On June 8, 1976, Martin Vargas and Barry Mills entered the Mayfair Branch of Lloyd’s Bank in Fresno. Vargas threatened a bank employee with a handgun and they took over $100,000 in cash. Daniel Cavanaugh drove the “get-away car”. Robbin Bryan, 1 a companion of Cavanaugh, attempted to flee to Canada with Cavanaugh thereafter.

All four parties were jointly charged and tried together by jury. Vargas, Mills and Cavanaugh each were convicted of armed bank robbery, in violation of 18 U.S.C. § 2113 (d). Bryan was convicted of being an accessory after the fact, 18 U.S.C. § 3 . Each defendant appeals from his or her conviction on several grounds.

We affirm.

I. ROBBIN BRYAN

A. Motion for Severance

Bryan contends that the trial court erred in denying her motion to sever her trial from that of her co-defendants pursuant to Fed.R.Crim.P. 14. We disagree.

The four appellants were “alleged to have participated in the same . . .series of acts or transactions constituting the offenses charged”. Therefore, the appellants were properly joined for trial pursuant to Fed.R.Crim.P. 8(b). See United States v. Adams, 581 F.2d 193, 197 (9th Cir. *696 1978). Because the joinder of parties was authorized by Rule 8(b), the denial of the motion for severance under Fed.R.Crim.P. 14 will not be disturbed unless Bryan can prove that the court abused its discretion; the test is whether a joint trial was so prejudicial as to require the judge to exercise his discretion in but one way. Id. at 197-98 .

Bryan has failed to make the requisite showing of prejudice. The jurors could easily compartmentalize the evidence against the defendants. See United States v. Hobson, 519 F.2d 765, 772 (9th Cir.), cert. denied, 423 U.S. 931 , 96 S.Ct. 283 , 46 L.Ed.2d 261 (1975). Moreover, the instructions to the jury were calculated to minimize any prejudice resulting from joinder. See Adams, 581 F.2d at 198 . We find no abuse of discretion.

B. Comment on Exercise of Constitutional Right

Bryan complains that a federal agent impermissibly commented on her right to remain silent after arrest, when the agent testified at the trial that Bryan consented to talk to the agent “on a selective basis”. Bryan argues that the district court erred in denying her motion to strike the testimony.

In United States v. Haro-Portillo, 531 F.2d 962 (9th Cir. 1976), an arrested suspect voluntarily talked to a federal agent for a time, after which he refused to answer any more questions. We held that the suspect’s constitutional right to remain silent was not violated when the agent testified at trial to the substance of their conversation, without commenting further on the defendant’s assertion of his right. Id. at 963-64 .

In the present ease, the agent testified, in relevant part:

The witness in this case did no more than did the witness in Haro-Portillo . Bryan’s rights were not violated.

C. Sufficiency of the Evidence

Bryan contends that there was insufficient evidence to prove that she acted with “actual knowledge” of Cavanaugh’s participation in the robbery, an essential element of her offense of accessory after the fact.

The verdict of the jury must be sustained if there was “ ‘relevant evidence from which the jury could reasonably find [the defendant] guilty beyond a reasonable doubt, viewing the evidence in light favorable to the Government’ ”. United States v. Rojas, 554 F.2d 938, 943 (9th Cir. 1977). Actual knowledge, as an element of the offense of accessory after the fact, may be shown entirely through circumstantial evidence. See U. S. v. Rux, 412 F.2d 331, 333 (9th Cir. 1969).

In this case, the evidence showed that Bryan purchased a car with 150 twenty-dollar bills two days after the robbery, and that she sold the car for half the purchase price two weeks later. Bryan and Cavanaugh were apprehended together as they attempted to enter Canada. The trunk of the car in which they were apprehended contained a locked briefcase with over $18,-000 in cash inside. The key to the briefcase and a .357 Magnum handgun were found in Bryan’s purse by border police.

There is substantial circumstantial evidence to support a finding that, beyond a reasonable doubt, Bryan had actual knowledge of Cavanaugh’s participation in the robbery.

D. Jury Instruction Regarding Actual Knowledge

The trial court instructed the jury that Bryan could not be found guilty of the offense of accessory after the fact unless she assisted Cavanaugh with “actual knowledge of his participation in the bank rob *697 bery”. Bryan requested an instruction defining “actual knowledge” as “positive knowledge in contrast to imputed or inferred knowledge”. The court denied this request on the ground that it would erroneously lead the jury to believe that they' could not infer actual knowledge from circumstantial evidence. We uphold the decision of the trial court.

The adequacy of the jury instructions is determined by examining the instructions as a whole. United States v. Kaplan, 554 F.2d 958, 968 (9th Cir.), cert. denied sub nom. Stradley v. United States, 434 U.S. 956 , 98 S.Ct. 483 , 54 L.Ed.2d 315 (1977). The refusal to give a requested instruction will not be overturned “ ‘if the charge as a whole adequately covers the' theory of the defense’ ”. Id. (quoting from United States v. Blane, 375 F.2d 249, 252 (6th Cir.), cert. denied, 389 U.S. 835 , 88 S.Ct. 41 , 19 L.Ed.2d 96 (1967)).

In this case, the jury was instructed that “[a]n act is done knowingly if done voluntarily and intentionally, and not because of mistake or accident or other innocent reason”. Additionally, the jury was instructed that Bryan could not be found guilty unless she acted “with the specific purpose or design to prevent or hinder apprehension, trial or punishment”. Taken as a whole, the instructions regarding the requirement of actual knowledge were clearly sufficient.

II. MARTIN VARGAS

A. Admissibility of Evidence of a Subsequent Crime

Outside the presence of the jury, the government informed the court of its intent to introduce evidence of a similar bank robbery, to which Vargas had pled guilty. The trial court ruled that the evidence would be admissible for the limited purpose of proving identity or modus operandi, as permitted by Fed.R.Evid. 404(b). Vargas contends that the court committed reversible error by failing to make a finding that the two robberies were sufficiently similar to allow admission pursuant to Rule 404(b).

No evidence of the subsequent robbery was introduced at the trial; therefore, we need not consider whether the evidence was admissible under Rule 404(b). See 28 U.S.C. § 2111 ; United States v. Moore, 580 F.2d 360, 363 (9th Cir. 1978).

Vargas contends that the admissibility ruling deterred him from taking the stand. The admission of the evidence under Rule 404(b) was not conditioned upon Vargas taking the stand; thus the trial court’s ruling could not have deterred Vargas from taking the stand. Furthermore, Vargas did not indicate his desire to take the stand nor move to preclude impeachment by evidence of the other crime under the provisions of Fed.R.Evid. 609(a). We find no error.

B. Testimony of Billy Harris

Billy Harris, a convicted felon, testified against Vargas as a government witness. Vargas complains that Harris was given a reduced sentence on felony charges in exchange for his testimony and that Harris was “hostile” to Vargas. Vargas argues that Harris’s credibility was so questionable that the admission of his testimony denied Vargas a fair trial.

Harris unquestionably was a competent witness. Fed.R.Evid. 601. Under present law the granting of a reduced sentence in .exchange for testimony affects the weight, not the admissibility, of the testimony. Darden v. United States, 405 F.2d 1054, 1056 (9th Cir. 1969). The same is true with respect to hostility harbored by a witness against a party. See Moore, 580 F.2d at 364 ; United States v. Kartman, 417 F.2d 893, 897 (9th Cir. 1969). The credibility of the witness was a question for the jury.

C. Vindictive Sentencing

Vargas was sentenced to twenty years in prison. The statutory maximum penalty for a violation of 18 U.S.C. § 2113 (d) is twenty-five years. The sentence is within the statutory maximum and ordinarily is not reviewable. However, Vargas contends that a pretrial conference was held, at which there was some discussion of a possible plea bargain, and that the *698 district judge indicated that a lesser sentence would be appropriate if Vargas would plead guilty. There is nothing in the record on appeal to justify this assertion by the appellant. The pretrial conference was not reported and no mention was made of this contention at the time of sentencing, nor was any post-trial motion brought, raising this contention. Vargas relies solely upon an affidavit of his attorney appended to his brief on appeal. An affidavit of the prosecuting attorney was attached to the appellee’s brief which reflected a different recollection of the conference, raising a factual dispute as to what occurred at the pretrial conference.

Consideration on this appeal cannot be given to these affidavits, because they are not a part of the record on appeal. Frizell v. United States, 394 F.2d 783, 794 (9th Cir. 1968). In order to augment the record on appeal concerning proceedings which were not reported, the provisions of Rule 10(c) of the Federal Rules of Appellate Procedure should be followed. Rule 10(c) requires that appellant must prepare a statement of the evidence or proceedings from the best available means. This statement is then served on the appellee, who may serve objections or propose amendments. The statement and any objections or proposed amendments are thus submitted to the district court for settlement and approval. Fed.R.App.P. 10(c); 7 Moore’s Federal Practice, ¶210.06(2). This procedure affords the appropriate method to augment the record and to resolve any factual disputes as to the evidence or proceedings in the trial court.

Appellant made no attempt to follow the procedures prescribed by Rule 10(c). Nor did he attempt, during or immediately after the in-chambers conference, to preserve in the transcript the substance of the court’s alleged remarks. It was his responsibility to do so in order to make a proper record for appeal. Since no record is provided upon which his claim can be evaluated, it must be denied. United States v. Dunham Concrete Products, Inc., 475 F.2d 1241, 1251 (5th Cir. 1973).

Brown v. United States, 314 F.2d 293 (9th Cir. 1963) and United States v. Piascik, 559 F.2d 545, 550 (9th Cir. 1974) are distinguishable. In both cases the error complained of on appeal — failure to comply with the mandate of 28 U.S.C. § 753 (b) that a record be made of “all proceedings in criminal cases . in open court” — was fully apparent on the face of the record on appeal. See also United States v. Selva, 546 F.2d 1173 , after remand, 559 F.2d 1303 (5th Cir. 1977); United States v. Workcuff, 137 U.S. App.D.C. 263, 422 F.2d 700 (1970). In contrast, the error asserted in this case — enhancement of appellant’s sentence because he elected to stand trial — is not reflected in the record on appeal. Failure to record the in-chambers proceedings in which the error allegedly occurred is not asserted as error, and clearly did not violate the statute.

Appellant will have an opportunity to raise his constitutional claim, and if necessary to resolve the dispute as to what occurred in the conference, in post-conviction proceedings under § 2255. In this respect, too, appellant is in a different position than Brown. See 314 F.2d at 295 n.1.

III. DANIEL CAVANAUGH

Cavanaugh raises three contentions, the first of which is shared by Mills.

A. Request for Continuance

During its case-in-chief, the government called as a witness one Debbie Kenney whose testimony tended to incriminate both Mills and Cavanaugh. After she had testified, been cross-examined and dismissed, counsel for Cavanaugh and Mills requested a one-day continuance on the grounds she was a surprise witness and time was needed to obtain evidence to attack her credibility or to rebut her testimony. The trial court denied the motion. Cavanaugh and Mills both argue that the trial court abused its discretion in denying the motion for continuance.

The trial court has great latitude in granting or denying continuances. The Supreme Court in Avery v. Alabama, 308 U.S. *699 444, 446 , 60 S.Ct. 321, 322 , 84 L.Ed. 377 (1940) stated:

There are, of course, rare occasions when the denial of a continuance could be an abuse of discretion, but a clear abuse would have to be found. See United States v. Michelson, 559 F.2d 567, 572 (9th Cir. 1978); Daut v. United States, 405 F.2d 312, 315 (9th Cir. 1968), cert. denied, 402 U.S. 945 , 91 S.Ct. 1624 , 29 L.Ed.2d 114 (1971); Wright, Federal Practice and Procedure, Criminal § 832. There was no abuse of discretion in this case.

B. Hearing on Competence

Cavanaugh argues that the trial court erred by failing to initiate a hearing on his competence to stand trial.

If the evidence is sufficient to raise a genuine doubt in the mind of a reasonable trial judge concerning the defendant’s competence, due process requires the trial judge to hold a competency hearing on his own motion. Bassett v. McCarthy, 549 F.2d 616, 619 (9th Cir.), cert. denied, 434 U.S. 849 , 98 S.Ct. 158 , 54 L.Ed.2d 117 (1977); see 18 U.S.C. § 4244 ; Pate v. Robinson, 383 U.S. 375, 385 , 86 S.Ct. 836 , 15 L.Ed.2d 815 (1966). The constitutional standard of competence is whether a defendant “ ‘has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding — and whether he has a rational as well as factual understanding of the proceedings against him’ ”. Dusky v. United States, 362 U.S. 402 , 80 S.Ct. 788 , 4 L.Ed.2d 824 (1960); Bassett, 549 F.2d at 618 . Bare assertions by defendant’s counsel that defendant is not competent to stand trial generally are not sufficient to raise the requisite doubt. See De Kaplany v. Enomoto, 540 F.2d 975 , 982-83 & n.8 (9th Cir. 1976) (en banc), cert. denied, 429 U.S. 1075 , 97 S.Ct. 815 , 50 L.Ed.2d 793 (1977); see also United States v. Ives, 574 F.2d 1002, 1004 (9th Cir. 1978).

In this case, the record reveals that Cavanaugh was alert, rational and responsive throughout the trial. Cavanaugh testified, at a hearing on a motion to suppress, that during the month immediately preceding trial, and at Cavanaugh’s request, jail officials had given Cavanaugh sedatives that made him drowsy. However, there is no evidence that he took any drugs at the time of his trial. The only other evidence of incompetence consisted of the unsupported assertions of Cavanaugh and his counsel that the discomfort of living in a jail cell had impaired Cavanaugh’s mental ability to testify and to respond to cross-examination.

The evidence was insufficient to raise a genuine doubt about Cavanaugh’s ability to communicate rationally with his lawyer and to understand the proceedings against him. The trial court was not required to hold a competency hearing on its own motion.

C. Sentencing Criteria

In sentencing Cavanaugh, the trial judge took particular note of Cavanaugh’s history of drug abuse, his lengthy criminal record and his failure to achieve rehabilitation during prior prison terms. Cavanaugh complains that the trial court gave excessive consideration to his use of illegal drugs.

A federal judge is granted wide discretion in sentencing and may “appropriately conduct an inquiry broad in scope, largely unlimited either as to the kind of information he may consider, or the source from which it may come”. United States v. Tucker, 404 U.S. 443, 446 , 92 S.Ct. 589, 591 , 30 L.Ed .2d 592 (1972); United States v. Stevenson, 573 F.2d 1105, 1108 (9th Cir. 1978). We find no abuse of discretion.

IV. BARRY MILLS

A. Appointment of New Counsel

One week before the date set for trial, Mills requested the substitution of ap *700 pointed counsel. The appointed counsel had first appeared on behalf of Mills nearly two months earlier. In support of his motion for substitution, Mills asserted that he was unable to agree with counsel concerning a question of trial strategy and that his counsel had failed to prepare the case adequately. The trial court denied the request, finding that the attorney was competent and adequately prepared and that substitution of counsel at that date would cause an unwarranted delay in the trial. On appeal, Mills contends that he was entitled to a substitution of counsel because he was embroiled in an irreconcilable conflict with his attorney.

The denial of a motion to dismiss counsel is a matter resting within the sound discretion of the trial judge. Good v. United States, 378 F.2d 934, 935 (9th Cir. 1967). However, the court’s discretion is not without limit. In Brown v. Craven, 424 F.2d 1166 (9th Cir. 1970), we held that refusal to allow the substitution of attorneys may result in a denial of the constitutional right to effective assistance of counsel if the defendant and his attorney are embroiled in an “irreconcilable conflict”. Id. at 1170 . In applying the rule developed in Craven , we consider a number of factors, including the timeliness of the motion to dismiss counsel, the adequacy of the court’s inquiry into the defendant’s complaint, and whether the conflict between the defendant and his counsel was so great that it resulted in a total lack of communication preventing an adequate defense. See id. at 1169-70 ; United States v. Michelson, 559 F.2d 567, 571-72 (9th Cir. 1977) (motion filed late); United States v. Jones, 512 F.2d 347, 350 (9th Cir. 1975) (adequate hearing); United States v. Main, 443 F.2d 900, 901 (9th Cir.), cert. denied, 404 U.S. 958 , 92 S.Ct. 328 , 30 L.Ed.2d 276 (1971), (no showing of total lack of communication).

In this case, the court held an adequate and fair hearing on Mills’s motion. The record shows that Mills and his attorney were not embroiled in a conflict resulting in a total lack of communication. Although Mills asserted at the hearing that he refused to discuss his “alibi defense” with his counsel, it was apparent that his counsel was able to prepare all other facets of the case. Indeed, at the hearing Mills complained more about the infrequency of his meetings with his attorney than about his reluctance to communicate with counsel. Mills’s attorney ultimately presented an adequate defense which included the presentation of the alibi witness. Finally, we note that Mills did not present his motion until one week before trial, and substitution of counsel almost certainly would have delayed the trial. Under these circumstances, we hold that Mills was not deprived of effective counsel.

The trial court did not abuse its discretion in denying Mills’s motion to dismiss counsel.

B. Jury Instruction for Offense of Aiding and Abetting

The court instructed the jury that any one of the defendants charged with armed bank robbery could be found guilty of that offense if he either directly committed the offense or aided and abetted the commission of the offense. 2 Mills contends that the court committed reversible error by failing to instruct further that Mills could not be found guilty of aiding and abetting an armed bank robber unless he knew that the robber carried a deadly weapon.

Mills did not object to the instructions; therefore, he is entitled to no relief on appeal unless the omission from the jury instructions amounts to plain error. Fed.R.Crim.P. 52(b); United States v. Houston, 547 F.2d 104, 107-108 (9th Cir. 1976). We will not reverse for plain error unless it appears necessary to prevent a miscarriage of justice. Id.; United States v. Eskridge, 456 F.2d 1202, 1205 (9th Cir.) cert. denied, 409 U.S. 883 , 93 S.Ct. 171 , 34 L.Ed.2d 138 (1972

*701 The jury was instructed generally that Mills could not be convicted unless he “willfully” aided another person committing armed bank robbery. The evidence shows that Mills passed within a few feet of Vargas while Vargas had his gun drawn inside the bank; it is difficult to conceive that the jury would have rendered a different verdict had it been specifically instructed that knowledge of the gun was an essential element. This differs from United States v. Short, 493 F.2d 1170 (9th Cir. 1974), relied upon by Mills, because in that case the trial judge had erroneously instructed the jury that knowledge of the weapon was not an element of the crime. There was no plain error.

V. CONCLUSION

The judgment of the district court is affirmed.

. Daniel Cavanaugh and Robbin Bryan are now married, and Robbin has taken the name “Cavanaugh”. To avoid confusion, we will continue to refer to her as “Bryan” in this opinion.

. Title 18 § 2(a) provides: