashed
192: order shipped 7/27/13, check cashed
3081: order shipped 7/27/13, check cashed

The last checks were cashed, and the last orders shipped today. This concludes the group buy. Everyone be sure to share news about how you use the encoders.